License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2009-06-03 05:17:38 +08:00
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/*
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* This file contains the 64-bit "server" PowerPC variant
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* of the low level exception handling including exception
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* vectors, exception return, part of the slb and stab
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* handling and other fixed offset specific things.
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*
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* This file is meant to be #included from head_64.S due to
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2011-03-31 09:57:33 +08:00
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* position dependent assembly.
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2009-06-03 05:17:38 +08:00
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*
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* Most of this originates from head_64.S and thus has the same
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* copyright history.
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*
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*/
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powerpc: Rework lazy-interrupt handling
The current implementation of lazy interrupts handling has some
issues that this tries to address.
We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.
The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.
Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.
This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.
The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.
When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.
We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).
This removes the need to play with the decrementer to try to create
fake interrupts, among others.
In addition, this adds a few refinements:
- We no longer hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.
- Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.
- On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)
- We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.
Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2:
- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
to retrigger an interrupt without preventing hard-enable
v3:
- Fix or vs. ori bug on Book3E
- Fix enabling of interrupts for some exceptions on Book3E
v4:
- Fix resend of doorbells on return from interrupt on Book3E
v5:
- Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.
v6:
- 32-bit compile fix
- more compile fixes with various .config combos
- factor out the asm code to soft-disable interrupts
- remove the C wrapper around preempt_schedule_irq
v7:
- Fix a bug with hard irq state tracking on native power7
2012-03-06 15:27:59 +08:00
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#include <asm/hw_irq.h>
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2009-07-15 04:52:52 +08:00
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#include <asm/exception-64s.h>
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2010-11-18 23:06:17 +08:00
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#include <asm/ptrace.h>
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2014-12-10 02:56:52 +08:00
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#include <asm/cpuidle.h>
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2016-09-30 17:43:18 +08:00
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#include <asm/head-64.h>
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2018-07-06 00:25:01 +08:00
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#include <asm/feature-fixups.h>
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2019-04-18 14:51:24 +08:00
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#include <asm/kup.h>
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2009-07-15 04:52:52 +08:00
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2019-06-22 21:15:35 +08:00
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/* PACA save area offsets (exgen, exmc, etc) */
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#define EX_R9 0
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#define EX_R10 8
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#define EX_R11 16
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#define EX_R12 24
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#define EX_R13 32
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#define EX_DAR 40
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#define EX_DSISR 48
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#define EX_CCR 52
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#define EX_CFAR 56
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#define EX_PPR 64
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#define EX_CTR 72
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.if EX_SIZE != 10
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.error "EX_SIZE is wrong"
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.endif
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2019-08-02 18:56:47 +08:00
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/*
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* Following are fixed section helper macros.
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*
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* EXC_REAL_BEGIN/END - real, unrelocated exception vectors
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* EXC_VIRT_BEGIN/END - virt (AIL), unrelocated exception vectors
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* TRAMP_REAL_BEGIN - real, unrelocated helpers (virt may call these)
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* TRAMP_VIRT_BEGIN - virt, unreloc helpers (in practice, real can use)
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* EXC_COMMON - After switching to virtual, relocated mode.
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*/
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2019-08-02 18:56:43 +08:00
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#define EXC_REAL_BEGIN(name, start, size) \
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FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
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#define EXC_REAL_END(name, start, size) \
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FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
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#define EXC_VIRT_BEGIN(name, start, size) \
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FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
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#define EXC_VIRT_END(name, start, size) \
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FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
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#define EXC_COMMON_BEGIN(name) \
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USE_TEXT_SECTION(); \
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.balign IFETCH_ALIGN_BYTES; \
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.global name; \
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_ASM_NOKPROBE_SYMBOL(name); \
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DEFINE_FIXED_SYMBOL(name); \
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name:
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#define TRAMP_REAL_BEGIN(name) \
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FIXED_SECTION_ENTRY_BEGIN(real_trampolines, name)
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#define TRAMP_VIRT_BEGIN(name) \
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FIXED_SECTION_ENTRY_BEGIN(virt_trampolines, name)
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#define EXC_REAL_NONE(start, size) \
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FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##unused, start, size); \
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FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##unused, start, size)
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#define EXC_VIRT_NONE(start, size) \
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FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size); \
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FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size)
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2019-06-22 21:15:27 +08:00
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/*
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* We're short on space and time in the exception prolog, so we can't
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* use the normal LOAD_REG_IMMEDIATE macro to load the address of label.
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* Instead we get the base of the kernel from paca->kernelbase and or in the low
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* part of label. This requires that the label be within 64KB of kernelbase, and
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* that kernelbase be 64K aligned.
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*/
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#define LOAD_HANDLER(reg, label) \
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ld reg,PACAKBASE(r13); /* get high part of &label */ \
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ori reg,reg,FIXED_SYMBOL_ABS_ADDR(label)
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#define __LOAD_HANDLER(reg, label) \
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ld reg,PACAKBASE(r13); \
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ori reg,reg,(ABS_ADDR(label))@l
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/*
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* Branches from unrelocated code (e.g., interrupts) to labels outside
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* head-y require >64K offsets.
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*/
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#define __LOAD_FAR_HANDLER(reg, label) \
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ld reg,PACAKBASE(r13); \
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ori reg,reg,(ABS_ADDR(label))@l; \
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addis reg,reg,(ABS_ADDR(label))@h
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/*
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* Branch to label using its 0xC000 address. This results in instruction
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* address suitable for MSR[IR]=0 or 1, which allows relocation to be turned
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* on using mtmsr rather than rfid.
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*
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* This could set the 0xc bits for !RELOCATABLE as an immediate, rather than
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* load KBASE for a slight optimisation.
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*/
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#define BRANCH_TO_C000(reg, label) \
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
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__LOAD_FAR_HANDLER(reg, label); \
|
2019-06-22 21:15:27 +08:00
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mtctr reg; \
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bctr
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2020-02-26 01:35:10 +08:00
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/*
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* Interrupt code generation macros
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*/
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2020-02-26 01:35:28 +08:00
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#define IVEC .L_IVEC_\name\() /* Interrupt vector address */
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#define IHSRR .L_IHSRR_\name\() /* Sets SRR or HSRR registers */
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#define IHSRR_IF_HVMODE .L_IHSRR_IF_HVMODE_\name\() /* HSRR if HV else SRR */
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#define IAREA .L_IAREA_\name\() /* PACA save area */
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#define IVIRT .L_IVIRT_\name\() /* Has virt mode entry point */
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#define IISIDE .L_IISIDE_\name\() /* Uses SRR0/1 not DAR/DSISR */
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#define IDAR .L_IDAR_\name\() /* Uses DAR (or SRR0) */
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#define IDSISR .L_IDSISR_\name\() /* Uses DSISR (or SRR1) */
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#define ISET_RI .L_ISET_RI_\name\() /* Run common code w/ MSR[RI]=1 */
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#define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
|
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#define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
|
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#define IMASK .L_IMASK_\name\() /* IRQ soft-mask bit */
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#define IKVM_SKIP .L_IKVM_SKIP_\name\() /* Generate KVM skip handler */
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#define IKVM_REAL .L_IKVM_REAL_\name\() /* Real entry tests KVM */
|
2020-02-26 01:35:14 +08:00
|
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#define __IKVM_REAL(name) .L_IKVM_REAL_ ## name
|
2020-02-26 01:35:28 +08:00
|
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#define IKVM_VIRT .L_IKVM_VIRT_\name\() /* Virt entry tests KVM */
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#define ISTACK .L_ISTACK_\name\() /* Set regular kernel stack */
|
2020-02-26 01:35:14 +08:00
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#define __ISTACK(name) .L_ISTACK_ ## name
|
2020-02-26 01:35:28 +08:00
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#define IRECONCILE .L_IRECONCILE_\name\() /* Do RECONCILE_IRQ_STATE */
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#define IKUAP .L_IKUAP_\name\() /* Do KUAP lock */
|
2020-02-26 01:35:10 +08:00
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#define INT_DEFINE_BEGIN(n) \
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.macro int_define_ ## n name
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#define INT_DEFINE_END(n) \
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.endm ; \
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int_define_ ## n n ; \
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do_define_int n
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.macro do_define_int name
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.ifndef IVEC
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.error "IVEC not defined"
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.endif
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.ifndef IHSRR
|
2020-02-26 01:35:27 +08:00
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IHSRR=0
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.endif
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.ifndef IHSRR_IF_HVMODE
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IHSRR_IF_HVMODE=0
|
2020-02-26 01:35:10 +08:00
|
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.endif
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.ifndef IAREA
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IAREA=PACA_EXGEN
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.endif
|
2020-02-26 01:35:19 +08:00
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.ifndef IVIRT
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IVIRT=1
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.endif
|
2020-02-26 01:35:18 +08:00
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.ifndef IISIDE
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IISIDE=0
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.endif
|
2020-02-26 01:35:10 +08:00
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.ifndef IDAR
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IDAR=0
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.endif
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.ifndef IDSISR
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IDSISR=0
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.endif
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.ifndef ISET_RI
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ISET_RI=1
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.endif
|
2020-02-26 01:35:22 +08:00
|
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.ifndef IBRANCH_TO_COMMON
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IBRANCH_TO_COMMON=1
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|
.endif
|
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.ifndef IREALMODE_COMMON
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IREALMODE_COMMON=0
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.else
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|
|
.if ! IBRANCH_TO_COMMON
|
|
|
|
.error "IREALMODE_COMMON=1 but IBRANCH_TO_COMMON=0"
|
|
|
|
.endif
|
2020-02-26 01:35:10 +08:00
|
|
|
.endif
|
|
|
|
.ifndef IMASK
|
|
|
|
IMASK=0
|
|
|
|
.endif
|
2020-02-26 01:35:12 +08:00
|
|
|
.ifndef IKVM_SKIP
|
|
|
|
IKVM_SKIP=0
|
|
|
|
.endif
|
2020-02-26 01:35:10 +08:00
|
|
|
.ifndef IKVM_REAL
|
|
|
|
IKVM_REAL=0
|
|
|
|
.endif
|
|
|
|
.ifndef IKVM_VIRT
|
|
|
|
IKVM_VIRT=0
|
|
|
|
.endif
|
2020-02-26 01:35:11 +08:00
|
|
|
.ifndef ISTACK
|
|
|
|
ISTACK=1
|
|
|
|
.endif
|
|
|
|
.ifndef IRECONCILE
|
|
|
|
IRECONCILE=1
|
|
|
|
.endif
|
|
|
|
.ifndef IKUAP
|
|
|
|
IKUAP=1
|
|
|
|
.endif
|
2020-02-26 01:35:10 +08:00
|
|
|
.endm
|
|
|
|
|
2019-06-22 21:15:27 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
|
|
|
|
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
|
|
|
|
/*
|
2020-02-26 01:35:29 +08:00
|
|
|
* All interrupts which set HSRR registers, as well as SRESET and MCE and
|
|
|
|
* syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
|
|
|
|
* so they all generally need to test whether they were taken in guest context.
|
|
|
|
*
|
|
|
|
* Note: SRESET and MCE may also be sent to the guest by the hypervisor, and be
|
|
|
|
* taken with MSR[HV]=0.
|
|
|
|
*
|
|
|
|
* Interrupts which set SRR registers (with the above exceptions) do not
|
|
|
|
* elevate to MSR[HV]=1 mode, though most can be taken when running with
|
|
|
|
* MSR[HV]=1 (e.g., bare metal kernel and userspace). So these interrupts do
|
|
|
|
* not need to test whether a guest is running because they get delivered to
|
|
|
|
* the guest directly, including nested HV KVM guests.
|
|
|
|
*
|
|
|
|
* The exception is PR KVM, where the guest runs with MSR[PR]=1 and the host
|
|
|
|
* runs with MSR[HV]=0, so the host takes all interrupts on behalf of the
|
|
|
|
* guest. PR KVM runs with LPCR[AIL]=0 which causes interrupts to always be
|
|
|
|
* delivered to the real-mode entry point, therefore such interrupts only test
|
|
|
|
* KVM in their real mode handlers, and only when PR KVM is possible.
|
|
|
|
*
|
|
|
|
* Interrupts that are taken in MSR[HV]=0 and escalate to MSR[HV]=1 are always
|
|
|
|
* delivered in real-mode when the MMU is in hash mode because the MMU
|
|
|
|
* registers are not set appropriately to translate host addresses. In nested
|
|
|
|
* radix mode these can be delivered in virt-mode as the host translations are
|
|
|
|
* used implicitly (see: effective LPID, effective PID).
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If an interrupt is taken while a guest is running, it is immediately routed
|
|
|
|
* to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
|
|
|
|
* to kvmppc_interrupt_hv, which handles the PR guest case.
|
2019-06-22 21:15:27 +08:00
|
|
|
*/
|
|
|
|
#define kvmppc_interrupt kvmppc_interrupt_hv
|
|
|
|
#else
|
|
|
|
#define kvmppc_interrupt kvmppc_interrupt_pr
|
|
|
|
#endif
|
|
|
|
|
2020-02-26 01:35:24 +08:00
|
|
|
.macro KVMTEST name
|
2019-06-22 21:15:27 +08:00
|
|
|
lbz r10,HSTATE_IN_GUEST(r13)
|
|
|
|
cmpwi r10,0
|
2019-08-02 18:57:00 +08:00
|
|
|
bne \name\()_kvm
|
2019-06-22 21:15:27 +08:00
|
|
|
.endm
|
|
|
|
|
2020-02-26 01:35:17 +08:00
|
|
|
.macro GEN_KVM name
|
2020-02-26 01:35:21 +08:00
|
|
|
.balign IFETCH_ALIGN_BYTES
|
|
|
|
\name\()_kvm:
|
|
|
|
|
2020-02-26 01:35:17 +08:00
|
|
|
.if IKVM_SKIP
|
2019-06-22 21:15:27 +08:00
|
|
|
cmpwi r10,KVM_GUEST_MODE_SKIP
|
|
|
|
beq 89f
|
|
|
|
.else
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2020-02-26 01:35:17 +08:00
|
|
|
ld r10,IAREA+EX_CFAR(r13)
|
2019-06-22 21:15:27 +08:00
|
|
|
std r10,HSTATE_CFAR(r13)
|
2020-02-26 01:35:23 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2019-06-22 21:15:27 +08:00
|
|
|
.endif
|
|
|
|
|
2020-06-15 14:12:47 +08:00
|
|
|
ld r10,IAREA+EX_CTR(r13)
|
2020-02-26 01:35:21 +08:00
|
|
|
mtctr r10
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2020-02-26 01:35:17 +08:00
|
|
|
ld r10,IAREA+EX_PPR(r13)
|
2019-06-22 21:15:27 +08:00
|
|
|
std r10,HSTATE_PPR(r13)
|
2020-02-26 01:35:23 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
2020-02-26 01:35:21 +08:00
|
|
|
ld r11,IAREA+EX_R11(r13)
|
|
|
|
ld r12,IAREA+EX_R12(r13)
|
2019-06-22 21:15:27 +08:00
|
|
|
std r12,HSTATE_SCRATCH0(r13)
|
|
|
|
sldi r12,r9,32
|
2020-02-26 01:35:21 +08:00
|
|
|
ld r9,IAREA+EX_R9(r13)
|
|
|
|
ld r10,IAREA+EX_R10(r13)
|
2019-06-22 21:15:27 +08:00
|
|
|
/* HSRR variants have the 0x2 bit added to their trap number */
|
2020-02-26 01:35:27 +08:00
|
|
|
.if IHSRR_IF_HVMODE
|
2019-08-02 18:56:44 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2020-02-26 01:35:17 +08:00
|
|
|
ori r12,r12,(IVEC + 0x2)
|
2019-08-02 18:56:44 +08:00
|
|
|
FTR_SECTION_ELSE
|
2020-02-26 01:35:17 +08:00
|
|
|
ori r12,r12,(IVEC)
|
2019-08-02 18:56:44 +08:00
|
|
|
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
2020-02-26 01:35:17 +08:00
|
|
|
.elseif IHSRR
|
|
|
|
ori r12,r12,(IVEC+ 0x2)
|
2019-06-22 21:15:27 +08:00
|
|
|
.else
|
2020-02-26 01:35:17 +08:00
|
|
|
ori r12,r12,(IVEC)
|
2019-06-22 21:15:27 +08:00
|
|
|
.endif
|
2019-06-22 21:15:29 +08:00
|
|
|
b kvmppc_interrupt
|
2019-06-22 21:15:27 +08:00
|
|
|
|
2020-02-26 01:35:17 +08:00
|
|
|
.if IKVM_SKIP
|
2019-06-22 21:15:27 +08:00
|
|
|
89: mtocrf 0x80,r9
|
2020-06-15 14:12:47 +08:00
|
|
|
ld r10,IAREA+EX_CTR(r13)
|
2020-02-26 01:35:21 +08:00
|
|
|
mtctr r10
|
2020-02-26 01:35:17 +08:00
|
|
|
ld r9,IAREA+EX_R9(r13)
|
|
|
|
ld r10,IAREA+EX_R10(r13)
|
2020-02-26 01:35:21 +08:00
|
|
|
ld r11,IAREA+EX_R11(r13)
|
|
|
|
ld r12,IAREA+EX_R12(r13)
|
2020-02-26 01:35:27 +08:00
|
|
|
.if IHSRR_IF_HVMODE
|
2019-08-02 18:56:44 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
b kvmppc_skip_Hinterrupt
|
|
|
|
FTR_SECTION_ELSE
|
|
|
|
b kvmppc_skip_interrupt
|
|
|
|
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
2020-02-26 01:35:17 +08:00
|
|
|
.elseif IHSRR
|
2019-06-22 21:15:27 +08:00
|
|
|
b kvmppc_skip_Hinterrupt
|
|
|
|
.else
|
|
|
|
b kvmppc_skip_interrupt
|
|
|
|
.endif
|
|
|
|
.endif
|
|
|
|
.endm
|
|
|
|
|
|
|
|
#else
|
2020-02-26 01:35:24 +08:00
|
|
|
.macro KVMTEST name
|
2019-06-22 21:15:27 +08:00
|
|
|
.endm
|
2020-02-26 01:35:17 +08:00
|
|
|
.macro GEN_KVM name
|
2019-06-22 21:15:27 +08:00
|
|
|
.endm
|
|
|
|
#endif
|
|
|
|
|
2019-08-02 18:56:58 +08:00
|
|
|
/*
|
|
|
|
* This is the BOOK3S interrupt entry code macro.
|
|
|
|
*
|
|
|
|
* This can result in one of several things happening:
|
|
|
|
* - Branch to the _common handler, relocated, in virtual mode.
|
|
|
|
* These are normal interrupts (synchronous and asynchronous) handled by
|
|
|
|
* the kernel.
|
|
|
|
* - Branch to KVM, relocated but real mode interrupts remain in real mode.
|
|
|
|
* These occur when HSTATE_IN_GUEST is set. The interrupt may be caused by
|
|
|
|
* / intended for host or guest kernel, but KVM must always be involved
|
|
|
|
* because the machine state is set for guest execution.
|
|
|
|
* - Branch to the masked handler, unrelocated.
|
|
|
|
* These occur when maskable asynchronous interrupts are taken with the
|
|
|
|
* irq_soft_mask set.
|
|
|
|
* - Branch to an "early" handler in real mode but relocated.
|
|
|
|
* This is done if early=1. MCE and HMI use these to handle errors in real
|
|
|
|
* mode.
|
|
|
|
* - Fall through and continue executing in real, unrelocated mode.
|
|
|
|
* This is done if early=2.
|
|
|
|
*/
|
2020-02-26 01:35:19 +08:00
|
|
|
|
|
|
|
.macro GEN_BRANCH_TO_COMMON name, virt
|
2020-02-26 01:35:22 +08:00
|
|
|
.if IREALMODE_COMMON
|
|
|
|
LOAD_HANDLER(r10, \name\()_common)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
|
|
|
.else
|
2020-02-26 01:35:19 +08:00
|
|
|
.if \virt
|
|
|
|
#ifndef CONFIG_RELOCATABLE
|
|
|
|
b \name\()_common_virt
|
|
|
|
#else
|
|
|
|
LOAD_HANDLER(r10, \name\()_common_virt)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
|
|
|
#endif
|
|
|
|
.else
|
|
|
|
LOAD_HANDLER(r10, \name\()_common_real)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
|
|
|
.endif
|
2020-02-26 01:35:22 +08:00
|
|
|
.endif
|
2020-02-26 01:35:19 +08:00
|
|
|
.endm
|
|
|
|
|
2020-02-26 01:35:15 +08:00
|
|
|
.macro GEN_INT_ENTRY name, virt, ool=0
|
2019-08-02 18:56:58 +08:00
|
|
|
SET_SCRATCH0(r13) /* save r13 */
|
|
|
|
GET_PACA(r13)
|
2020-02-26 01:35:15 +08:00
|
|
|
std r9,IAREA+EX_R9(r13) /* save r9 */
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
mfspr r9,SPRN_PPR
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
2019-08-02 18:56:58 +08:00
|
|
|
HMT_MEDIUM
|
2020-02-26 01:35:15 +08:00
|
|
|
std r10,IAREA+EX_R10(r13) /* save r10 - r12 */
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
mfspr r10,SPRN_CFAR
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2019-08-02 18:56:58 +08:00
|
|
|
.if \ool
|
|
|
|
.if !\virt
|
|
|
|
b tramp_real_\name
|
|
|
|
.pushsection .text
|
|
|
|
TRAMP_REAL_BEGIN(tramp_real_\name)
|
|
|
|
.else
|
|
|
|
b tramp_virt_\name
|
|
|
|
.pushsection .text
|
|
|
|
TRAMP_VIRT_BEGIN(tramp_virt_\name)
|
|
|
|
.endif
|
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
std r9,IAREA+EX_PPR(r13)
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
std r10,IAREA+EX_CFAR(r13)
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2019-08-02 18:56:58 +08:00
|
|
|
INTERRUPT_TO_KERNEL
|
2020-02-26 01:35:19 +08:00
|
|
|
mfctr r10
|
|
|
|
std r10,IAREA+EX_CTR(r13)
|
2019-08-02 18:56:58 +08:00
|
|
|
mfcr r9
|
2020-02-26 01:35:15 +08:00
|
|
|
std r11,IAREA+EX_R11(r13)
|
|
|
|
std r12,IAREA+EX_R12(r13)
|
2019-08-02 18:56:58 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* DAR/DSISR, SCRATCH0 must be read before setting MSR[RI],
|
|
|
|
* because a d-side MCE will clobber those registers so is
|
|
|
|
* not recoverable if they are live.
|
|
|
|
*/
|
|
|
|
GET_SCRATCH0(r10)
|
2020-02-26 01:35:15 +08:00
|
|
|
std r10,IAREA+EX_R13(r13)
|
2020-02-26 01:35:18 +08:00
|
|
|
.if IDAR && !IISIDE
|
2020-02-26 01:35:15 +08:00
|
|
|
.if IHSRR
|
2019-08-02 18:56:58 +08:00
|
|
|
mfspr r10,SPRN_HDAR
|
|
|
|
.else
|
|
|
|
mfspr r10,SPRN_DAR
|
|
|
|
.endif
|
2020-02-26 01:35:15 +08:00
|
|
|
std r10,IAREA+EX_DAR(r13)
|
2019-08-02 18:56:58 +08:00
|
|
|
.endif
|
2020-02-26 01:35:18 +08:00
|
|
|
.if IDSISR && !IISIDE
|
2020-02-26 01:35:15 +08:00
|
|
|
.if IHSRR
|
2019-08-02 18:56:58 +08:00
|
|
|
mfspr r10,SPRN_HDSISR
|
|
|
|
.else
|
|
|
|
mfspr r10,SPRN_DSISR
|
|
|
|
.endif
|
2020-02-26 01:35:15 +08:00
|
|
|
stw r10,IAREA+EX_DSISR(r13)
|
2019-08-02 18:56:58 +08:00
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:27 +08:00
|
|
|
.if IHSRR_IF_HVMODE
|
2020-02-26 01:35:19 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
mfspr r11,SPRN_HSRR0 /* save HSRR0 */
|
|
|
|
mfspr r12,SPRN_HSRR1 /* and HSRR1 */
|
|
|
|
FTR_SECTION_ELSE
|
|
|
|
mfspr r11,SPRN_SRR0 /* save SRR0 */
|
|
|
|
mfspr r12,SPRN_SRR1 /* and SRR1 */
|
|
|
|
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
|
|
|
.elseif IHSRR
|
|
|
|
mfspr r11,SPRN_HSRR0 /* save HSRR0 */
|
|
|
|
mfspr r12,SPRN_HSRR1 /* and HSRR1 */
|
|
|
|
.else
|
|
|
|
mfspr r11,SPRN_SRR0 /* save SRR0 */
|
|
|
|
mfspr r12,SPRN_SRR1 /* and SRR1 */
|
2019-08-02 18:56:58 +08:00
|
|
|
.endif
|
2020-02-26 01:35:22 +08:00
|
|
|
|
|
|
|
.if IBRANCH_TO_COMMON
|
2020-02-26 01:35:19 +08:00
|
|
|
GEN_BRANCH_TO_COMMON \name \virt
|
|
|
|
.endif
|
|
|
|
|
2019-08-02 18:56:58 +08:00
|
|
|
.if \ool
|
|
|
|
.popsection
|
|
|
|
.endif
|
|
|
|
.endm
|
|
|
|
|
2019-06-22 21:15:34 +08:00
|
|
|
/*
|
2020-02-26 01:35:19 +08:00
|
|
|
* __GEN_COMMON_ENTRY is required to receive the branch from interrupt
|
2020-02-26 01:35:21 +08:00
|
|
|
* entry, except in the case of the real-mode handlers which require
|
|
|
|
* __GEN_REALMODE_COMMON_ENTRY.
|
|
|
|
*
|
2020-02-26 01:35:19 +08:00
|
|
|
* This switches to virtual mode and sets MSR[RI].
|
2019-06-22 21:15:34 +08:00
|
|
|
*/
|
2020-02-26 01:35:19 +08:00
|
|
|
.macro __GEN_COMMON_ENTRY name
|
|
|
|
DEFINE_FIXED_SYMBOL(\name\()_common_real)
|
|
|
|
\name\()_common_real:
|
2020-02-26 01:35:21 +08:00
|
|
|
.if IKVM_REAL
|
2020-02-26 01:35:24 +08:00
|
|
|
KVMTEST \name
|
2020-02-26 01:35:21 +08:00
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
ld r10,PACAKMSR(r13) /* get MSR value for kernel */
|
|
|
|
/* MSR[RI] is clear iff using SRR regs */
|
|
|
|
.if IHSRR == EXC_HV_OR_STD
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
xori r10,r10,MSR_RI
|
|
|
|
END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE)
|
|
|
|
.elseif ! IHSRR
|
|
|
|
xori r10,r10,MSR_RI
|
|
|
|
.endif
|
|
|
|
mtmsrd r10
|
|
|
|
|
|
|
|
.if IVIRT
|
2020-02-26 01:35:21 +08:00
|
|
|
.if IKVM_VIRT
|
|
|
|
b 1f /* skip the virt test coming from real */
|
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
.balign IFETCH_ALIGN_BYTES
|
|
|
|
DEFINE_FIXED_SYMBOL(\name\()_common_virt)
|
|
|
|
\name\()_common_virt:
|
2020-02-26 01:35:21 +08:00
|
|
|
.if IKVM_VIRT
|
2020-02-26 01:35:24 +08:00
|
|
|
KVMTEST \name
|
2020-02-26 01:35:21 +08:00
|
|
|
1:
|
|
|
|
.endif
|
2020-02-26 01:35:19 +08:00
|
|
|
.endif /* IVIRT */
|
|
|
|
.endm
|
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
/*
|
|
|
|
* Don't switch to virt mode. Used for early MCE and HMI handlers that
|
|
|
|
* want to run in real mode.
|
|
|
|
*/
|
|
|
|
.macro __GEN_REALMODE_COMMON_ENTRY name
|
|
|
|
DEFINE_FIXED_SYMBOL(\name\()_common_real)
|
|
|
|
\name\()_common_real:
|
|
|
|
.if IKVM_REAL
|
2020-02-26 01:35:24 +08:00
|
|
|
KVMTEST \name
|
2020-02-26 01:35:21 +08:00
|
|
|
.endif
|
|
|
|
.endm
|
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
.macro __GEN_COMMON_BODY name
|
2020-02-26 01:35:20 +08:00
|
|
|
.if IMASK
|
2020-06-11 16:12:02 +08:00
|
|
|
.if ! ISTACK
|
|
|
|
.error "No support for masked interrupt to use custom stack"
|
|
|
|
.endif
|
|
|
|
|
|
|
|
/* If coming from user, skip soft-mask tests. */
|
|
|
|
andi. r10,r12,MSR_PR
|
|
|
|
bne 2f
|
|
|
|
|
|
|
|
/* Kernel code running below __end_interrupts is implicitly
|
|
|
|
* soft-masked */
|
|
|
|
LOAD_HANDLER(r10, __end_interrupts)
|
|
|
|
cmpld r11,r10
|
|
|
|
li r10,IMASK
|
|
|
|
blt- 1f
|
|
|
|
|
|
|
|
/* Test the soft mask state against our interrupt's bit */
|
2020-02-26 01:35:20 +08:00
|
|
|
lbz r10,PACAIRQSOFTMASK(r13)
|
2020-06-11 16:12:02 +08:00
|
|
|
1: andi. r10,r10,IMASK
|
2020-02-26 01:35:20 +08:00
|
|
|
/* Associate vector numbers with bits in paca->irq_happened */
|
|
|
|
.if IVEC == 0x500 || IVEC == 0xea0
|
|
|
|
li r10,PACA_IRQ_EE
|
|
|
|
.elseif IVEC == 0x900
|
|
|
|
li r10,PACA_IRQ_DEC
|
|
|
|
.elseif IVEC == 0xa00 || IVEC == 0xe80
|
|
|
|
li r10,PACA_IRQ_DBELL
|
|
|
|
.elseif IVEC == 0xe60
|
|
|
|
li r10,PACA_IRQ_HMI
|
|
|
|
.elseif IVEC == 0xf00
|
|
|
|
li r10,PACA_IRQ_PMI
|
|
|
|
.else
|
|
|
|
.abort "Bad maskable vector"
|
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:27 +08:00
|
|
|
.if IHSRR_IF_HVMODE
|
2020-02-26 01:35:20 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
bne masked_Hinterrupt
|
|
|
|
FTR_SECTION_ELSE
|
|
|
|
bne masked_interrupt
|
|
|
|
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
|
|
|
.elseif IHSRR
|
|
|
|
bne masked_Hinterrupt
|
|
|
|
.else
|
|
|
|
bne masked_interrupt
|
|
|
|
.endif
|
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if ISTACK
|
2019-08-02 18:56:55 +08:00
|
|
|
andi. r10,r12,MSR_PR /* See if coming from user */
|
2020-06-11 16:12:02 +08:00
|
|
|
2: mr r10,r1 /* Save r1 */
|
2019-08-02 18:56:55 +08:00
|
|
|
subi r1,r1,INT_FRAME_SIZE /* alloc frame on kernel stack */
|
2019-08-02 18:56:59 +08:00
|
|
|
beq- 100f
|
2019-08-02 18:56:55 +08:00
|
|
|
ld r1,PACAKSAVE(r13) /* kernel stack to use */
|
2019-08-02 18:56:59 +08:00
|
|
|
100: tdgei r1,-INT_FRAME_SIZE /* trap if r1 is in userspace */
|
|
|
|
EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,0
|
2019-08-02 18:56:55 +08:00
|
|
|
.endif
|
2019-08-02 18:56:56 +08:00
|
|
|
|
|
|
|
std r9,_CCR(r1) /* save CR in stackframe */
|
|
|
|
std r11,_NIP(r1) /* save SRR0 in stackframe */
|
|
|
|
std r12,_MSR(r1) /* save SRR1 in stackframe */
|
|
|
|
std r10,0(r1) /* make stack chain pointer */
|
|
|
|
std r0,GPR0(r1) /* save r0 in stackframe */
|
|
|
|
std r10,GPR1(r1) /* save r1 in stackframe */
|
2019-08-02 18:56:55 +08:00
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
.if ISET_RI
|
|
|
|
li r10,MSR_RI
|
|
|
|
mtmsrd r10,1 /* Set MSR_RI */
|
|
|
|
.endif
|
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if ISTACK
|
|
|
|
.if IKUAP
|
2019-08-02 18:56:55 +08:00
|
|
|
kuap_save_amr_and_lock r9, r10, cr1, cr0
|
|
|
|
.endif
|
2019-08-02 18:56:59 +08:00
|
|
|
beq 101f /* if from kernel mode */
|
2019-08-02 18:56:55 +08:00
|
|
|
ACCOUNT_CPU_USER_ENTRY(r13, r9, r10)
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
ld r9,IAREA+EX_PPR(r13) /* Read PPR from paca */
|
|
|
|
std r9,_PPR(r1)
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
2019-08-02 18:56:59 +08:00
|
|
|
101:
|
2019-08-02 18:56:55 +08:00
|
|
|
.else
|
2020-02-26 01:35:16 +08:00
|
|
|
.if IKUAP
|
2019-08-02 18:56:54 +08:00
|
|
|
kuap_save_amr_and_lock r9, r10, cr1
|
|
|
|
.endif
|
2019-08-02 18:56:55 +08:00
|
|
|
.endif
|
|
|
|
|
2019-08-02 18:56:56 +08:00
|
|
|
/* Save original regs values from save area to stack frame. */
|
2020-02-26 01:35:16 +08:00
|
|
|
ld r9,IAREA+EX_R9(r13) /* move r9, r10 to stackframe */
|
|
|
|
ld r10,IAREA+EX_R10(r13)
|
2019-08-02 18:56:56 +08:00
|
|
|
std r9,GPR9(r1)
|
|
|
|
std r10,GPR10(r1)
|
2020-02-26 01:35:16 +08:00
|
|
|
ld r9,IAREA+EX_R11(r13) /* move r11 - r13 to stackframe */
|
|
|
|
ld r10,IAREA+EX_R12(r13)
|
|
|
|
ld r11,IAREA+EX_R13(r13)
|
2019-08-02 18:56:56 +08:00
|
|
|
std r9,GPR11(r1)
|
|
|
|
std r10,GPR12(r1)
|
|
|
|
std r11,GPR13(r1)
|
2020-02-26 01:35:18 +08:00
|
|
|
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
SAVE_NVGPRS(r1)
|
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if IDAR
|
2020-02-26 01:35:18 +08:00
|
|
|
.if IISIDE
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r10,_NIP(r1)
|
|
|
|
.else
|
2020-02-26 01:35:16 +08:00
|
|
|
ld r10,IAREA+EX_DAR(r13)
|
2019-08-02 18:56:57 +08:00
|
|
|
.endif
|
|
|
|
std r10,_DAR(r1)
|
|
|
|
.endif
|
2020-02-26 01:35:18 +08:00
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if IDSISR
|
2020-02-26 01:35:18 +08:00
|
|
|
.if IISIDE
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r10,_MSR(r1)
|
|
|
|
lis r11,DSISR_SRR1_MATCH_64S@h
|
|
|
|
and r10,r10,r11
|
|
|
|
.else
|
2020-02-26 01:35:16 +08:00
|
|
|
lwz r10,IAREA+EX_DSISR(r13)
|
2019-08-02 18:56:57 +08:00
|
|
|
.endif
|
|
|
|
std r10,_DSISR(r1)
|
|
|
|
.endif
|
2020-02-26 01:35:18 +08:00
|
|
|
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2020-02-26 01:35:16 +08:00
|
|
|
ld r10,IAREA+EX_CFAR(r13)
|
2019-08-02 18:56:56 +08:00
|
|
|
std r10,ORIG_GPR3(r1)
|
2020-02-26 01:35:23 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2020-02-26 01:35:19 +08:00
|
|
|
ld r10,IAREA+EX_CTR(r13)
|
2019-08-02 18:56:56 +08:00
|
|
|
std r10,_CTR(r1)
|
|
|
|
std r2,GPR2(r1) /* save r2 in stackframe */
|
|
|
|
SAVE_4GPRS(3, r1) /* save r3 - r6 in stackframe */
|
|
|
|
SAVE_2GPRS(7, r1) /* save r7, r8 in stackframe */
|
|
|
|
mflr r9 /* Get LR, later save to stack */
|
|
|
|
ld r2,PACATOC(r13) /* get kernel TOC into r2 */
|
|
|
|
std r9,_LINK(r1)
|
|
|
|
lbz r10,PACAIRQSOFTMASK(r13)
|
|
|
|
mfspr r11,SPRN_XER /* save XER in stackframe */
|
|
|
|
std r10,SOFTE(r1)
|
|
|
|
std r11,_XER(r1)
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
li r9,IVEC
|
2019-08-02 18:56:56 +08:00
|
|
|
std r9,_TRAP(r1) /* set trap number */
|
|
|
|
li r10,0
|
|
|
|
ld r11,exception_marker@toc(r2)
|
|
|
|
std r10,RESULT(r1) /* clear regs->result */
|
|
|
|
std r11,STACK_FRAME_OVERHEAD-16(r1) /* mark the frame */
|
2019-08-02 18:56:55 +08:00
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if ISTACK
|
2019-08-02 18:56:55 +08:00
|
|
|
ACCOUNT_STOLEN_TIME
|
2019-08-02 18:56:54 +08:00
|
|
|
.endif
|
2019-08-02 18:56:57 +08:00
|
|
|
|
2020-02-26 01:35:16 +08:00
|
|
|
.if IRECONCILE
|
2019-08-02 18:56:57 +08:00
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
.endif
|
2019-08-02 18:56:54 +08:00
|
|
|
.endm
|
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
/*
|
|
|
|
* On entry r13 points to the paca, r9-r13 are saved in the paca,
|
|
|
|
* r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
|
|
|
|
* SRR1, and relocation is on.
|
|
|
|
*
|
|
|
|
* If stack=0, then the stack is already set in r1, and r1 is saved in r10.
|
|
|
|
* PPR save and CPU accounting is not done for the !stack case (XXX why not?)
|
|
|
|
*/
|
|
|
|
.macro GEN_COMMON name
|
|
|
|
__GEN_COMMON_ENTRY \name
|
|
|
|
__GEN_COMMON_BODY \name
|
|
|
|
.endm
|
|
|
|
|
2019-06-28 13:33:27 +08:00
|
|
|
/*
|
|
|
|
* Restore all registers including H/SRR0/1 saved in a stack frame of a
|
|
|
|
* standard exception.
|
|
|
|
*/
|
2020-02-26 01:35:27 +08:00
|
|
|
.macro EXCEPTION_RESTORE_REGS hsrr=0
|
2019-06-28 13:33:27 +08:00
|
|
|
/* Move original SRR0 and SRR1 into the respective regs */
|
|
|
|
ld r9,_MSR(r1)
|
|
|
|
.if \hsrr
|
|
|
|
mtspr SPRN_HSRR1,r9
|
|
|
|
.else
|
|
|
|
mtspr SPRN_SRR1,r9
|
|
|
|
.endif
|
|
|
|
ld r9,_NIP(r1)
|
|
|
|
.if \hsrr
|
|
|
|
mtspr SPRN_HSRR0,r9
|
|
|
|
.else
|
|
|
|
mtspr SPRN_SRR0,r9
|
|
|
|
.endif
|
|
|
|
ld r9,_CTR(r1)
|
|
|
|
mtctr r9
|
|
|
|
ld r9,_XER(r1)
|
|
|
|
mtxer r9
|
|
|
|
ld r9,_LINK(r1)
|
|
|
|
mtlr r9
|
|
|
|
ld r9,_CCR(r1)
|
|
|
|
mtcr r9
|
|
|
|
REST_8GPRS(2, r1)
|
|
|
|
REST_4GPRS(10, r1)
|
|
|
|
REST_GPR(0, r1)
|
|
|
|
/* restore original r1. */
|
|
|
|
ld r1,GPR1(r1)
|
|
|
|
.endm
|
2019-06-22 21:15:34 +08:00
|
|
|
|
|
|
|
#define RUNLATCH_ON \
|
|
|
|
BEGIN_FTR_SECTION \
|
|
|
|
ld r3, PACA_THREAD_INFO(r13); \
|
|
|
|
ld r4,TI_LOCAL_FLAGS(r3); \
|
|
|
|
andi. r0,r4,_TLF_RUNLATCH; \
|
|
|
|
beql ppc64_runlatch_on_trampoline; \
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
|
|
|
|
|
2019-06-22 21:15:27 +08:00
|
|
|
/*
|
|
|
|
* When the idle code in power4_idle puts the CPU into NAP mode,
|
|
|
|
* it has to do so in a loop, and relies on the external interrupt
|
|
|
|
* and decrementer interrupt entry code to get it out of the loop.
|
|
|
|
* It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
|
|
|
|
* to signal that it is in the loop and needs help to get out.
|
|
|
|
*/
|
|
|
|
#ifdef CONFIG_PPC_970_NAP
|
|
|
|
#define FINISH_NAP \
|
|
|
|
BEGIN_FTR_SECTION \
|
|
|
|
ld r11, PACA_THREAD_INFO(r13); \
|
|
|
|
ld r9,TI_LOCAL_FLAGS(r11); \
|
|
|
|
andi. r10,r9,_TLF_NAPPING; \
|
|
|
|
bnel power4_fixup_nap; \
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
|
|
|
|
#else
|
|
|
|
#define FINISH_NAP
|
|
|
|
#endif
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
/*
|
2016-09-28 09:31:48 +08:00
|
|
|
* There are a few constraints to be concerned with.
|
|
|
|
* - Real mode exceptions code/data must be located at their physical location.
|
|
|
|
* - Virtual mode exceptions must be mapped at their 0xc000... location.
|
|
|
|
* - Fixed location code must not call directly beyond the __end_interrupts
|
|
|
|
* area when built with CONFIG_RELOCATABLE. LOAD_HANDLER / bctr sequence
|
|
|
|
* must be used.
|
|
|
|
* - LOAD_HANDLER targets must be within first 64K of physical 0 /
|
|
|
|
* virtual 0xc00...
|
|
|
|
* - Conditional branch targets must be within +/-32K of caller.
|
|
|
|
*
|
|
|
|
* "Virtual exceptions" run with relocation on (MSR_IR=1, MSR_DR=1), and
|
|
|
|
* therefore don't have to run in physically located code or rfid to
|
|
|
|
* virtual mode kernel code. However on relocatable kernels they do have
|
|
|
|
* to branch to KERNELBASE offset because the rest of the kernel (outside
|
|
|
|
* the exception vectors) may be located elsewhere.
|
|
|
|
*
|
|
|
|
* Virtual exceptions correspond with physical, except their entry points
|
|
|
|
* are offset by 0xc000000000000000 and also tend to get an added 0x4000
|
|
|
|
* offset applied. Virtual exceptions are enabled with the Alternate
|
|
|
|
* Interrupt Location (AIL) bit set in the LPCR. However this does not
|
|
|
|
* guarantee they will be delivered virtually. Some conditions (see the ISA)
|
|
|
|
* cause exceptions to be delivered in real mode.
|
|
|
|
*
|
2020-06-11 16:12:03 +08:00
|
|
|
* The scv instructions are a special case. They get a 0x3000 offset applied.
|
|
|
|
* scv exceptions have unique reentrancy properties, see below.
|
|
|
|
*
|
2016-09-28 09:31:48 +08:00
|
|
|
* It's impossible to receive interrupts below 0x300 via AIL.
|
|
|
|
*
|
|
|
|
* KVM: None of the virtual exceptions are from the guest. Anything that
|
|
|
|
* escalated to HV=1 from HV=0 is delivered via real mode handlers.
|
|
|
|
*
|
|
|
|
*
|
2009-06-03 05:17:38 +08:00
|
|
|
* We layout physical memory as follows:
|
|
|
|
* 0x0000 - 0x00ff : Secondary processor spin code
|
2016-09-28 09:31:48 +08:00
|
|
|
* 0x0100 - 0x18ff : Real mode pSeries interrupt vectors
|
2020-06-11 16:12:03 +08:00
|
|
|
* 0x1900 - 0x2fff : Real mode trampolines
|
|
|
|
* 0x3000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors
|
2016-09-28 09:31:48 +08:00
|
|
|
* 0x5900 - 0x6fff : Relon mode trampolines
|
2009-06-03 05:17:38 +08:00
|
|
|
* 0x7000 - 0x7fff : FWNMI data area
|
2016-09-28 09:31:48 +08:00
|
|
|
* 0x8000 - .... : Common interrupt handlers, remaining early
|
|
|
|
* setup code, rest of kernel.
|
2016-09-21 15:44:07 +08:00
|
|
|
*
|
|
|
|
* We could reclaim 0x4000-0x42ff for real mode trampolines if the space
|
|
|
|
* is necessary. Until then it's more consistent to explicitly put VIRT_NONE
|
|
|
|
* vectors there.
|
2016-09-28 09:31:48 +08:00
|
|
|
*/
|
|
|
|
OPEN_FIXED_SECTION(real_vectors, 0x0100, 0x1900)
|
2020-06-11 16:12:03 +08:00
|
|
|
OPEN_FIXED_SECTION(real_trampolines, 0x1900, 0x3000)
|
|
|
|
OPEN_FIXED_SECTION(virt_vectors, 0x3000, 0x5900)
|
2016-09-28 09:31:48 +08:00
|
|
|
OPEN_FIXED_SECTION(virt_trampolines, 0x5900, 0x7000)
|
2019-02-26 16:51:07 +08:00
|
|
|
|
|
|
|
#ifdef CONFIG_PPC_POWERNV
|
2019-03-01 20:56:36 +08:00
|
|
|
.globl start_real_trampolines
|
|
|
|
.globl end_real_trampolines
|
|
|
|
.globl start_virt_trampolines
|
|
|
|
.globl end_virt_trampolines
|
2019-02-26 16:51:07 +08:00
|
|
|
#endif
|
|
|
|
|
2016-09-28 09:31:48 +08:00
|
|
|
#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
|
|
|
|
/*
|
|
|
|
* Data area reserved for FWNMI option.
|
|
|
|
* This address (0x7000) is fixed by the RPA.
|
|
|
|
* pseries and powernv need to keep the whole page from
|
|
|
|
* 0x7000 to 0x8000 free for use by the firmware
|
2009-06-03 05:17:38 +08:00
|
|
|
*/
|
2016-09-28 09:31:48 +08:00
|
|
|
ZERO_FIXED_SECTION(fwnmi_page, 0x7000, 0x8000)
|
|
|
|
OPEN_TEXT_SECTION(0x8000)
|
|
|
|
#else
|
|
|
|
OPEN_TEXT_SECTION(0x7000)
|
|
|
|
#endif
|
|
|
|
|
|
|
|
USE_FIXED_SECTION(real_vectors)
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
/*
|
|
|
|
* This is the start of the interrupt handlers for pSeries
|
|
|
|
* This code runs with relocation off.
|
|
|
|
* Code from here to __end_interrupts gets copied down to real
|
|
|
|
* address 0x100 when we are running a relocatable kernel.
|
|
|
|
* Therefore any relative branches in this section must only
|
|
|
|
* branch to labels in this section.
|
|
|
|
*/
|
|
|
|
.globl __start_interrupts
|
|
|
|
__start_interrupts:
|
|
|
|
|
2020-06-11 16:12:03 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x3000 - System Call Vectored Interrupt (syscall).
|
|
|
|
* This is a synchronous interrupt invoked with the "scv" instruction. The
|
|
|
|
* system call does not alter the HV bit, so it is directed to the OS.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* scv instructions enter the kernel without changing EE, RI, ME, or HV.
|
|
|
|
* In particular, this means we can take a maskable interrupt at any point
|
|
|
|
* in the scv handler, which is unlike any other interrupt. This is solved
|
|
|
|
* by treating the instruction addresses below __end_interrupts as being
|
|
|
|
* soft-masked.
|
|
|
|
*
|
|
|
|
* AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and
|
|
|
|
* ensure scv is never executed with relocation off, which means AIL-0
|
|
|
|
* should never happen.
|
|
|
|
*
|
|
|
|
* Before leaving the below __end_interrupts text, at least of the following
|
|
|
|
* must be true:
|
|
|
|
* - MSR[PR]=1 (i.e., return to userspace)
|
|
|
|
* - MSR_EE|MSR_RI is set (no reentrant exceptions)
|
|
|
|
* - Standard kernel environment is set up (stack, paca, etc)
|
|
|
|
*
|
|
|
|
* Call convention:
|
|
|
|
*
|
|
|
|
* syscall register convention is in Documentation/powerpc/syscall64-abi.rst
|
|
|
|
*/
|
|
|
|
EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
|
|
|
|
/* SCV 0 */
|
|
|
|
mr r9,r13
|
|
|
|
GET_PACA(r13)
|
|
|
|
mflr r11
|
|
|
|
mfctr r12
|
|
|
|
li r10,IRQS_ALL_DISABLED
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
b system_call_vectored_tramp
|
|
|
|
#else
|
|
|
|
b system_call_vectored_common
|
|
|
|
#endif
|
|
|
|
nop
|
|
|
|
|
|
|
|
/* SCV 1 - 127 */
|
|
|
|
.rept 127
|
|
|
|
mr r9,r13
|
|
|
|
GET_PACA(r13)
|
|
|
|
mflr r11
|
|
|
|
mfctr r12
|
|
|
|
li r10,IRQS_ALL_DISABLED
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
li r0,-1 /* cause failure */
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
b system_call_vectored_sigill_tramp
|
|
|
|
#else
|
|
|
|
b system_call_vectored_sigill
|
|
|
|
#endif
|
|
|
|
.endr
|
|
|
|
EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000)
|
|
|
|
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
|
|
|
|
__LOAD_HANDLER(r10, system_call_vectored_common)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
|
|
|
|
|
|
|
TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
|
|
|
|
__LOAD_HANDLER(r10, system_call_vectored_sigill)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
2016-09-21 15:44:07 +08:00
|
|
|
/* No virt vectors corresponding with 0x0..0x100 */
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x4000, 0x100)
|
2016-09-21 15:44:07 +08:00
|
|
|
|
2016-10-13 10:17:14 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x100 - System Reset Interrupt (SRESET aka NMI).
|
|
|
|
* This is a non-maskable, asynchronous interrupt always taken in real-mode.
|
|
|
|
* It is caused by:
|
|
|
|
* - Wake from power-saving state, on powernv.
|
|
|
|
* - An NMI from another CPU, triggered by firmware or hypercall.
|
|
|
|
* - As crash/debug signal injected from BMC, firmware or hypervisor.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Power-save wakeup is the only performance critical path, so this is
|
|
|
|
* determined quickly as possible first. In this case volatile registers
|
|
|
|
* can be discarded and SPRs like CFAR don't need to be read.
|
|
|
|
*
|
|
|
|
* If not a powersave wakeup, then it's run as a regular interrupt, however
|
|
|
|
* it uses its own stack and PACA save area to preserve the regular kernel
|
|
|
|
* environment for debugging.
|
|
|
|
*
|
|
|
|
* This interrupt is not maskable, so triggering it when MSR[RI] is clear,
|
|
|
|
* or SCRATCH0 is in use, etc. may cause a crash. It's also not entirely
|
|
|
|
* correct to switch to virtual mode to run the regular interrupt handler
|
|
|
|
* because it might be interrupted when the MMU is in a bad state (e.g., SLB
|
|
|
|
* is clear).
|
|
|
|
*
|
|
|
|
* FWNMI:
|
|
|
|
* PAPR specifies a "fwnmi" facility which sends the sreset to a different
|
|
|
|
* entry point with a different register set up. Some hypervisors will
|
|
|
|
* send the sreset to 0x100 in the guest if it is not fwnmi capable.
|
|
|
|
*
|
|
|
|
* KVM:
|
|
|
|
* Unlike most SRR interrupts, this may be taken by the host while executing
|
|
|
|
* in a guest, so a KVM test is required. KVM will pull the CPU out of guest
|
|
|
|
* mode and then raise the sreset.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(system_reset)
|
|
|
|
IVEC=0x100
|
|
|
|
IAREA=PACA_EXNMI
|
2020-02-26 01:35:19 +08:00
|
|
|
IVIRT=0 /* no virt entry point */
|
2020-02-26 01:35:14 +08:00
|
|
|
/*
|
|
|
|
* MSR_RI is not enabled, because PACA_EXNMI and nmi stack is
|
|
|
|
* being used, so a nested NMI exception would corrupt it.
|
|
|
|
*/
|
|
|
|
ISET_RI=0
|
|
|
|
ISTACK=0
|
|
|
|
IRECONCILE=0
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(system_reset)
|
|
|
|
|
2019-06-22 21:15:15 +08:00
|
|
|
EXC_REAL_BEGIN(system_reset, 0x100, 0x100)
|
2011-01-24 15:42:41 +08:00
|
|
|
#ifdef CONFIG_PPC_P7_NAP
|
2016-10-13 10:17:14 +08:00
|
|
|
/*
|
|
|
|
* If running native on arch 2.06 or later, check if we are waking up
|
2017-06-25 01:29:01 +08:00
|
|
|
* from nap/sleep/winkle, and branch to idle handler. This tests SRR1
|
|
|
|
* bits 46:47. A non-0 value indicates that we are coming from a power
|
|
|
|
* saving state. The idle wakeup handler initially runs in real mode,
|
|
|
|
* but we branch to the 0xc000... address so we can turn on relocation
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
|
|
|
* with mtmsrd later, after SPRs are restored.
|
|
|
|
*
|
|
|
|
* Careful to minimise cost for the fast path (idle wakeup) while
|
|
|
|
* also avoiding clobbering CFAR for the debug path (non-idle).
|
|
|
|
*
|
|
|
|
* For the idle wake case volatile registers can be clobbered, which
|
|
|
|
* is why we use those initially. If it turns out to not be an idle
|
|
|
|
* wake, carefully put everything back the way it was, so we can use
|
|
|
|
* common exception macros to handle it.
|
2011-01-24 15:42:41 +08:00
|
|
|
*/
|
2019-06-22 21:15:32 +08:00
|
|
|
BEGIN_FTR_SECTION
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
|
|
|
SET_SCRATCH0(r13)
|
|
|
|
GET_PACA(r13)
|
|
|
|
std r3,PACA_EXNMI+0*8(r13)
|
|
|
|
std r4,PACA_EXNMI+1*8(r13)
|
|
|
|
std r5,PACA_EXNMI+2*8(r13)
|
2019-06-22 21:15:15 +08:00
|
|
|
mfspr r3,SPRN_SRR1
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
|
|
|
mfocrf r4,0x80
|
|
|
|
rlwinm. r5,r3,47-31,30,31
|
|
|
|
bne+ system_reset_idle_wake
|
|
|
|
/* Not powersave wakeup. Restore regs for regular interrupt handler. */
|
|
|
|
mtocrf 0x80,r4
|
|
|
|
ld r3,PACA_EXNMI+0*8(r13)
|
|
|
|
ld r4,PACA_EXNMI+1*8(r13)
|
|
|
|
ld r5,PACA_EXNMI+2*8(r13)
|
|
|
|
GET_SCRATCH0(r13)
|
2019-06-22 21:15:32 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
2016-10-13 10:17:14 +08:00
|
|
|
#endif
|
KVM: PPC: Allow book3s_hv guests to use SMT processor modes
This lifts the restriction that book3s_hv guests can only run one
hardware thread per core, and allows them to use up to 4 threads
per core on POWER7. The host still has to run single-threaded.
This capability is advertised to qemu through a new KVM_CAP_PPC_SMT
capability. The return value of the ioctl querying this capability
is the number of vcpus per virtual CPU core (vcore), currently 4.
To use this, the host kernel should be booted with all threads
active, and then all the secondary threads should be offlined.
This will put the secondary threads into nap mode. KVM will then
wake them from nap mode and use them for running guest code (while
they are still offline). To wake the secondary threads, we send
them an IPI using a new xics_wake_cpu() function, implemented in
arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage
we assume that the platform has a XICS interrupt controller and
we are using icp-native.c to drive it. Since the woken thread will
need to acknowledge and clear the IPI, we also export the base
physical address of the XICS registers using kvmppc_set_xics_phys()
for use in the low-level KVM book3s code.
When a vcpu is created, it is assigned to a virtual CPU core.
The vcore number is obtained by dividing the vcpu number by the
number of threads per core in the host. This number is exported
to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes
to run the guest in single-threaded mode, it should make all vcpu
numbers be multiples of the number of threads per core.
We distinguish three states of a vcpu: runnable (i.e., ready to execute
the guest), blocked (that is, idle), and busy in host. We currently
implement a policy that the vcore can run only when all its threads
are runnable or blocked. This way, if a vcpu needs to execute elsewhere
in the kernel or in qemu, it can do so without being starved of CPU
by the other vcpus.
When a vcore starts to run, it executes in the context of one of the
vcpu threads. The other vcpu threads all go to sleep and stay asleep
until something happens requiring the vcpu thread to return to qemu,
or to wake up to run the vcore (this can happen when another vcpu
thread goes from busy in host state to blocked).
It can happen that a vcpu goes from blocked to runnable state (e.g.
because of an interrupt), and the vcore it belongs to is already
running. In that case it can start to run immediately as long as
the none of the vcpus in the vcore have started to exit the guest.
We send the next free thread in the vcore an IPI to get it to start
to execute the guest. It synchronizes with the other threads via
the vcore->entry_exit_count field to make sure that it doesn't go
into the guest if the other vcpus are exiting by the time that it
is ready to actually enter the guest.
Note that there is no fixed relationship between the hardware thread
number and the vcpu number. Hardware threads are assigned to vcpus
as they become runnable, so we will always use the lower-numbered
hardware threads in preference to higher-numbered threads if not all
the vcpus in the vcore are runnable, regardless of which vcpus are
runnable.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:23:08 +08:00
|
|
|
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY system_reset, virt=0
|
2016-12-20 02:30:05 +08:00
|
|
|
/*
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
|
|
|
* In theory, we should not enable relocation here if it was disabled
|
|
|
|
* in SRR1, because the MMU may not be configured to support it (e.g.,
|
|
|
|
* SLB may have been cleared). In practice, there should only be a few
|
|
|
|
* small windows where that's the case, and sreset is considered to
|
|
|
|
* be dangerous anyway.
|
2016-12-20 02:30:05 +08:00
|
|
|
*/
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_END(system_reset, 0x100, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x4100, 0x100)
|
2016-10-13 10:17:14 +08:00
|
|
|
|
|
|
|
#ifdef CONFIG_PPC_P7_NAP
|
powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case
The idle wake up code in the system reset interrupt is not very
optimal. There are two requirements: perform idle wake up quickly;
and save everything including CFAR for non-idle interrupts, with
no performance requirement.
The problem with placing the idle test in the middle of the handler
and using the normal handler code to save CFAR, is that it's quite
costly (e.g., mfcfar is serialising, speculative workarounds get
applied, SRR1 has to be reloaded, etc). It also prevents the standard
interrupt handler boilerplate being used.
This pain can be avoided by using a dedicated idle interrupt handler
at the start of the interrupt handler, which restores all registers
back to the way they were in case it was not an idle wake up. CFAR
is preserved without saving it before the non-idle case by making that
the fall-through, and idle is a taken branch.
Performance seems to be in the noise, but possibly around 0.5% faster,
the executed instructions certainly look better. The bigger benefit is
being able to drop in standard interrupt handlers after the idle code,
which helps with subsequent cleanup and consolidation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup BE by using DOTSYM for idle_return_gpr_loss call]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:19 +08:00
|
|
|
TRAMP_REAL_BEGIN(system_reset_idle_wake)
|
|
|
|
/* We are waking up from idle, so may clobber any volatile register */
|
|
|
|
cmpwi cr1,r5,2
|
|
|
|
bltlr cr1 /* no state loss, return to idle caller with r3=SRR1 */
|
|
|
|
BRANCH_TO_C000(r12, DOTSYM(idle_return_gpr_loss))
|
KVM: PPC: Allow book3s_hv guests to use SMT processor modes
This lifts the restriction that book3s_hv guests can only run one
hardware thread per core, and allows them to use up to 4 threads
per core on POWER7. The host still has to run single-threaded.
This capability is advertised to qemu through a new KVM_CAP_PPC_SMT
capability. The return value of the ioctl querying this capability
is the number of vcpus per virtual CPU core (vcore), currently 4.
To use this, the host kernel should be booted with all threads
active, and then all the secondary threads should be offlined.
This will put the secondary threads into nap mode. KVM will then
wake them from nap mode and use them for running guest code (while
they are still offline). To wake the secondary threads, we send
them an IPI using a new xics_wake_cpu() function, implemented in
arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage
we assume that the platform has a XICS interrupt controller and
we are using icp-native.c to drive it. Since the woken thread will
need to acknowledge and clear the IPI, we also export the base
physical address of the XICS registers using kvmppc_set_xics_phys()
for use in the low-level KVM book3s code.
When a vcpu is created, it is assigned to a virtual CPU core.
The vcore number is obtained by dividing the vcpu number by the
number of threads per core in the host. This number is exported
to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes
to run the guest in single-threaded mode, it should make all vcpu
numbers be multiples of the number of threads per core.
We distinguish three states of a vcpu: runnable (i.e., ready to execute
the guest), blocked (that is, idle), and busy in host. We currently
implement a policy that the vcore can run only when all its threads
are runnable or blocked. This way, if a vcpu needs to execute elsewhere
in the kernel or in qemu, it can do so without being starved of CPU
by the other vcpus.
When a vcore starts to run, it executes in the context of one of the
vcpu threads. The other vcpu threads all go to sleep and stay asleep
until something happens requiring the vcpu thread to return to qemu,
or to wake up to run the vcore (this can happen when another vcpu
thread goes from busy in host state to blocked).
It can happen that a vcpu goes from blocked to runnable state (e.g.
because of an interrupt), and the vcore it belongs to is already
running. In that case it can start to run immediately as long as
the none of the vcpus in the vcore have started to exit the guest.
We send the next free thread in the vcore an IPI to get it to start
to execute the guest. It synchronizes with the other threads via
the vcore->entry_exit_count field to make sure that it doesn't go
into the guest if the other vcpus are exiting by the time that it
is ready to actually enter the guest.
Note that there is no fixed relationship between the hardware thread
number and the vcpu number. Hardware threads are assigned to vcpus
as they become runnable, so we will always use the lower-numbered
hardware threads in preference to higher-numbered threads if not all
the vcpus in the vcore are runnable, regardless of which vcpus are
runnable.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:23:08 +08:00
|
|
|
#endif
|
|
|
|
|
2019-06-28 14:33:20 +08:00
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
|
|
/*
|
|
|
|
* Vectors for the FWNMI option. Share common code.
|
|
|
|
*/
|
|
|
|
TRAMP_REAL_BEGIN(system_reset_fwnmi)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY system_reset, virt=0
|
2019-06-28 14:33:20 +08:00
|
|
|
|
|
|
|
#endif /* CONFIG_PPC_PSERIES */
|
|
|
|
|
2016-12-20 02:30:04 +08:00
|
|
|
EXC_COMMON_BEGIN(system_reset_common)
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_ENTRY system_reset
|
2016-12-20 02:30:05 +08:00
|
|
|
/*
|
|
|
|
* Increment paca->in_nmi then enable MSR_RI. SLB or MCE will be able
|
|
|
|
* to recover, but nested NMI will notice in_nmi and not recover
|
|
|
|
* because of the use of the NMI stack. in_nmi reentrancy is tested in
|
|
|
|
* system_reset_exception.
|
|
|
|
*/
|
|
|
|
lhz r10,PACA_IN_NMI(r13)
|
|
|
|
addi r10,r10,1
|
|
|
|
sth r10,PACA_IN_NMI(r13)
|
|
|
|
li r10,MSR_RI
|
|
|
|
mtmsrd r10,1
|
2014-02-26 08:08:25 +08:00
|
|
|
|
2016-12-20 02:30:06 +08:00
|
|
|
mr r10,r1
|
|
|
|
ld r1,PACA_NMI_EMERG_SP(r13)
|
|
|
|
subi r1,r1,INT_FRAME_SIZE
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_BODY system_reset
|
2019-06-22 21:15:21 +08:00
|
|
|
/*
|
2020-02-26 01:35:30 +08:00
|
|
|
* Set IRQS_ALL_DISABLED unconditionally so irqs_disabled() does
|
2019-06-22 21:15:21 +08:00
|
|
|
* the right thing. We do not want to reconcile because that goes
|
|
|
|
* through irq tracing which we don't want in NMI.
|
|
|
|
*
|
2020-05-08 12:33:55 +08:00
|
|
|
* Save PACAIRQHAPPENED to RESULT (otherwise unused), and set HARD_DIS
|
2020-02-26 01:35:30 +08:00
|
|
|
* as we are running with MSR[EE]=0.
|
2019-06-22 21:15:21 +08:00
|
|
|
*/
|
|
|
|
li r10,IRQS_ALL_DISABLED
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
lbz r10,PACAIRQHAPPENED(r13)
|
2020-05-08 12:33:55 +08:00
|
|
|
std r10,RESULT(r1)
|
2020-02-26 01:35:30 +08:00
|
|
|
ori r10,r10,PACA_IRQ_HARD_DIS
|
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
2019-06-22 21:15:21 +08:00
|
|
|
|
2019-06-22 21:15:20 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl system_reset_exception
|
2018-03-26 23:01:03 +08:00
|
|
|
|
|
|
|
/* Clear MSR_RI before setting SRR0 and SRR1. */
|
2019-06-28 13:33:22 +08:00
|
|
|
li r9,0
|
2018-03-26 23:01:03 +08:00
|
|
|
mtmsrd r9,1
|
2016-12-20 02:30:05 +08:00
|
|
|
|
|
|
|
/*
|
2018-03-26 23:01:03 +08:00
|
|
|
* MSR_RI is clear, now we can decrement paca->in_nmi.
|
2016-12-20 02:30:05 +08:00
|
|
|
*/
|
|
|
|
lhz r10,PACA_IN_NMI(r13)
|
|
|
|
subi r10,r10,1
|
|
|
|
sth r10,PACA_IN_NMI(r13)
|
|
|
|
|
2018-03-26 23:01:03 +08:00
|
|
|
/*
|
|
|
|
* Restore soft mask settings.
|
|
|
|
*/
|
2020-05-08 12:33:55 +08:00
|
|
|
ld r10,RESULT(r1)
|
2018-03-26 23:01:03 +08:00
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
|
|
|
ld r10,SOFTE(r1)
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
|
2020-04-29 14:56:54 +08:00
|
|
|
kuap_restore_amr r9, r10
|
2020-02-26 01:35:27 +08:00
|
|
|
EXCEPTION_RESTORE_REGS
|
2018-03-26 23:01:03 +08:00
|
|
|
RFI_TO_USER_OR_KERNEL
|
2016-09-21 15:43:30 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM system_reset
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x200 - Machine Check Interrupt (MCE).
|
|
|
|
* This is a non-maskable interrupt always taken in real-mode. It can be
|
|
|
|
* synchronous or asynchronous, caused by hardware or software, and it may be
|
|
|
|
* taken in a power-saving state.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Similarly to system reset, this uses its own stack and PACA save area,
|
|
|
|
* the difference is re-entrancy is allowed on the machine check stack.
|
|
|
|
*
|
|
|
|
* machine_check_early is run in real mode, and carefully decodes the
|
|
|
|
* machine check and tries to handle it (e.g., flush the SLB if there was an
|
|
|
|
* error detected there), determines if it was recoverable and logs the
|
|
|
|
* event.
|
|
|
|
*
|
2020-02-26 01:35:30 +08:00
|
|
|
* This early code does not "reconcile" irq soft-mask state like SRESET or
|
|
|
|
* regular interrupts do, so irqs_disabled() among other things may not work
|
|
|
|
* properly (irq disable/enable already doesn't work because irq tracing can
|
|
|
|
* not work in real mode).
|
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* Then, depending on the execution context when the interrupt is taken, there
|
|
|
|
* are 3 main actions:
|
|
|
|
* - Executing in kernel mode. The event is queued with irq_work, which means
|
|
|
|
* it is handled when it is next safe to do so (i.e., the kernel has enabled
|
|
|
|
* interrupts), which could be immediately when the interrupt returns. This
|
|
|
|
* avoids nasty issues like switching to virtual mode when the MMU is in a
|
|
|
|
* bad state, or when executing OPAL code. (SRESET is exposed to such issues,
|
|
|
|
* but it has different priorities). Check to see if the CPU was in power
|
|
|
|
* save, and return via the wake up code if it was.
|
|
|
|
*
|
|
|
|
* - Executing in user mode. machine_check_exception is run like a normal
|
|
|
|
* interrupt handler, which processes the data generated by the early handler.
|
|
|
|
*
|
|
|
|
* - Executing in guest mode. The interrupt is run with its KVM test, and
|
|
|
|
* branches to KVM to deal with. KVM may queue the event for the host
|
|
|
|
* to report later.
|
|
|
|
*
|
|
|
|
* This interrupt is not maskable, so if it triggers when MSR[RI] is clear,
|
|
|
|
* or SCRATCH0 is in use, it may cause a crash.
|
|
|
|
*
|
|
|
|
* KVM:
|
|
|
|
* See SRESET.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(machine_check_early)
|
|
|
|
IVEC=0x200
|
|
|
|
IAREA=PACA_EXMC
|
2020-02-26 01:35:19 +08:00
|
|
|
IVIRT=0 /* no virt entry point */
|
2020-02-26 01:35:22 +08:00
|
|
|
IREALMODE_COMMON=1
|
2019-08-02 18:56:36 +08:00
|
|
|
/*
|
|
|
|
* MSR_RI is not enabled, because PACA_EXMC is being used, so a
|
|
|
|
* nested machine check corrupts it. machine_check_common enables
|
|
|
|
* MSR_RI.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
ISET_RI=0
|
|
|
|
ISTACK=0
|
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
|
|
|
IRECONCILE=0
|
|
|
|
IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
|
|
|
|
INT_DEFINE_END(machine_check_early)
|
|
|
|
|
|
|
|
INT_DEFINE_BEGIN(machine_check)
|
|
|
|
IVEC=0x200
|
|
|
|
IAREA=PACA_EXMC
|
2020-02-26 01:35:19 +08:00
|
|
|
IVIRT=0 /* no virt entry point */
|
2020-02-26 01:35:14 +08:00
|
|
|
ISET_RI=0
|
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(machine_check)
|
|
|
|
|
|
|
|
EXC_REAL_BEGIN(machine_check, 0x200, 0x100)
|
|
|
|
GEN_INT_ENTRY machine_check_early, virt=0
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_END(machine_check, 0x200, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x4200, 0x100)
|
2019-08-02 18:56:36 +08:00
|
|
|
|
2019-08-02 18:56:37 +08:00
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
|
|
TRAMP_REAL_BEGIN(machine_check_fwnmi)
|
|
|
|
/* See comment at machine_check exception, don't turn on RI */
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY machine_check_early, virt=0
|
2019-08-02 18:56:37 +08:00
|
|
|
#endif
|
|
|
|
|
2019-08-02 18:56:40 +08:00
|
|
|
#define MACHINE_CHECK_HANDLER_WINDUP \
|
|
|
|
/* Clear MSR_RI before setting SRR0 and SRR1. */\
|
|
|
|
li r9,0; \
|
|
|
|
mtmsrd r9,1; /* Clear MSR_RI */ \
|
|
|
|
/* Decrement paca->in_mce now RI is clear. */ \
|
|
|
|
lhz r12,PACA_IN_MCE(r13); \
|
|
|
|
subi r12,r12,1; \
|
|
|
|
sth r12,PACA_IN_MCE(r13); \
|
2020-02-26 01:35:27 +08:00
|
|
|
EXCEPTION_RESTORE_REGS
|
2019-08-02 18:56:40 +08:00
|
|
|
|
2019-08-02 18:56:36 +08:00
|
|
|
EXC_COMMON_BEGIN(machine_check_early_common)
|
2020-02-26 01:35:21 +08:00
|
|
|
__GEN_REALMODE_COMMON_ENTRY machine_check_early
|
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
|
|
|
* Switch to mc_emergency stack and handle re-entrancy (we limit
|
|
|
|
* the nested MCE upto level 4 to avoid stack overflow).
|
|
|
|
* Save MCE registers srr1, srr0, dar and dsisr and then set ME=1
|
|
|
|
*
|
|
|
|
* We use paca->in_mce to check whether this is the first entry or
|
|
|
|
* nested machine check. We increment paca->in_mce to track nested
|
|
|
|
* machine checks.
|
|
|
|
*
|
|
|
|
* If this is the first entry then set stack pointer to
|
|
|
|
* paca->mc_emergency_sp, otherwise r1 is already pointing to
|
|
|
|
* stack frame on mc_emergency stack.
|
|
|
|
*
|
|
|
|
* NOTE: We are here with MSR_ME=0 (off), which means we risk a
|
|
|
|
* checkstop if we get another machine check exception before we do
|
|
|
|
* rfid with MSR_ME=1.
|
2017-04-19 21:05:47 +08:00
|
|
|
*
|
|
|
|
* This interrupt can wake directly from idle. If that is the case,
|
|
|
|
* the machine check is handled then the idle wakeup code is called
|
2018-07-05 16:47:00 +08:00
|
|
|
* to restore state.
|
2016-09-21 15:43:31 +08:00
|
|
|
*/
|
|
|
|
lhz r10,PACA_IN_MCE(r13)
|
|
|
|
cmpwi r10,0 /* Are we in nested machine check */
|
2019-08-02 18:56:36 +08:00
|
|
|
cmpwi cr1,r10,MAX_MCE_DEPTH /* Are we at maximum nesting */
|
2016-09-21 15:43:31 +08:00
|
|
|
addi r10,r10,1 /* increment paca->in_mce */
|
|
|
|
sth r10,PACA_IN_MCE(r13)
|
2019-08-02 18:56:36 +08:00
|
|
|
|
|
|
|
mr r10,r1 /* Save r1 */
|
|
|
|
bne 1f
|
|
|
|
/* First machine check entry */
|
|
|
|
ld r1,PACAMCEMERGSP(r13) /* Use MC emergency stack */
|
2019-08-02 18:56:39 +08:00
|
|
|
1: /* Limit nested MCE to level 4 to avoid stack overflow */
|
|
|
|
bgt cr1,unrecoverable_mce /* Check if we hit limit of 4 */
|
|
|
|
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
|
2019-08-02 18:56:36 +08:00
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_BODY machine_check_early
|
2019-08-02 18:56:36 +08:00
|
|
|
|
2018-09-11 22:27:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2019-08-02 18:56:38 +08:00
|
|
|
bl enable_machine_check
|
2018-09-11 22:27:23 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
|
2019-08-02 18:56:38 +08:00
|
|
|
li r10,MSR_RI
|
|
|
|
mtmsrd r10,1
|
|
|
|
|
2020-05-08 12:33:56 +08:00
|
|
|
/*
|
|
|
|
* Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
|
|
|
|
* system_reset_common)
|
|
|
|
*/
|
|
|
|
li r10,IRQS_ALL_DISABLED
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
lbz r10,PACAIRQHAPPENED(r13)
|
|
|
|
std r10,RESULT(r1)
|
|
|
|
ori r10,r10,PACA_IRQ_HARD_DIS
|
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl machine_check_early
|
|
|
|
std r3,RESULT(r1) /* Save result */
|
|
|
|
ld r12,_MSR(r1)
|
2017-04-19 21:05:47 +08:00
|
|
|
|
2020-05-08 12:33:56 +08:00
|
|
|
/*
|
|
|
|
* Restore soft mask settings.
|
|
|
|
*/
|
|
|
|
ld r10,RESULT(r1)
|
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
|
|
|
ld r10,SOFTE(r1)
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
|
2019-08-02 18:56:28 +08:00
|
|
|
#ifdef CONFIG_PPC_P7_NAP
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
|
|
|
* Check if thread was in power saving mode. We come here when any
|
|
|
|
* of the following is true:
|
|
|
|
* a. thread wasn't in power saving mode
|
|
|
|
* b. thread was in power saving mode with no state loss,
|
|
|
|
* supervisor state loss or hypervisor state loss.
|
|
|
|
*
|
|
|
|
* Go back to nap/sleep/winkle mode again if (b) is true.
|
|
|
|
*/
|
2019-06-22 21:15:32 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2017-04-19 21:05:47 +08:00
|
|
|
rlwinm. r11,r12,47-31,30,31
|
2017-05-04 18:41:12 +08:00
|
|
|
bne machine_check_idle_common
|
2019-06-22 21:15:32 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
|
2016-09-21 15:43:31 +08:00
|
|
|
#endif
|
2017-04-19 21:05:47 +08:00
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
|
|
|
|
/*
|
2019-08-02 18:56:28 +08:00
|
|
|
* Check if we are coming from guest. If yes, then run the normal
|
2019-08-02 18:57:00 +08:00
|
|
|
* exception handler which will take the
|
|
|
|
* machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
|
|
|
|
* to guest.
|
2016-09-21 15:43:31 +08:00
|
|
|
*/
|
|
|
|
lbz r11,HSTATE_IN_GUEST(r13)
|
|
|
|
cmpwi r11,0 /* Check if coming from guest */
|
2019-08-02 18:56:41 +08:00
|
|
|
bne mce_deliver /* continue if we are. */
|
2016-09-21 15:43:31 +08:00
|
|
|
#endif
|
2019-08-02 18:56:28 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Check if we are coming from userspace. If yes, then run the normal
|
|
|
|
* exception handler which will deliver the MC event to this kernel.
|
|
|
|
*/
|
|
|
|
andi. r11,r12,MSR_PR /* See if coming from user. */
|
2019-08-02 18:56:41 +08:00
|
|
|
bne mce_deliver /* continue in V mode if we are. */
|
2019-08-02 18:56:28 +08:00
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
2019-08-02 18:56:28 +08:00
|
|
|
* At this point we are coming from kernel context.
|
2016-09-21 15:43:31 +08:00
|
|
|
* Queue up the MCE event and return from the interrupt.
|
|
|
|
* But before that, check if this is an un-recoverable exception.
|
|
|
|
* If yes, then stay on emergency stack and panic.
|
|
|
|
*/
|
|
|
|
andi. r11,r12,MSR_RI
|
2019-08-02 18:56:39 +08:00
|
|
|
beq unrecoverable_mce
|
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
|
|
|
* Check if we have successfully handled/recovered from error, if not
|
|
|
|
* then stay on emergency stack and panic.
|
|
|
|
*/
|
|
|
|
ld r3,RESULT(r1) /* Load result */
|
|
|
|
cmpdi r3,0 /* see if we handled MCE successfully */
|
2019-08-02 18:56:39 +08:00
|
|
|
beq unrecoverable_mce /* if !handled then panic */
|
powerpc/64s/exception: machine check pseries should skip the late handler for kernel MCEs
The powernv machine check handler copes with taking a MCE from one of
three contexts, guest, kernel, and user. In each case the early
handler runs first on a special stack, then:
- The guest case branches to the KVM interrupt handler (via standard
interrupt macros).
- The user case will run the "late" handler which is like a normal
interrupt that runs in virtual mode and uses the regular kernel
stack.
- The kernel case queues the event and schedules it for processing
with irq work.
The last case is important, it must not enable virtual memory because
the MMU state may not be set up to deal with that (e.g., SLB might be
clear), it must not use the regular kernel stack for similar reasons
(e.g., might be in OPAL with OPAL stack in r1), and the kernel does
not expect anything to touch its stack if interrupts are disabled.
The pseries handler does not do this queueing, but instead it always
runs the late handler for host MCEs, which has some of the same
problems.
Now that pseries is using machine_check_events, change it to do the
same as powernv and queue events for kernel MCEs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-11-npiggin@gmail.com
2019-08-02 18:56:35 +08:00
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
|
|
|
* Return from MC interrupt.
|
|
|
|
* Queue up the MCE event so that we can log it later, while
|
|
|
|
* returning from kernel or opal call.
|
|
|
|
*/
|
|
|
|
bl machine_check_queue_event
|
|
|
|
MACHINE_CHECK_HANDLER_WINDUP
|
2019-08-02 18:56:29 +08:00
|
|
|
RFI_TO_KERNEL
|
powerpc/64s/exception: machine check pseries should skip the late handler for kernel MCEs
The powernv machine check handler copes with taking a MCE from one of
three contexts, guest, kernel, and user. In each case the early
handler runs first on a special stack, then:
- The guest case branches to the KVM interrupt handler (via standard
interrupt macros).
- The user case will run the "late" handler which is like a normal
interrupt that runs in virtual mode and uses the regular kernel
stack.
- The kernel case queues the event and schedules it for processing
with irq work.
The last case is important, it must not enable virtual memory because
the MMU state may not be set up to deal with that (e.g., SLB might be
clear), it must not use the regular kernel stack for similar reasons
(e.g., might be in OPAL with OPAL stack in r1), and the kernel does
not expect anything to touch its stack if interrupts are disabled.
The pseries handler does not do this queueing, but instead it always
runs the late handler for host MCEs, which has some of the same
problems.
Now that pseries is using machine_check_events, change it to do the
same as powernv and queue events for kernel MCEs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-11-npiggin@gmail.com
2019-08-02 18:56:35 +08:00
|
|
|
|
2019-08-02 18:56:41 +08:00
|
|
|
mce_deliver:
|
|
|
|
/*
|
|
|
|
* This is a host user or guest MCE. Restore all registers, then
|
|
|
|
* run the "late" handler. For host user, this will run the
|
|
|
|
* machine_check_exception handler in virtual mode like a normal
|
|
|
|
* interrupt handler. For guest, this will trigger the KVM test
|
|
|
|
* and branch to the KVM interrupt similarly to other interrupts.
|
|
|
|
*/
|
2019-08-02 18:56:32 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
ld r10,ORIG_GPR3(r1)
|
|
|
|
mtspr SPRN_CFAR,r10
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2016-09-21 15:43:31 +08:00
|
|
|
MACHINE_CHECK_HANDLER_WINDUP
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY machine_check, virt=0
|
2016-09-21 15:43:31 +08:00
|
|
|
|
2019-08-02 18:56:40 +08:00
|
|
|
EXC_COMMON_BEGIN(machine_check_common)
|
|
|
|
/*
|
|
|
|
* Machine check is different because we use a different
|
|
|
|
* save area: PACA_EXMC instead of PACA_EXGEN.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON machine_check
|
|
|
|
|
2019-08-02 18:56:40 +08:00
|
|
|
FINISH_NAP
|
|
|
|
/* Enable MSR_RI when finished with PACA_EXMC */
|
|
|
|
li r10,MSR_RI
|
|
|
|
mtmsrd r10,1
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl machine_check_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2019-08-02 18:56:40 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM machine_check
|
|
|
|
|
|
|
|
|
2019-08-02 18:56:40 +08:00
|
|
|
#ifdef CONFIG_PPC_P7_NAP
|
|
|
|
/*
|
|
|
|
* This is an idle wakeup. Low level machine check has already been
|
|
|
|
* done. Queue the event then call the idle code to do the wake up.
|
|
|
|
*/
|
|
|
|
EXC_COMMON_BEGIN(machine_check_idle_common)
|
|
|
|
bl machine_check_queue_event
|
|
|
|
|
|
|
|
/*
|
2020-05-08 12:33:53 +08:00
|
|
|
* GPR-loss wakeups are relatively straightforward, because the
|
|
|
|
* idle sleep code has saved all non-volatile registers on its
|
|
|
|
* own stack, and r1 in PACAR1.
|
2019-08-02 18:56:40 +08:00
|
|
|
*
|
2020-05-08 12:33:53 +08:00
|
|
|
* For no-loss wakeups the r1 and lr registers used by the
|
|
|
|
* early machine check handler have to be restored first. r2 is
|
|
|
|
* the kernel TOC, so no need to restore it.
|
2019-08-02 18:56:40 +08:00
|
|
|
*
|
|
|
|
* Then decrement MCE nesting after finishing with the stack.
|
|
|
|
*/
|
|
|
|
ld r3,_MSR(r1)
|
|
|
|
ld r4,_LINK(r1)
|
2020-05-08 12:33:53 +08:00
|
|
|
ld r1,GPR1(r1)
|
2019-08-02 18:56:40 +08:00
|
|
|
|
|
|
|
lhz r11,PACA_IN_MCE(r13)
|
|
|
|
subi r11,r11,1
|
|
|
|
sth r11,PACA_IN_MCE(r13)
|
|
|
|
|
|
|
|
mtlr r4
|
|
|
|
rlwinm r10,r3,47-31,30,31
|
|
|
|
cmpwi cr1,r10,2
|
2020-05-08 12:33:53 +08:00
|
|
|
bltlr cr1 /* no state loss, return to idle caller with r3=SRR1 */
|
2019-08-02 18:56:40 +08:00
|
|
|
b idle_return_gpr_loss
|
|
|
|
#endif
|
|
|
|
|
2019-08-02 18:56:39 +08:00
|
|
|
EXC_COMMON_BEGIN(unrecoverable_mce)
|
|
|
|
/*
|
|
|
|
* We are going down. But there are chances that we might get hit by
|
|
|
|
* another MCE during panic path and we may run into unstable state
|
|
|
|
* with no way out. Hence, turn ME bit off while going down, so that
|
|
|
|
* when another MCE is hit during panic path, system will checkstop
|
|
|
|
* and hypervisor will get restarted cleanly by SP.
|
|
|
|
*/
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
li r10,0 /* clear MSR_RI */
|
|
|
|
mtmsrd r10,1
|
|
|
|
bl disable_machine_check
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
|
|
|
|
ld r10,PACAKMSR(r13)
|
|
|
|
li r3,MSR_ME
|
|
|
|
andc r10,r10,r3
|
|
|
|
mtmsrd r10
|
|
|
|
|
2020-05-08 12:33:54 +08:00
|
|
|
lhz r12,PACA_IN_MCE(r13)
|
|
|
|
subi r12,r12,1
|
|
|
|
sth r12,PACA_IN_MCE(r13)
|
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/* Invoke machine_check_exception to print MCE event and panic. */
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl machine_check_exception
|
2019-08-02 18:56:39 +08:00
|
|
|
|
2016-09-21 15:43:31 +08:00
|
|
|
/*
|
2019-08-02 18:56:39 +08:00
|
|
|
* We will not reach here. Even if we did, there is no way out.
|
|
|
|
* Call unrecoverable_exception and die.
|
2016-09-21 15:43:31 +08:00
|
|
|
*/
|
2019-08-02 18:56:39 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2016-09-21 15:43:31 +08:00
|
|
|
bl unrecoverable_exception
|
2019-08-02 18:56:39 +08:00
|
|
|
b .
|
2016-09-21 15:43:31 +08:00
|
|
|
|
2020-02-26 01:35:14 +08:00
|
|
|
|
|
|
|
/**
|
2020-02-26 01:35:28 +08:00
|
|
|
* Interrupt 0x300 - Data Storage Interrupt (DSI).
|
|
|
|
* This is a synchronous interrupt generated due to a data access exception,
|
|
|
|
* e.g., a load orstore which does not have a valid page table entry with
|
|
|
|
* permissions. DAWR matches also fault here, as do RC updates, and minor misc
|
|
|
|
* errors e.g., copy/paste, AMO, certain invalid CI accesses, etc.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* - Hash MMU
|
|
|
|
* Go to do_hash_page first to see if the HPT can be filled from an entry in
|
|
|
|
* the Linux page table. Hash faults can hit in kernel mode in a fairly
|
|
|
|
* arbitrary state (e.g., interrupts disabled, locks held) when accessing
|
|
|
|
* "non-bolted" regions, e.g., vmalloc space. However these should always be
|
|
|
|
* backed by Linux page tables.
|
2020-02-26 01:35:14 +08:00
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* If none is found, do a Linux page fault. Linux page faults can happen in
|
|
|
|
* kernel mode due to user copy operations of course.
|
2020-02-26 01:35:14 +08:00
|
|
|
*
|
2020-11-17 21:56:17 +08:00
|
|
|
* KVM: The KVM HDSI handler may perform a load with MSR[DR]=1 in guest
|
|
|
|
* MMU context, which may cause a DSI in the host, which must go to the
|
|
|
|
* KVM handler. MSR[IR] is not enabled, so the real-mode handler will
|
|
|
|
* always be used regardless of AIL setting.
|
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* - Radix MMU
|
|
|
|
* The hardware loads from the Linux page table directly, so a fault goes
|
|
|
|
* immediately to Linux page fault.
|
2020-02-26 01:35:14 +08:00
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* Conditions like DAWR match are handled on the way in to Linux page fault.
|
2020-02-26 01:35:14 +08:00
|
|
|
*/
|
2020-02-26 01:35:10 +08:00
|
|
|
INT_DEFINE_BEGIN(data_access)
|
|
|
|
IVEC=0x300
|
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
2020-02-26 01:35:12 +08:00
|
|
|
IKVM_SKIP=1
|
2020-02-26 01:35:10 +08:00
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(data_access)
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_REAL_BEGIN(data_access, 0x300, 0x80)
|
2020-02-26 01:35:26 +08:00
|
|
|
GEN_INT_ENTRY data_access, virt=0
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_REAL_END(data_access, 0x300, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
|
2020-02-26 01:35:10 +08:00
|
|
|
GEN_INT_ENTRY data_access, virt=1
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_VIRT_END(data_access, 0x4300, 0x80)
|
2016-09-21 15:43:32 +08:00
|
|
|
EXC_COMMON_BEGIN(data_access_common)
|
2020-02-26 01:35:11 +08:00
|
|
|
GEN_COMMON data_access
|
2019-08-02 18:57:01 +08:00
|
|
|
ld r4,_DAR(r1)
|
|
|
|
ld r5,_DSISR(r1)
|
2016-09-21 15:43:32 +08:00
|
|
|
BEGIN_MMU_FTR_SECTION
|
2019-08-02 18:57:01 +08:00
|
|
|
ld r6,_MSR(r1)
|
|
|
|
li r3,0x300
|
2016-09-21 15:43:32 +08:00
|
|
|
b do_hash_page /* Try to handle as hpte fault */
|
|
|
|
MMU_FTR_SECTION_ELSE
|
|
|
|
b handle_page_fault
|
|
|
|
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
|
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM data_access
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x380 - Data Segment Interrupt (DSLB).
|
|
|
|
* This is a synchronous interrupt in response to an MMU fault missing SLB
|
|
|
|
* entry for HPT, or an address outside RPT translation range.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* - HPT:
|
|
|
|
* This refills the SLB, or reports an access fault similarly to a bad page
|
|
|
|
* fault. When coming from user-mode, the SLB handler may access any kernel
|
|
|
|
* data, though it may itself take a DSLB. When coming from kernel mode,
|
|
|
|
* recursive faults must be avoided so access is restricted to the kernel
|
|
|
|
* image text/data, kernel stack, and any data allocated below
|
|
|
|
* ppc64_bolted_size (first segment). The kernel handler must avoid stomping
|
|
|
|
* on user-handler data structures.
|
|
|
|
*
|
2020-11-17 21:56:17 +08:00
|
|
|
* KVM: Same as 0x300, DSLB must test for KVM guest.
|
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* A dedicated save area EXSLB is used (XXX: but it actually need not be
|
|
|
|
* these days, we could use EXGEN).
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(data_access_slb)
|
|
|
|
IVEC=0x380
|
|
|
|
IAREA=PACA_EXSLB
|
|
|
|
IRECONCILE=0
|
|
|
|
IDAR=1
|
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(data_access_slb)
|
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
|
2020-02-26 01:35:26 +08:00
|
|
|
GEN_INT_ENTRY data_access_slb, virt=0
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_END(data_access_slb, 0x380, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY data_access_slb, virt=1
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
|
2018-09-14 23:30:51 +08:00
|
|
|
EXC_COMMON_BEGIN(data_access_slb_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON data_access_slb
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r4,_DAR(r1)
|
2018-09-14 23:30:51 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2019-03-29 15:42:57 +08:00
|
|
|
BEGIN_MMU_FTR_SECTION
|
|
|
|
/* HPT case, do SLB fault */
|
2018-09-14 23:30:51 +08:00
|
|
|
bl do_slb_fault
|
|
|
|
cmpdi r3,0
|
|
|
|
bne- 1f
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b fast_interrupt_return
|
2018-09-14 23:30:51 +08:00
|
|
|
1: /* Error case */
|
2019-03-29 15:42:57 +08:00
|
|
|
MMU_FTR_SECTION_ELSE
|
|
|
|
/* Radix case, access is outside page table range */
|
|
|
|
li r3,-EFAULT
|
|
|
|
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
|
2018-09-14 23:30:51 +08:00
|
|
|
std r3,RESULT(r1)
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
ld r4,_DAR(r1)
|
|
|
|
ld r5,RESULT(r1)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl do_bad_slb_fault
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2018-09-14 23:30:51 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM data_access_slb
|
|
|
|
|
2016-09-21 15:43:33 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x400 - Instruction Storage Interrupt (ISI).
|
|
|
|
* This is a synchronous interrupt in response to an MMU fault due to an
|
|
|
|
* instruction fetch.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Similar to DSI, though in response to fetch. The faulting address is found
|
|
|
|
* in SRR0 (rather than DAR), and status in SRR1 (rather than DSISR).
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(instruction_access)
|
|
|
|
IVEC=0x400
|
2020-02-26 01:35:18 +08:00
|
|
|
IISIDE=1
|
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(instruction_access)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(instruction_access, 0x400, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_access, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(instruction_access, 0x400, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_access, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(instruction_access, 0x4400, 0x80)
|
2016-09-21 15:43:34 +08:00
|
|
|
EXC_COMMON_BEGIN(instruction_access_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON instruction_access
|
2019-08-02 18:57:01 +08:00
|
|
|
ld r4,_DAR(r1)
|
|
|
|
ld r5,_DSISR(r1)
|
2016-09-21 15:43:34 +08:00
|
|
|
BEGIN_MMU_FTR_SECTION
|
2019-08-02 18:57:01 +08:00
|
|
|
ld r6,_MSR(r1)
|
|
|
|
li r3,0x400
|
2016-09-21 15:43:34 +08:00
|
|
|
b do_hash_page /* Try to handle as hpte fault */
|
|
|
|
MMU_FTR_SECTION_ELSE
|
|
|
|
b handle_page_fault
|
|
|
|
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
|
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM instruction_access
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
|
|
|
|
* This is a synchronous interrupt in response to an MMU fault due to an
|
|
|
|
* instruction fetch.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Similar to DSLB, though in response to fetch. The faulting address is found
|
|
|
|
* in SRR0 (rather than DAR).
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(instruction_access_slb)
|
|
|
|
IVEC=0x480
|
|
|
|
IAREA=PACA_EXSLB
|
|
|
|
IRECONCILE=0
|
2020-02-26 01:35:18 +08:00
|
|
|
IISIDE=1
|
|
|
|
IDAR=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(instruction_access_slb)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_access_slb, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_access_slb, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
|
2018-09-14 23:30:51 +08:00
|
|
|
EXC_COMMON_BEGIN(instruction_access_slb_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON instruction_access_slb
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r4,_DAR(r1)
|
2018-09-14 23:30:51 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2019-03-29 15:42:57 +08:00
|
|
|
BEGIN_MMU_FTR_SECTION
|
|
|
|
/* HPT case, do SLB fault */
|
2018-09-14 23:30:51 +08:00
|
|
|
bl do_slb_fault
|
|
|
|
cmpdi r3,0
|
|
|
|
bne- 1f
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b fast_interrupt_return
|
2018-09-14 23:30:51 +08:00
|
|
|
1: /* Error case */
|
2019-03-29 15:42:57 +08:00
|
|
|
MMU_FTR_SECTION_ELSE
|
|
|
|
/* Radix case, access is outside page table range */
|
|
|
|
li r3,-EFAULT
|
|
|
|
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
|
2018-09-14 23:30:51 +08:00
|
|
|
std r3,RESULT(r1)
|
2016-09-21 15:43:35 +08:00
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r4,_DAR(r1)
|
2018-09-14 23:30:51 +08:00
|
|
|
ld r5,RESULT(r1)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl do_bad_slb_fault
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:35 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM instruction_access_slb
|
|
|
|
|
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x500 - External Interrupt.
|
|
|
|
* This is an asynchronous maskable interrupt in response to an "external
|
|
|
|
* exception" from the interrupt controller or hypervisor (e.g., device
|
|
|
|
* interrupt). It is maskable in hardware by clearing MSR[EE], and
|
|
|
|
* soft-maskable with IRQS_DISABLED mask (i.e., local_irq_disable()).
|
|
|
|
*
|
|
|
|
* When running in HV mode, Linux sets up the LPCR[LPES] bit such that
|
|
|
|
* interrupts are delivered with HSRR registers, guests use SRRs, which
|
|
|
|
* reqiures IHSRR_IF_HVMODE.
|
|
|
|
*
|
|
|
|
* On bare metal POWER9 and later, Linux sets the LPCR[HVICE] bit such that
|
|
|
|
* external interrupts are delivered as Hypervisor Virtualization Interrupts
|
|
|
|
* rather than External Interrupts.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This calls into Linux IRQ handler. NVGPRs are not saved to reduce overhead,
|
|
|
|
* because registers at the time of the interrupt are not so important as it is
|
|
|
|
* asynchronous.
|
|
|
|
*
|
|
|
|
* If soft masked, the masked handler will note the pending interrupt for
|
|
|
|
* replay, and clear MSR[EE] in the interrupted context.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(hardware_interrupt)
|
|
|
|
IVEC=0x500
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR_IF_HVMODE=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IMASK=IRQS_DISABLED
|
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(hardware_interrupt)
|
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hardware_interrupt, virt=0
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_END(hardware_interrupt, 0x500, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hardware_interrupt, virt=1
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(hardware_interrupt_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON hardware_interrupt
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl do_IRQ
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:36 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM hardware_interrupt
|
|
|
|
|
2016-09-21 15:43:36 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x600 - Alignment Interrupt
|
|
|
|
* This is a synchronous interrupt in response to data alignment fault.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(alignment)
|
|
|
|
IVEC=0x600
|
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(alignment)
|
|
|
|
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_REAL_BEGIN(alignment, 0x600, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY alignment, virt=0
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_REAL_END(alignment, 0x600, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY alignment, virt=1
|
2019-02-26 16:51:09 +08:00
|
|
|
EXC_VIRT_END(alignment, 0x4600, 0x100)
|
2016-09-21 15:43:37 +08:00
|
|
|
EXC_COMMON_BEGIN(alignment_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON alignment
|
2016-09-21 15:43:37 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl alignment_exception
|
2020-02-26 01:35:38 +08:00
|
|
|
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:37 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM alignment
|
|
|
|
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x700 - Program Interrupt (program check).
|
|
|
|
* This is a synchronous interrupt in response to various instruction faults:
|
|
|
|
* traps, privilege errors, TM errors, floating point exceptions.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This interrupt may use the "emergency stack" in some cases when being taken
|
|
|
|
* from kernel context, which complicates handling.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(program_check)
|
|
|
|
IVEC=0x700
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(program_check)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(program_check, 0x700, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY program_check, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(program_check, 0x700, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(program_check, 0x4700, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY program_check, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(program_check, 0x4700, 0x100)
|
2016-09-21 15:43:38 +08:00
|
|
|
EXC_COMMON_BEGIN(program_check_common)
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_ENTRY program_check
|
|
|
|
|
powerpc/64s: Use emergency stack for kernel TM Bad Thing program checks
When using transactional memory (TM), the CPU can be in one of six
states as far as TM is concerned, encoded in the Machine State
Register (MSR). Certain state transitions are illegal and if attempted
trigger a "TM Bad Thing" type program check exception.
If we ever hit one of these exceptions it's treated as a bug, ie. we
oops, and kill the process and/or panic, depending on configuration.
One case where we can trigger a TM Bad Thing, is when returning to
userspace after a system call or interrupt, using RFID. When this
happens the CPU first restores the user register state, in particular
r1 (the stack pointer) and then attempts to update the MSR. However
the MSR update is not allowed and so we take the program check with
the user register state, but the kernel MSR.
This tricks the exception entry code into thinking we have a bad
kernel stack pointer, because the MSR says we're coming from the
kernel, but r1 is pointing to userspace.
To avoid this we instead always switch to the emergency stack if we
take a TM Bad Thing from the kernel. That way none of the user
register values are used, other than for printing in the oops message.
This is the fix for CVE-2017-1000255.
Fixes: 5d176f751ee3 ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Rewrite change log & comments, tweak asm slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-17 18:42:26 +08:00
|
|
|
/*
|
|
|
|
* It's possible to receive a TM Bad Thing type program check with
|
|
|
|
* userspace register values (in particular r1), but with SRR1 reporting
|
|
|
|
* that we came from the kernel. Normally that would confuse the bad
|
|
|
|
* stack logic, and we would report a bad kernel stack pointer. Instead
|
|
|
|
* we switch to the emergency stack if we're taking a TM Bad Thing from
|
|
|
|
* the kernel.
|
|
|
|
*/
|
powerpc/64s/exception: remove bad stack branch
The bad stack test in interrupt handlers has a few problems. For
performance it is taken in the common case, which is a fetch bubble
and a waste of i-cache.
For code development and maintainence, it requires yet another stack
frame setup routine, and that constrains all exception handlers to
follow the same register save pattern which inhibits future
optimisation.
Remove the test/branch and replace it with a trap. Teach the program
check handler to use the emergency stack for this case.
This does not result in quite so nice a message, however the SRR0 and
SRR1 of the crashed interrupt can be seen in r11 and r12, as is the
original r1 (adjusted by INT_FRAME_SIZE). These are the most important
parts to debugging the issue.
The original r9-12 and cr0 is lost, which is the main downside.
kernel BUG at linux/arch/powerpc/kernel/exceptions-64s.S:847!
Oops: Exception in kernel mode, sig: 5 [#1]
BE SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted
NIP: c000000000009108 LR: c000000000cadbcc CTR: c0000000000090f0
REGS: c0000000fffcbd70 TRAP: 0700 Not tainted
MSR: 9000000000021032 <SF,HV,ME,IR,DR,RI> CR: 28222448 XER: 20040000
CFAR: c000000000009100 IRQMASK: 0
GPR00: 000000000000003d fffffffffffffd00 c0000000018cfb00 c0000000f02b3166
GPR04: fffffffffffffffd 0000000000000007 fffffffffffffffb 0000000000000030
GPR08: 0000000000000037 0000000028222448 0000000000000000 c000000000ca8de0
GPR12: 9000000002009032 c000000001ae0000 c000000000010a00 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: c0000000f00322c0 c000000000f85200 0000000000000004 ffffffffffffffff
GPR24: fffffffffffffffe 0000000000000000 0000000000000000 000000000000000a
GPR28: 0000000000000000 0000000000000000 c0000000f02b391c c0000000f02b3167
NIP [c000000000009108] decrementer_common+0x18/0x160
LR [c000000000cadbcc] .vsnprintf+0x3ec/0x4f0
Call Trace:
Instruction dump:
996d098a 994d098b 38610070 480246ed 48005518 60000000 38200000 718a4000
7c2a0b78 3821fd00 41c20008 e82d0970 <0981fd00> f92101a0 f9610170 f9810178
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:18 +08:00
|
|
|
|
|
|
|
andi. r10,r12,MSR_PR
|
|
|
|
bne 2f /* If userspace, go normal path */
|
|
|
|
|
|
|
|
andis. r10,r12,(SRR1_PROGTM)@h
|
|
|
|
bne 1f /* If TM, emergency */
|
|
|
|
|
|
|
|
cmpdi r1,-INT_FRAME_SIZE /* check if r1 is in userspace */
|
|
|
|
blt 2f /* normal path if not */
|
|
|
|
|
|
|
|
/* Use the emergency stack */
|
|
|
|
1: andi. r10,r12,MSR_PR /* Set CR0 correctly for label */
|
powerpc/64s: Use emergency stack for kernel TM Bad Thing program checks
When using transactional memory (TM), the CPU can be in one of six
states as far as TM is concerned, encoded in the Machine State
Register (MSR). Certain state transitions are illegal and if attempted
trigger a "TM Bad Thing" type program check exception.
If we ever hit one of these exceptions it's treated as a bug, ie. we
oops, and kill the process and/or panic, depending on configuration.
One case where we can trigger a TM Bad Thing, is when returning to
userspace after a system call or interrupt, using RFID. When this
happens the CPU first restores the user register state, in particular
r1 (the stack pointer) and then attempts to update the MSR. However
the MSR update is not allowed and so we take the program check with
the user register state, but the kernel MSR.
This tricks the exception entry code into thinking we have a bad
kernel stack pointer, because the MSR says we're coming from the
kernel, but r1 is pointing to userspace.
To avoid this we instead always switch to the emergency stack if we
take a TM Bad Thing from the kernel. That way none of the user
register values are used, other than for printing in the oops message.
This is the fix for CVE-2017-1000255.
Fixes: 5d176f751ee3 ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Rewrite change log & comments, tweak asm slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-17 18:42:26 +08:00
|
|
|
/* 3 in EXCEPTION_PROLOG_COMMON */
|
|
|
|
mr r10,r1 /* Save r1 */
|
|
|
|
ld r1,PACAEMERGSP(r13) /* Use emergency stack */
|
|
|
|
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
|
2020-02-26 01:35:14 +08:00
|
|
|
__ISTACK(program_check)=0
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_BODY program_check
|
2019-08-02 18:56:59 +08:00
|
|
|
b 3f
|
powerpc/64s/exception: remove bad stack branch
The bad stack test in interrupt handlers has a few problems. For
performance it is taken in the common case, which is a fetch bubble
and a waste of i-cache.
For code development and maintainence, it requires yet another stack
frame setup routine, and that constrains all exception handlers to
follow the same register save pattern which inhibits future
optimisation.
Remove the test/branch and replace it with a trap. Teach the program
check handler to use the emergency stack for this case.
This does not result in quite so nice a message, however the SRR0 and
SRR1 of the crashed interrupt can be seen in r11 and r12, as is the
original r1 (adjusted by INT_FRAME_SIZE). These are the most important
parts to debugging the issue.
The original r9-12 and cr0 is lost, which is the main downside.
kernel BUG at linux/arch/powerpc/kernel/exceptions-64s.S:847!
Oops: Exception in kernel mode, sig: 5 [#1]
BE SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted
NIP: c000000000009108 LR: c000000000cadbcc CTR: c0000000000090f0
REGS: c0000000fffcbd70 TRAP: 0700 Not tainted
MSR: 9000000000021032 <SF,HV,ME,IR,DR,RI> CR: 28222448 XER: 20040000
CFAR: c000000000009100 IRQMASK: 0
GPR00: 000000000000003d fffffffffffffd00 c0000000018cfb00 c0000000f02b3166
GPR04: fffffffffffffffd 0000000000000007 fffffffffffffffb 0000000000000030
GPR08: 0000000000000037 0000000028222448 0000000000000000 c000000000ca8de0
GPR12: 9000000002009032 c000000001ae0000 c000000000010a00 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: c0000000f00322c0 c000000000f85200 0000000000000004 ffffffffffffffff
GPR24: fffffffffffffffe 0000000000000000 0000000000000000 000000000000000a
GPR28: 0000000000000000 0000000000000000 c0000000f02b391c c0000000f02b3167
NIP [c000000000009108] decrementer_common+0x18/0x160
LR [c000000000cadbcc] .vsnprintf+0x3ec/0x4f0
Call Trace:
Instruction dump:
996d098a 994d098b 38610070 480246ed 48005518 60000000 38200000 718a4000
7c2a0b78 3821fd00 41c20008 e82d0970 <0981fd00> f92101a0 f9610170 f9810178
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-28 14:33:18 +08:00
|
|
|
2:
|
2020-02-26 01:35:14 +08:00
|
|
|
__ISTACK(program_check)=1
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_BODY program_check
|
2019-08-02 18:56:59 +08:00
|
|
|
3:
|
2016-09-21 15:43:38 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl program_check_exception
|
2020-02-26 01:35:38 +08:00
|
|
|
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:38 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM program_check
|
|
|
|
|
2011-06-29 08:18:26 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/*
|
|
|
|
* Interrupt 0x800 - Floating-Point Unavailable Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to executing an fp instruction
|
|
|
|
* with MSR[FP]=0.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This will load FP registers and enable the FP bit if coming from userspace,
|
|
|
|
* otherwise report a bad kernel use of FP.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(fp_unavailable)
|
|
|
|
IVEC=0x800
|
|
|
|
IRECONCILE=0
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(fp_unavailable)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(fp_unavailable, 0x800, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY fp_unavailable, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(fp_unavailable, 0x800, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(fp_unavailable, 0x4800, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY fp_unavailable, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(fp_unavailable, 0x4800, 0x100)
|
2016-09-21 15:43:39 +08:00
|
|
|
EXC_COMMON_BEGIN(fp_unavailable_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON fp_unavailable
|
2016-09-21 15:43:39 +08:00
|
|
|
bne 1f /* if from user, just load it up */
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl kernel_fp_unavailable_exception
|
2019-08-26 19:10:23 +08:00
|
|
|
0: trap
|
|
|
|
EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
|
2016-09-21 15:43:39 +08:00
|
|
|
1:
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
|
|
|
|
* transaction), go do TM stuff
|
|
|
|
*/
|
|
|
|
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
|
|
|
|
bne- 2f
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_TM)
|
|
|
|
#endif
|
|
|
|
bl load_up_fpu
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b fast_interrupt_return
|
2016-09-21 15:43:39 +08:00
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
2: /* User process was in a transaction */
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl fp_unavailable_tm
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:39 +08:00
|
|
|
#endif
|
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM fp_unavailable
|
|
|
|
|
2011-04-05 12:20:31 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x900 - Decrementer Interrupt.
|
|
|
|
* This is an asynchronous interrupt in response to a decrementer exception
|
|
|
|
* (e.g., DEC has wrapped below zero). It is maskable in hardware by clearing
|
|
|
|
* MSR[EE], and soft-maskable with IRQS_DISABLED mask (i.e.,
|
|
|
|
* local_irq_disable()).
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This calls into Linux timer handler. NVGPRs are not saved (see 0x500).
|
|
|
|
*
|
|
|
|
* If soft masked, the masked handler will note the pending interrupt for
|
|
|
|
* replay, and bump the decrementer to a high value, leaving MSR[EE] enabled
|
|
|
|
* in the interrupted context.
|
|
|
|
* If PPC_WATCHDOG is configured, the soft masked handler will actually set
|
|
|
|
* things back up to run soft_nmi_interrupt as a regular interrupt handler
|
|
|
|
* on the emergency stack.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(decrementer)
|
|
|
|
IVEC=0x900
|
|
|
|
IMASK=IRQS_DISABLED
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(decrementer)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(decrementer, 0x900, 0x80)
|
2020-02-26 01:35:26 +08:00
|
|
|
GEN_INT_ENTRY decrementer, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(decrementer, 0x900, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY decrementer, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(decrementer, 0x4900, 0x80)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(decrementer_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON decrementer
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl timer_interrupt
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:40 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM decrementer
|
|
|
|
|
powerpc: Fix "attempt to move .org backwards" error
Building a 64-bit powerpc kernel with PR KVM enabled currently gives
this error:
AS arch/powerpc/kernel/head_64.o
arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:258: Error: attempt to move .org backwards
make[2]: *** [arch/powerpc/kernel/head_64.o] Error 1
This happens because the MASKABLE_EXCEPTION_PSERIES macro turns into
33 instructions, but we only have space for 32 at the decrementer
interrupt vector (from 0x900 to 0x980).
In the code generated by the MASKABLE_EXCEPTION_PSERIES macro, we
currently have two instances of the HMT_MEDIUM macro, which has the
effect of setting the SMT thread priority to medium. One is the
first instruction, and is overwritten by a no-op on processors where
we save the PPR (processor priority register), that is, POWER7 or
later. The other is after we have saved the PPR.
In order to reduce the code at 0x900 by one instruction, we omit the
first HMT_MEDIUM. On processors without SMT this will have no effect
since HMT_MEDIUM is a no-op there. On POWER5 and RS64 machines this
will mean that the first few instructions take a little longer in the
case where a decrementer interrupt occurs when the hardware thread is
running at low SMT priority. On POWER6 and later machines, the
hardware automatically boosts the thread priority when a decrementer
interrupt is taken if the thread priority was below medium, so this
change won't make any difference.
The alternative would be to branch out of line after saving the CFAR.
However, that would incur an extra overhead on all processors, whereas
the approach adopted here only adds overhead on older threaded processors.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 01:51:40 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x980 - Hypervisor Decrementer Interrupt.
|
|
|
|
* This is an asynchronous interrupt, similar to 0x900 but for the HDEC
|
|
|
|
* register.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Linux does not use this outside KVM where it's used to keep a host timer
|
|
|
|
* while the guest is given control of DEC. It should normally be caught by
|
|
|
|
* the KVM test and routed there.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(hdecrementer)
|
|
|
|
IVEC=0x980
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:25 +08:00
|
|
|
ISTACK=0
|
|
|
|
IRECONCILE=0
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(hdecrementer)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(hdecrementer, 0x980, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hdecrementer, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(hdecrementer, 0x980, 0x80)
|
|
|
|
EXC_VIRT_BEGIN(hdecrementer, 0x4980, 0x80)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hdecrementer, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(hdecrementer, 0x4980, 0x80)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(hdecrementer_common)
|
2020-02-26 01:35:25 +08:00
|
|
|
__GEN_COMMON_ENTRY hdecrementer
|
|
|
|
/*
|
|
|
|
* Hypervisor decrementer interrupts not caught by the KVM test
|
|
|
|
* shouldn't occur but are sometimes left pending on exit from a KVM
|
|
|
|
* guest. We don't need to do anything to clear them, as they are
|
|
|
|
* edge-triggered.
|
|
|
|
*
|
|
|
|
* Be careful to avoid touching the kernel stack.
|
|
|
|
*/
|
|
|
|
ld r10,PACA_EXGEN+EX_CTR(r13)
|
|
|
|
mtctr r10
|
|
|
|
mtcrf 0x80,r9
|
|
|
|
ld r9,PACA_EXGEN+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXGEN+EX_R11(r13)
|
|
|
|
ld r12,PACA_EXGEN+EX_R12(r13)
|
|
|
|
ld r13,PACA_EXGEN+EX_R13(r13)
|
|
|
|
HRFI_TO_KERNEL
|
2016-09-21 15:43:41 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM hdecrementer
|
|
|
|
|
2011-04-05 12:20:31 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
|
|
|
|
* This is an asynchronous interrupt in response to a msgsndp doorbell.
|
|
|
|
* It is maskable in hardware by clearing MSR[EE], and soft-maskable with
|
|
|
|
* IRQS_DISABLED mask (i.e., local_irq_disable()).
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* Guests may use this for IPIs between threads in a core if the
|
|
|
|
* hypervisor supports it. NVGPRS are not saved (see 0x500).
|
|
|
|
*
|
|
|
|
* If soft masked, the masked handler will note the pending interrupt for
|
|
|
|
* replay, leaving MSR[EE] enabled in the interrupted context because the
|
|
|
|
* doorbells are edge triggered.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(doorbell_super)
|
|
|
|
IVEC=0xa00
|
|
|
|
IMASK=IRQS_DISABLED
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(doorbell_super)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(doorbell_super, 0xa00, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY doorbell_super, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(doorbell_super, 0xa00, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY doorbell_super, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(doorbell_super, 0x4a00, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(doorbell_super_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON doorbell_super
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2016-09-21 15:43:42 +08:00
|
|
|
#ifdef CONFIG_PPC_DOORBELL
|
2020-02-26 01:35:13 +08:00
|
|
|
bl doorbell_exception
|
2016-09-21 15:43:42 +08:00
|
|
|
#else
|
2020-02-26 01:35:13 +08:00
|
|
|
bl unknown_exception
|
2016-09-21 15:43:42 +08:00
|
|
|
#endif
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:42 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM doorbell_super
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2019-08-02 18:56:46 +08:00
|
|
|
EXC_REAL_NONE(0xb00, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x4b00, 0x100)
|
2016-09-21 15:43:43 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xc00 - System Call Interrupt (syscall, hcall).
|
|
|
|
* This is a synchronous interrupt invoked with the "sc" instruction. The
|
|
|
|
* system call is invoked with "sc 0" and does not alter the HV bit, so it
|
|
|
|
* is directed to the currently running OS. The hypercall is invoked with
|
|
|
|
* "sc 1" and it sets HV=1, so it elevates to hypervisor.
|
2017-06-08 23:35:04 +08:00
|
|
|
*
|
|
|
|
* In HPT, sc 1 always goes to 0xc00 real mode. In RADIX, sc 1 can go to
|
|
|
|
* 0x4c00 virtual mode.
|
|
|
|
*
|
2020-02-26 01:35:28 +08:00
|
|
|
* Handling:
|
|
|
|
* If the KVM test fires then it was due to a hypercall and is accordingly
|
|
|
|
* routed to KVM. Otherwise this executes a normal Linux system call.
|
|
|
|
*
|
2017-06-08 23:35:04 +08:00
|
|
|
* Call convention:
|
|
|
|
*
|
2019-08-28 16:27:29 +08:00
|
|
|
* syscall and hypercalls register conventions are documented in
|
|
|
|
* Documentation/powerpc/syscall64-abi.rst and
|
|
|
|
* Documentation/powerpc/papr_hcalls.rst respectively.
|
2017-06-08 23:35:04 +08:00
|
|
|
*
|
|
|
|
* The intersection of volatile registers that don't contain possible
|
2017-07-18 13:32:44 +08:00
|
|
|
* inputs is: cr0, xer, ctr. We may use these as scratch regs upon entry
|
|
|
|
* without saving, though xer is not a good idea to use, as hardware may
|
|
|
|
* interpret some bits so it may be costly to change them.
|
2017-06-08 23:35:04 +08:00
|
|
|
*/
|
2020-02-26 01:35:17 +08:00
|
|
|
INT_DEFINE_BEGIN(system_call)
|
|
|
|
IVEC=0xc00
|
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(system_call)
|
|
|
|
|
2019-06-22 21:15:31 +08:00
|
|
|
.macro SYSTEM_CALL virt
|
2017-01-30 18:21:40 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
|
2017-06-08 23:35:04 +08:00
|
|
|
/*
|
|
|
|
* There is a little bit of juggling to get syscall and hcall
|
2017-07-18 13:32:44 +08:00
|
|
|
* working well. Save r13 in ctr to avoid using SPRG scratch
|
|
|
|
* register.
|
2017-06-08 23:35:04 +08:00
|
|
|
*
|
|
|
|
* Userspace syscalls have already saved the PPR, hcalls must save
|
|
|
|
* it before setting HMT_MEDIUM.
|
|
|
|
*/
|
2019-06-22 21:15:31 +08:00
|
|
|
mtctr r13
|
|
|
|
GET_PACA(r13)
|
|
|
|
std r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
INTERRUPT_TO_KERNEL
|
2020-02-26 01:35:24 +08:00
|
|
|
KVMTEST system_call /* uses r10, branch to system_call_kvm */
|
2019-06-22 21:15:31 +08:00
|
|
|
mfctr r9
|
2017-01-30 18:21:40 +08:00
|
|
|
#else
|
2019-06-22 21:15:31 +08:00
|
|
|
mr r9,r13
|
|
|
|
GET_PACA(r13)
|
|
|
|
INTERRUPT_TO_KERNEL
|
2017-01-30 18:21:40 +08:00
|
|
|
#endif
|
2016-09-21 15:43:44 +08:00
|
|
|
|
2017-10-09 18:54:05 +08:00
|
|
|
#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
|
2019-06-22 21:15:31 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
cmpdi r0,0x1ebe
|
|
|
|
beq- 1f
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
|
|
|
|
#endif
|
2016-09-21 15:43:44 +08:00
|
|
|
|
2019-06-28 13:33:20 +08:00
|
|
|
/* We reach here with PACA in r13, r13 in r9. */
|
2019-06-22 21:15:31 +08:00
|
|
|
mfspr r11,SPRN_SRR0
|
|
|
|
mfspr r12,SPRN_SRR1
|
2019-06-28 13:33:20 +08:00
|
|
|
|
|
|
|
HMT_MEDIUM
|
|
|
|
|
|
|
|
.if ! \virt
|
2019-06-22 21:15:31 +08:00
|
|
|
__LOAD_HANDLER(r10, system_call_common)
|
|
|
|
mtspr SPRN_SRR0,r10
|
|
|
|
ld r10,PACAKMSR(r13)
|
|
|
|
mtspr SPRN_SRR1,r10
|
|
|
|
RFI_TO_KERNEL
|
|
|
|
b . /* prevent speculative execution */
|
|
|
|
.else
|
2019-06-28 13:33:20 +08:00
|
|
|
li r10,MSR_RI
|
|
|
|
mtmsrd r10,1 /* Set RI (EE=0) */
|
2019-06-22 21:15:31 +08:00
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
__LOAD_HANDLER(r10, system_call_common)
|
|
|
|
mtctr r10
|
|
|
|
bctr
|
2016-09-21 15:43:44 +08:00
|
|
|
#else
|
2019-06-22 21:15:31 +08:00
|
|
|
b system_call_common
|
|
|
|
#endif
|
|
|
|
.endif
|
|
|
|
|
|
|
|
#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
|
|
|
|
/* Fast LE/BE switch system call */
|
|
|
|
1: mfspr r12,SPRN_SRR1
|
|
|
|
xori r12,r12,MSR_LE
|
|
|
|
mtspr SPRN_SRR1,r12
|
|
|
|
mr r13,r9
|
|
|
|
RFI_TO_USER /* return to userspace */
|
|
|
|
b . /* prevent speculative execution */
|
2016-09-21 15:43:44 +08:00
|
|
|
#endif
|
2019-06-22 21:15:31 +08:00
|
|
|
.endm
|
2016-09-21 15:43:44 +08:00
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_BEGIN(system_call, 0xc00, 0x100)
|
2019-06-22 21:15:31 +08:00
|
|
|
SYSTEM_CALL 0
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_END(system_call, 0xc00, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
|
2019-06-22 21:15:31 +08:00
|
|
|
SYSTEM_CALL 1
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_END(system_call, 0x4c00, 0x100)
|
2016-09-21 15:43:44 +08:00
|
|
|
|
2017-06-08 23:35:04 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
|
2020-02-26 01:35:21 +08:00
|
|
|
TRAMP_REAL_BEGIN(system_call_kvm)
|
2017-06-08 23:35:04 +08:00
|
|
|
/*
|
|
|
|
* This is a hcall, so register convention is as above, with these
|
|
|
|
* differences:
|
|
|
|
* r13 = PACA
|
2017-07-18 13:32:44 +08:00
|
|
|
* ctr = orig r13
|
|
|
|
* orig r10 saved in PACA
|
2017-06-08 23:35:04 +08:00
|
|
|
*/
|
|
|
|
/*
|
|
|
|
* Save the PPR (on systems that support it) before changing to
|
|
|
|
* HMT_MEDIUM. That allows the KVM code to save that value into the
|
|
|
|
* guest state (it is the guest's PPR value).
|
|
|
|
*/
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
2020-02-26 01:35:21 +08:00
|
|
|
mfspr r10,SPRN_PPR
|
|
|
|
std r10,HSTATE_PPR(r13)
|
2020-02-26 01:35:23 +08:00
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
2017-06-08 23:35:04 +08:00
|
|
|
HMT_MEDIUM
|
|
|
|
mfctr r10
|
2017-07-18 13:32:44 +08:00
|
|
|
SET_SCRATCH0(r10)
|
2020-02-26 01:35:21 +08:00
|
|
|
mfcr r10
|
|
|
|
std r12,HSTATE_SCRATCH0(r13)
|
|
|
|
sldi r12,r10,32
|
|
|
|
ori r12,r12,0xc00
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
/*
|
|
|
|
* Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
|
|
|
|
* outside the head section.
|
|
|
|
*/
|
|
|
|
__LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
|
|
|
|
mtctr r10
|
|
|
|
ld r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
bctr
|
|
|
|
#else
|
|
|
|
ld r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
b kvmppc_interrupt
|
|
|
|
#endif
|
2017-06-08 23:35:04 +08:00
|
|
|
#endif
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2016-09-21 15:43:44 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xd00 - Trace Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to instruction step or
|
|
|
|
* breakpoint faults.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(single_step)
|
|
|
|
IVEC=0xd00
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(single_step)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(single_step, 0xd00, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY single_step, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(single_step, 0xd00, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY single_step, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(single_step, 0x4d00, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(single_step_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON single_step
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl single_step_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2011-06-29 08:18:26 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM single_step
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
|
|
|
|
* This is a synchronous interrupt in response to an MMU fault caused by a
|
|
|
|
* guest data access.
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This should always get routed to KVM. In radix MMU mode, this is caused
|
|
|
|
* by a guest nested radix access that can't be performed due to the
|
|
|
|
* partition scope page table. In hash mode, this can be caused by guests
|
|
|
|
* running with translation disabled (virtual real mode) or with VPM enabled.
|
|
|
|
* KVM will update the page table structures or disallow the access.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(h_data_storage)
|
|
|
|
IVEC=0xe00
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IDAR=1
|
|
|
|
IDSISR=1
|
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(h_data_storage)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(h_data_storage, 0xe00, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_data_storage, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(h_data_storage, 0xe00, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_data_storage, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(h_data_storage, 0x4e00, 0x20)
|
2016-09-21 15:43:46 +08:00
|
|
|
EXC_COMMON_BEGIN(h_data_storage_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON h_data_storage
|
2016-09-21 15:43:46 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2018-12-14 13:29:05 +08:00
|
|
|
BEGIN_MMU_FTR_SECTION
|
2019-08-02 18:56:57 +08:00
|
|
|
ld r4,_DAR(r1)
|
2018-12-14 13:29:05 +08:00
|
|
|
li r5,SIGSEGV
|
|
|
|
bl bad_page_fault
|
|
|
|
MMU_FTR_SECTION_ELSE
|
2016-09-21 15:43:46 +08:00
|
|
|
bl unknown_exception
|
2018-12-14 13:29:05 +08:00
|
|
|
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:46 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM h_data_storage
|
|
|
|
|
powerpc: Save CFAR before branching in interrupt entry paths
Some of the interrupt vectors on 64-bit POWER server processors are
only 32 bytes long, which is not enough for the full first-level
interrupt handler. For these we currently just have a branch to an
out-of-line handler. However, this means that we corrupt the CFAR
(come-from address register) on POWER7 and later processors.
To fix this, we split the EXCEPTION_PROLOG_1 macro into two pieces:
EXCEPTION_PROLOG_0 contains the part up to the point where the CFAR
is saved in the PACA, and EXCEPTION_PROLOG_1 contains the rest. We
then put EXCEPTION_PROLOG_0 in the short interrupt vectors before
we branch to the out-of-line handler, which contains the rest of the
first-level interrupt handler. To facilitate this, we define new
_OOL (out of line) variants of STD_EXCEPTION_PSERIES, etc.
In order to get EXCEPTION_PROLOG_0 to be short enough, i.e., no more
than 6 instructions, it was necessary to move the stores that move
the PPR and CFAR values into the PACA into __EXCEPTION_PROLOG_1 and
to get rid of one of the two HMT_MEDIUM instructions. Previously
there was a HMT_MEDIUM_PPR_DISCARD before the prolog, which was
nop'd out on processors with the PPR (POWER7 and later), and then
another HMT_MEDIUM inside the HMT_MEDIUM_PPR_SAVE macro call inside
__EXCEPTION_PROLOG_1, which was nop'd out on processors without PPR.
Now the HMT_MEDIUM inside EXCEPTION_PROLOG_0 is there unconditionally
and the HMT_MEDIUM_PPR_DISCARD is not strictly necessary, although
this leaves it in for the interrupt vectors where there is room for
it.
Previously we had a handler for hypervisor maintenance interrupts at
0xe50, which doesn't leave enough room for the vector for hypervisor
emulation assist interrupts at 0xe40, since we need 8 instructions.
The 0xe50 vector was only used on POWER6, as the HMI vector was moved
to 0xe60 on POWER7. Since we don't support running in hypervisor mode
on POWER6, we just remove the handler at 0xe50.
This also changes denorm_exception_hv to use EXCEPTION_PROLOG_0
instead of open-coding it, and removes the HMT_MEDIUM_PPR_DISCARD
from the relocation-on vectors (since any CPU that supports
relocation-on interrupts also has the PPR).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-05 02:10:15 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
|
|
|
|
* This is a synchronous interrupt in response to an MMU fault caused by a
|
|
|
|
* guest instruction fetch, similar to HDSI.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(h_instr_storage)
|
|
|
|
IVEC=0xe20
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(h_instr_storage)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(h_instr_storage, 0xe20, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_instr_storage, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(h_instr_storage, 0xe20, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_instr_storage, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(h_instr_storage_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON h_instr_storage
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl unknown_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:47 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM h_instr_storage
|
|
|
|
|
powerpc: Save CFAR before branching in interrupt entry paths
Some of the interrupt vectors on 64-bit POWER server processors are
only 32 bytes long, which is not enough for the full first-level
interrupt handler. For these we currently just have a branch to an
out-of-line handler. However, this means that we corrupt the CFAR
(come-from address register) on POWER7 and later processors.
To fix this, we split the EXCEPTION_PROLOG_1 macro into two pieces:
EXCEPTION_PROLOG_0 contains the part up to the point where the CFAR
is saved in the PACA, and EXCEPTION_PROLOG_1 contains the rest. We
then put EXCEPTION_PROLOG_0 in the short interrupt vectors before
we branch to the out-of-line handler, which contains the rest of the
first-level interrupt handler. To facilitate this, we define new
_OOL (out of line) variants of STD_EXCEPTION_PSERIES, etc.
In order to get EXCEPTION_PROLOG_0 to be short enough, i.e., no more
than 6 instructions, it was necessary to move the stores that move
the PPR and CFAR values into the PACA into __EXCEPTION_PROLOG_1 and
to get rid of one of the two HMT_MEDIUM instructions. Previously
there was a HMT_MEDIUM_PPR_DISCARD before the prolog, which was
nop'd out on processors with the PPR (POWER7 and later), and then
another HMT_MEDIUM inside the HMT_MEDIUM_PPR_SAVE macro call inside
__EXCEPTION_PROLOG_1, which was nop'd out on processors without PPR.
Now the HMT_MEDIUM inside EXCEPTION_PROLOG_0 is there unconditionally
and the HMT_MEDIUM_PPR_DISCARD is not strictly necessary, although
this leaves it in for the interrupt vectors where there is room for
it.
Previously we had a handler for hypervisor maintenance interrupts at
0xe50, which doesn't leave enough room for the vector for hypervisor
emulation assist interrupts at 0xe40, since we need 8 instructions.
The 0xe50 vector was only used on POWER6, as the HMI vector was moved
to 0xe60 on POWER7. Since we don't support running in hypervisor mode
on POWER6, we just remove the handler at 0xe50.
This also changes denorm_exception_hv to use EXCEPTION_PROLOG_0
instead of open-coding it, and removes the HMT_MEDIUM_PPR_DISCARD
from the relocation-on vectors (since any CPU that supports
relocation-on interrupts also has the PPR).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-05 02:10:15 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(emulation_assist)
|
|
|
|
IVEC=0xe40
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(emulation_assist)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(emulation_assist, 0xe40, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY emulation_assist, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(emulation_assist, 0xe40, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY emulation_assist, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(emulation_assist, 0x4e40, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(emulation_assist_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON emulation_assist
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl emulation_assist_interrupt
|
2020-02-26 01:35:38 +08:00
|
|
|
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:48 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM emulation_assist
|
|
|
|
|
powerpc: Save CFAR before branching in interrupt entry paths
Some of the interrupt vectors on 64-bit POWER server processors are
only 32 bytes long, which is not enough for the full first-level
interrupt handler. For these we currently just have a branch to an
out-of-line handler. However, this means that we corrupt the CFAR
(come-from address register) on POWER7 and later processors.
To fix this, we split the EXCEPTION_PROLOG_1 macro into two pieces:
EXCEPTION_PROLOG_0 contains the part up to the point where the CFAR
is saved in the PACA, and EXCEPTION_PROLOG_1 contains the rest. We
then put EXCEPTION_PROLOG_0 in the short interrupt vectors before
we branch to the out-of-line handler, which contains the rest of the
first-level interrupt handler. To facilitate this, we define new
_OOL (out of line) variants of STD_EXCEPTION_PSERIES, etc.
In order to get EXCEPTION_PROLOG_0 to be short enough, i.e., no more
than 6 instructions, it was necessary to move the stores that move
the PPR and CFAR values into the PACA into __EXCEPTION_PROLOG_1 and
to get rid of one of the two HMT_MEDIUM instructions. Previously
there was a HMT_MEDIUM_PPR_DISCARD before the prolog, which was
nop'd out on processors with the PPR (POWER7 and later), and then
another HMT_MEDIUM inside the HMT_MEDIUM_PPR_SAVE macro call inside
__EXCEPTION_PROLOG_1, which was nop'd out on processors without PPR.
Now the HMT_MEDIUM inside EXCEPTION_PROLOG_0 is there unconditionally
and the HMT_MEDIUM_PPR_DISCARD is not strictly necessary, although
this leaves it in for the interrupt vectors where there is room for
it.
Previously we had a handler for hypervisor maintenance interrupts at
0xe50, which doesn't leave enough room for the vector for hypervisor
emulation assist interrupts at 0xe40, since we need 8 instructions.
The 0xe50 vector was only used on POWER6, as the HMI vector was moved
to 0xe60 on POWER7. Since we don't support running in hypervisor mode
on POWER6, we just remove the handler at 0xe50.
This also changes denorm_exception_hv to use EXCEPTION_PROLOG_0
instead of open-coding it, and removes the HMT_MEDIUM_PPR_DISCARD
from the relocation-on vectors (since any CPU that supports
relocation-on interrupts also has the PPR).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-05 02:10:15 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
|
|
|
|
* This is an asynchronous interrupt caused by a Hypervisor Maintenance
|
|
|
|
* Exception. It is always taken in real mode but uses HSRR registers
|
|
|
|
* unlike SRESET and MCE.
|
|
|
|
*
|
|
|
|
* It is maskable in hardware by clearing MSR[EE], and partially soft-maskable
|
|
|
|
* with IRQS_DISABLED mask (i.e., local_irq_disable()).
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This is a special case, this is handled similarly to machine checks, with an
|
|
|
|
* initial real mode handler that is not soft-masked, which attempts to fix the
|
|
|
|
* problem. Then a regular handler which is soft-maskable and reports the
|
|
|
|
* problem.
|
|
|
|
*
|
|
|
|
* The emergency stack is used for the early real mode handler.
|
|
|
|
*
|
|
|
|
* XXX: unclear why MCE and HMI schemes could not be made common, e.g.,
|
|
|
|
* either use soft-masking for the MCE, or use irq_work for the HMI.
|
|
|
|
*
|
|
|
|
* KVM:
|
|
|
|
* Unlike MCE, this calls into KVM without calling the real mode handler
|
|
|
|
* first.
|
2016-09-21 15:44:07 +08:00
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(hmi_exception_early)
|
|
|
|
IVEC=0xe60
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:22 +08:00
|
|
|
IREALMODE_COMMON=1
|
2020-02-26 01:35:14 +08:00
|
|
|
ISTACK=0
|
|
|
|
IRECONCILE=0
|
|
|
|
IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(hmi_exception_early)
|
|
|
|
|
|
|
|
INT_DEFINE_BEGIN(hmi_exception)
|
|
|
|
IVEC=0xe60
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IMASK=IRQS_DISABLED
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(hmi_exception)
|
|
|
|
|
2019-06-28 14:33:21 +08:00
|
|
|
EXC_REAL_BEGIN(hmi_exception, 0xe60, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hmi_exception_early, virt=0, ool=1
|
2019-06-28 14:33:21 +08:00
|
|
|
EXC_REAL_END(hmi_exception, 0xe60, 0x20)
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x4e60, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
|
2019-06-28 14:33:22 +08:00
|
|
|
EXC_COMMON_BEGIN(hmi_exception_early_common)
|
2020-02-26 01:35:21 +08:00
|
|
|
__GEN_REALMODE_COMMON_ENTRY hmi_exception_early
|
|
|
|
|
powerpc/64s: Exception macro for stack frame and initial register save
This code is common to a few exceptions, and another user will be added.
This causes a trivial change to generated code:
- 604: std r9,416(r1)
- 608: mfspr r11,314
- 60c: std r11,368(r1)
- 610: mfspr r12,315
+ 604: mfspr r11,314
+ 608: mfspr r12,315
+ 60c: std r9,416(r1)
+ 610: std r11,368(r1)
machine_check_powernv_early could also use this, but that requires non
trivial changes to generated code, so that's for another patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-20 02:30:03 +08:00
|
|
|
mr r10,r1 /* Save r1 */
|
|
|
|
ld r1,PACAEMERGSP(r13) /* Use emergency stack for realmode */
|
2016-09-21 15:43:49 +08:00
|
|
|
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
|
2019-08-02 18:56:54 +08:00
|
|
|
|
2020-02-26 01:35:19 +08:00
|
|
|
__GEN_COMMON_BODY hmi_exception_early
|
2019-08-02 18:56:54 +08:00
|
|
|
|
2016-09-21 15:43:49 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2019-06-28 14:33:22 +08:00
|
|
|
bl hmi_exception_realmode
|
2017-09-15 13:25:48 +08:00
|
|
|
cmpdi cr0,r3,0
|
2019-06-28 13:33:25 +08:00
|
|
|
bne 1f
|
2017-09-15 13:25:48 +08:00
|
|
|
|
2020-02-26 01:35:27 +08:00
|
|
|
EXCEPTION_RESTORE_REGS hsrr=1
|
2018-01-10 00:07:15 +08:00
|
|
|
HRFI_TO_USER_OR_KERNEL
|
2017-09-15 13:25:48 +08:00
|
|
|
|
2019-06-28 13:33:25 +08:00
|
|
|
1:
|
2016-09-21 15:43:49 +08:00
|
|
|
/*
|
|
|
|
* Go to virtual mode and pull the HMI event information from
|
|
|
|
* firmware.
|
|
|
|
*/
|
2020-02-26 01:35:27 +08:00
|
|
|
EXCEPTION_RESTORE_REGS hsrr=1
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY hmi_exception, virt=0
|
2016-09-21 15:43:49 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM hmi_exception_early
|
|
|
|
|
2017-09-15 13:25:48 +08:00
|
|
|
EXC_COMMON_BEGIN(hmi_exception_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON hmi_exception
|
2019-06-22 21:15:21 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
2019-06-22 21:15:20 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl handle_hmi_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
powerpc: Save CFAR before branching in interrupt entry paths
Some of the interrupt vectors on 64-bit POWER server processors are
only 32 bytes long, which is not enough for the full first-level
interrupt handler. For these we currently just have a branch to an
out-of-line handler. However, this means that we corrupt the CFAR
(come-from address register) on POWER7 and later processors.
To fix this, we split the EXCEPTION_PROLOG_1 macro into two pieces:
EXCEPTION_PROLOG_0 contains the part up to the point where the CFAR
is saved in the PACA, and EXCEPTION_PROLOG_1 contains the rest. We
then put EXCEPTION_PROLOG_0 in the short interrupt vectors before
we branch to the out-of-line handler, which contains the rest of the
first-level interrupt handler. To facilitate this, we define new
_OOL (out of line) variants of STD_EXCEPTION_PSERIES, etc.
In order to get EXCEPTION_PROLOG_0 to be short enough, i.e., no more
than 6 instructions, it was necessary to move the stores that move
the PPR and CFAR values into the PACA into __EXCEPTION_PROLOG_1 and
to get rid of one of the two HMT_MEDIUM instructions. Previously
there was a HMT_MEDIUM_PPR_DISCARD before the prolog, which was
nop'd out on processors with the PPR (POWER7 and later), and then
another HMT_MEDIUM inside the HMT_MEDIUM_PPR_SAVE macro call inside
__EXCEPTION_PROLOG_1, which was nop'd out on processors without PPR.
Now the HMT_MEDIUM inside EXCEPTION_PROLOG_0 is there unconditionally
and the HMT_MEDIUM_PPR_DISCARD is not strictly necessary, although
this leaves it in for the interrupt vectors where there is room for
it.
Previously we had a handler for hypervisor maintenance interrupts at
0xe50, which doesn't leave enough room for the vector for hypervisor
emulation assist interrupts at 0xe40, since we need 8 instructions.
The 0xe50 vector was only used on POWER6, as the HMI vector was moved
to 0xe60 on POWER7. Since we don't support running in hypervisor mode
on POWER6, we just remove the handler at 0xe50.
This also changes denorm_exception_hv to use EXCEPTION_PROLOG_0
instead of open-coding it, and removes the HMT_MEDIUM_PPR_DISCARD
from the relocation-on vectors (since any CPU that supports
relocation-on interrupts also has the PPR).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-05 02:10:15 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM hmi_exception
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
|
|
|
|
* This is an asynchronous interrupt in response to a msgsnd doorbell.
|
|
|
|
* Similar to the 0xa00 doorbell but for host rather than guest.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(h_doorbell)
|
|
|
|
IVEC=0xe80
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IMASK=IRQS_DISABLED
|
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(h_doorbell)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(h_doorbell, 0xe80, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_doorbell, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(h_doorbell, 0xe80, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_doorbell, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(h_doorbell, 0x4e80, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(h_doorbell_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON h_doorbell
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2016-09-21 15:43:50 +08:00
|
|
|
#ifdef CONFIG_PPC_DOORBELL
|
2020-02-26 01:35:13 +08:00
|
|
|
bl doorbell_exception
|
2016-09-21 15:43:50 +08:00
|
|
|
#else
|
2020-02-26 01:35:13 +08:00
|
|
|
bl unknown_exception
|
2016-09-21 15:43:50 +08:00
|
|
|
#endif
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:50 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM h_doorbell
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
|
|
|
|
* This is an asynchronous interrupt in response to an "external exception".
|
|
|
|
* Similar to 0x500 but for host only.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(h_virt_irq)
|
|
|
|
IVEC=0xea0
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IMASK=IRQS_DISABLED
|
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(h_virt_irq)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(h_virt_irq, 0xea0, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_virt_irq, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(h_virt_irq, 0xea0, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_virt_irq, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(h_virt_irq_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON h_virt_irq
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl do_IRQ
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:51 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM h_virt_irq
|
|
|
|
|
2016-07-08 14:37:06 +08:00
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0xec0, 0x20)
|
|
|
|
EXC_VIRT_NONE(0x4ec0, 0x20)
|
|
|
|
EXC_REAL_NONE(0xee0, 0x20)
|
|
|
|
EXC_VIRT_NONE(0x4ee0, 0x20)
|
2016-09-21 15:43:52 +08:00
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/*
|
|
|
|
* Interrupt 0xf00 - Performance Monitor Interrupt (PMI, PMU).
|
|
|
|
* This is an asynchronous interrupt in response to a PMU exception.
|
|
|
|
* It is maskable in hardware by clearing MSR[EE], and soft-maskable with
|
|
|
|
* IRQS_PMI_DISABLED mask (NOTE: NOT local_irq_disable()).
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This calls into the perf subsystem.
|
|
|
|
*
|
|
|
|
* Like the watchdog soft-nmi, it appears an NMI interrupt to Linux, in that it
|
|
|
|
* runs under local_irq_disable. However it may be soft-masked in
|
|
|
|
* powerpc-specific code.
|
|
|
|
*
|
|
|
|
* If soft masked, the masked handler will note the pending interrupt for
|
|
|
|
* replay, and clear MSR[EE] in the interrupted context.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(performance_monitor)
|
|
|
|
IVEC=0xf00
|
|
|
|
IMASK=IRQS_PMI_DISABLED
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(performance_monitor)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(performance_monitor, 0xf00, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY performance_monitor, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(performance_monitor, 0xf00, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY performance_monitor, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(performance_monitor, 0x4f00, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(performance_monitor_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON performance_monitor
|
2020-02-26 01:35:13 +08:00
|
|
|
FINISH_NAP
|
|
|
|
RUNLATCH_ON
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl performance_monitor_exception
|
2020-02-26 01:35:38 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:53 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM performance_monitor
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xf20 - Vector Unavailable Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to
|
|
|
|
* executing a vector (or altivec) instruction with MSR[VEC]=0.
|
|
|
|
* Similar to FP unavailable.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(altivec_unavailable)
|
|
|
|
IVEC=0xf20
|
|
|
|
IRECONCILE=0
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(altivec_unavailable)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(altivec_unavailable, 0xf20, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY altivec_unavailable, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(altivec_unavailable, 0xf20, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(altivec_unavailable, 0x4f20, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY altivec_unavailable, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(altivec_unavailable, 0x4f20, 0x20)
|
2016-09-21 15:43:54 +08:00
|
|
|
EXC_COMMON_BEGIN(altivec_unavailable_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON altivec_unavailable
|
2016-09-21 15:43:54 +08:00
|
|
|
#ifdef CONFIG_ALTIVEC
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
beq 1f
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
BEGIN_FTR_SECTION_NESTED(69)
|
|
|
|
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
|
|
|
|
* transaction), go do TM stuff
|
|
|
|
*/
|
|
|
|
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
|
|
|
|
bne- 2f
|
|
|
|
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
|
|
|
|
#endif
|
|
|
|
bl load_up_altivec
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b fast_interrupt_return
|
2016-09-21 15:43:54 +08:00
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
2: /* User process was in a transaction */
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl altivec_unavailable_tm
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:54 +08:00
|
|
|
#endif
|
|
|
|
1:
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
|
|
|
|
#endif
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl altivec_unavailable_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:54 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM altivec_unavailable
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xf40 - VSX Unavailable Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to
|
|
|
|
* executing a VSX instruction with MSR[VSX]=0.
|
|
|
|
* Similar to FP unavailable.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(vsx_unavailable)
|
|
|
|
IVEC=0xf40
|
|
|
|
IRECONCILE=0
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(vsx_unavailable)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(vsx_unavailable, 0xf40, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY vsx_unavailable, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(vsx_unavailable, 0xf40, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(vsx_unavailable, 0x4f40, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY vsx_unavailable, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(vsx_unavailable, 0x4f40, 0x20)
|
2016-09-21 15:43:55 +08:00
|
|
|
EXC_COMMON_BEGIN(vsx_unavailable_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON vsx_unavailable
|
2016-09-21 15:43:55 +08:00
|
|
|
#ifdef CONFIG_VSX
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
beq 1f
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
BEGIN_FTR_SECTION_NESTED(69)
|
|
|
|
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
|
|
|
|
* transaction), go do TM stuff
|
|
|
|
*/
|
|
|
|
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
|
|
|
|
bne- 2f
|
|
|
|
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
|
|
|
|
#endif
|
|
|
|
b load_up_vsx
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
|
|
2: /* User process was in a transaction */
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl vsx_unavailable_tm
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:55 +08:00
|
|
|
#endif
|
|
|
|
1:
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
|
|
|
|
#endif
|
|
|
|
RECONCILE_IRQ_STATE(r10, r11)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl vsx_unavailable_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:55 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM vsx_unavailable
|
|
|
|
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xf60 - Facility Unavailable Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to
|
|
|
|
* executing an instruction without access to the facility that can be
|
|
|
|
* resolved by the OS (e.g., FSCR, MSR).
|
|
|
|
* Similar to FP unavailable.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(facility_unavailable)
|
|
|
|
IVEC=0xf60
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(facility_unavailable)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(facility_unavailable, 0xf60, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY facility_unavailable, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(facility_unavailable, 0xf60, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY facility_unavailable, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(facility_unavailable_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON facility_unavailable
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl facility_unavailable_exception
|
powerpc/64s: Fix restore of NV GPRs after facility unavailable exception
Commit 702f09805222 ("powerpc/64s/exception: Remove lite interrupt
return") changed the interrupt return path to not restore non-volatile
registers by default, and explicitly restore them in paths where it is
required.
But it missed that the facility unavailable exception can sometimes
modify user registers, ie. when it does emulation of move from DSCR.
This is seen as a failure of the dscr_sysfs_thread_test:
test: dscr_sysfs_thread_test
[cpu 0] User DSCR should be 1 but is 0
failure: dscr_sysfs_thread_test
So restore non-volatile GPRs after facility unavailable exceptions.
Currently the hypervisor facility unavailable exception is also wired
up to call facility_unavailable_exception().
In practice we should never take a hypervisor facility unavailable
exception for the DSCR. On older bare metal systems we set HFSCR_DSCR
unconditionally in __init_HFSCR, or on newer systems it should be
enabled via the "data-stream-control-register" device tree CPU
feature.
Even if it's not, since commit f3c99f97a3cd ("KVM: PPC: Book3S HV:
Don't access HFSCR, LPIDR or LPCR when running nested"), the KVM code
has unconditionally set HFSCR_DSCR when running guests.
So we should only get a hypervisor facility unavailable for the DSCR
if skiboot has disabled the "data-stream-control-register" feature,
and we are somehow in guest context but not via KVM.
Given all that, it should be unnecessary to add a restore of
non-volatile GPRs after the hypervisor facility exception, because we
never expect to hit that path. But equally we may as well add the
restore, because we never expect to hit that path, and if we ever did,
at least we would correctly restore the registers to their post
emulation state.
In future we can split the non-HV and HV facility unavailable handling
so that there is no emulation in the HV handler, and then remove the
restore for the HV case.
Fixes: 702f09805222 ("powerpc/64s/exception: Remove lite interrupt return")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200526061808.2472279-1-mpe@ellerman.id.au
2020-05-26 14:18:08 +08:00
|
|
|
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:56 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM facility_unavailable
|
|
|
|
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
|
|
|
|
* This is a synchronous interrupt in response to
|
|
|
|
* executing an instruction without access to the facility that can only
|
|
|
|
* be resolved in HV mode (e.g., HFSCR).
|
|
|
|
* Similar to FP unavailable.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(h_facility_unavailable)
|
|
|
|
IVEC=0xf80
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
|
|
|
IKVM_VIRT=1
|
|
|
|
INT_DEFINE_END(h_facility_unavailable)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(h_facility_unavailable, 0xf80, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_facility_unavailable, virt=0, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(h_facility_unavailable, 0xf80, 0x20)
|
|
|
|
EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY h_facility_unavailable, virt=1, ool=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(h_facility_unavailable_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON h_facility_unavailable
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl facility_unavailable_exception
|
powerpc/64s: Fix restore of NV GPRs after facility unavailable exception
Commit 702f09805222 ("powerpc/64s/exception: Remove lite interrupt
return") changed the interrupt return path to not restore non-volatile
registers by default, and explicitly restore them in paths where it is
required.
But it missed that the facility unavailable exception can sometimes
modify user registers, ie. when it does emulation of move from DSCR.
This is seen as a failure of the dscr_sysfs_thread_test:
test: dscr_sysfs_thread_test
[cpu 0] User DSCR should be 1 but is 0
failure: dscr_sysfs_thread_test
So restore non-volatile GPRs after facility unavailable exceptions.
Currently the hypervisor facility unavailable exception is also wired
up to call facility_unavailable_exception().
In practice we should never take a hypervisor facility unavailable
exception for the DSCR. On older bare metal systems we set HFSCR_DSCR
unconditionally in __init_HFSCR, or on newer systems it should be
enabled via the "data-stream-control-register" device tree CPU
feature.
Even if it's not, since commit f3c99f97a3cd ("KVM: PPC: Book3S HV:
Don't access HFSCR, LPIDR or LPCR when running nested"), the KVM code
has unconditionally set HFSCR_DSCR when running guests.
So we should only get a hypervisor facility unavailable for the DSCR
if skiboot has disabled the "data-stream-control-register" feature,
and we are somehow in guest context but not via KVM.
Given all that, it should be unnecessary to add a restore of
non-volatile GPRs after the hypervisor facility exception, because we
never expect to hit that path. But equally we may as well add the
restore, because we never expect to hit that path, and if we ever did,
at least we would correctly restore the registers to their post
emulation state.
In future we can split the non-HV and HV facility unavailable handling
so that there is no emulation in the HV handler, and then remove the
restore for the HV case.
Fixes: 702f09805222 ("powerpc/64s/exception: Remove lite interrupt return")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200526061808.2472279-1-mpe@ellerman.id.au
2020-05-26 14:18:08 +08:00
|
|
|
REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:43:57 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM h_facility_unavailable
|
|
|
|
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0xfa0, 0x20)
|
|
|
|
EXC_VIRT_NONE(0x4fa0, 0x20)
|
|
|
|
EXC_REAL_NONE(0xfc0, 0x20)
|
|
|
|
EXC_VIRT_NONE(0x4fc0, 0x20)
|
|
|
|
EXC_REAL_NONE(0xfe0, 0x20)
|
|
|
|
EXC_VIRT_NONE(0x4fe0, 0x20)
|
|
|
|
|
|
|
|
EXC_REAL_NONE(0x1000, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5000, 0x100)
|
|
|
|
EXC_REAL_NONE(0x1100, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5100, 0x100)
|
2013-02-14 00:21:38 +08:00
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
#ifdef CONFIG_CBE_RAS
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(cbe_system_error)
|
|
|
|
IVEC=0x1200
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(cbe_system_error)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY cbe_system_error, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(cbe_system_error, 0x1200, 0x100)
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x5200, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(cbe_system_error_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON cbe_system_error
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl cbe_system_error_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2020-02-26 01:35:21 +08:00
|
|
|
|
|
|
|
GEN_KVM cbe_system_error
|
|
|
|
|
2016-09-30 17:43:18 +08:00
|
|
|
#else /* CONFIG_CBE_RAS */
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0x1200, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5200, 0x100)
|
2016-09-30 17:43:18 +08:00
|
|
|
#endif
|
2011-06-29 08:18:26 +08:00
|
|
|
|
2016-09-21 15:43:59 +08:00
|
|
|
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(instruction_breakpoint)
|
|
|
|
IVEC=0x1300
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(instruction_breakpoint)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(instruction_breakpoint, 0x1300, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_breakpoint, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(instruction_breakpoint, 0x1300, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY instruction_breakpoint, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(instruction_breakpoint_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON instruction_breakpoint
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl instruction_breakpoint_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:44:00 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM instruction_breakpoint
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0x1400, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5400, 0x100)
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2020-02-26 01:35:28 +08:00
|
|
|
/**
|
|
|
|
* Interrupt 0x1500 - Soft Patch Interrupt
|
|
|
|
*
|
|
|
|
* Handling:
|
|
|
|
* This is an implementation specific interrupt which can be used for a
|
|
|
|
* range of exceptions.
|
|
|
|
*
|
|
|
|
* This interrupt handler is unique in that it runs the denormal assist
|
|
|
|
* code even for guests (and even in guest context) without going to KVM,
|
|
|
|
* for speed. POWER9 does not raise denorm exceptions, so this special case
|
|
|
|
* could be phased out in future to reduce special cases.
|
|
|
|
*/
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(denorm_exception)
|
|
|
|
IVEC=0x1500
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-07-08 15:49:42 +08:00
|
|
|
IBRANCH_TO_COMMON=0
|
2020-02-26 01:35:21 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(denorm_exception)
|
|
|
|
|
|
|
|
EXC_REAL_BEGIN(denorm_exception, 0x1500, 0x100)
|
|
|
|
GEN_INT_ENTRY denorm_exception, virt=0
|
2012-09-10 08:35:26 +08:00
|
|
|
#ifdef CONFIG_PPC_DENORMALISATION
|
2020-02-26 01:35:22 +08:00
|
|
|
andis. r10,r12,(HSRR1_DENORM)@h /* denorm? */
|
2016-09-21 15:43:31 +08:00
|
|
|
bne+ denorm_assist
|
|
|
|
#endif
|
2020-02-26 01:35:19 +08:00
|
|
|
GEN_BRANCH_TO_COMMON denorm_exception, virt=0
|
2020-02-26 01:35:14 +08:00
|
|
|
EXC_REAL_END(denorm_exception, 0x1500, 0x100)
|
2016-09-21 15:44:01 +08:00
|
|
|
#ifdef CONFIG_PPC_DENORMALISATION
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_BEGIN(denorm_exception, 0x5500, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY denorm_exception, virt=1
|
2020-02-26 01:35:22 +08:00
|
|
|
andis. r10,r12,(HSRR1_DENORM)@h /* denorm? */
|
2019-08-02 18:56:49 +08:00
|
|
|
bne+ denorm_assist
|
2020-02-26 01:35:19 +08:00
|
|
|
GEN_BRANCH_TO_COMMON denorm_exception, virt=1
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_END(denorm_exception, 0x5500, 0x100)
|
2016-09-21 15:44:01 +08:00
|
|
|
#else
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x5500, 0x100)
|
2016-09-21 15:43:31 +08:00
|
|
|
#endif
|
2011-06-29 08:18:26 +08:00
|
|
|
|
2012-09-10 08:35:26 +08:00
|
|
|
#ifdef CONFIG_PPC_DENORMALISATION
|
2016-09-30 17:43:18 +08:00
|
|
|
TRAMP_REAL_BEGIN(denorm_assist)
|
2012-09-10 08:35:26 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
/*
|
|
|
|
* To denormalise we need to move a copy of the register to itself.
|
|
|
|
* For POWER6 do that here for all FP regs.
|
|
|
|
*/
|
|
|
|
mfmsr r10
|
|
|
|
ori r10,r10,(MSR_FP|MSR_FE0|MSR_FE1)
|
|
|
|
xori r10,r10,(MSR_FE0|MSR_FE1)
|
|
|
|
mtmsrd r10
|
|
|
|
sync
|
2013-05-30 05:33:18 +08:00
|
|
|
|
2019-06-22 21:15:33 +08:00
|
|
|
.Lreg=0
|
|
|
|
.rept 32
|
|
|
|
fmr .Lreg,.Lreg
|
|
|
|
.Lreg=.Lreg+1
|
|
|
|
.endr
|
2013-05-30 05:33:18 +08:00
|
|
|
|
2012-09-10 08:35:26 +08:00
|
|
|
FTR_SECTION_ELSE
|
|
|
|
/*
|
|
|
|
* To denormalise we need to move a copy of the register to itself.
|
|
|
|
* For POWER7 do that here for the first 32 VSX registers only.
|
|
|
|
*/
|
|
|
|
mfmsr r10
|
|
|
|
oris r10,r10,MSR_VSX@h
|
|
|
|
mtmsrd r10
|
|
|
|
sync
|
2013-05-30 05:33:18 +08:00
|
|
|
|
2019-06-22 21:15:33 +08:00
|
|
|
.Lreg=0
|
|
|
|
.rept 32
|
|
|
|
XVCPSGNDP(.Lreg,.Lreg,.Lreg)
|
|
|
|
.Lreg=.Lreg+1
|
|
|
|
.endr
|
2013-05-30 05:33:18 +08:00
|
|
|
|
2012-09-10 08:35:26 +08:00
|
|
|
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)
|
2013-05-30 05:33:19 +08:00
|
|
|
|
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
b denorm_done
|
|
|
|
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
|
|
|
|
/*
|
|
|
|
* To denormalise we need to move a copy of the register to itself.
|
|
|
|
* For POWER8 we need to do that for all 64 VSX registers
|
|
|
|
*/
|
2019-06-22 21:15:33 +08:00
|
|
|
.Lreg=32
|
|
|
|
.rept 32
|
|
|
|
XVCPSGNDP(.Lreg,.Lreg,.Lreg)
|
|
|
|
.Lreg=.Lreg+1
|
|
|
|
.endr
|
|
|
|
|
2013-05-30 05:33:19 +08:00
|
|
|
denorm_done:
|
2018-09-13 13:33:47 +08:00
|
|
|
mfspr r11,SPRN_HSRR0
|
|
|
|
subi r11,r11,4
|
2012-09-10 08:35:26 +08:00
|
|
|
mtspr SPRN_HSRR0,r11
|
|
|
|
mtcrf 0x80,r9
|
|
|
|
ld r9,PACA_EXGEN+EX_R9(r13)
|
2020-02-26 01:35:23 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
ld r10,PACA_EXGEN+EX_PPR(r13)
|
|
|
|
mtspr SPRN_PPR,r10
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
|
2013-08-12 14:12:06 +08:00
|
|
|
BEGIN_FTR_SECTION
|
|
|
|
ld r10,PACA_EXGEN+EX_CFAR(r13)
|
|
|
|
mtspr SPRN_CFAR,r10
|
|
|
|
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
|
2012-09-10 08:35:26 +08:00
|
|
|
ld r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXGEN+EX_R11(r13)
|
|
|
|
ld r12,PACA_EXGEN+EX_R12(r13)
|
|
|
|
ld r13,PACA_EXGEN+EX_R13(r13)
|
2018-01-10 00:07:15 +08:00
|
|
|
HRFI_TO_UNKNOWN
|
2012-09-10 08:35:26 +08:00
|
|
|
b .
|
|
|
|
#endif
|
|
|
|
|
2020-02-26 01:35:14 +08:00
|
|
|
EXC_COMMON_BEGIN(denorm_exception_common)
|
|
|
|
GEN_COMMON denorm_exception
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl unknown_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:44:01 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM denorm_exception
|
|
|
|
|
2016-09-21 15:44:01 +08:00
|
|
|
|
|
|
|
#ifdef CONFIG_CBE_RAS
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(cbe_maintenance)
|
|
|
|
IVEC=0x1600
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(cbe_maintenance)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY cbe_maintenance, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(cbe_maintenance, 0x1600, 0x100)
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x5600, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(cbe_maintenance_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON cbe_maintenance
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl cbe_maintenance_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2020-02-26 01:35:21 +08:00
|
|
|
|
|
|
|
GEN_KVM cbe_maintenance
|
|
|
|
|
2016-09-21 15:44:01 +08:00
|
|
|
#else /* CONFIG_CBE_RAS */
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0x1600, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5600, 0x100)
|
2016-09-21 15:44:01 +08:00
|
|
|
#endif
|
|
|
|
|
2016-09-21 15:44:02 +08:00
|
|
|
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(altivec_assist)
|
|
|
|
IVEC=0x1700
|
2020-02-26 01:35:29 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_REAL=1
|
2020-02-26 01:35:29 +08:00
|
|
|
#endif
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_END(altivec_assist)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(altivec_assist, 0x1700, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY altivec_assist, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(altivec_assist, 0x1700, 0x100)
|
|
|
|
EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY altivec_assist, virt=1
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_VIRT_END(altivec_assist, 0x5700, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(altivec_assist_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON altivec_assist
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2016-09-21 15:44:03 +08:00
|
|
|
#ifdef CONFIG_ALTIVEC
|
2020-02-26 01:35:13 +08:00
|
|
|
bl altivec_assist_exception
|
2020-02-26 01:35:38 +08:00
|
|
|
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
|
2016-09-21 15:44:03 +08:00
|
|
|
#else
|
2020-02-26 01:35:13 +08:00
|
|
|
bl unknown_exception
|
2016-09-21 15:44:03 +08:00
|
|
|
#endif
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-09-21 15:44:03 +08:00
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
GEN_KVM altivec_assist
|
|
|
|
|
2016-09-21 15:44:01 +08:00
|
|
|
|
|
|
|
#ifdef CONFIG_CBE_RAS
|
2020-02-26 01:35:14 +08:00
|
|
|
INT_DEFINE_BEGIN(cbe_thermal)
|
|
|
|
IVEC=0x1800
|
2020-02-26 01:35:27 +08:00
|
|
|
IHSRR=1
|
2020-02-26 01:35:14 +08:00
|
|
|
IKVM_SKIP=1
|
|
|
|
IKVM_REAL=1
|
|
|
|
INT_DEFINE_END(cbe_thermal)
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_INT_ENTRY cbe_thermal, virt=0
|
2019-08-02 18:56:47 +08:00
|
|
|
EXC_REAL_END(cbe_thermal, 0x1800, 0x100)
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_VIRT_NONE(0x5800, 0x100)
|
2020-02-26 01:35:13 +08:00
|
|
|
EXC_COMMON_BEGIN(cbe_thermal_common)
|
2020-02-26 01:35:14 +08:00
|
|
|
GEN_COMMON cbe_thermal
|
2020-02-26 01:35:13 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl cbe_thermal_exception
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2020-02-26 01:35:21 +08:00
|
|
|
|
|
|
|
GEN_KVM cbe_thermal
|
|
|
|
|
2016-09-21 15:44:01 +08:00
|
|
|
#else /* CONFIG_CBE_RAS */
|
2016-12-06 09:41:12 +08:00
|
|
|
EXC_REAL_NONE(0x1800, 0x100)
|
|
|
|
EXC_VIRT_NONE(0x5800, 0x100)
|
2016-09-21 15:44:01 +08:00
|
|
|
#endif
|
|
|
|
|
2019-08-02 18:56:47 +08:00
|
|
|
|
2017-08-01 20:00:52 +08:00
|
|
|
#ifdef CONFIG_PPC_WATCHDOG
|
2017-07-13 05:35:52 +08:00
|
|
|
|
2020-02-26 01:35:20 +08:00
|
|
|
INT_DEFINE_BEGIN(soft_nmi)
|
|
|
|
IVEC=0x900
|
|
|
|
ISTACK=0
|
2020-02-26 01:35:31 +08:00
|
|
|
IRECONCILE=0 /* Soft-NMI may fire under local_irq_disable */
|
2020-02-26 01:35:20 +08:00
|
|
|
INT_DEFINE_END(soft_nmi)
|
2017-07-13 05:35:52 +08:00
|
|
|
|
2017-07-29 20:50:27 +08:00
|
|
|
/*
|
|
|
|
* Branch to soft_nmi_interrupt using the emergency stack. The emergency
|
|
|
|
* stack is one that is usable by maskable interrupts so long as MSR_EE
|
|
|
|
* remains off. It is used for recovery when something has corrupted the
|
|
|
|
* normal kernel stack, for example. The "soft NMI" must not use the process
|
|
|
|
* stack because we want irq disabled sections to avoid touching the stack
|
|
|
|
* at all (other than PMU interrupts), so use the emergency stack for this,
|
|
|
|
* and run it entirely with interrupts hard disabled.
|
|
|
|
*/
|
2017-07-13 05:35:52 +08:00
|
|
|
EXC_COMMON_BEGIN(soft_nmi_common)
|
2020-02-26 01:35:20 +08:00
|
|
|
mfspr r11,SPRN_SRR0
|
2017-07-13 05:35:52 +08:00
|
|
|
mr r10,r1
|
|
|
|
ld r1,PACAEMERGSP(r13)
|
|
|
|
subi r1,r1,INT_FRAME_SIZE
|
2020-02-26 01:35:20 +08:00
|
|
|
__GEN_COMMON_BODY soft_nmi
|
2020-02-26 01:35:31 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
|
|
|
|
* system_reset_common)
|
|
|
|
*/
|
|
|
|
li r10,IRQS_ALL_DISABLED
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
lbz r10,PACAIRQHAPPENED(r13)
|
2020-05-08 12:33:55 +08:00
|
|
|
std r10,RESULT(r1)
|
2020-02-26 01:35:31 +08:00
|
|
|
ori r10,r10,PACA_IRQ_HARD_DIS
|
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
|
|
|
|
2019-06-22 21:15:20 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
bl soft_nmi_interrupt
|
2020-02-26 01:35:31 +08:00
|
|
|
|
|
|
|
/* Clear MSR_RI before setting SRR0 and SRR1. */
|
|
|
|
li r9,0
|
|
|
|
mtmsrd r9,1
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Restore soft mask settings.
|
|
|
|
*/
|
2020-05-08 12:33:55 +08:00
|
|
|
ld r10,RESULT(r1)
|
2020-02-26 01:35:31 +08:00
|
|
|
stb r10,PACAIRQHAPPENED(r13)
|
|
|
|
ld r10,SOFTE(r1)
|
|
|
|
stb r10,PACAIRQSOFTMASK(r13)
|
|
|
|
|
2020-04-29 14:56:54 +08:00
|
|
|
kuap_restore_amr r9, r10
|
2020-02-26 01:35:31 +08:00
|
|
|
EXCEPTION_RESTORE_REGS hsrr=0
|
|
|
|
RFI_TO_KERNEL
|
2017-07-13 05:35:52 +08:00
|
|
|
|
2017-08-01 20:00:52 +08:00
|
|
|
#endif /* CONFIG_PPC_WATCHDOG */
|
2016-09-21 15:44:01 +08:00
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
/*
|
2012-11-15 02:49:48 +08:00
|
|
|
* An interrupt came in while soft-disabled. We set paca->irq_happened, then:
|
|
|
|
* - If it was a decrementer interrupt, we bump the dec to max and and return.
|
|
|
|
* - If it was a doorbell we return immediately since doorbells are edge
|
|
|
|
* triggered and won't automatically refire.
|
2014-07-29 21:10:01 +08:00
|
|
|
* - If it was a HMI we return immediately since we handled it in realmode
|
|
|
|
* and it won't refire.
|
2018-02-03 15:17:50 +08:00
|
|
|
* - Else it is one of PACA_IRQ_MUST_HARD_MASK, so hard disable and return.
|
2012-11-15 02:49:48 +08:00
|
|
|
* This is called with r10 containing the value to OR to the paca field.
|
2009-06-03 05:17:38 +08:00
|
|
|
*/
|
2020-02-26 01:35:27 +08:00
|
|
|
.macro MASKED_INTERRUPT hsrr=0
|
2019-06-22 21:15:11 +08:00
|
|
|
.if \hsrr
|
|
|
|
masked_Hinterrupt:
|
|
|
|
.else
|
|
|
|
masked_interrupt:
|
|
|
|
.endif
|
|
|
|
lbz r11,PACAIRQHAPPENED(r13)
|
|
|
|
or r11,r11,r10
|
|
|
|
stb r11,PACAIRQHAPPENED(r13)
|
|
|
|
cmpwi r10,PACA_IRQ_DEC
|
|
|
|
bne 1f
|
|
|
|
lis r10,0x7fff
|
|
|
|
ori r10,r10,0xffff
|
|
|
|
mtspr SPRN_DEC,r10
|
2020-02-26 01:35:20 +08:00
|
|
|
#ifdef CONFIG_PPC_WATCHDOG
|
|
|
|
b soft_nmi_common
|
|
|
|
#else
|
|
|
|
b 2f
|
|
|
|
#endif
|
2019-06-22 21:15:11 +08:00
|
|
|
1: andi. r10,r10,PACA_IRQ_MUST_HARD_MASK
|
|
|
|
beq 2f
|
2020-02-26 01:35:20 +08:00
|
|
|
xori r12,r12,MSR_EE /* clear MSR_EE */
|
2019-06-22 21:15:11 +08:00
|
|
|
.if \hsrr
|
2020-02-26 01:35:20 +08:00
|
|
|
mtspr SPRN_HSRR1,r12
|
2019-06-22 21:15:11 +08:00
|
|
|
.else
|
2020-02-26 01:35:20 +08:00
|
|
|
mtspr SPRN_SRR1,r12
|
2019-06-22 21:15:11 +08:00
|
|
|
.endif
|
|
|
|
ori r11,r11,PACA_IRQ_HARD_DIS
|
|
|
|
stb r11,PACAIRQHAPPENED(r13)
|
|
|
|
2: /* done */
|
2020-02-26 01:35:20 +08:00
|
|
|
ld r10,PACA_EXGEN+EX_CTR(r13)
|
|
|
|
mtctr r10
|
2019-06-22 21:15:11 +08:00
|
|
|
mtcrf 0x80,r9
|
|
|
|
std r1,PACAR1(r13)
|
|
|
|
ld r9,PACA_EXGEN+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXGEN+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXGEN+EX_R11(r13)
|
2020-02-26 01:35:20 +08:00
|
|
|
ld r12,PACA_EXGEN+EX_R12(r13)
|
2020-06-11 16:12:02 +08:00
|
|
|
ld r13,PACA_EXGEN+EX_R13(r13)
|
|
|
|
/* May return to masked low address where r13 is not set up */
|
2019-06-22 21:15:11 +08:00
|
|
|
.if \hsrr
|
|
|
|
HRFI_TO_KERNEL
|
|
|
|
.else
|
|
|
|
RFI_TO_KERNEL
|
|
|
|
.endif
|
|
|
|
b .
|
|
|
|
.endm
|
2016-09-28 09:31:48 +08:00
|
|
|
|
2018-05-22 07:00:00 +08:00
|
|
|
TRAMP_REAL_BEGIN(stf_barrier_fallback)
|
|
|
|
std r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
std r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
sync
|
|
|
|
ld r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
ori 31,31,0
|
|
|
|
.rept 14
|
|
|
|
b 1f
|
|
|
|
1:
|
|
|
|
.endr
|
|
|
|
blr
|
|
|
|
|
2020-11-17 13:59:13 +08:00
|
|
|
/* Clobbers r10, r11, ctr */
|
|
|
|
.macro L1D_DISPLACEMENT_FLUSH
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
|
2018-01-17 21:58:18 +08:00
|
|
|
ld r11,PACA_L1D_FLUSH_SIZE(r13)
|
|
|
|
srdi r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
mtctr r11
|
2018-02-21 03:08:26 +08:00
|
|
|
DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
|
|
|
|
/* order ld/st prior to dcbt stop all streams with flushing */
|
|
|
|
sync
|
2018-01-17 21:58:18 +08:00
|
|
|
|
|
|
|
/*
|
2020-11-17 13:59:12 +08:00
|
|
|
* The load addresses are at staggered offsets within cachelines,
|
2018-01-17 21:58:18 +08:00
|
|
|
* which suits some pipelines better (on others it should not
|
|
|
|
* hurt).
|
|
|
|
*/
|
|
|
|
1:
|
|
|
|
ld r11,(0x80 + 8)*0(r10)
|
|
|
|
ld r11,(0x80 + 8)*1(r10)
|
|
|
|
ld r11,(0x80 + 8)*2(r10)
|
|
|
|
ld r11,(0x80 + 8)*3(r10)
|
|
|
|
ld r11,(0x80 + 8)*4(r10)
|
|
|
|
ld r11,(0x80 + 8)*5(r10)
|
|
|
|
ld r11,(0x80 + 8)*6(r10)
|
|
|
|
ld r11,(0x80 + 8)*7(r10)
|
|
|
|
addi r10,r10,0x80*8
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
bdnz 1b
|
2020-11-17 13:59:13 +08:00
|
|
|
.endm
|
2020-11-17 13:59:12 +08:00
|
|
|
|
2020-11-17 13:59:13 +08:00
|
|
|
TRAMP_REAL_BEGIN(entry_flush_fallback)
|
|
|
|
std r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
std r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
std r11,PACA_EXRFI+EX_R11(r13)
|
|
|
|
mfctr r9
|
|
|
|
L1D_DISPLACEMENT_FLUSH
|
2020-11-17 13:59:12 +08:00
|
|
|
mtctr r9
|
|
|
|
ld r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXRFI+EX_R11(r13)
|
|
|
|
blr
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
|
|
|
|
TRAMP_REAL_BEGIN(rfi_flush_fallback)
|
|
|
|
SET_SCRATCH0(r13);
|
|
|
|
GET_PACA(r13);
|
powerpc/64s: Make rfi_flush_fallback a little more robust
Because rfi_flush_fallback runs immediately before the return to
userspace it currently runs with the user r1 (stack pointer). This
means if we oops in there we will report a bad kernel stack pointer in
the exception entry path, eg:
Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4
Oops: Bad kernel stack pointer, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7
NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80
GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020
...
NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80
LR [0000000010053e00] 0x10053e00
Although the NIP tells us where we were, and the TRAP number tells us
what happened, it would still be nicer if we could report the actual
exception rather than barfing about the stack pointer.
We an do that fairly simply by loading the kernel stack pointer on
entry and restoring the user value before returning. That way we see a
regular oops such as:
Unrecoverable exception 4100 at c00000000000239c
Oops: Unrecoverable exception, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40
NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: 0
...
NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80
LR [0000000010053e00] 0x10053e00
Call Trace:
[c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable)
Note this shouldn't make the kernel stack pointer vulnerable to a
meltdown attack, because it should be flushed from the cache before we
return to userspace. The user r1 value will be in the cache, because
we load it in the return path, but that is harmless.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-07-26 20:42:44 +08:00
|
|
|
std r1,PACA_EXRFI+EX_R12(r13)
|
|
|
|
ld r1,PACAKSAVE(r13)
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
std r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
std r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
std r11,PACA_EXRFI+EX_R11(r13)
|
|
|
|
mfctr r9
|
2020-11-17 13:59:13 +08:00
|
|
|
L1D_DISPLACEMENT_FLUSH
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
mtctr r9
|
|
|
|
ld r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXRFI+EX_R11(r13)
|
powerpc/64s: Make rfi_flush_fallback a little more robust
Because rfi_flush_fallback runs immediately before the return to
userspace it currently runs with the user r1 (stack pointer). This
means if we oops in there we will report a bad kernel stack pointer in
the exception entry path, eg:
Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4
Oops: Bad kernel stack pointer, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7
NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80
GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020
...
NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80
LR [0000000010053e00] 0x10053e00
Although the NIP tells us where we were, and the TRAP number tells us
what happened, it would still be nicer if we could report the actual
exception rather than barfing about the stack pointer.
We an do that fairly simply by loading the kernel stack pointer on
entry and restoring the user value before returning. That way we see a
regular oops such as:
Unrecoverable exception 4100 at c00000000000239c
Oops: Unrecoverable exception, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40
NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: 0
...
NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80
LR [0000000010053e00] 0x10053e00
Call Trace:
[c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable)
Note this shouldn't make the kernel stack pointer vulnerable to a
meltdown attack, because it should be flushed from the cache before we
return to userspace. The user r1 value will be in the cache, because
we load it in the return path, but that is harmless.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-07-26 20:42:44 +08:00
|
|
|
ld r1,PACA_EXRFI+EX_R12(r13)
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
GET_SCRATCH0(r13);
|
|
|
|
rfid
|
|
|
|
|
|
|
|
TRAMP_REAL_BEGIN(hrfi_flush_fallback)
|
|
|
|
SET_SCRATCH0(r13);
|
|
|
|
GET_PACA(r13);
|
powerpc/64s: Make rfi_flush_fallback a little more robust
Because rfi_flush_fallback runs immediately before the return to
userspace it currently runs with the user r1 (stack pointer). This
means if we oops in there we will report a bad kernel stack pointer in
the exception entry path, eg:
Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4
Oops: Bad kernel stack pointer, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7
NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80
GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020
...
NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80
LR [0000000010053e00] 0x10053e00
Although the NIP tells us where we were, and the TRAP number tells us
what happened, it would still be nicer if we could report the actual
exception rather than barfing about the stack pointer.
We an do that fairly simply by loading the kernel stack pointer on
entry and restoring the user value before returning. That way we see a
regular oops such as:
Unrecoverable exception 4100 at c00000000000239c
Oops: Unrecoverable exception, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40
NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: 0
...
NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80
LR [0000000010053e00] 0x10053e00
Call Trace:
[c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable)
Note this shouldn't make the kernel stack pointer vulnerable to a
meltdown attack, because it should be flushed from the cache before we
return to userspace. The user r1 value will be in the cache, because
we load it in the return path, but that is harmless.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-07-26 20:42:44 +08:00
|
|
|
std r1,PACA_EXRFI+EX_R12(r13)
|
|
|
|
ld r1,PACAKSAVE(r13)
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
std r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
std r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
std r11,PACA_EXRFI+EX_R11(r13)
|
|
|
|
mfctr r9
|
2020-11-17 13:59:13 +08:00
|
|
|
L1D_DISPLACEMENT_FLUSH
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
mtctr r9
|
|
|
|
ld r9,PACA_EXRFI+EX_R9(r13)
|
|
|
|
ld r10,PACA_EXRFI+EX_R10(r13)
|
|
|
|
ld r11,PACA_EXRFI+EX_R11(r13)
|
powerpc/64s: Make rfi_flush_fallback a little more robust
Because rfi_flush_fallback runs immediately before the return to
userspace it currently runs with the user r1 (stack pointer). This
means if we oops in there we will report a bad kernel stack pointer in
the exception entry path, eg:
Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4
Oops: Bad kernel stack pointer, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7
NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80
GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020
...
NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80
LR [0000000010053e00] 0x10053e00
Although the NIP tells us where we were, and the TRAP number tells us
what happened, it would still be nicer if we could report the actual
exception rather than barfing about the stack pointer.
We an do that fairly simply by loading the kernel stack pointer on
entry and restoring the user value before returning. That way we see a
regular oops such as:
Unrecoverable exception 4100 at c00000000000239c
Oops: Unrecoverable exception, sig: 6 [#1]
LE SMP NR_CPUS=32 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40
NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040
REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty)
MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000
CFAR: c00000000000bac8 IRQMASK: 0
...
NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80
LR [0000000010053e00] 0x10053e00
Call Trace:
[c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable)
Note this shouldn't make the kernel stack pointer vulnerable to a
meltdown attack, because it should be flushed from the cache before we
return to userspace. The user r1 value will be in the cache, because
we load it in the return path, but that is harmless.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-07-26 20:42:44 +08:00
|
|
|
ld r1,PACA_EXRFI+EX_R12(r13)
|
powerpc/64s: Add support for RFI flush of L1-D cache
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10 00:07:15 +08:00
|
|
|
GET_SCRATCH0(r13);
|
|
|
|
hrfid
|
|
|
|
|
2020-06-11 16:12:03 +08:00
|
|
|
TRAMP_REAL_BEGIN(rfscv_flush_fallback)
|
|
|
|
/* system call volatile */
|
|
|
|
mr r7,r13
|
|
|
|
GET_PACA(r13);
|
|
|
|
mr r8,r1
|
|
|
|
ld r1,PACAKSAVE(r13)
|
|
|
|
mfctr r9
|
|
|
|
ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
|
|
|
|
ld r11,PACA_L1D_FLUSH_SIZE(r13)
|
|
|
|
srdi r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
|
|
|
|
mtctr r11
|
|
|
|
DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
|
|
|
|
|
|
|
|
/* order ld/st prior to dcbt stop all streams with flushing */
|
|
|
|
sync
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The load adresses are at staggered offsets within cachelines,
|
|
|
|
* which suits some pipelines better (on others it should not
|
|
|
|
* hurt).
|
|
|
|
*/
|
|
|
|
1:
|
|
|
|
ld r11,(0x80 + 8)*0(r10)
|
|
|
|
ld r11,(0x80 + 8)*1(r10)
|
|
|
|
ld r11,(0x80 + 8)*2(r10)
|
|
|
|
ld r11,(0x80 + 8)*3(r10)
|
|
|
|
ld r11,(0x80 + 8)*4(r10)
|
|
|
|
ld r11,(0x80 + 8)*5(r10)
|
|
|
|
ld r11,(0x80 + 8)*6(r10)
|
|
|
|
ld r11,(0x80 + 8)*7(r10)
|
|
|
|
addi r10,r10,0x80*8
|
|
|
|
bdnz 1b
|
|
|
|
|
|
|
|
mtctr r9
|
|
|
|
li r9,0
|
|
|
|
li r10,0
|
|
|
|
li r11,0
|
|
|
|
mr r1,r8
|
|
|
|
mr r13,r7
|
|
|
|
RFSCV
|
|
|
|
|
2020-02-26 01:35:20 +08:00
|
|
|
USE_TEXT_SECTION()
|
2020-11-17 13:59:13 +08:00
|
|
|
|
|
|
|
_GLOBAL(do_uaccess_flush)
|
|
|
|
UACCESS_FLUSH_FIXUP_SECTION
|
|
|
|
nop
|
|
|
|
nop
|
|
|
|
nop
|
|
|
|
blr
|
|
|
|
L1D_DISPLACEMENT_FLUSH
|
|
|
|
blr
|
|
|
|
_ASM_NOKPROBE_SYMBOL(do_uaccess_flush)
|
|
|
|
EXPORT_SYMBOL(do_uaccess_flush)
|
|
|
|
|
|
|
|
|
|
|
|
MASKED_INTERRUPT
|
|
|
|
MASKED_INTERRUPT hsrr=1
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2013-09-20 12:52:50 +08:00
|
|
|
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
|
2020-02-26 01:35:21 +08:00
|
|
|
kvmppc_skip_interrupt:
|
2013-09-20 12:52:50 +08:00
|
|
|
/*
|
|
|
|
* Here all GPRs are unchanged from when the interrupt happened
|
|
|
|
* except for r13, which is saved in SPRG_SCRATCH0.
|
|
|
|
*/
|
|
|
|
mfspr r13, SPRN_SRR0
|
|
|
|
addi r13, r13, 4
|
|
|
|
mtspr SPRN_SRR0, r13
|
|
|
|
GET_SCRATCH0(r13)
|
2018-01-10 00:07:15 +08:00
|
|
|
RFI_TO_KERNEL
|
2013-09-20 12:52:50 +08:00
|
|
|
b .
|
|
|
|
|
2020-02-26 01:35:21 +08:00
|
|
|
kvmppc_skip_Hinterrupt:
|
2013-09-20 12:52:50 +08:00
|
|
|
/*
|
|
|
|
* Here all GPRs are unchanged from when the interrupt happened
|
|
|
|
* except for r13, which is saved in SPRG_SCRATCH0.
|
|
|
|
*/
|
|
|
|
mfspr r13, SPRN_HSRR0
|
|
|
|
addi r13, r13, 4
|
|
|
|
mtspr SPRN_HSRR0, r13
|
|
|
|
GET_SCRATCH0(r13)
|
2018-01-10 00:07:15 +08:00
|
|
|
HRFI_TO_KERNEL
|
2013-09-20 12:52:50 +08:00
|
|
|
b .
|
|
|
|
#endif
|
|
|
|
|
2012-11-02 14:21:43 +08:00
|
|
|
/*
|
|
|
|
* Relocation-on interrupts: A subset of the interrupts can be delivered
|
|
|
|
* with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
|
|
|
|
* it. Addresses are the same as the original interrupt addresses, but
|
|
|
|
* offset by 0xc000000000004000.
|
|
|
|
* It's impossible to receive interrupts below 0x300 via this mechanism.
|
|
|
|
* KVM: None of these traps are from the guest ; anything that escalated
|
|
|
|
* to HV=1 from HV=0 is delivered via real mode handlers.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* This uses the standard macro, since the original 0x300 vector
|
|
|
|
* only has extra guff for STAB-based processors -- which never
|
|
|
|
* come here.
|
|
|
|
*/
|
2016-09-30 17:43:18 +08:00
|
|
|
|
2016-09-28 09:31:48 +08:00
|
|
|
EXC_COMMON_BEGIN(ppc64_runlatch_on_trampoline)
|
2014-02-04 13:04:35 +08:00
|
|
|
b __ppc64_runlatch_on
|
2012-03-01 09:45:27 +08:00
|
|
|
|
2016-09-28 09:31:48 +08:00
|
|
|
USE_FIXED_SECTION(virt_trampolines)
|
powerpc/book3s64: Fix branching to OOL handlers in relocatable kernel
Some of the interrupt vectors on 64-bit POWER server processors are only
32 bytes long (8 instructions), which is not enough for the full
first-level interrupt handler. For these we need to branch to an
out-of-line (OOL) handler. But when we are running a relocatable kernel,
interrupt vectors till __end_interrupts marker are copied down to real
address 0x100. So, branching to labels (ie. OOL handlers) outside this
section must be handled differently (see LOAD_HANDLER()), considering
relocatable kernel, which would need at least 4 instructions.
However, branching from interrupt vector means that we corrupt the
CFAR (come-from address register) on POWER7 and later processors as
mentioned in commit 1707dd16. So, EXCEPTION_PROLOG_0 (6 instructions)
that contains the part up to the point where the CFAR is saved in the
PACA should be part of the short interrupt vectors before we branch out
to OOL handlers.
But as mentioned already, there are interrupt vectors on 64-bit POWER
server processors that are only 32 bytes long (like vectors 0x4f00,
0x4f20, etc.), which cannot accomodate the above two cases at the same
time owing to space constraint. Currently, in these interrupt vectors,
we simply branch out to OOL handlers, without using LOAD_HANDLER(),
which leaves us vulnerable when running a relocatable kernel (eg. kdump
case). While this has been the case for sometime now and kdump is used
widely, we were fortunate not to see any problems so far, for three
reasons:
1. In almost all cases, production kernel (relocatable) is used for
kdump as well, which would mean that crashed kernel's OOL handler
would be at the same place where we end up branching to, from short
interrupt vector of kdump kernel.
2. Also, OOL handler was unlikely the reason for crash in almost all
the kdump scenarios, which meant we had a sane OOL handler from
crashed kernel that we branched to.
3. On most 64-bit POWER server processors, page size is large enough
that marking interrupt vector code as executable (see commit
429d2e83) leads to marking OOL handler code from crashed kernel,
that sits right below interrupt vector code from kdump kernel, as
executable as well.
Let us fix this by moving the __end_interrupts marker down past OOL
handlers to make sure that we also copy OOL handlers to real address
0x100 when running a relocatable kernel.
This fix has been tested successfully in kdump scenario, on an LPAR with
4K page size by using different default/production kernel and kdump
kernel.
Also tested by manually corrupting the OOL handlers in the first kernel
and then kdump'ing, and then causing the OOL handlers to fire - mpe.
Fixes: c1fb6816fb1b ("powerpc: Add relocation on exception vector handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-15 20:48:02 +08:00
|
|
|
/*
|
2020-06-11 16:12:02 +08:00
|
|
|
* All code below __end_interrupts is treated as soft-masked. If
|
|
|
|
* any code runs here with MSR[EE]=1, it must then cope with pending
|
|
|
|
* soft interrupt being raised (i.e., by ensuring it is replayed).
|
|
|
|
*
|
powerpc/book3s64: Fix branching to OOL handlers in relocatable kernel
Some of the interrupt vectors on 64-bit POWER server processors are only
32 bytes long (8 instructions), which is not enough for the full
first-level interrupt handler. For these we need to branch to an
out-of-line (OOL) handler. But when we are running a relocatable kernel,
interrupt vectors till __end_interrupts marker are copied down to real
address 0x100. So, branching to labels (ie. OOL handlers) outside this
section must be handled differently (see LOAD_HANDLER()), considering
relocatable kernel, which would need at least 4 instructions.
However, branching from interrupt vector means that we corrupt the
CFAR (come-from address register) on POWER7 and later processors as
mentioned in commit 1707dd16. So, EXCEPTION_PROLOG_0 (6 instructions)
that contains the part up to the point where the CFAR is saved in the
PACA should be part of the short interrupt vectors before we branch out
to OOL handlers.
But as mentioned already, there are interrupt vectors on 64-bit POWER
server processors that are only 32 bytes long (like vectors 0x4f00,
0x4f20, etc.), which cannot accomodate the above two cases at the same
time owing to space constraint. Currently, in these interrupt vectors,
we simply branch out to OOL handlers, without using LOAD_HANDLER(),
which leaves us vulnerable when running a relocatable kernel (eg. kdump
case). While this has been the case for sometime now and kdump is used
widely, we were fortunate not to see any problems so far, for three
reasons:
1. In almost all cases, production kernel (relocatable) is used for
kdump as well, which would mean that crashed kernel's OOL handler
would be at the same place where we end up branching to, from short
interrupt vector of kdump kernel.
2. Also, OOL handler was unlikely the reason for crash in almost all
the kdump scenarios, which meant we had a sane OOL handler from
crashed kernel that we branched to.
3. On most 64-bit POWER server processors, page size is large enough
that marking interrupt vector code as executable (see commit
429d2e83) leads to marking OOL handler code from crashed kernel,
that sits right below interrupt vector code from kdump kernel, as
executable as well.
Let us fix this by moving the __end_interrupts marker down past OOL
handlers to make sure that we also copy OOL handlers to real address
0x100 when running a relocatable kernel.
This fix has been tested successfully in kdump scenario, on an LPAR with
4K page size by using different default/production kernel and kdump
kernel.
Also tested by manually corrupting the OOL handlers in the first kernel
and then kdump'ing, and then causing the OOL handlers to fire - mpe.
Fixes: c1fb6816fb1b ("powerpc: Add relocation on exception vector handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-15 20:48:02 +08:00
|
|
|
* The __end_interrupts marker must be past the out-of-line (OOL)
|
|
|
|
* handlers, so that they are copied to real address 0x100 when running
|
|
|
|
* a relocatable kernel. This ensures they can be reached from the short
|
|
|
|
* trampoline handlers (like 0x4f00, 0x4f20, etc.) which branch
|
|
|
|
* directly, without using LOAD_HANDLER().
|
|
|
|
*/
|
|
|
|
.align 7
|
|
|
|
.globl __end_interrupts
|
|
|
|
__end_interrupts:
|
2016-09-28 09:31:48 +08:00
|
|
|
DEFINE_FIXED_SYMBOL(__end_interrupts)
|
2013-01-10 14:44:19 +08:00
|
|
|
|
2013-03-25 09:31:31 +08:00
|
|
|
#ifdef CONFIG_PPC_970_NAP
|
2019-07-11 10:24:03 +08:00
|
|
|
/*
|
|
|
|
* Called by exception entry code if _TLF_NAPPING was set, this clears
|
|
|
|
* the NAPPING flag, and redirects the exception exit to
|
|
|
|
* power4_fixup_nap_return.
|
|
|
|
*/
|
|
|
|
.globl power4_fixup_nap
|
2016-10-11 15:47:56 +08:00
|
|
|
EXC_COMMON_BEGIN(power4_fixup_nap)
|
2013-03-25 09:31:31 +08:00
|
|
|
andc r9,r9,r10
|
|
|
|
std r9,TI_LOCAL_FLAGS(r11)
|
2019-07-11 10:24:03 +08:00
|
|
|
LOAD_REG_ADDR(r10, power4_idle_nap_return)
|
|
|
|
std r10,_NIP(r1)
|
|
|
|
blr
|
|
|
|
|
|
|
|
power4_idle_nap_return:
|
2013-03-25 09:31:31 +08:00
|
|
|
blr
|
|
|
|
#endif
|
|
|
|
|
2016-09-28 09:31:48 +08:00
|
|
|
CLOSE_FIXED_SECTION(real_vectors);
|
|
|
|
CLOSE_FIXED_SECTION(real_trampolines);
|
|
|
|
CLOSE_FIXED_SECTION(virt_vectors);
|
|
|
|
CLOSE_FIXED_SECTION(virt_trampolines);
|
|
|
|
|
|
|
|
USE_TEXT_SECTION()
|
|
|
|
|
2019-08-02 18:56:38 +08:00
|
|
|
/* MSR[RI] should be clear because this uses SRR[01] */
|
|
|
|
enable_machine_check:
|
|
|
|
mflr r0
|
|
|
|
bcl 20,31,$+4
|
|
|
|
0: mflr r3
|
|
|
|
addi r3,r3,(1f - 0b)
|
|
|
|
mtspr SPRN_SRR0,r3
|
|
|
|
mfmsr r3
|
|
|
|
ori r3,r3,MSR_ME
|
|
|
|
mtspr SPRN_SRR1,r3
|
|
|
|
RFI_TO_KERNEL
|
|
|
|
1: mtlr r0
|
|
|
|
blr
|
|
|
|
|
2019-08-02 18:56:39 +08:00
|
|
|
/* MSR[RI] should be clear because this uses SRR[01] */
|
|
|
|
disable_machine_check:
|
|
|
|
mflr r0
|
|
|
|
bcl 20,31,$+4
|
|
|
|
0: mflr r3
|
|
|
|
addi r3,r3,(1f - 0b)
|
|
|
|
mtspr SPRN_SRR0,r3
|
|
|
|
mfmsr r3
|
|
|
|
li r4,MSR_ME
|
|
|
|
andc r3,r3,r4
|
|
|
|
mtspr SPRN_SRR1,r3
|
|
|
|
RFI_TO_KERNEL
|
|
|
|
1: mtlr r0
|
|
|
|
blr
|
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
/*
|
|
|
|
* Hash table stuff
|
|
|
|
*/
|
2016-10-13 11:43:52 +08:00
|
|
|
.balign IFETCH_ALIGN_BYTES
|
2014-02-04 13:06:11 +08:00
|
|
|
do_hash_page:
|
2017-10-19 12:08:43 +08:00
|
|
|
#ifdef CONFIG_PPC_BOOK3S_64
|
2018-01-19 09:50:40 +08:00
|
|
|
lis r0,(DSISR_BAD_FAULT_64S | DSISR_DABRMATCH | DSISR_KEYFAULT)@h
|
2017-07-19 12:49:27 +08:00
|
|
|
ori r0,r0,DSISR_BAD_FAULT_64S@l
|
2019-08-02 18:57:01 +08:00
|
|
|
and. r0,r5,r0 /* weird error? */
|
2009-06-03 05:17:38 +08:00
|
|
|
bne- handle_page_fault /* if not, try to insert a HPTE */
|
2020-07-27 14:09:47 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If we are in an "NMI" (e.g., an interrupt when soft-disabled), then
|
|
|
|
* don't call hash_page, just fail the fault. This is required to
|
|
|
|
* prevent re-entrancy problems in the hash code, namely perf
|
|
|
|
* interrupts hitting while something holds H_PAGE_BUSY, and taking a
|
|
|
|
* hash fault. See the comment in hash_preload().
|
|
|
|
*/
|
2019-01-12 17:55:50 +08:00
|
|
|
ld r11, PACA_THREAD_INFO(r13)
|
2020-07-27 14:09:47 +08:00
|
|
|
lwz r0,TI_PREEMPT(r11)
|
|
|
|
andis. r0,r0,NMI_MASK@h
|
|
|
|
bne 77f
|
2009-06-03 05:17:38 +08:00
|
|
|
|
|
|
|
/*
|
2019-08-02 18:57:01 +08:00
|
|
|
* r3 contains the trap number
|
|
|
|
* r4 contains the faulting address
|
|
|
|
* r5 contains dsisr
|
|
|
|
* r6 msr
|
2009-06-03 05:17:38 +08:00
|
|
|
*
|
powerpc: Rework lazy-interrupt handling
The current implementation of lazy interrupts handling has some
issues that this tries to address.
We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.
The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.
Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.
This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.
The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.
When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.
We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).
This removes the need to play with the decrementer to try to create
fake interrupts, among others.
In addition, this adds a few refinements:
- We no longer hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.
- Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.
- On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)
- We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.
Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2:
- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
to retrigger an interrupt without preventing hard-enable
v3:
- Fix or vs. ori bug on Book3E
- Fix enabling of interrupts for some exceptions on Book3E
v4:
- Fix resend of doorbells on return from interrupt on Book3E
v5:
- Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.
v6:
- 32-bit compile fix
- more compile fixes with various .config combos
- factor out the asm code to soft-disable interrupts
- remove the C wrapper around preempt_schedule_irq
v7:
- Fix a bug with hard irq state tracking on native power7
2012-03-06 15:27:59 +08:00
|
|
|
* at return r3 = 0 for success, 1 for page fault, negative for error
|
2009-06-03 05:17:38 +08:00
|
|
|
*/
|
2015-12-01 11:36:44 +08:00
|
|
|
bl __hash_page /* build HPTE if possible */
|
|
|
|
cmpdi r3,0 /* see if __hash_page succeeded */
|
2009-06-03 05:17:38 +08:00
|
|
|
|
powerpc: Rework lazy-interrupt handling
The current implementation of lazy interrupts handling has some
issues that this tries to address.
We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.
The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.
Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.
This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.
The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.
When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.
We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).
This removes the need to play with the decrementer to try to create
fake interrupts, among others.
In addition, this adds a few refinements:
- We no longer hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.
- Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.
- On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)
- We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.
Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2:
- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
to retrigger an interrupt without preventing hard-enable
v3:
- Fix or vs. ori bug on Book3E
- Fix enabling of interrupts for some exceptions on Book3E
v4:
- Fix resend of doorbells on return from interrupt on Book3E
v5:
- Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.
v6:
- 32-bit compile fix
- more compile fixes with various .config combos
- factor out the asm code to soft-disable interrupts
- remove the C wrapper around preempt_schedule_irq
v7:
- Fix a bug with hard irq state tracking on native power7
2012-03-06 15:27:59 +08:00
|
|
|
/* Success */
|
2020-02-26 01:35:38 +08:00
|
|
|
beq interrupt_return /* Return from exception on success */
|
2009-06-03 05:17:38 +08:00
|
|
|
|
powerpc: Rework lazy-interrupt handling
The current implementation of lazy interrupts handling has some
issues that this tries to address.
We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.
The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.
Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.
This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.
The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.
When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.
We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).
This removes the need to play with the decrementer to try to create
fake interrupts, among others.
In addition, this adds a few refinements:
- We no longer hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.
- Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.
- On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)
- We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.
Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2:
- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
to retrigger an interrupt without preventing hard-enable
v3:
- Fix or vs. ori bug on Book3E
- Fix enabling of interrupts for some exceptions on Book3E
v4:
- Fix resend of doorbells on return from interrupt on Book3E
v5:
- Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.
v6:
- 32-bit compile fix
- more compile fixes with various .config combos
- factor out the asm code to soft-disable interrupts
- remove the C wrapper around preempt_schedule_irq
v7:
- Fix a bug with hard irq state tracking on native power7
2012-03-06 15:27:59 +08:00
|
|
|
/* Error */
|
|
|
|
blt- 13f
|
2017-06-14 02:42:00 +08:00
|
|
|
|
2019-08-02 18:57:01 +08:00
|
|
|
/* Reload DAR/DSISR into r4/r5 for the DABR check below */
|
|
|
|
ld r4,_DAR(r1)
|
|
|
|
ld r5,_DSISR(r1)
|
2017-10-19 12:08:43 +08:00
|
|
|
#endif /* CONFIG_PPC_BOOK3S_64 */
|
2010-03-30 07:59:25 +08:00
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
/* Here we have a page fault that hash_page can't handle. */
|
|
|
|
handle_page_fault:
|
2019-08-02 18:57:01 +08:00
|
|
|
11: andis. r0,r5,DSISR_DABRMATCH@h
|
2017-06-14 02:42:00 +08:00
|
|
|
bne- handle_dabr_fault
|
2009-06-03 05:17:38 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2014-02-04 13:04:35 +08:00
|
|
|
bl do_page_fault
|
2009-06-03 05:17:38 +08:00
|
|
|
cmpdi r3,0
|
2020-02-26 01:35:38 +08:00
|
|
|
beq+ interrupt_return
|
2009-06-03 05:17:38 +08:00
|
|
|
mr r5,r3
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2019-08-02 18:56:42 +08:00
|
|
|
ld r4,_DAR(r1)
|
2014-02-04 13:04:35 +08:00
|
|
|
bl bad_page_fault
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2012-03-07 13:48:45 +08:00
|
|
|
/* We have a data breakpoint exception - handle it */
|
|
|
|
handle_dabr_fault:
|
|
|
|
ld r4,_DAR(r1)
|
|
|
|
ld r5,_DSISR(r1)
|
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
2014-02-04 13:04:35 +08:00
|
|
|
bl do_break
|
powerpc/watchpoint: Restore NV GPRs while returning from exception
powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:
# cat /proc/kallsyms | grep kthread_create_list
c00000000121c8b8 d kthread_create_list
Add watchpoint on kthread_create_list->prev:
# perf record -e mem:0xc00000000121c8c0
Run some workload such that new kthread gets invoked. eg, I just
logged out from console:
list_add corruption. next->prev should be prev (c000000001214e00), \
but was c00000000121c8b8. (next=c00000000121c8b8).
WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
...
NIP __list_add_valid+0xb4/0xc0
LR __list_add_valid+0xb0/0xc0
Call Trace:
__list_add_valid+0xb0/0xc0 (unreliable)
__kthread_create_on_node+0xe0/0x260
kthread_create_on_node+0x34/0x50
create_worker+0xe8/0x260
worker_thread+0x444/0x560
kthread+0x160/0x1a0
ret_from_kernel_thread+0x5c/0x70
List corruption happened because it uses 'load into non-volatile
register' instruction:
Snippet from __kthread_create_on_node:
c000000000136be8: addis r29,r2,-19
c000000000136bec: ld r29,31424(r29)
if (!__list_add_valid(new, prev, next))
c000000000136bf0: mr r3,r30
c000000000136bf4: mr r5,r28
c000000000136bf8: mr r4,r29
c000000000136bfc: bl c00000000059a2f8 <__list_add_valid+0x8>
Register state from WARN_ON():
GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0
Watchpoint hit at 0xc000000000136bec.
addis r29,r2,-19
=> r29 = 0xc000000001344e00 + (-19 << 16)
=> r29 = 0xc000000001214e00
ld r29,31424(r29)
=> r29 = *(0xc000000001214e00 + 31424)
=> r29 = *(0xc00000000121c8c0)
0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.
Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-13 11:30:14 +08:00
|
|
|
/*
|
|
|
|
* do_break() may have changed the NV GPRS while handling a breakpoint.
|
2020-02-26 01:35:38 +08:00
|
|
|
* If so, we need to restore them with their updated values.
|
powerpc/watchpoint: Restore NV GPRs while returning from exception
powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:
# cat /proc/kallsyms | grep kthread_create_list
c00000000121c8b8 d kthread_create_list
Add watchpoint on kthread_create_list->prev:
# perf record -e mem:0xc00000000121c8c0
Run some workload such that new kthread gets invoked. eg, I just
logged out from console:
list_add corruption. next->prev should be prev (c000000001214e00), \
but was c00000000121c8b8. (next=c00000000121c8b8).
WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
...
NIP __list_add_valid+0xb4/0xc0
LR __list_add_valid+0xb0/0xc0
Call Trace:
__list_add_valid+0xb0/0xc0 (unreliable)
__kthread_create_on_node+0xe0/0x260
kthread_create_on_node+0x34/0x50
create_worker+0xe8/0x260
worker_thread+0x444/0x560
kthread+0x160/0x1a0
ret_from_kernel_thread+0x5c/0x70
List corruption happened because it uses 'load into non-volatile
register' instruction:
Snippet from __kthread_create_on_node:
c000000000136be8: addis r29,r2,-19
c000000000136bec: ld r29,31424(r29)
if (!__list_add_valid(new, prev, next))
c000000000136bf0: mr r3,r30
c000000000136bf4: mr r5,r28
c000000000136bf8: mr r4,r29
c000000000136bfc: bl c00000000059a2f8 <__list_add_valid+0x8>
Register state from WARN_ON():
GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0
Watchpoint hit at 0xc000000000136bec.
addis r29,r2,-19
=> r29 = 0xc000000001344e00 + (-19 << 16)
=> r29 = 0xc000000001214e00
ld r29,31424(r29)
=> r29 = *(0xc000000001214e00 + 31424)
=> r29 = *(0xc00000000121c8c0)
0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.
Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-13 11:30:14 +08:00
|
|
|
*/
|
2020-02-26 01:35:38 +08:00
|
|
|
REST_NVGPRS(r1)
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2012-03-07 13:48:45 +08:00
|
|
|
|
2009-06-03 05:17:38 +08:00
|
|
|
|
2017-10-19 12:08:43 +08:00
|
|
|
#ifdef CONFIG_PPC_BOOK3S_64
|
2009-06-03 05:17:38 +08:00
|
|
|
/* We have a page fault that hash_page could handle but HV refused
|
|
|
|
* the PTE insertion
|
|
|
|
*/
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
13: mr r5,r3
|
2009-06-03 05:17:38 +08:00
|
|
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
|
|
|
ld r4,_DAR(r1)
|
2014-02-04 13:04:35 +08:00
|
|
|
bl low_hash_fault
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|
2016-04-29 21:26:07 +08:00
|
|
|
#endif
|
2009-06-03 05:17:38 +08:00
|
|
|
|
powerpc: Allow perf_counters to access user memory at interrupt time
This provides a mechanism to allow the perf_counters code to access
user memory in a PMU interrupt routine. Such an access can cause
various kinds of interrupt: SLB miss, MMU hash table miss, segment
table miss, or TLB miss, depending on the processor. This commit
only deals with 64-bit classic/server processors, which use an MMU
hash table. 32-bit processors are already able to access user memory
at interrupt time. Since we don't soft-disable on 32-bit, we avoid
the possibility of reentering hash_page or the TLB miss handlers,
since they run with interrupts disabled.
On 64-bit processors, an SLB miss interrupt on a user address will
update the slb_cache and slb_cache_ptr fields in the paca. This is
OK except in the case where a PMU interrupt occurs in switch_slb,
which also accesses those fields. To prevent this, we hard-disable
interrupts in switch_slb. Interrupts are already soft-disabled at
this point, and will get hard-enabled when they get soft-enabled
later.
This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice,
and to make sure that it clears the slb_cache_ptr when called from
other callers than switch_slb, the existing routine is renamed to
__slb_flush_and_rebolt, which is called by switch_slb and the new
version of slb_flush_and_rebolt.
Similarly, switch_stab (used on POWER3 and RS64 processors) gets a
hard_irq_disable() to protect the per-cpu variables used there and
in ste_allocate.
If a MMU hashtable miss interrupt occurs, normally we would call
hash_page to look up the Linux PTE for the address and create a HPTE.
However, hash_page is fairly complex and takes some locks, so to
avoid the possibility of deadlock, we check the preemption count
to see if we are in a (pseudo-)NMI handler, and if so, we don't call
hash_page but instead treat it like a bad access that will get
reported up through the exception table mechanism. An interrupt
whose handler runs even though the interrupt occurred when
soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI
handler, which should use nmi_enter()/nmi_exit() rather than
irq_enter()/irq_exit().
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-08-17 13:17:54 +08:00
|
|
|
/*
|
|
|
|
* We come here as a result of a DSI at a point where we don't want
|
|
|
|
* to call hash_page, such as when we are accessing memory (possibly
|
|
|
|
* user memory) inside a PMU interrupt that occurred while interrupts
|
|
|
|
* were soft-disabled. We want to invoke the exception handler for
|
|
|
|
* the access, or panic if there isn't a handler.
|
|
|
|
*/
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
77: addi r3,r1,STACK_FRAME_OVERHEAD
|
powerpc: Allow perf_counters to access user memory at interrupt time
This provides a mechanism to allow the perf_counters code to access
user memory in a PMU interrupt routine. Such an access can cause
various kinds of interrupt: SLB miss, MMU hash table miss, segment
table miss, or TLB miss, depending on the processor. This commit
only deals with 64-bit classic/server processors, which use an MMU
hash table. 32-bit processors are already able to access user memory
at interrupt time. Since we don't soft-disable on 32-bit, we avoid
the possibility of reentering hash_page or the TLB miss handlers,
since they run with interrupts disabled.
On 64-bit processors, an SLB miss interrupt on a user address will
update the slb_cache and slb_cache_ptr fields in the paca. This is
OK except in the case where a PMU interrupt occurs in switch_slb,
which also accesses those fields. To prevent this, we hard-disable
interrupts in switch_slb. Interrupts are already soft-disabled at
this point, and will get hard-enabled when they get soft-enabled
later.
This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice,
and to make sure that it clears the slb_cache_ptr when called from
other callers than switch_slb, the existing routine is renamed to
__slb_flush_and_rebolt, which is called by switch_slb and the new
version of slb_flush_and_rebolt.
Similarly, switch_stab (used on POWER3 and RS64 processors) gets a
hard_irq_disable() to protect the per-cpu variables used there and
in ste_allocate.
If a MMU hashtable miss interrupt occurs, normally we would call
hash_page to look up the Linux PTE for the address and create a HPTE.
However, hash_page is fairly complex and takes some locks, so to
avoid the possibility of deadlock, we check the preemption count
to see if we are in a (pseudo-)NMI handler, and if so, we don't call
hash_page but instead treat it like a bad access that will get
reported up through the exception table mechanism. An interrupt
whose handler runs even though the interrupt occurred when
soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI
handler, which should use nmi_enter()/nmi_exit() rather than
irq_enter()/irq_exit().
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-08-17 13:17:54 +08:00
|
|
|
li r5,SIGSEGV
|
2014-02-04 13:04:35 +08:00
|
|
|
bl bad_page_fault
|
powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-02-26 01:35:37 +08:00
|
|
|
b interrupt_return
|