Mark intentional fall throughs in switch statements with a consistent
comment.
In most of the cases, a new comment line containing text "fall through"
is inserted. In some of the cases, existing comment contained a variation
of the text "fall through" (for example, "FALL THROUGH" or "drop through").
In such cases, the existing comment is modified to contain "fall through".
Lastly, in two cases, code segments were described in comments as "fall
througs", but were in reality "breaks out" of switch statement. In such
cases, existing comments are accordingly modified.
Apart from making code easier to follow and debug, this change enables
some static code analysers to interpret newly inserted comments as their
annotations (and, therefore, not issue warnings of type "fall through in
switch statement", which is desireable, since marked fallthroughs are
intentional).
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17588/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Replace several instances of multiple assignment with individual
assignments.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17587/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move invocation of fpu_emu() to be out of if statement condition.
This makes code easier to follow and debug, and fixes a checkpatch
warning.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17586/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Declare function srl128() as static, since it it used just locally
to the source file.
This also removes a sparse warning for corresponding file.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17585/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
These are the main MIPS changes for 4.15.
Fixes:
- ralink: Fix MT7620 PCI build issues (4.5)
- Disable cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN for 32-bit SMP
(4.1)
- Fix MIPS64 FP save/restore on 32-bit kernels (4.0)
- ptrace: Pick up ptrace/seccomp changed syscall numbers (3.19)
- ralink: Fix MT7628 pinmux (3.19)
- BCM47XX: Fix LED inversion on WRT54GSv1 (3.17)
- Fix n32 core dumping as o32 since regset support (3.13)
- ralink: Drop obsolete USB_ARCH_HAS_HCD select
Build system:
- Default to "generic" (multiplatform) system type instead of IP22
- Use generic little endian MIPS32 r2 configuration as default defconfig
instead of ip22_defconfig
FPU emulation:
- Fix exception generation for certain R6 FPU instructions
SMP:
- Allow __cpu_number_map to be larger than NR_CPUS for sparse CPU id
spaces
Miscellaneous:
- Add iomem resource for kernel bss section for kexec/kdump
- Atomics: Nudge writes on bit unlock
- DT files: Standardise "ok" -> "okay"
Platform support:
BMIPS:
- Enable HARDIRQS_SW_RESEND
Broadcom BCM63XX:
- Add clkdev lookup support
- Update clk driver, UART driver, DTs to handle named refclk from DTs
- Split apart various clocks to more closely match hardware
- Add ethernet clocks
Cavium Octeon:
- Remove usage of cvmx_wait() in favour of __delay()
ImgTec Pistachio:
- DT: Drop deprecated dwmmc num-slots property
Ingenic JZ4780:
- Add NFS root to Ci20 defconfig
- Add watchdog to Ci20 DT & defconfig, and allow building of watchdog
driver with this SoC
Generic (multiplatform):
- Migrate xilfpga (MIPSfpga) platform to the generic platform
Lantiq xway:
- Fix ASC0/ASC1 clocks
Minor cleanups:
- Define virt_to_pfn()
- Make thread_saved_pc static
- Simplify 32-bit sign extension in __read_64bit_c0_split()
- DMA: Use vma_pages() helper
- FPU emulation: Replace unsigned with unsigned int
- MM: Removed unused lastpfn
- Alchemy: Make clk_ops const
- Lasat: Use setup_timer() helper
- ralink: Use BIT() in MT7620 PCI driver
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Merge tag 'mips_4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips
Pull MIPS updates from James Hogan:
"These are the main MIPS changes for 4.15.
Fixes:
- ralink: Fix MT7620 PCI build issues (4.5)
- Disable cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN for 32-bit SMP
(4.1)
- Fix MIPS64 FP save/restore on 32-bit kernels (4.0)
- ptrace: Pick up ptrace/seccomp changed syscall numbers (3.19)
- ralink: Fix MT7628 pinmux (3.19)
- BCM47XX: Fix LED inversion on WRT54GSv1 (3.17)
- Fix n32 core dumping as o32 since regset support (3.13)
- ralink: Drop obsolete USB_ARCH_HAS_HCD select
Build system:
- Default to "generic" (multiplatform) system type instead of IP22
- Use generic little endian MIPS32 r2 configuration as default
defconfig instead of ip22_defconfig
FPU emulation:
- Fix exception generation for certain R6 FPU instructions
SMP:
- Allow __cpu_number_map to be larger than NR_CPUS for sparse CPU id
spaces
Miscellaneous:
- Add iomem resource for kernel bss section for kexec/kdump
- Atomics: Nudge writes on bit unlock
- DT files: Standardise "ok" -> "okay"
Minor cleanups:
- Define virt_to_pfn()
- Make thread_saved_pc static
- Simplify 32-bit sign extension in __read_64bit_c0_split()
- DMA: Use vma_pages() helper
- FPU emulation: Replace unsigned with unsigned int
- MM: Removed unused lastpfn
- Alchemy: Make clk_ops const
- Lasat: Use setup_timer() helper
- ralink: Use BIT() in MT7620 PCI driver
Platform support:
BMIPS:
- Enable HARDIRQS_SW_RESEND
Broadcom BCM63XX:
- Add clkdev lookup support
- Update clk driver, UART driver, DTs to handle named refclk from DTs
- Split apart various clocks to more closely match hardware
- Add ethernet clocks
Cavium Octeon:
- Remove usage of cvmx_wait() in favour of __delay()
ImgTec Pistachio:
- DT: Drop deprecated dwmmc num-slots property
Ingenic JZ4780:
- Add NFS root to Ci20 defconfig
- Add watchdog to Ci20 DT & defconfig, and allow building of watchdog
driver with this SoC
Generic (multiplatform):
- Migrate xilfpga (MIPSfpga) platform to the generic platform
Lantiq xway:
- Fix ASC0/ASC1 clocks"
* tag 'mips_4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips: (46 commits)
MIPS: Add iomem resource for kernel bss section.
MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work for 32-bit SMP
MIPS: BMIPS: Enable HARDIRQS_SW_RESEND
MIPS: pci: Make use of the BIT() macro inside the mt7620 driver
MIPS: pci: Remove KERN_WARN instance inside the mt7620 driver
MIPS: pci: Remove duplicate define in mt7620 driver
MIPS: ralink: Fix typo in mt7628 pinmux function
MIPS: ralink: Fix MT7628 pinmux
MIPS: Fix odd fp register warnings with MIPS64r2
watchdog: jz4780: Allow selection of jz4740-wdt driver
MIPS/ptrace: Update syscall nr on register changes
MIPS/ptrace: Pick up ptrace/seccomp changed syscalls
MIPS: Fix an n32 core file generation regset support regression
MIPS: Fix MIPS64 FP save/restore on 32-bit kernels
MIPS: page.h: Define virt_to_pfn()
MIPS: Xilfpga: Switch to using generic defconfigs
MIPS: generic: Add support for MIPSfpga
MIPS: Set defconfig target to a generic system for 32r2el
MIPS: Kconfig: Set default MIPS system type as generic
MIPS: DTS: Remove num-slots from Pistachio SoC
...
Fix occurences of unsigned integer variable declarations that are
not preferred by standards of checkpatch scripts. This removes a
significant number of checkpatch warnings for files in math-emu
directory (several files become completely warning-free), and thus
makes easier to spot (now and in the future) other, perhaps more
significant, checkpatch errors and warnings.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17582/
Signed-off-by: James Hogan <jhogan@kernel.org>
Fix final phase of <CLASS|MADDF|MSUBF|MAX|MIN|MAXA|MINA>.<D|S>
emulation. Provide proper generation of SIGFPE signal and updating
debugfs FP exception stats in cases of any exception flags set in
preceding phases of emulation.
CLASS.<D|S> instruction may generate "Unimplemented Operation" FP
exception. <MADDF|MSUBF>.<D|S> instructions may generate "Inexact",
"Unimplemented Operation", "Invalid Operation", "Overflow", and
"Underflow" FP exceptions. <MAX|MIN|MAXA|MINA>.<D|S> instructions
can generate "Unimplemented Operation" and "Invalid Operation" FP
exceptions.
The proper final processing of the cases when any FP exception
flag is set is achieved by replacing "break" statement with "goto
copcsr" statement. With such solution, this patch brings the final
phase of emulation of the above instructions consistent with the
one corresponding to the previously implemented emulation of other
related FPU instructions (ADD, SUB, etc.).
Fixes: 38db37ba06 ("MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction")
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.3+
Patchwork: https://patchwork.linux-mips.org/patch/17581/
Signed-off-by: James Hogan <jhogan@kernel.org>
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>
The FPU emulator includes 2 calls to pr_err() which are triggered by
invalid instruction encodings for MIPSr6 cmp.cond.fmt instructions.
These cases are not kernel errors, merely invalid instructions which are
already handled by delivering a SIGILL which will provide notification
that something failed in cases where that makes sense.
In cases where that SIGILL is somewhat expected & being handled, for
example when crashme happens to generate one of the affected bad
encodings, the message is printed with no useful context about what
triggered it & spams the kernel log for no good reason.
Remove the pr_err() calls to make crashme run silently & treat the bad
encodings the same way we do others, with a SIGILL & no further kernel
log output.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: f8c3c6717a ("MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction")
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org> # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/17253/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add FP emulation debugfs statistics for individual instructions. The
debugfs files that contain counter values are placed in a separate
directory called "instructions". This means that the default path for
these new stat is "/sys/kernel/debug/mips/fpuemustats/instructions".
Each instruction counter is mapped to the debugfs file that has the
same name as instruction name. The lowercase is choosen as more
commonly used case for instruction names.
One example of usage:
mips_host::/sys/kernel/debug/mips/fpuemustats/instructions # grep "" *
The shortened output of this command is:
abs.d:34
abs.s:5711
add.d:10401
add.s:399307
bc1eqz:3199
...
...
...
sub.s:167211
trunc.l.d:375
trunc.l.s:8054
trunc.w.d:421
trunc.w.s:27032
The limitation of this patch is that it handles R6 FP emulation
instructions only. There are altogether 114 handled instructions.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17145/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add capability for the user to clear all FP emu debugfs counters.
This is achieved by having a special debugfs file "fpuemustats_clear"
(under default location "/sys/kernel/debug/mips"). Each access to the
file results in setting all counters to zero (it is enough, let's say,
to issue a "cat /sys/kernel/debug/mips/fpuemustats_clear").
This functionality already exists for R2 emulation statistics,
but was missing for FP emulation statistics. The implementation in
this patch is consistent with its R2 emulation counterpart.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17144/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add FP emu debugfs counter for branches.
The new counter is displayed the same way as existing counter, and
its default path is /sys/kernel/debug/mips/fpuemustats/.
The limitation of this counter is that it counts only R6 branch
instructions BC1NEZ and BC1EQZ.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17143/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix content of CLASS.D output bits 32-63 to match hardware behavior.
Prior to this patch, bits 32-63 of CLASS.D output were not
initialized, causing different 32-63 bits content of CLASS.D, based on
circumstances. However, the hardware consistently returns all these
bits zeroed. The documentation is not clear whether these bits should
be zero or unpredictable. Since technically "all zero" case still can
be viewed as belonging to "unpredictable" class of results, it is
better to zero bits 32-63.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17142/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reimplement RINT.<D|S> kernel emulation so that all RINT.<D|S>
specifications are met.
For the sake of simplicity, let's analyze RINT.S only. Prior to
this patch, RINT.S emulation was essentially implemented as (in
pseudocode) <output> = ieee754sp_flong(ieee754sp_tlong(<input>)),
where ieee754sp_tlong() and ieee754sp_flong() are functions
providing conversion from double to integer, and from integer
to double, respectively. On surface, this implementation looks
correct, but actually fails in many cases. Following problems
were detected:
1. NaN and infinity cases will not be handled properly. The
function ieee754sp_flong() never returns NaN nor infinity.
2. For RINT.S, for all inputs larger than LONG_MAX, and smaller
than FLT_MAX, the result will be wrong, and the overflow
exception will be erroneously set. A similar problem for
negative inputs exists as well.
3. For some rounding modes, for some negative inputs close to zero,
the return value will be zero, and should be -zero. This is
because ieee754sp_flong() never returns -zero.
This patch removes the problems above by implementing dedicated
functions for RINT.<D|S> emulation.
The core of the new function functionality is adapted version of
the core of the function ieee754sp_tlong(). However, there are many
details that are implemented to match RINT.<D|S> specification. It
should be said that the functionality of ieee754sp_tlong() actually
closely corresponds to CVT.L.S instruction, and it is used while
emulating CVT.L.S. However, RINT.S and CVT.L.S instructions differ
in many aspects. This patch fulfills missing support for RINT.<D|S>.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17141/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix CMP.Sxxx.<D|S> SIGILL crashes by fixing main switch/case statement
in fpu_emul() function so that inadvertent fall-troughs are prevented.
Consider, let's say, CMP.SAF.S instruction when one of inputs is zero
and another input is a signaling NaN. The desired output is zero, and
the exception flag "invalid operation" set. For such case, the main
portion of the implementation is within "d_fmt" case of the main
"switch/case" statement in fpu_emul() function. The execution will
follow one of "if-else" branches that doesn't contain "goto cop1scr;"
statement, and will therefore reach the end of "d_fmt" case. It will
subsequently fall through to the next case, "l_fmt". After following
similar pattern, the execution will fall through to the succeeding
case, which is "default". The "default" case contains "return SIGILL;"
statement only. This means that the caller application will crash
with "illegal instruction" message.
It is obvious that above described fall-throughs are unnecessary and
harmful. This patch rectifies that behavior by providing "break;"
statements at the end of cases "d_fmt" and "l_fmt".
There are 22 instructions affected by this problem:
CMP.<SAF|SEQ|SLE|SLT|SNE|SOR|SUEQ|SULE|SULT|SUN|SUNE>.<D|S>.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17140/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Implement fused multiply-add with correct accuracy.
Fused multiply-add operation has better accuracy than respective
sequential execution of multiply and add operations applied on the
same inputs. This is because accuracy errors accumulate in latter
case.
This patch implements fused multiply-add with the same accuracy
as it is implemented in hardware, using 128-bit intermediate
calculations.
One test case example (raw bits) that this patch fixes:
MADDF.D fd,fs,ft:
fd = 0x00000ca000000000
fs = ft = 0x3f40624dd2f1a9fc
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16891/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Implement fused multiply-add with correct accuracy.
Fused multiply-add operation has better accuracy than respective
sequential execution of multiply and add operations applied on the
same inputs. This is because accuracy errors accumulate in latter
case.
This patch implements fused multiply-add with the same accuracy
as it is implemented in hardware, using 64-bit intermediate
calculations.
One test case example (raw bits) that this patch fixes:
MADDF.S fd,fs,ft:
fd = 0x22575225
fs = ft = 0x3727c5ac
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16890/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix definition and usage of "maddf_flags" enumeration. Avoid duplicate
definition and apply more common capitalization.
This patch does not change any scenario. It just makes MADDF and
MSUBF emulation code more readable and easier to maintain, and
hopefully prevents future bugs as well.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the cases of <MADDF|MSUBF>.<D|S> when any of two multiplicands is
+0 or -0, and the third input is also +0 or -0. Depending on the signs
of inputs, certain special cases must be handled.
A relevant example:
MADDF.S fd,fs,ft:
If fs contains +0.0, ft contains -0.0, and fd contains 0.0, fd is
going to contain +0.0 (without this patch, it used to contain -0.0).
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the cases of <MADDF|MSUBF>.<D|S> when any of two multiplicands is
infinity. The correct behavior in such cases is affected by the nature
of third input. Cases of addition of infinities with opposite signs
and subtraction of infinities with same signs may arise and must be
handles separately. Also, the value od flags argument (that determines
whether the instruction is MADDF or MSUBF) affects the outcome.
Relevant examples:
MADDF.S fd,fs,ft:
If fs contains +inf, ft contains +inf, and fd contains -inf, fd is
going to contain indef (without this patch, it used to contain
-inf).
MSUBF.S fd,fs,ft:
If fs contains +inf, ft contains 1.0, and fd contains +0.0, fd is
going to contain -inf (without this patch, it used to contain +inf).
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16887/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the cases of <MADDF|MSUBF>.<D|S> when any of three inputs is any
NaN. Correct behavior of <MADDF|MSUBF>.<D|S> fd, fs, ft is following:
- if any of inputs is sNaN, return a sNaN using following rules: if
only one input is sNaN, return that one; if more than one input is
sNaN, order of precedence for return value is fd, fs, ft
- if no input is sNaN, but at least one of inputs is qNaN, return a
qNaN using following rules: if only one input is qNaN, return that
one; if more than one input is qNaN, order of precedence for
return value is fd, fs, ft
The previous code contained correct handling of some above cases, but
not all. Also, such handling was scattered into various cases of
"switch (CLPAIR(xc, yc))" statement, and elsewhere. With this patch,
this logic is placed in one place, and "switch (CLPAIR(xc, yc))" is
significantly simplified.
A relevant example:
MADDF.S fd,fs,ft:
If fs contains qNaN1, ft contains qNaN2, and fd contains qNaN3, fd
is going to contain qNaN3 (without this patch, it used to contain
qNaN1).
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16886/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix following special cases for MINA>.<D|S>:
- if one of the inputs is zero, and the other is subnormal, normal,
or infinity, the value of the former should be returned (that is,
a zero).
- if one of the inputs is infinity, and the other input is normal,
or subnormal, the value of the latter should be returned.
The previous implementation's logic for such cases was incorrect - it
appears as if it implements MAXA, and not MINA instruction.
A relevant example:
MINA.S fd,fs,ft:
If fs contains 100.0, and ft contains 0.0, fd is going to contain
0.0 (without this patch, it used to contain 100.0).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16885/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the value returned by <MAXA|MINA>.<D|S> fd,fs,ft, if both inputs
are infinite. The previous implementation returned always the value
contained in ft in such cases. The correct behavior is specified
in Mips instruction set manual and is as follows:
fs ft MAXA MINA
---------------------------------
inf inf inf inf
inf -inf inf -inf
-inf inf inf -inf
-inf -inf -inf -inf
A relevant example:
MAXA.S fd,fs,ft:
If fs contains +inf, and ft contains -inf, fd is going to contain
+inf (without this patch, it used to contain -inf).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16884/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the value returned by <MAXA|MINA>.<D|S>, if the inputs are normal
fp numbers of the same absolute value, but opposite signs.
A relevant example:
MAXA.S fd,fs,ft:
If fs contains -3.0, and ft contains +3.0, fd is going to contain
+3.0 (without this patch, it used to contain -3.0).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16883/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the value returned by <MAX|MIN>.<D|S>, if both inputs are negative
normal fp numbers. The previous logic did not take into account that
if both inputs have the same sign, there should be separate treatment
of the cases when both inputs are negative and when both inputs are
positive.
A relevant example:
MAX.S fd,fs,ft:
If fs contains -5.0, and ft contains -7.0, fd is going to contain
-5.0 (without this patch, it used to contain -7.0).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16882/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:
fs ft MAX MIN MAXA MINA
---------------------------------------------
0 0 0 0 0 0
0 -0 0 -0 0 -0
-0 0 0 -0 0 -0
-0 -0 -0 -0 -0 -0
Prior to this patch, some of the above cases were yielding correct
results. However, for the sake of code consistency, all such cases
are rewritten in this patch.
A relevant example:
MAX.S fd,fs,ft:
If fs contains +0.0, and ft contains -0.0, fd is going to contain
+0.0 (without this patch, it used to contain -0.0).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16881/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S> fd,fs,ft, if both
inputs are quiet NaNs. The <MAX|MAXA|MIN|MINA>.<D|S> specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.
A relevant example:
MAX.S fd,fs,ft:
If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
qNaN1 (without this patch, it used to contain qNaN2).
Fixes: a79f5f9ba5 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The fault_addr argument to fpu_emulator_cop1Handler(), fpux_emu() and
cop1Emulate() has up until now been declared as:
void *__user *fault_addr
This is essentially a pointer in user memory which points to a pointer
to void. This is not the intent for our code, which is actually
operating on a pointer to a pointer to void where the pointer to void is
pointing at user memory. ie. the pointer is in kernel memory & points to
user memory.
This mismatch produces a lot of sparse warnings that look like this:
arch/mips/math-emu/cp1emu.c:1485:45:
warning: incorrect type in assignment (different address spaces)
expected void *[noderef] <asn:1><noident>
got unsigned int [noderef] [usertype] <asn:1>*[assigned] va
Fix these by modifying the declaration of the fault_addr argument to:
void __user **fault_addr
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
GCC-7 complains about a boolean value being used with an arithmetic
AND:
arch/mips/math-emu/cp1emu.c: In function 'cop1Emulate':
arch/mips/math-emu/cp1emu.c:838:14: warning: '~' on a boolean expression [-Wbool-operation]
fpr = (x) & ~(cop1_64bit(xcp) == 0); \
^
arch/mips/math-emu/cp1emu.c:1068:3: note: in expansion of macro 'DITOREG'
DITOREG(dval, MIPSInst_RT(ir));
^~~~~~~
arch/mips/math-emu/cp1emu.c:838:14: note: did you mean to use logical not?
fpr = (x) & ~(cop1_64bit(xcp) == 0); \
Since cop1_64bit() returns and int, just flip the LSB.
Suggested-by: Maciej W. Rozycki <macro@imgtec.com>
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Reviewed-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17058/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"Boston platform support:
- Document DT bindings
- Add CLK driver for board clocks
CM:
- Avoid per-core locking with CM3 & higher
- WARN on attempt to lock invalid VP, not BUG
CPS:
- Select CONFIG_SYS_SUPPORTS_SCHED_SMT for MIPSr6
- Prevent multi-core with dcache aliasing
- Handle cores not powering down more gracefully
- Handle spurious VP starts more gracefully
DSP:
- Add lwx & lhx missaligned access support
eBPF:
- Add MIPS support along with many supporting change to add the
required infrastructure
Generic arch code:
- Misc sysmips MIPS_ATOMIC_SET fixes
- Drop duplicate HAVE_SYSCALL_TRACEPOINTS
- Negate error syscall return in trace
- Correct forced syscall errors
- Traced negative syscalls should return -ENOSYS
- Allow samples/bpf/tracex5 to access syscall arguments for sane
traces
- Cleanup from old Kconfig options in defconfigs
- Fix PREF instruction usage by memcpy for MIPS R6
- Fix various special cases in the FPU eulation
- Fix some special cases in MIPS16e2 support
- Fix MIPS I ISA /proc/cpuinfo reporting
- Sort MIPS Kconfig alphabetically
- Fix minimum alignment requirement of IRQ stack as required by
ABI / GCC
- Fix special cases in the module loader
- Perform post-DMA cache flushes on systems with MAARs
- Probe the I6500 CPU
- Cleanup cmpxchg and add support for 1 and 2 byte operations
- Use queued read/write locks (qrwlock)
- Use queued spinlocks (qspinlock)
- Add CPU shared FTLB feature detection
- Handle tlbex-tlbp race condition
- Allow storing pgd in C0_CONTEXT for MIPSr6
- Use current_cpu_type() in m4kc_tlbp_war()
- Support Boston in the generic kernel
Generic platform:
- yamon-dt: Pull YAMON DT shim code out of SEAD-3 board
- yamon-dt: Support > 256MB of RAM
- yamon-dt: Use serial* rather than uart* aliases
- Abstract FDT fixup application
- Set RTC_ALWAYS_BCD to 0
- Add a MAINTAINERS entry
core kernel:
- qspinlock.c: include linux/prefetch.h
Loongson 3:
- Add support
Perf:
- Add I6500 support
SEAD-3:
- Remove GIC timer from DT
- Set interrupt-parent per-device, not at root node
- Fix GIC interrupt specifiers
SMP:
- Skip IPI setup if we only have a single CPU
VDSO:
- Make comment match reality
- Improvements to time code in VDSO"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (86 commits)
locking/qspinlock: Include linux/prefetch.h
MIPS: Fix MIPS I ISA /proc/cpuinfo reporting
MIPS: Fix minimum alignment requirement of IRQ stack
MIPS: generic: Support MIPS Boston development boards
MIPS: DTS: img: Don't attempt to build-in all .dtb files
clk: boston: Add a driver for MIPS Boston board clocks
dt-bindings: Document img,boston-clock binding
MIPS: Traced negative syscalls should return -ENOSYS
MIPS: Correct forced syscall errors
MIPS: Negate error syscall return in trace
MIPS: Drop duplicate HAVE_SYSCALL_TRACEPOINTS select
MIPS16e2: Provide feature overrides for non-MIPS16 systems
MIPS: MIPS16e2: Report ASE presence in /proc/cpuinfo
MIPS: MIPS16e2: Subdecode extended LWSP/SWSP instructions
MIPS: MIPS16e2: Identify ASE presence
MIPS: VDSO: Fix a mismatch between comment and preprocessor constant
MIPS: VDSO: Add implementation of gettimeofday() fallback
MIPS: VDSO: Add implementation of clock_gettime() fallback
MIPS: VDSO: Fix conversions in do_monotonic()/do_monotonic_coarse()
MIPS: Use current_cpu_type() in m4kc_tlbp_war()
...
Update commit 1ac944007b ("MIPS: math-emu: Add mfhc1 & mthc1
support.") and like done throughout `cop1Emulate' for other cases also
for the MFHC1 and MTHC1 instructions return SIGILL right away rather
than jumping to a single `return' statement.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Terminate FPU emulation immediately whenever an ISA mode switch has been
observed. This is so that we do not interpret machine code in the wrong
mode, for example when a regular MIPS FPU instruction has been placed in
a delay slot of a jump that switches into the MIPS16 mode, as with the
following code (taken from a GCC test suite case):
00400650 <set_fast_math>:
400650: 3c020100 lui v0,0x100
400654: 03e00008 jr ra
400658: 44c2f800 ctc1 v0,c1_fcsr
40065c: 00000000 nop
[...]
004012d0 <__libc_csu_init>:
4012d0: f000 6a02 li v0,2
4012d4: f150 0b1c la v1,3f9430 <_DYNAMIC-0x6df0>
4012d8: f400 3240 sll v0,16
4012dc: e269 addu v0,v1
4012de: 659a move gp,v0
4012e0: f00c 64f6 save a0-a2,48,ra,s0-s1
4012e4: 673c move s1,gp
4012e6: f010 9978 lw v1,-32744(s1)
4012ea: d204 sw v0,16(sp)
4012ec: eb40 jalr v1
4012ee: 653b move t9,v1
4012f0: f010 997c lw v1,-32740(s1)
4012f4: f030 9920 lw s1,-32736(s1)
4012f8: e32f subu v1,s1
4012fa: 326b sra v0,v1,2
4012fc: d206 sw v0,24(sp)
4012fe: 220c beqz v0,401318 <__libc_csu_init+0x48>
401300: 6800 li s0,0
401302: 99e0 lw a3,0(s1)
401304: 4801 addiu s0,1
401306: 960e lw a2,56(sp)
401308: 4904 addiu s1,4
40130a: 950d lw a1,52(sp)
40130c: 940c lw a0,48(sp)
40130e: ef40 jalr a3
401310: 653f move t9,a3
401312: 9206 lw v0,24(sp)
401314: ea0a cmp v0,s0
401316: 61f5 btnez 401302 <__libc_csu_init+0x32>
401318: 6476 restore 48,ra,s0-s1
40131a: e8a0 jrc ra
Here `set_fast_math' is called from `40130e' (`40130f' with the ISA bit)
and emulation triggers for the CTC1 instruction. As it is in a jump
delay slot emulation continues from `401312' (`401313' with the ISA
bit). However we have no path to handle MIPS16 FPU code emulation,
because there are no MIPS16 FPU instructions. So the default emulation
path is taken, interpreting a 32-bit word fetched by `get_user' from
`401313' as a regular MIPS instruction, which is:
401313: f5ea0a92 sdc1 $f10,2706(t7)
This makes the FPU emulator proceed with the supposed SDC1 instruction
and consequently makes the program considered here terminate with
SIGSEGV.
A similar although less severe issue exists with pure-microMIPS
processors in the case where similarly an FPU instruction is emulated in
a delay slot of a register jump that (incorrectly) switches into the
regular MIPS mode. A subsequent instruction fetch from the jump's
target is supposed to cause an Address Error exception, however instead
we proceed with regular MIPS FPU emulation.
For simplicity then, always terminate the emulation loop whenever a mode
change is detected, denoted by an ISA mode bit flip. As from commit
377cb1b6c1 ("MIPS: Disable MIPS16/microMIPS crap for platforms not
supporting these ASEs.") the result of `get_isa16_mode' can be hardcoded
to 0, so we need to examine the ISA mode bit by hand.
This complements commit 102cedc32a ("MIPS: microMIPS: Floating point
support.") which added JALX decoding to FPU emulation.
Fixes: 102cedc32a ("MIPS: microMIPS: Floating point support.")
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 3.9+
Patchwork: https://patchwork.linux-mips.org/patch/16393/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Correct the treatment of branching conditions for BC1EQZ and BC1NEZ
instructions in function isBranchInstr().
Previously, corresponding conditions were swapped, which in turn meant
that, for these two instructions, function isBranchInstr() returned
wrong value in its output parameter contpc.
This change is actually an extension of the fix done by the commit
93583e178e ("MIPS: math-emu: Fix BC1{EQ,NE}Z emulation"). That commit
dealt with a similar problem in function cop1Emulate(), while this
commit deals with condition handling in function isBranchInstr().
The code styles of changes in these two commits are kept as
consistent as possible.
Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: james.hogan@imgtec.com
Cc: leonid.yegoshin@imgtec.com
Cc: petar.jovanovic@imgtec.com
Cc: goran.ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15489/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
But first update the code that uses these facilities with the
new header.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Update code that relied on sched.h including various MM types for them.
This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:
-include $(srctree)/include/linux/kconfig.h
This commit removes explicit includes except the following:
* arch/s390/include/asm/facilities_src.h
* tools/testing/radix-tree/linux/kernel.h
These two are used for host programs.
Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 432c6bacbd ("MIPS: Use per-mm page to execute branch delay slot
instructions") accidentally removed use of the MIPS_FPU_EMU_INC_STATS
macro from do_dsemulret, leading to the ds_emul file in debugfs always
returning zero even though we perform delay slot emulations.
Fix this by re-adding the use of the MIPS_FPU_EMU_INC_STATS macro.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 432c6bacbd ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14301/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.8. Also includes is a
minor SSB cleanup as SSB code traditionally is merged through the MIPS
tree:
ATH25:
- MIPS: Add default configuration for ath25
Boot:
- For zboot, copy appended dtb to the end of the kernel
- store the appended dtb address in a variable
BPF:
- Fix off by one error in offset allocation
Cobalt code:
- Fix typos
Core code:
- debugfs_create_file returns NULL on error, so don't use IS_ERR for
testing for errors.
- Fix double locking issue in RM7000 S-cache code. This would only
affect RM7000 ARC systems on reboot.
- Fix page table corruption on THP permission changes.
- Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels.
David says, there are no compatibility issues raised by this fix.
- Move some signal code around.
- Rewrite r4k count/compare clockevent device registration such that
min_delta_ticks/max_delta_ticks files are guaranteed to be
initialized.
- Only register r4k count/compare as clockevent device if we can
assume the clock to be constant.
- Fix MSA asm warnings in control reg accessors
- uasm and tlbex fixes and tweaking.
- Print segment physical address when EU=1.
- Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO.
- CP: Allow booting by VP other than VP 0
- Cache handling fixes and optimizations for r4k class caches
- Add hotplug support for R6 processors
- Cleanup hotplug bits in kconfig
- traps: return correct si code for accessing nonmapped addresses
- Remove cpu_has_safe_index_cacheops
Lantiq:
- Register IRQ handler for virtual IRQ number
- Fix EIU interrupt loading code
- Use the real EXIN count
- Fix build error.
Loongson 3:
- Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES
Octeon:
- Delete built-in DTB pruning code for D-Link DSR-1000N.
- Clean up GPIO definitions in dlink_dsr-1000n.dts.
- Add more LEDs to the DSR-100n DTS
- Fix off by one in octeon_irq_gpio_map()
- Typo fixes
- Enable SATA by default in cavium_octeon_defconfig
- Support readq/writeq()
- Remove forced mappings of USB interrupts.
- Ensure DMA descriptors are always in the low 4GB
- Improve USB reset code for OCTEON II.
Pistachio:
- Add maintainers entry for pistachio SoC Support
- Remove plat_setup_iocoherency
Ralink:
- Fix pwm UART in spis group pinmux.
SSB:
- Change bare unsigned to unsigned int to suit coding style
Tools:
- Fix reloc tool compiler warnings.
Other:
- Delete use of ARCH_WANT_OPTIONAL_GPIOLIB"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits)
MIPS: mm: Fix definition of R6 cache instruction
MIPS: tools: Fix relocs tool compiler warnings
MIPS: Cobalt: Fix typo
MIPS: Octeon: Fix typo
MIPS: Lantiq: Fix build failure
MIPS: Use CPHYSADDR to implement mips32 __pa
MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.
MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.
MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.
MIPS: store the appended dtb address in a variable
MIPS: ZBOOT: copy appended dtb to the end of the kernel
MIPS: ralink: fix spis group pinmux
MIPS: Factor o32 specific code into signal_o32.c
MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
MIPS: Use per-mm page to execute branch delay slot instructions
MIPS: Modify error handling
MIPS: c-r4k: Use SMP calls for CM indexed cache ops
MIPS: c-r4k: Avoid small flush_icache_range SMP calls
MIPS: c-r4k: Local flush_icache_range cache op override
MIPS: c-r4k: Split r4k_flush_kernel_vmap_range()
...
The use of config_enabled() against config options is ambiguous. In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED(). Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention
clearer.
This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.
I noticed two cases where config_enabled() is used against a tristate
option:
- config_enabled(CONFIG_HWMON)
[ drivers/net/wireless/ath/ath10k/thermal.c ]
- config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
[ drivers/gpu/drm/gma500/opregion.c ]
I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.
Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will Drewry <wad@chromium.org>
Cc: Nikolay Martynov <mar.kolya@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Rafal Milecki <zajec5@gmail.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tony Wu <tung7970@gmail.com>
Cc: Huaitong Han <huaitong.han@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some cases the kernel needs to execute an instruction from the delay
slot of an emulated branch instruction. These cases include:
- Emulated floating point branch instructions (bc1[ft]l?) for systems
which don't include an FPU, or upon which the kernel is run with the
"nofpu" parameter.
- MIPSr6 systems running binaries targeting older revisions of the
architecture, which may include branch instructions whose encodings
are no longer valid in MIPSr6.
Executing instructions from such delay slots is done by writing the
instruction to memory followed by a trap, as part of an "emuframe", and
executing it. This avoids the requirement of an emulator for the entire
MIPS instruction set. Prior to this patch such emuframes are written to
the user stack and executed from there.
This patch moves FP branch delay emuframes off of the user stack and
into a per-mm page. Allocating a page per-mm leaves userland with access
to only what it had access to previously, and compared to other
solutions is relatively simple.
When a thread requires a delay slot emulation, it is allocated a frame.
A thread may only have one frame allocated at any one time, since it may
only ever be executing one instruction at any one time. In order to
ensure that we can free up allocated frame later, its index is recorded
in struct thread_struct. In the typical case, after executing the delay
slot instruction we'll execute a break instruction with the BRK_MEMU
code. This traps back to the kernel & leads to a call to do_dsemulret
which frees the allocated frame & moves the user PC back to the
instruction that would have executed following the emulated branch.
In some cases the delay slot instruction may be invalid, such as a
branch, or may trigger an exception. In these cases the BRK_MEMU break
instruction will not be hit. In order to ensure that frames are freed
this patch introduces dsemul_thread_cleanup() and calls it to free any
allocated frame upon thread exit. If the instruction generated an
exception & leads to a signal being delivered to the thread, or indeed
if a signal simply happens to be delivered to the thread whilst it is
executing from the struct emuframe, then we need to take care to exit
the frame appropriately. This is done by either rolling back the user PC
to the branch or advancing it to the continuation PC prior to signal
delivery, using dsemul_thread_rollback(). If this were not done then a
sigreturn would return to the struct emuframe, and if that frame had
meanwhile been used in response to an emulated branch instruction within
the signal handler then we would execute the wrong user code.
Whilst a user could theoretically place something like a compact branch
to self in a delay slot and cause their thread to become stuck in an
infinite loop with the frame never being deallocated, this would:
- Only affect the users single process.
- Be architecturally invalid since there would be a branch in the
delay slot, which is forbidden.
- Be extremely unlikely to happen by mistake, and provide a program
with no more ability to harm the system than a simple infinite loop
would.
If a thread requires a delay slot emulation & no frame is available to
it (ie. the process has enough other threads that all frames are
currently in use) then the thread joins a waitqueue. It will sleep until
a frame is freed by another thread in the process.
Since we now know whether a thread has an allocated frame due to our
tracking of its index, the cookie field of struct emuframe is removed as
we can be more certain whether we have a valid frame. Since a thread may
only ever have a single frame at any given time, the epc field of struct
emuframe is also removed & the PC to continue from is instead stored in
struct thread_struct. Together these changes simplify & shrink struct
emuframe somewhat, allowing twice as many frames to fit into the page
allocated for them.
The primary benefit of this patch is that we are now free to mark the
user stack non-executable where that is possible.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13764/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The opcodes currently defined in inst.h as cbcond0_op & cbcond1_op are
actually defined in the MIPS base instruction set manuals as pop10 &
pop30 respectively. Rename them as such, for consistency with the
documentation.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The opcodes currently defined in inst.h as beqzcjic_op & bnezcjialc_op
are actually defined in the MIPS base instruction set manuals as pop66 &
pop76 respectively. Rename them as such, for consistency with the
documentation.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When emulating a jalr instruction with rd == $0, the code in
isBranchInstr was incorrectly writing to GPR $0 which should actually
always remain zeroed. This would lead to any further instructions
emulated which use $0 operating on a bogus value until the task is next
context switched, at which point the value of $0 in the task context
would be restored to the correct zero by a store in SAVE_SOME. Fix this
by not writing to rd if it is $0.
Fixes: 102cedc32a ("MIPS: microMIPS: Floating point support.")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable <stable@vger.kernel.org> # v3.10
Patchwork: https://patchwork.linux-mips.org/patch/13160/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
A line incrementing the re variable was indented a level too deep in
ieee754dp_mul, making the code unclear to read. Fix the indentation.
This appears to have been copied verbatim along with the rest of the
multiplication code to ieee754dp_maddf, now _dp_maddf, too so fix the
indentation there too.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13158/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
