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linux/arch/arm/kernel/sleep.S

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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
/* SPDX-License-Identifier: GPL-2.0 */
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
#include <linux/linkage.h>
ARM: pm: allow generic sleep code to be used with SMP CPU idle Allow the generic sleep code to be used with SMP CPU idle by storing N CPU stack pointers rather than just one. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-11 19:32:19 +08:00
#include <linux/threads.h>
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/glue-cache.h>
#include <asm/glue-proc.h>
.text
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
/*
* Implementation of MPIDR hash algorithm through shifting
* and OR'ing.
*
* @dst: register containing hash result
* @rs0: register containing affinity level 0 bit shift
* @rs1: register containing affinity level 1 bit shift
* @rs2: register containing affinity level 2 bit shift
* @mpidr: register containing MPIDR value
* @mask: register containing MPIDR mask
*
* Pseudo C-code:
*
*u32 dst;
*
*compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 mpidr, u32 mask) {
* u32 aff0, aff1, aff2;
* u32 mpidr_masked = mpidr & mask;
* aff0 = mpidr_masked & 0xff;
* aff1 = mpidr_masked & 0xff00;
* aff2 = mpidr_masked & 0xff0000;
* dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2);
*}
* Input registers: rs0, rs1, rs2, mpidr, mask
* Output register: dst
* Note: input and output registers must be disjoint register sets
(eg: a macro instance with mpidr = r1 and dst = r1 is invalid)
*/
.macro compute_mpidr_hash dst, rs0, rs1, rs2, mpidr, mask
and \mpidr, \mpidr, \mask @ mask out MPIDR bits
and \dst, \mpidr, #0xff @ mask=aff0
ARM( mov \dst, \dst, lsr \rs0 ) @ dst=aff0>>rs0
THUMB( lsr \dst, \dst, \rs0 )
and \mask, \mpidr, #0xff00 @ mask = aff1
ARM( orr \dst, \dst, \mask, lsr \rs1 ) @ dst|=(aff1>>rs1)
THUMB( lsr \mask, \mask, \rs1 )
THUMB( orr \dst, \dst, \mask )
and \mask, \mpidr, #0xff0000 @ mask = aff2
ARM( orr \dst, \dst, \mask, lsr \rs2 ) @ dst|=(aff2>>rs2)
THUMB( lsr \mask, \mask, \rs2 )
THUMB( orr \dst, \dst, \mask )
.endm
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
/*
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
* Save CPU state for a suspend. This saves the CPU general purpose
* registers, and allocates space on the kernel stack to save the CPU
* specific registers and some other data for resume.
* r0 = suspend function arg0
* r1 = suspend function
ARM: suspend: use hash of cpu_logical_map value to index into save array Currently we hash the MPIDR of the CPU being suspended to determine which entry in the sleep_save_sp array to use. In some situations, such as when we want to resume on another physical CPU, the MPIDR of another CPU should be used instead. So let's use the value of cpu_logical_map(smp_processor_id()) in place of the MPIDR in the suspend path. This will result in the same index being used as with the previous code unless the caller has modified cpu_logical_map() beforehand with the MPIDR of the physical CPU the suspending logical CPU will resume on. Consequently, if doing a physical CPU migration, cpu_logical_map() must be updated appropriately somewhere between cpu_pm_enter() and cpu_suspend(). The register allocation in __cpu_suspend is reworked in order to better accommodate the additional argument. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com>
2013-07-19 04:50:59 +08:00
* r2 = MPIDR value the resuming CPU will use
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
*/
ARM: pm: hide 1st and 2nd arguments to cpu_suspend from platform code The first and second arguments shouldn't concern platform code, so hide them from each platforms caller. Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-23 00:41:48 +08:00
ENTRY(__cpu_suspend)
ARM: pm: convert cpu_suspend() to a normal function cpu_suspend() has a weird calling method which makes it only possible to call from assembly code: it returns with a modified stack pointer to finish the suspend, but on resume, it 'returns' via a provided pointer. We can make cpu_suspend() appear to be a normal function merely by swapping the resume pointer argument and the link register. Do so, and update all callers to take account of this more traditional behaviour. Acked-by: Frank Hofmann <frank.hofmann@tomtom.com> Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-13 22:58:34 +08:00
stmfd sp!, {r4 - r11, lr}
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
#ifdef MULTI_CPU
ldr r10, =processor
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
ldr r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
ARM: pm: allow generic sleep code to be used with SMP CPU idle Allow the generic sleep code to be used with SMP CPU idle by storing N CPU stack pointers rather than just one. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-11 19:32:19 +08:00
#else
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
ldr r4, =cpu_suspend_size
ARM: pm: extract common code from MULTI_CPU/!MULTI_CPU paths Very little code is different between these two paths now, so extract the common code. Acked-by: Frank Hofmann <frank.hofmann@tomtom.com> Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-13 20:53:06 +08:00
#endif
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
mov r5, sp @ current virtual SP
ARM: implement support for vmap'ed stacks Wire up the generic support for managing task stack allocations via vmalloc, and implement the entry code that detects whether we faulted because of a stack overrun (or future stack overrun caused by pushing the pt_regs array) While this adds a fair amount of tricky entry asm code, it should be noted that it only adds a TST + branch to the svc_entry path. The code implementing the non-trivial handling of the overflow stack is emitted out-of-line into the .text section. Since on ARM, we rely on do_translation_fault() to keep PMD level page table entries that cover the vmalloc region up to date, we need to ensure that we don't hit such a stale PMD entry when accessing the stack. So we do a dummy read from the new stack while still running from the old one on the context switch path, and bump the vmalloc_seq counter when PMD level entries in the vmalloc range are modified, so that the MM switch fetches the latest version of the entries. Note that we need to increase the per-mode stack by 1 word, to gain some space to stash a GPR until we know it is safe to touch the stack. However, due to the cacheline alignment of the struct, this does not actually increase the memory footprint of the struct stack array at all. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-09-23 15:15:53 +08:00
#ifdef CONFIG_VMAP_STACK
@ Run the suspend code from the overflow stack so we don't have to rely
@ on vmalloc-to-phys conversions anywhere in the arch suspend code.
@ The original SP value captured in R5 will be restored on the way out.
ARM: percpu: add SMP_ON_UP support Permit the use of the TPIDRPRW system register for carrying the per-CPU offset in generic SMP configurations that also target non-SMP capable ARMv6 cores. This uses the SMP_ON_UP code patching framework to turn all TPIDRPRW accesses into reads/writes of entry #0 in the __per_cpu_offset array. While at it, switch over some existing direct TPIDRPRW accesses in asm code to invocations of a new helper that is patched in the same way when necessary. Note that CPU_V6+SMP without SMP_ON_UP results in a kernel that does not boot on v6 CPUs without SMP extensions, so add this dependency to Kconfig as well. Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-11-25 17:26:44 +08:00
ldr_this_cpu sp, overflow_stack_ptr, r6, r7
ARM: implement support for vmap'ed stacks Wire up the generic support for managing task stack allocations via vmalloc, and implement the entry code that detects whether we faulted because of a stack overrun (or future stack overrun caused by pushing the pt_regs array) While this adds a fair amount of tricky entry asm code, it should be noted that it only adds a TST + branch to the svc_entry path. The code implementing the non-trivial handling of the overflow stack is emitted out-of-line into the .text section. Since on ARM, we rely on do_translation_fault() to keep PMD level page table entries that cover the vmalloc region up to date, we need to ensure that we don't hit such a stale PMD entry when accessing the stack. So we do a dummy read from the new stack while still running from the old one on the context switch path, and bump the vmalloc_seq counter when PMD level entries in the vmalloc range are modified, so that the MM switch fetches the latest version of the entries. Note that we need to increase the per-mode stack by 1 word, to gain some space to stash a GPR until we know it is safe to touch the stack. However, due to the cacheline alignment of the struct, this does not actually increase the memory footprint of the struct stack array at all. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-09-23 15:15:53 +08:00
#endif
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn
sub sp, sp, r4 @ allocate CPU state on stack
ldr r3, =sleep_save_sp
ARM: suspend: use hash of cpu_logical_map value to index into save array Currently we hash the MPIDR of the CPU being suspended to determine which entry in the sleep_save_sp array to use. In some situations, such as when we want to resume on another physical CPU, the MPIDR of another CPU should be used instead. So let's use the value of cpu_logical_map(smp_processor_id()) in place of the MPIDR in the suspend path. This will result in the same index being used as with the previous code unless the caller has modified cpu_logical_map() beforehand with the MPIDR of the physical CPU the suspending logical CPU will resume on. Consequently, if doing a physical CPU migration, cpu_logical_map() must be updated appropriately somewhere between cpu_pm_enter() and cpu_suspend(). The register allocation in __cpu_suspend is reworked in order to better accommodate the additional argument. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com>
2013-07-19 04:50:59 +08:00
stmfd sp!, {r0, r1} @ save suspend func arg and pointer
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
ldr r3, [r3, #SLEEP_SAVE_SP_VIRT]
ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded PC relative arithmetic, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that ALT_SMP() expects a single instruction so move the macro invocation after it. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 16:25:34 +08:00
ALT_SMP(W(nop)) @ don't use adr_l inside ALT_SMP()
ARM: suspend: use hash of cpu_logical_map value to index into save array Currently we hash the MPIDR of the CPU being suspended to determine which entry in the sleep_save_sp array to use. In some situations, such as when we want to resume on another physical CPU, the MPIDR of another CPU should be used instead. So let's use the value of cpu_logical_map(smp_processor_id()) in place of the MPIDR in the suspend path. This will result in the same index being used as with the previous code unless the caller has modified cpu_logical_map() beforehand with the MPIDR of the physical CPU the suspending logical CPU will resume on. Consequently, if doing a physical CPU migration, cpu_logical_map() must be updated appropriately somewhere between cpu_pm_enter() and cpu_suspend(). The register allocation in __cpu_suspend is reworked in order to better accommodate the additional argument. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com>
2013-07-19 04:50:59 +08:00
ALT_UP_B(1f)
ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded PC relative arithmetic, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that ALT_SMP() expects a single instruction so move the macro invocation after it. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 16:25:34 +08:00
adr_l r0, mpidr_hash
ARM: suspend: use hash of cpu_logical_map value to index into save array Currently we hash the MPIDR of the CPU being suspended to determine which entry in the sleep_save_sp array to use. In some situations, such as when we want to resume on another physical CPU, the MPIDR of another CPU should be used instead. So let's use the value of cpu_logical_map(smp_processor_id()) in place of the MPIDR in the suspend path. This will result in the same index being used as with the previous code unless the caller has modified cpu_logical_map() beforehand with the MPIDR of the physical CPU the suspending logical CPU will resume on. Consequently, if doing a physical CPU migration, cpu_logical_map() must be updated appropriately somewhere between cpu_pm_enter() and cpu_suspend(). The register allocation in __cpu_suspend is reworked in order to better accommodate the additional argument. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com>
2013-07-19 04:50:59 +08:00
/* This ldmia relies on the memory layout of the mpidr_hash struct */
ldmia r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts
compute_mpidr_hash r0, r6, r7, r8, r2, r1
add r3, r3, r0, lsl #2
1: mov r2, r5 @ virtual SP
mov r1, r4 @ size of save block
add r0, sp, #8 @ pointer to save block
ARM: pm: convert some assembly to C Convert some of the sleep.S guts to C code, which makes it easier to use our macros and to add L2 cache handling. We provide a helper function, __cpu_suspend_save(), which deals with saving the common state, setting up for resume, and flushing caches. The remainder left as assembly code is the saving of the CPU general purpose registers, and allocating space on the stack to save the CPU specific registers and resume state. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 18:52:33 +08:00
bl __cpu_suspend_save
ARM: replace BSYM() with badr assembly macro BSYM() was invented to allow us to work around a problem with the assembler, where local symbols resolved by the assembler for the 'adr' instruction did not take account of their ISA. Since we don't want BSYM() used elsewhere, replace BSYM() with a new macro 'badr', which is like the 'adr' pseudo-op, but with the BSYM() mechanics integrated into it. This ensures that the BSYM()-ification is only used in conjunction with 'adr'. Acked-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-21 21:17:25 +08:00
badr lr, cpu_suspend_abort
ARM: pm: rejig suspend follow-on function calling convention Save the suspend function pointer onto the stack for use when returning. Allocate r2 to pass an argument to the suspend function. Acked-by: Frank Hofmann <frank.hofmann@tomtom.com> Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-13 22:28:40 +08:00
ldmfd sp!, {r0, pc} @ call suspend fn
ARM: pm: hide 1st and 2nd arguments to cpu_suspend from platform code The first and second arguments shouldn't concern platform code, so hide them from each platforms caller. Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-23 00:41:48 +08:00
ENDPROC(__cpu_suspend)
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
.ltorg
ARM: pm: allow suspend finisher to return error codes There are SoCs where attempting to enter a low power state is ignored, and the CPU continues executing instructions with all state preserved. It is over-complex at that point to disable the MMU just to call the resume path. Instead, allow the suspend finisher to return error codes to abort suspend in this circumstance, where the cpu_suspend internals will then unwind the saved state on the stack. Also omit the tlb flush as no changes to the page tables will have happened. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02 16:54:01 +08:00
cpu_suspend_abort:
ARM: pm: only use preallocated page table during resume Only use the preallocated page table during the resume, not while suspending. This avoids the overhead of having to switch unnecessarily to the resume page table in the suspend path. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-28 05:39:09 +08:00
ldmia sp!, {r1 - r3} @ pop phys pgd, virt SP, phys resume fn
ARM: pm: force non-zero return value from __cpu_suspend when aborting Ensure that the return value from __cpu_suspend is non-zero when aborting. Zero indicates a successful suspend occurred. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-27 18:17:36 +08:00
teq r0, #0
moveq r0, #1 @ force non-zero value
ARM: pm: allow suspend finisher to return error codes There are SoCs where attempting to enter a low power state is ignored, and the CPU continues executing instructions with all state preserved. It is over-complex at that point to disable the MMU just to call the resume path. Instead, allow the suspend finisher to return error codes to abort suspend in this circumstance, where the cpu_suspend internals will then unwind the saved state on the stack. Also omit the tlb flush as no changes to the page tables will have happened. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02 16:54:01 +08:00
mov sp, r2
ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_suspend_abort)
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
/*
* r0 = control register value
*/
ARM: pm: get rid of cpu_resume_turn_mmu_on We don't require cpu_resume_turn_mmu_on as we can combine the ldr instruction with the following code provided we ensure that cpu_resume_mmu is aligned for older CPUs. Note that we also align to a 32-byte boundary to ensure that the code can't cross a section boundary. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 06:26:18 +08:00
.align 5
ARM: suspend: use idmap_pgd instead of suspend_pgd The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped in order to re-enable the MMU when coming out of suspend. Currently, this is accomplished by maintaining a suspend_pgd with the relevant mapping put in place at init time. This patch replaces the use of suspend_pgd with the new idmap_pgd. cpu_resume_mmu is placed in the .idmap.text section so that it is included in the identity map. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dave Martin <dave.martin@linaro.org> Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-15 19:11:19 +08:00
.pushsection .idmap.text,"ax"
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
ENTRY(cpu_resume_mmu)
ldr r3, =cpu_resume_after_mmu
ARM: LPAE: add ISBs around MMU enabling code Before we enable the MMU, we must ensure that the TTBR registers contain sane values. After the MMU has been enabled, we jump to the *virtual* address of the following function, so we also need to ensure that the SCTLR write has taken effect. This patch adds ISB instructions around the SCTLR write to ensure the visibility of the above. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-11-23 01:30:28 +08:00
instr_sync
ARM: pm: preallocate a page table for suspend/resume Preallocate a page table and setup an identity mapping for the MMU enable code. This means we don't have to "borrow" a page table to do this, avoiding complexities with L2 cache coherency. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-27 03:28:52 +08:00
mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc
mrc p15, 0, r0, c0, c0, 0 @ read id reg
ARM: LPAE: add ISBs around MMU enabling code Before we enable the MMU, we must ensure that the TTBR registers contain sane values. After the MMU has been enabled, we jump to the *virtual* address of the following function, so we also need to ensure that the SCTLR write has taken effect. This patch adds ISB instructions around the SCTLR write to ensure the visibility of the above. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-11-23 01:30:28 +08:00
instr_sync
ARM: pm: preallocate a page table for suspend/resume Preallocate a page table and setup an identity mapping for the MMU enable code. This means we don't have to "borrow" a page table to do this, avoiding complexities with L2 cache coherency. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-27 03:28:52 +08:00
mov r0, r0
mov r0, r0
ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-30 23:29:12 +08:00
ret r3 @ jump to virtual address
ARM: pm: get rid of cpu_resume_turn_mmu_on We don't require cpu_resume_turn_mmu_on as we can combine the ldr instruction with the following code provided we ensure that cpu_resume_mmu is aligned for older CPUs. Note that we also align to a 32-byte boundary to ensure that the code can't cross a section boundary. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-01 06:26:18 +08:00
ENDPROC(cpu_resume_mmu)
ARM: suspend: use idmap_pgd instead of suspend_pgd The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped in order to re-enable the MMU when coming out of suspend. Currently, this is accomplished by maintaining a suspend_pgd with the relevant mapping put in place at init time. This patch replaces the use of suspend_pgd with the new idmap_pgd. cpu_resume_mmu is placed in the .idmap.text section so that it is included in the identity map. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dave Martin <dave.martin@linaro.org> Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-15 19:11:19 +08:00
.popsection
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
cpu_resume_after_mmu:
ARM: mm: switch to swapper_pg_dir early for vmap'ed stack When onlining a CPU, switch to swapper_pg_dir as soon as possible so that it is guaranteed that the vmap'ed stack is mapped before it is used. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-01-25 02:51:58 +08:00
#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE)
@ Before using the vmap'ed stack, we have to switch to swapper_pg_dir
@ as the ID map does not cover the vmalloc region.
mrc p15, 0, ip, c2, c0, 1 @ read TTBR1
mcr p15, 0, ip, c2, c0, 0 @ set TTBR0
instr_sync
#endif
ARM: pm: move cpu_init() call into core code As we have core code dealing with CPU suspend/resume, we can re-initialize the CPUs exception banked registers via that code rather than having platforms deal with that level of detail. So, move the call to cpu_init() out of platform code into core code. Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-21 23:32:58 +08:00
bl cpu_init @ restore the und/abt/irq banked regs
ARM: pm: allow suspend finisher to return error codes There are SoCs where attempting to enter a low power state is ignored, and the CPU continues executing instructions with all state preserved. It is over-complex at that point to disable the MMU just to call the resume path. Instead, allow the suspend finisher to return error codes to abort suspend in this circumstance, where the cpu_suspend internals will then unwind the saved state on the stack. Also omit the tlb flush as no changes to the page tables will have happened. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02 16:54:01 +08:00
mov r0, #0 @ return zero on success
ARM: pm: preserve r4 - r11 across a suspend Make cpu_suspend()..return function preserve r4 to r11 across a suspend cycle. This is in preparation of relieving platform support code from this task. Acked-by: Frank Hofmann <frank.hofmann@tomtom.com> Tested-by: Kevin Hilman <khilman@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-13 22:04:14 +08:00
ldmfd sp!, {r4 - r11, pc}
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
ENDPROC(cpu_resume_after_mmu)
ARM: 8324/1: move cpu_resume() to .text section Move cpu_resume() to the .text section where it belongs. Change the adr reference to sleep_save_sp to an explicit PC relative reference so sleep_save_sp itself can remain in .data. This helps prevent linker failure on large kernels, as the code in the .data section may be too far away to be in range for normal b/bl instructions. Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-25 14:39:21 +08:00
.text
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
.align
ARM: fix EFM32 build breakage caused by cpu_resume_arm Fix: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr r9,1f+1' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12 16:24:17 +08:00
ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to perform low-level platform initialization. This results in a try to install HYP stubs for the second time for each CPU and results in false HYP/SVC mode mismatch detection. The HYP stubs are already installed at the beginning of the kernel initialization on the boot CPU (head.S) or in the secondary_startup() for other CPUs. To fix this issue MCPM code should use a cpu_resume() routine without HYP stubs installation. This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid XU3/XU4/HC1 boards. Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-18 16:31:41 +08:00
#ifdef CONFIG_MCPM
.arm
THUMB( .thumb )
ENTRY(cpu_resume_no_hyp)
ARM_BE8(setend be) @ ensure we are in BE mode
b no_hyp
#endif
ARM: fix EFM32 build breakage caused by cpu_resume_arm Fix: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr r9,1f+1' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12 16:24:17 +08:00
#ifdef CONFIG_MMU
ARM: 8389/1: Add cpu_resume_arm() for firmwares that resume in ARM state Some platforms always enter the kernel in the ARM state even if the kernel is compiled for THUMB2. Add a small wrapper on top of cpu_resume() that switches into THUMB2 state. This provides the functionality to fix a problem reported by Kevin Hilman on next-20150601 where the ifc6410 fails to boot a THUMB2 kernel because the platform's firmware always enters the kernel in ARM mode from deep idle states. (rmk: tweaked to work without BSYM->badr changes.) Reported-by: Kevin Hilman <khilman@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-10 02:24:23 +08:00
.arm
ENTRY(cpu_resume_arm)
ARM: fix new BSYM() usage introduced via for-arm-soc branch Commit 32e55a777f83 ("ARM: 8389/1: Add cpu_resume_arm() for firmwares that resume in ARM state") needed to introduce a new usage of BSYM() to fix a problem with a previous patch. This in turn causes a conflict with the "bsym" branch which removes this symbol, replacing it with a 'badr' assembly macro. Fix this up. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-13 04:19:35 +08:00
THUMB( badr r9, 1f ) @ Kernel is entered in ARM.
ARM: 8389/1: Add cpu_resume_arm() for firmwares that resume in ARM state Some platforms always enter the kernel in the ARM state even if the kernel is compiled for THUMB2. Add a small wrapper on top of cpu_resume() that switches into THUMB2 state. This provides the functionality to fix a problem reported by Kevin Hilman on next-20150601 where the ifc6410 fails to boot a THUMB2 kernel because the platform's firmware always enters the kernel in ARM mode from deep idle states. (rmk: tweaked to work without BSYM->badr changes.) Reported-by: Kevin Hilman <khilman@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-10 02:24:23 +08:00
THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
THUMB( .thumb ) @ switch to Thumb now.
THUMB(1: )
ARM: fix EFM32 build breakage caused by cpu_resume_arm Fix: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr r9,1f+1' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12 16:24:17 +08:00
#endif
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
ENTRY(cpu_resume)
ARM: set BE8 if LE in head code If we are booting in LE and compiled for BE8, then add code to set the state to bE8. Since the instruction stream is always LE, we do not need to do anything special to the instruction. Also ensure that the secondary processors are started in the same mode. Note, we do add about 20 bytes to the kernel image, but it seems easier to do this than adding another configuration to change. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2013-02-01 17:40:42 +08:00
ARM_BE8(setend be) @ ensure we are in BE mode
ARM: 8053/1: kernel: sleep: restore HYP mode configuration in cpu_resume On CPUs with virtualization extensions the kernel installs HYP mode configuration on both primary and secondary cpus upon cold boot. On platforms where CPUs are shutdown in idle paths (ie CPU core gating), when a CPU resumes from low-power states it currently does not execute code that reinstalls the HYP configuration, which means that the kernel cannot run eg KVM properly on such machines. This patch, mirroring cold-boot behaviour, executes position independent code that reinstalls HYP configuration and drops to SVC mode safely on warmboot, so that deep idle states can be enabled in kernel running as hosts on platforms with power management HW. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Dave Martin <dave.martin@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Nicolas Pitre <nico@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-09 00:31:40 +08:00
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install_secondary
#endif
safe_svcmode_maskall r1
ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to perform low-level platform initialization. This results in a try to install HYP stubs for the second time for each CPU and results in false HYP/SVC mode mismatch detection. The HYP stubs are already installed at the beginning of the kernel initialization on the boot CPU (head.S) or in the secondary_startup() for other CPUs. To fix this issue MCPM code should use a cpu_resume() routine without HYP stubs installation. This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid XU3/XU4/HC1 boards. Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-18 16:31:41 +08:00
no_hyp:
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
mov r1, #0
ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
ALT_UP_B(1f)
ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded PC relative arithmetic, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that ALT_SMP() expects a single instruction so move the macro invocation after it. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 16:25:34 +08:00
adr_l r2, mpidr_hash @ r2 = struct mpidr_hash phys address
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
/*
* This ldmia relies on the memory layout of the mpidr_hash
* struct mpidr_hash.
*/
ldmia r2, { r3-r6 } @ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts
compute_mpidr_hash r1, r4, r5, r6, r0, r3
1:
ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded PC relative arithmetic, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that ALT_SMP() expects a single instruction so move the macro invocation after it. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 16:25:34 +08:00
ldr_l r0, sleep_save_sp + SLEEP_SAVE_SP_PHYS
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
ldr r0, [r0, r1, lsl #2]
ARM: pm: only use preallocated page table during resume Only use the preallocated page table during the resume, not while suspending. This avoids the overhead of having to switch unnecessarily to the resume page table in the suspend path. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-28 05:39:09 +08:00
@ load phys pgd, stack, resume fn
ARM( ldmia r0!, {r1, sp, pc} )
THUMB( ldmia r0!, {r1, r2, r3} )
THUMB( mov sp, r2 )
THUMB( bx r3 )
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
ENDPROC(cpu_resume)
ARM: fix EFM32 build breakage caused by cpu_resume_arm Fix: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr r9,1f+1' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12 16:24:17 +08:00
#ifdef CONFIG_MMU
ARM: 8389/1: Add cpu_resume_arm() for firmwares that resume in ARM state Some platforms always enter the kernel in the ARM state even if the kernel is compiled for THUMB2. Add a small wrapper on top of cpu_resume() that switches into THUMB2 state. This provides the functionality to fix a problem reported by Kevin Hilman on next-20150601 where the ifc6410 fails to boot a THUMB2 kernel because the platform's firmware always enters the kernel in ARM mode from deep idle states. (rmk: tweaked to work without BSYM->badr changes.) Reported-by: Kevin Hilman <khilman@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-10 02:24:23 +08:00
ENDPROC(cpu_resume_arm)
ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to perform low-level platform initialization. This results in a try to install HYP stubs for the second time for each CPU and results in false HYP/SVC mode mismatch detection. The HYP stubs are already installed at the beginning of the kernel initialization on the boot CPU (head.S) or in the secondary_startup() for other CPUs. To fix this issue MCPM code should use a cpu_resume() routine without HYP stubs installation. This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid XU3/XU4/HC1 boards. Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-18 16:31:41 +08:00
#endif
#ifdef CONFIG_MCPM
ENDPROC(cpu_resume_no_hyp)
ARM: fix EFM32 build breakage caused by cpu_resume_arm Fix: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr r9,1f+1' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12 16:24:17 +08:00
#endif
ARM: pm: add generic CPU suspend/resume support This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-06 23:48:39 +08:00
ARM: 8324/1: move cpu_resume() to .text section Move cpu_resume() to the .text section where it belongs. Change the adr reference to sleep_save_sp to an explicit PC relative reference so sleep_save_sp itself can remain in .data. This helps prevent linker failure on large kernels, as the code in the .data section may be too far away to be in range for normal b/bl instructions. Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-25 14:39:21 +08:00
.data
ARM: align .data section Robert Jarzmik reports that his PXA25x system fails to boot with 4.12, failing at __flush_whole_cache in arch/arm/mm/proc-xscale.S:215: 0xc0019e20 <+0>: ldr r1, [pc, #788] 0xc0019e24 <+4>: ldr r0, [r1] <== here with r1 containing 0xc06f82cd, which is the address of "clean_addr". Examination of the System.map shows: c06f22c8 D user_pmd_table c06f22cc d __warned.19178 c06f22cd d clean_addr indicating that a .data.unlikely section has appeared just before the .data section from proc-xscale.S. According to objdump -h, it appears that our assembly files default their .data alignment to 2**0, which is bad news if the preceding .data section size is not power-of-2 aligned at link time. Add the appropriate .align directives to all assembly files in arch/arm that are missing them where we require an appropriate alignment. Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-07-26 19:49:31 +08:00
.align 2
ARM: kernel: implement stack pointer save array through MPIDR hashing Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
2013-05-16 17:34:30 +08:00
.type sleep_save_sp, #object
ENTRY(sleep_save_sp)
.space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp
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