Patches adding support for hibernation on ARM - ARM hibernation / suspend-to-disk - Change soft_restart to use non-tracing raw_local_irq_disable
Patches based on v3.14-rc5 tag, verified hibernation on beaglebone black on a branch based on 3.13 merged with initial omap support from Russ Dill which can be found here (includes v1 patchset): http://git.linaro.org/git-ro/people/sebastian.capella/linux.git hibernation_3.13_russMerge
[PATCH v8 1/2] ARM: avoid tracers in soft_restart arch/arm/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Use raw_local_irq_disable in place of local_irq_disable to avoid infinite abort recursion while tracing. (unchanged since v3)
[PATCH v8 2/2] ARM hibernation / suspend-to-disk arch/arm/kernel/Makefile | 1 + arch/arm/kernel/hibernate.c | 107 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/mm/Kconfig | 5 ++ include/linux/suspend.h | 2 + 4 files changed, 115 insertions(+)
Adds support for ARM based hibernation
Additional notes: -----------------
There are two checkpatch warnings added by this patch. These follow behavior in existing hibernation implementations on other platforms.
WARNING: externs should be avoided in .c files #108: FILE: arch/arm/kernel/hibernate.c:25: +extern const void __nosave_begin, __nosave_end;
This extern is picking up the linker nosave region definitions, only used in hibernate. Follows same extern line used mips, powerpc, s390, sh, sparc, x86 & unicore32
WARNING: externs should be avoided in .c files #186: FILE: arch/arm/kernel/hibernate.c:103: + extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
This extern is used in the arch/arm/ in hibernate, process and bL_switcher
Changes in v8: -------------- * remove definition and use of __pa_symbol
Changes in v7: -------------- * remove use of RELOC_HIDE macro * remove unused #includes * fixup comment for arch_restore_image * ensure alignment of resume stack on 8 byte boundary
Changes in v6: -------------- * Simplify static variable names
Changes in v5: -------------- * Fixed checkpatch warning on trailing whitespace
Changes in v4: -------------- * updated comment for soft_restart with review feedback * dropped freeze_processes patch which was queued separately to 3.14 by Rafael Wysocki: https://lkml.org/lkml/2014/2/25/683
Changes in v3: -------------- * added comment to use of soft_restart * drop irq disable soft_restart patch * add patch to avoid tracers in soft_restart by using raw_local_irq_*
Changes in v2: -------------- * Removed unneeded flush_thread, use of __naked and cpu_init. * dropped Cyril Chemparathy cyril@ti.com from Cc: list as emails are bouncing.
Thanks,
Sebastian Capella
Use of tracers in local_irq_disable is causes recursive aborts when called with irqs disabled and using a temporary stack (hibernation). Replace local_irq_disable with raw_local_irq_disable instead to avoid tracers.
Signed-off-by: Sebastian Capella sebastian.capella@linaro.org Cc: Russell King linux@arm.linux.org.uk Cc: Andrew Morton akpm@linux-foundation.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Will Deacon will.deacon@arm.com Cc: Robin Holt robin.m.holt@gmail.com Cc: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: Konstantin Khlebnikov k.khlebnikov@samsung.com Cc: Steven Capper steve.capper@linaro.org Cc: Stephen Warren swarren@nvidia.com Cc: Tejun Heo tj@kernel.org --- arch/arm/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 92f7b15..f58b723 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -100,7 +100,7 @@ void soft_restart(unsigned long addr) u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
/* Disable interrupts first */ - local_irq_disable(); + raw_local_irq_disable(); local_fiq_disable();
/* Disable the L2 if we're the last man standing. */
From: Russ Dill Russ.Dill@ti.com
Enable hibernation for ARM architectures and provide ARM architecture specific calls used during hibernation.
The swsusp hibernation framework depends on the platform first having functional suspend/resume.
Then, in order to enable hibernation on a given platform, a platform_hibernation_ops structure may need to be registered with the system in order to save/restore any SoC-specific / cpu specific state needing (re)init over a suspend-to-disk/resume-from-disk cycle.
For example:
- "secure" SoCs that have different sets of control registers and/or different CR reg access patterns.
- SoCs with L2 caches as the activation sequence there is SoC-dependent; a full off-on cycle for L2 is not done by the hibernation support code.
- SoCs requiring steps on wakeup _before_ the "generic" parts done by cpu_suspend / cpu_resume can work correctly.
- SoCs having persistent state which is maintained during suspend and resume, but will be lost during the power off cycle after suspend-to-disk.
This is a rebase/rework of Frank Hofmann's v5 hibernation patchset.
Acked-by: Russ Dill Russ.Dill@ti.com Cc: "Rafael J. Wysocki" rjw@rjwysocki.net Signed-off-by: Sebastian Capella sebastian.capella@linaro.org Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: Russell King linux@arm.linux.org.uk Cc: Len Brown len.brown@intel.com Cc: Nicolas Pitre nico@linaro.org Cc: Santosh Shilimkar santosh.shilimkar@ti.com Cc: Will Deacon will.deacon@arm.com Cc: Jonathan Austin jonathan.austin@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: "Uwe Kleine-König" u.kleine-koenig@pengutronix.de Cc: Stephen Boyd sboyd@codeaurora.org Cc: Laura Abbott lauraa@codeaurora.org Cc: Jiang Liu liuj97@gmail.com Cc: Sricharan R r.sricharan@ti.com Cc: Victor Kamensky victor.kamensky@linaro.org Cc: Stefano Stabellini stefano.stabellini@eu.citrix.com Cc: Ben Dooks ben.dooks@codethink.co.uk --- arch/arm/kernel/Makefile | 1 + arch/arm/kernel/hibernate.c | 107 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/mm/Kconfig | 5 ++ include/linux/suspend.h | 2 + 4 files changed, 115 insertions(+) create mode 100644 arch/arm/kernel/hibernate.c
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index a30fc9b..8afa848 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_ARM_CPU_SUSPEND) += sleep.o suspend.o +obj-$(CONFIG_HIBERNATION) += hibernate.o obj-$(CONFIG_SMP) += smp.o ifdef CONFIG_MMU obj-$(CONFIG_SMP) += smp_tlb.o diff --git a/arch/arm/kernel/hibernate.c b/arch/arm/kernel/hibernate.c new file mode 100644 index 0000000..036293d --- /dev/null +++ b/arch/arm/kernel/hibernate.c @@ -0,0 +1,107 @@ +/* + * Hibernation support specific for ARM + * + * Derived from work on ARM hibernation support by: + * + * Ubuntu project, hibernation support for mach-dove + * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu) + * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.) + * https://lkml.org/lkml/2010/6/18/4 + * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html + * https://patchwork.kernel.org/patch/96442/ + * + * Copyright (C) 2006 Rafael J. Wysocki rjw@sisk.pl + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include <linux/mm.h> +#include <linux/suspend.h> +#include <asm/system_misc.h> +#include <asm/idmap.h> +#include <asm/suspend.h> +#include <asm/memory.h> + +extern const void __nosave_begin, __nosave_end; + +int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = __phys_to_pfn(__pa(&__nosave_begin)); + unsigned long nosave_end_pfn = __phys_to_pfn(__pa(&__nosave_end - 1)); + + return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn); +} + +void notrace save_processor_state(void) +{ + WARN_ON(num_online_cpus() != 1); + local_fiq_disable(); +} + +void notrace restore_processor_state(void) +{ + local_fiq_enable(); +} + +/* + * Snapshot kernel memory and reset the system. + * + * swsusp_save() is executed in the suspend finisher so that the CPU + * context pointer and memory are part of the saved image, which is + * required by the resume kernel image to restart execution from + * swsusp_arch_suspend(). + * + * soft_restart is not technically needed, but is used to get success + * returned from cpu_suspend. + * + * When soft reboot completes, the hibernation snapshot is written out. + */ +static int notrace arch_save_image(unsigned long unused) +{ + int ret; + + ret = swsusp_save(); + if (ret == 0) + soft_restart(virt_to_phys(cpu_resume)); + return ret; +} + +/* + * Save the current CPU state before suspend / poweroff. + */ +int notrace swsusp_arch_suspend(void) +{ + return cpu_suspend(0, arch_save_image); +} + +/* + * Restore page contents for physical pages that were in use during loading + * hibernation image. Switch to idmap_pgd so the physical page tables + * are overwritten with the same contents. + */ +static void notrace arch_restore_image(void *unused) +{ + struct pbe *pbe; + + cpu_switch_mm(idmap_pgd, &init_mm); + for (pbe = restore_pblist; pbe; pbe = pbe->next) + copy_page(pbe->orig_address, pbe->address); + + soft_restart(virt_to_phys(cpu_resume)); +} + +static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata; + +/* + * Resume from the hibernation image. + * Due to the kernel heap / data restore, stack contents change underneath + * and that would make function calls impossible; switch to a temporary + * stack within the nosave region to avoid that problem. + */ +int swsusp_arch_resume(void) +{ + extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); + call_with_stack(arch_restore_image, 0, + resume_stack + ARRAY_SIZE(resume_stack)); + return 0; +} diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 1f8fed9..83707702 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -611,6 +611,11 @@ config CPU_USE_DOMAINS config IO_36 bool
+config ARCH_HIBERNATION_POSSIBLE + bool + depends on MMU + default y if CPU_ARM920T || CPU_ARM926T || CPU_SA1100 || CPU_XSCALE || CPU_XSC3 || CPU_V6 || CPU_V6K || CPU_V7 + comment "Processor Features"
config ARM_LPAE diff --git a/include/linux/suspend.h b/include/linux/suspend.h index f73cabf..38bbf95 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -320,6 +320,8 @@ extern unsigned long get_safe_page(gfp_t gfp_mask); extern void hibernation_set_ops(const struct platform_hibernation_ops *ops); extern int hibernate(void); extern bool system_entering_hibernation(void); +asmlinkage int swsusp_save(void); +extern struct pbe *restore_pblist; #else /* CONFIG_HIBERNATION */ static inline void register_nosave_region(unsigned long b, unsigned long e) {} static inline void register_nosave_region_late(unsigned long b, unsigned long e) {}
linaro-kernel@lists.linaro.org
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Sebastian Capella