From: Sebastian Capella Date: Tue, 25 Mar 2014 00:20:29 +0000 (+0100) Subject: ARM: 8011/1: ARM hibernation / suspend-to-disk X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=603fb42a66499ab353466c7afa3d38beea20a8a9;p=linux-beck.git ARM: 8011/1: ARM hibernation / suspend-to-disk 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 Cc: "Rafael J. Wysocki" Signed-off-by: Sebastian Capella Acked-by: Pavel Machek Reviewed-by: Lorenzo Pieralisi [fixed duplicate virt_to_pfn() definition --rmk] Signed-off-by: Russell King --- diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index ab438cb5af55..58506175a3ea 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2294,6 +2294,11 @@ config ARCH_SUSPEND_POSSIBLE config ARM_CPU_SUSPEND def_bool PM_SLEEP +config ARCH_HIBERNATION_POSSIBLE + bool + depends on MMU + default y if ARCH_SUSPEND_POSSIBLE + endmenu source "net/Kconfig" diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index a766bcbaf8ad..10f0464206a2 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 000000000000..bb8b79648643 --- /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 + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include +#include +#include +#include +#include +#include + +extern const void __nosave_begin, __nosave_end; + +int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin); + unsigned long nosave_end_pfn = virt_to_pfn(&__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/include/linux/suspend.h b/include/linux/suspend.h index f73cabf59012..38bbf95109da 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) {}