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 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: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- arch/arm/include/asm/memory.h | 1 + arch/arm/kernel/Makefile | 1 + arch/arm/kernel/hibernate.c | 113 +++++++++++++++++++++++++++++++++++++++++ arch/arm/mm/Kconfig | 5 ++ include/linux/suspend.h | 2 + 5 files changed, 122 insertions(+) create mode 100644 arch/arm/kernel/hibernate.c
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 8756e4b..1079ea8 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -291,6 +291,7 @@ static inline void *phys_to_virt(phys_addr_t x) */ #define __pa(x) __virt_to_phys((unsigned long)(x)) #define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x))) +#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
extern phys_addr_t (*arch_virt_to_idmap)(unsigned long x); 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..a41e0e3 --- /dev/null +++ b/arch/arm/kernel/hibernate.c @@ -0,0 +1,113 @@ +/* + * 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/tlbflush.h> +#include <asm/cacheflush.h> +#include <asm/system_misc.h> +#include <asm/idmap.h> +#include <asm/suspend.h> + +extern const void __nosave_begin, __nosave_end; + +int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = + __pa_symbol(&__nosave_begin) >> PAGE_SHIFT; + unsigned long nosave_end_pfn = + PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT; + + 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); +} + +/* + * The framework loads the hibernation image into a linked list anchored + * at restore_pblist, for swsusp_arch_resume() to copy back to the proper + * destinations. + * + * To make this work if resume is triggered from initramfs, the + * pagetables need to be switched to allow writes to kernel mem. + */ +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 u8 resume_stack[PAGE_SIZE/2] __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 + sizeof(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) {}