Commit 603fb42a authored by Sebastian Capella's avatar Sebastian Capella Committed by Russell King
Browse files

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: default avatarRuss Dill <Russ.Dill@ti.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: default avatarSebastian Capella <sebastian.capella@linaro.org>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Reviewed-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[fixed duplicate virt_to_pfn() definition --rmk]
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 44ae903b

arch/arm/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -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"

arch/arm/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/arm/kernel/hibernate.c

0 → 100644
+107 −0
Original line number Diff line number Diff line 
/*

 * 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 = 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;

}

include/linux/suspend.h

+2 −0
Original line number Diff line number Diff line
@@ -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) {}

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