linux/arch/arm/kernel/hibernate.c
Sebastian Capella 603fb42a66 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 <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>
[fixed duplicate virt_to_pfn() definition --rmk]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-23 01:24:14 +01:00

108 lines
2.8 KiB
C

/*
* 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;
}