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/*
* 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>
#include <asm/sections.h>
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;
}
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