forked from Minki/linux
603fb42a66
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>
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/*
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* Hibernation support specific for ARM
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*
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* Derived from work on ARM hibernation support by:
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*
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* Ubuntu project, hibernation support for mach-dove
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* Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
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* Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
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* https://lkml.org/lkml/2010/6/18/4
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* https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html
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* https://patchwork.kernel.org/patch/96442/
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*
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* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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*
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* License terms: GNU General Public License (GPL) version 2
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*/
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#include <linux/mm.h>
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#include <linux/suspend.h>
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#include <asm/system_misc.h>
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#include <asm/idmap.h>
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#include <asm/suspend.h>
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#include <asm/memory.h>
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extern const void __nosave_begin, __nosave_end;
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int pfn_is_nosave(unsigned long pfn)
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{
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unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin);
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unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1);
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return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn);
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}
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void notrace save_processor_state(void)
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{
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WARN_ON(num_online_cpus() != 1);
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local_fiq_disable();
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}
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void notrace restore_processor_state(void)
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{
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local_fiq_enable();
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}
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/*
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* Snapshot kernel memory and reset the system.
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*
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* swsusp_save() is executed in the suspend finisher so that the CPU
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* context pointer and memory are part of the saved image, which is
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* required by the resume kernel image to restart execution from
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* swsusp_arch_suspend().
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*
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* soft_restart is not technically needed, but is used to get success
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* returned from cpu_suspend.
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*
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* When soft reboot completes, the hibernation snapshot is written out.
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*/
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static int notrace arch_save_image(unsigned long unused)
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{
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int ret;
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ret = swsusp_save();
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if (ret == 0)
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soft_restart(virt_to_phys(cpu_resume));
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return ret;
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}
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/*
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* Save the current CPU state before suspend / poweroff.
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*/
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int notrace swsusp_arch_suspend(void)
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{
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return cpu_suspend(0, arch_save_image);
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}
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/*
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* Restore page contents for physical pages that were in use during loading
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* hibernation image. Switch to idmap_pgd so the physical page tables
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* are overwritten with the same contents.
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*/
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static void notrace arch_restore_image(void *unused)
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{
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struct pbe *pbe;
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cpu_switch_mm(idmap_pgd, &init_mm);
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for (pbe = restore_pblist; pbe; pbe = pbe->next)
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copy_page(pbe->orig_address, pbe->address);
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soft_restart(virt_to_phys(cpu_resume));
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}
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static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata;
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/*
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* Resume from the hibernation image.
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* Due to the kernel heap / data restore, stack contents change underneath
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* and that would make function calls impossible; switch to a temporary
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* stack within the nosave region to avoid that problem.
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*/
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int swsusp_arch_resume(void)
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{
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extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
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call_with_stack(arch_restore_image, 0,
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resume_stack + ARRAY_SIZE(resume_stack));
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return 0;
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}
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