/* * 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> #include "reboot.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_idmap(cpu_resume), false); 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_idmap(cpu_resume), false); } 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) { call_with_stack(arch_restore_image, 0, resume_stack + ARRAY_SIZE(resume_stack)); return 0; }