| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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> |
| */ |
| |
| #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; |
| } |