1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Hibernation support specific for ARM 4 * 5 * Derived from work on ARM hibernation support by: 6 * 7 * Ubuntu project, hibernation support for mach-dove 8 * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu) 9 * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.) 10 * https://lkml.org/lkml/2010/6/18/4 11 * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html 12 * https://patchwork.kernel.org/patch/96442/ 13 * 14 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> 15 */ 16 17 #include <linux/mm.h> 18 #include <linux/suspend.h> 19 #include <asm/system_misc.h> 20 #include <asm/idmap.h> 21 #include <asm/suspend.h> 22 #include <asm/page.h> 23 #include <asm/sections.h> 24 #include "reboot.h" 25 26 int pfn_is_nosave(unsigned long pfn) 27 { 28 unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin); 29 unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1); 30 31 return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn); 32 } 33 34 void notrace save_processor_state(void) 35 { 36 WARN_ON(num_online_cpus() != 1); 37 local_fiq_disable(); 38 } 39 40 void notrace restore_processor_state(void) 41 { 42 local_fiq_enable(); 43 } 44 45 /* 46 * Snapshot kernel memory and reset the system. 47 * 48 * swsusp_save() is executed in the suspend finisher so that the CPU 49 * context pointer and memory are part of the saved image, which is 50 * required by the resume kernel image to restart execution from 51 * swsusp_arch_suspend(). 52 * 53 * soft_restart is not technically needed, but is used to get success 54 * returned from cpu_suspend. 55 * 56 * When soft reboot completes, the hibernation snapshot is written out. 57 */ 58 static int notrace arch_save_image(unsigned long unused) 59 { 60 int ret; 61 62 ret = swsusp_save(); 63 if (ret == 0) 64 _soft_restart(virt_to_idmap(cpu_resume), false); 65 return ret; 66 } 67 68 /* 69 * Save the current CPU state before suspend / poweroff. 70 */ 71 int notrace swsusp_arch_suspend(void) 72 { 73 return cpu_suspend(0, arch_save_image); 74 } 75 76 /* 77 * Restore page contents for physical pages that were in use during loading 78 * hibernation image. Switch to idmap_pgd so the physical page tables 79 * are overwritten with the same contents. 80 */ 81 static void notrace arch_restore_image(void *unused) 82 { 83 struct pbe *pbe; 84 85 cpu_switch_mm(idmap_pgd, &init_mm); 86 for (pbe = restore_pblist; pbe; pbe = pbe->next) 87 copy_page(pbe->orig_address, pbe->address); 88 89 _soft_restart(virt_to_idmap(cpu_resume), false); 90 } 91 92 static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata; 93 94 /* 95 * Resume from the hibernation image. 96 * Due to the kernel heap / data restore, stack contents change underneath 97 * and that would make function calls impossible; switch to a temporary 98 * stack within the nosave region to avoid that problem. 99 */ 100 int swsusp_arch_resume(void) 101 { 102 call_with_stack(arch_restore_image, 0, 103 resume_stack + ARRAY_SIZE(resume_stack)); 104 return 0; 105 } 106