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(addr: virt_to_idmap(cpu_resume), disable_l2: 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(to: pbe->orig_address, from: pbe->address); |
88 | |
89 | _soft_restart(addr: virt_to_idmap(cpu_resume), disable_l2: 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(fn: arch_restore_image, arg: 0, |
103 | sp: resume_stack + ARRAY_SIZE(resume_stack)); |
104 | return 0; |
105 | } |
106 | |