1 /*
2 * Hibernation support specific for ARM
3 *
4 * Derived from work on ARM hibernation support by:
5 *
6 * Ubuntu project, hibernation support for mach-dove
7 * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
8 * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
9 * https://lkml.org/lkml/2010/6/18/4
10 * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html
11 * https://patchwork.kernel.org/patch/96442/
12 *
13 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
14 *
15 * License terms: GNU General Public License (GPL) version 2
16 */
17
18 #include <linux/mm.h>
19 #include <linux/suspend.h>
20 #include <asm/system_misc.h>
21 #include <asm/idmap.h>
22 #include <asm/suspend.h>
23 #include <asm/memory.h>
24 #include <asm/sections.h>
25 #include "reboot.h"
26
27 int pfn_is_nosave(unsigned long pfn)
28 {
29 unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin);
30 unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1);
31
32 return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn);
33 }
34
35 void notrace save_processor_state(void)
36 {
37 WARN_ON(num_online_cpus() != 1);
38 local_fiq_disable();
39 }
40
41 void notrace restore_processor_state(void)
42 {
43 local_fiq_enable();
44 }
45
46 /*
47 * Snapshot kernel memory and reset the system.
48 *
49 * swsusp_save() is executed in the suspend finisher so that the CPU
50 * context pointer and memory are part of the saved image, which is
51 * required by the resume kernel image to restart execution from
52 * swsusp_arch_suspend().
53 *
54 * soft_restart is not technically needed, but is used to get success
55 * returned from cpu_suspend.
56 *
57 * When soft reboot completes, the hibernation snapshot is written out.
58 */
59 static int notrace arch_save_image(unsigned long unused)
60 {
61 int ret;
62
63 ret = swsusp_save();
64 if (ret == 0)
65 _soft_restart(virt_to_phys(cpu_resume), false);
66 return ret;
67 }
68
69 /*
70 * Save the current CPU state before suspend / poweroff.
71 */
72 int notrace swsusp_arch_suspend(void)
73 {
74 return cpu_suspend(0, arch_save_image);
75 }
76
77 /*
78 * Restore page contents for physical pages that were in use during loading
79 * hibernation image. Switch to idmap_pgd so the physical page tables
80 * are overwritten with the same contents.
81 */
82 static void notrace arch_restore_image(void *unused)
83 {
84 struct pbe *pbe;
85
86 cpu_switch_mm(idmap_pgd, &init_mm);
87 for (pbe = restore_pblist; pbe; pbe = pbe->next)
88 copy_page(pbe->orig_address, pbe->address);
89
90 _soft_restart(virt_to_phys(cpu_resume), false);
91 }
92
93 static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata;
94
95 /*
96 * Resume from the hibernation image.
97 * Due to the kernel heap / data restore, stack contents change underneath
98 * and that would make function calls impossible; switch to a temporary
99 * stack within the nosave region to avoid that problem.
100 */
101 int swsusp_arch_resume(void)
102 {
103 call_with_stack(arch_restore_image, 0,
104 resume_stack + ARRAY_SIZE(resume_stack));
105 return 0;
106 }
107
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