1 /*
2 * Hibernation support for x86-64
3 *
4 * Distribute under GPLv2
5 *
6 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
7 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
8 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
9 */
10
11 #include <linux/gfp.h>
12 #include <linux/smp.h>
13 #include <linux/suspend.h>
14
15 #include <asm/init.h>
16 #include <asm/proto.h>
17 #include <asm/page.h>
18 #include <asm/pgtable.h>
19 #include <asm/mtrr.h>
20 #include <asm/sections.h>
21 #include <asm/suspend.h>
22
23 /* Defined in hibernate_asm_64.S */
24 extern asmlinkage __visible int restore_image(void);
25
26 /*
27 * Address to jump to in the last phase of restore in order to get to the image
28 * kernel's text (this value is passed in the image header).
29 */
30 unsigned long restore_jump_address __visible;
31
32 /*
33 * Value of the cr3 register from before the hibernation (this value is passed
34 * in the image header).
35 */
36 unsigned long restore_cr3 __visible;
37
38 pgd_t *temp_level4_pgt __visible;
39
40 void *relocated_restore_code __visible;
41
alloc_pgt_page(void * context)42 static void *alloc_pgt_page(void *context)
43 {
44 return (void *)get_safe_page(GFP_ATOMIC);
45 }
46
set_up_temporary_mappings(void)47 static int set_up_temporary_mappings(void)
48 {
49 struct x86_mapping_info info = {
50 .alloc_pgt_page = alloc_pgt_page,
51 .pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
52 .kernel_mapping = true,
53 };
54 unsigned long mstart, mend;
55 int result;
56 int i;
57
58 temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
59 if (!temp_level4_pgt)
60 return -ENOMEM;
61
62 /* It is safe to reuse the original kernel mapping */
63 set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
64 init_level4_pgt[pgd_index(__START_KERNEL_map)]);
65
66 /* Set up the direct mapping from scratch */
67 for (i = 0; i < nr_pfn_mapped; i++) {
68 mstart = pfn_mapped[i].start << PAGE_SHIFT;
69 mend = pfn_mapped[i].end << PAGE_SHIFT;
70
71 result = kernel_ident_mapping_init(&info, temp_level4_pgt,
72 mstart, mend);
73
74 if (result)
75 return result;
76 }
77
78 return 0;
79 }
80
swsusp_arch_resume(void)81 asmlinkage int swsusp_arch_resume(void)
82 {
83 int error;
84
85 /* We have got enough memory and from now on we cannot recover */
86 if ((error = set_up_temporary_mappings()))
87 return error;
88
89 relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
90 if (!relocated_restore_code)
91 return -ENOMEM;
92 memcpy(relocated_restore_code, &core_restore_code,
93 &restore_registers - &core_restore_code);
94
95 restore_image();
96 return 0;
97 }
98
99 /*
100 * pfn_is_nosave - check if given pfn is in the 'nosave' section
101 */
102
pfn_is_nosave(unsigned long pfn)103 int pfn_is_nosave(unsigned long pfn)
104 {
105 unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
106 unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
107 return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
108 }
109
110 struct restore_data_record {
111 unsigned long jump_address;
112 unsigned long cr3;
113 unsigned long magic;
114 };
115
116 #define RESTORE_MAGIC 0x0123456789ABCDEFUL
117
118 /**
119 * arch_hibernation_header_save - populate the architecture specific part
120 * of a hibernation image header
121 * @addr: address to save the data at
122 */
arch_hibernation_header_save(void * addr,unsigned int max_size)123 int arch_hibernation_header_save(void *addr, unsigned int max_size)
124 {
125 struct restore_data_record *rdr = addr;
126
127 if (max_size < sizeof(struct restore_data_record))
128 return -EOVERFLOW;
129 rdr->jump_address = restore_jump_address;
130 rdr->cr3 = restore_cr3;
131 rdr->magic = RESTORE_MAGIC;
132 return 0;
133 }
134
135 /**
136 * arch_hibernation_header_restore - read the architecture specific data
137 * from the hibernation image header
138 * @addr: address to read the data from
139 */
arch_hibernation_header_restore(void * addr)140 int arch_hibernation_header_restore(void *addr)
141 {
142 struct restore_data_record *rdr = addr;
143
144 restore_jump_address = rdr->jump_address;
145 restore_cr3 = rdr->cr3;
146 return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
147 }
148