05f28f0d684af34c7d318a34d6dbeb483db44e5c
[linux-2.6.git] / arch / x86 / power / hibernate_64.c
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@suse.cz>
8  * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
9  */
10
11 #include <linux/smp.h>
12 #include <linux/suspend.h>
13 #include <asm/proto.h>
14 #include <asm/page.h>
15 #include <asm/pgtable.h>
16 #include <asm/mtrr.h>
17
18 /* References to section boundaries */
19 extern const void __nosave_begin, __nosave_end;
20
21 /* Defined in arch/x86_64/kernel/suspend_asm.S */
22 extern int restore_image(void);
23
24 /*
25  * Address to jump to in the last phase of restore in order to get to the image
26  * kernel's text (this value is passed in the image header).
27  */
28 unsigned long restore_jump_address;
29
30 /*
31  * Value of the cr3 register from before the hibernation (this value is passed
32  * in the image header).
33  */
34 unsigned long restore_cr3;
35
36 pgd_t *temp_level4_pgt;
37
38 void *relocated_restore_code;
39
40 static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
41 {
42         long i, j;
43
44         i = pud_index(address);
45         pud = pud + i;
46         for (; i < PTRS_PER_PUD; pud++, i++) {
47                 unsigned long paddr;
48                 pmd_t *pmd;
49
50                 paddr = address + i*PUD_SIZE;
51                 if (paddr >= end)
52                         break;
53
54                 pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
55                 if (!pmd)
56                         return -ENOMEM;
57                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
58                 for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
59                         unsigned long pe;
60
61                         if (paddr >= end)
62                                 break;
63                         pe = __PAGE_KERNEL_LARGE_EXEC | paddr;
64                         pe &= __supported_pte_mask;
65                         set_pmd(pmd, __pmd(pe));
66                 }
67         }
68         return 0;
69 }
70
71 static int set_up_temporary_mappings(void)
72 {
73         unsigned long start, end, next;
74         int error;
75
76         temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
77         if (!temp_level4_pgt)
78                 return -ENOMEM;
79
80         /* It is safe to reuse the original kernel mapping */
81         set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
82                 init_level4_pgt[pgd_index(__START_KERNEL_map)]);
83
84         /* Set up the direct mapping from scratch */
85         start = (unsigned long)pfn_to_kaddr(0);
86         end = (unsigned long)pfn_to_kaddr(end_pfn);
87
88         for (; start < end; start = next) {
89                 pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
90                 if (!pud)
91                         return -ENOMEM;
92                 next = start + PGDIR_SIZE;
93                 if (next > end)
94                         next = end;
95                 if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
96                         return error;
97                 set_pgd(temp_level4_pgt + pgd_index(start),
98                         mk_kernel_pgd(__pa(pud)));
99         }
100         return 0;
101 }
102
103 int swsusp_arch_resume(void)
104 {
105         int error;
106
107         /* We have got enough memory and from now on we cannot recover */
108         if ((error = set_up_temporary_mappings()))
109                 return error;
110
111         relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
112         if (!relocated_restore_code)
113                 return -ENOMEM;
114         memcpy(relocated_restore_code, &core_restore_code,
115                &restore_registers - &core_restore_code);
116
117         restore_image();
118         return 0;
119 }
120
121 /*
122  *      pfn_is_nosave - check if given pfn is in the 'nosave' section
123  */
124
125 int pfn_is_nosave(unsigned long pfn)
126 {
127         unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
128         unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
129         return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
130 }
131
132 struct restore_data_record {
133         unsigned long jump_address;
134         unsigned long cr3;
135         unsigned long magic;
136 };
137
138 #define RESTORE_MAGIC   0x0123456789ABCDEFUL
139
140 /**
141  *      arch_hibernation_header_save - populate the architecture specific part
142  *              of a hibernation image header
143  *      @addr: address to save the data at
144  */
145 int arch_hibernation_header_save(void *addr, unsigned int max_size)
146 {
147         struct restore_data_record *rdr = addr;
148
149         if (max_size < sizeof(struct restore_data_record))
150                 return -EOVERFLOW;
151         rdr->jump_address = restore_jump_address;
152         rdr->cr3 = restore_cr3;
153         rdr->magic = RESTORE_MAGIC;
154         return 0;
155 }
156
157 /**
158  *      arch_hibernation_header_restore - read the architecture specific data
159  *              from the hibernation image header
160  *      @addr: address to read the data from
161  */
162 int arch_hibernation_header_restore(void *addr)
163 {
164         struct restore_data_record *rdr = addr;
165
166         restore_jump_address = rdr->jump_address;
167         restore_cr3 = rdr->cr3;
168         return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
169 }