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Commit | Line | Data |
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2d4a34c9 | 1 | /* |
c5759124 | 2 | * Hibernation support specific for i386 - temporary page tables |
2d4a34c9 RW |
3 | * |
4 | * Distribute under GPLv2 | |
5 | * | |
6 | * Copyright (c) 2006 Rafael J. Wysocki <rjw@sisk.pl> | |
7 | */ | |
8 | ||
5a0e3ad6 | 9 | #include <linux/gfp.h> |
2d4a34c9 RW |
10 | #include <linux/suspend.h> |
11 | #include <linux/bootmem.h> | |
12 | ||
13 | #include <asm/system.h> | |
14 | #include <asm/page.h> | |
15 | #include <asm/pgtable.h> | |
97a70e54 | 16 | #include <asm/mmzone.h> |
2d4a34c9 | 17 | |
261f0ce5 | 18 | /* Defined in hibernate_asm_32.S */ |
2d4a34c9 RW |
19 | extern int restore_image(void); |
20 | ||
49c3df6a VG |
21 | /* References to section boundaries */ |
22 | extern const void __nosave_begin, __nosave_end; | |
23 | ||
2d4a34c9 RW |
24 | /* Pointer to the temporary resume page tables */ |
25 | pgd_t *resume_pg_dir; | |
26 | ||
27 | /* The following three functions are based on the analogous code in | |
261f0ce5 | 28 | * arch/x86/mm/init_32.c |
2d4a34c9 RW |
29 | */ |
30 | ||
31 | /* | |
32 | * Create a middle page table on a resume-safe page and put a pointer to it in | |
33 | * the given global directory entry. This only returns the gd entry | |
34 | * in non-PAE compilation mode, since the middle layer is folded. | |
35 | */ | |
36 | static pmd_t *resume_one_md_table_init(pgd_t *pgd) | |
37 | { | |
38 | pud_t *pud; | |
39 | pmd_t *pmd_table; | |
40 | ||
41 | #ifdef CONFIG_X86_PAE | |
42 | pmd_table = (pmd_t *)get_safe_page(GFP_ATOMIC); | |
43 | if (!pmd_table) | |
44 | return NULL; | |
45 | ||
46 | set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); | |
47 | pud = pud_offset(pgd, 0); | |
48 | ||
49 | BUG_ON(pmd_table != pmd_offset(pud, 0)); | |
50 | #else | |
51 | pud = pud_offset(pgd, 0); | |
52 | pmd_table = pmd_offset(pud, 0); | |
53 | #endif | |
54 | ||
55 | return pmd_table; | |
56 | } | |
57 | ||
58 | /* | |
59 | * Create a page table on a resume-safe page and place a pointer to it in | |
60 | * a middle page directory entry. | |
61 | */ | |
62 | static pte_t *resume_one_page_table_init(pmd_t *pmd) | |
63 | { | |
64 | if (pmd_none(*pmd)) { | |
65 | pte_t *page_table = (pte_t *)get_safe_page(GFP_ATOMIC); | |
66 | if (!page_table) | |
67 | return NULL; | |
68 | ||
69 | set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); | |
70 | ||
71 | BUG_ON(page_table != pte_offset_kernel(pmd, 0)); | |
72 | ||
73 | return page_table; | |
74 | } | |
75 | ||
76 | return pte_offset_kernel(pmd, 0); | |
77 | } | |
78 | ||
79 | /* | |
80 | * This maps the physical memory to kernel virtual address space, a total | |
81 | * of max_low_pfn pages, by creating page tables starting from address | |
82 | * PAGE_OFFSET. The page tables are allocated out of resume-safe pages. | |
83 | */ | |
84 | static int resume_physical_mapping_init(pgd_t *pgd_base) | |
85 | { | |
86 | unsigned long pfn; | |
87 | pgd_t *pgd; | |
88 | pmd_t *pmd; | |
89 | pte_t *pte; | |
90 | int pgd_idx, pmd_idx; | |
91 | ||
92 | pgd_idx = pgd_index(PAGE_OFFSET); | |
93 | pgd = pgd_base + pgd_idx; | |
94 | pfn = 0; | |
95 | ||
96 | for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { | |
97 | pmd = resume_one_md_table_init(pgd); | |
98 | if (!pmd) | |
99 | return -ENOMEM; | |
100 | ||
101 | if (pfn >= max_low_pfn) | |
102 | continue; | |
103 | ||
104 | for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD; pmd++, pmd_idx++) { | |
105 | if (pfn >= max_low_pfn) | |
106 | break; | |
107 | ||
108 | /* Map with big pages if possible, otherwise create | |
109 | * normal page tables. | |
110 | * NOTE: We can mark everything as executable here | |
111 | */ | |
112 | if (cpu_has_pse) { | |
113 | set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC)); | |
114 | pfn += PTRS_PER_PTE; | |
115 | } else { | |
116 | pte_t *max_pte; | |
117 | ||
118 | pte = resume_one_page_table_init(pmd); | |
119 | if (!pte) | |
120 | return -ENOMEM; | |
121 | ||
122 | max_pte = pte + PTRS_PER_PTE; | |
123 | for (; pte < max_pte; pte++, pfn++) { | |
124 | if (pfn >= max_low_pfn) | |
125 | break; | |
126 | ||
127 | set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); | |
128 | } | |
129 | } | |
130 | } | |
131 | } | |
97a70e54 RW |
132 | |
133 | resume_map_numa_kva(pgd_base); | |
134 | ||
2d4a34c9 RW |
135 | return 0; |
136 | } | |
137 | ||
138 | static inline void resume_init_first_level_page_table(pgd_t *pg_dir) | |
139 | { | |
140 | #ifdef CONFIG_X86_PAE | |
141 | int i; | |
142 | ||
143 | /* Init entries of the first-level page table to the zero page */ | |
144 | for (i = 0; i < PTRS_PER_PGD; i++) | |
145 | set_pgd(pg_dir + i, | |
146 | __pgd(__pa(empty_zero_page) | _PAGE_PRESENT)); | |
147 | #endif | |
148 | } | |
149 | ||
150 | int swsusp_arch_resume(void) | |
151 | { | |
152 | int error; | |
153 | ||
154 | resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC); | |
155 | if (!resume_pg_dir) | |
156 | return -ENOMEM; | |
157 | ||
158 | resume_init_first_level_page_table(resume_pg_dir); | |
159 | error = resume_physical_mapping_init(resume_pg_dir); | |
160 | if (error) | |
161 | return error; | |
162 | ||
163 | /* We have got enough memory and from now on we cannot recover */ | |
164 | restore_image(); | |
165 | return 0; | |
166 | } | |
49c3df6a VG |
167 | |
168 | /* | |
169 | * pfn_is_nosave - check if given pfn is in the 'nosave' section | |
170 | */ | |
171 | ||
172 | int pfn_is_nosave(unsigned long pfn) | |
173 | { | |
174 | unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT; | |
175 | unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT; | |
176 | return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); | |
177 | } |