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