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64909882 G |
1 | /* |
2 | * linux/arch/unicore32/kernel/hibernate.c | |
3 | * | |
4 | * Code specific to PKUnity SoC and UniCore ISA | |
5 | * | |
6 | * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> | |
7 | * Copyright (C) 2001-2010 Guan Xuetao | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/gfp.h> | |
15 | #include <linux/suspend.h> | |
16 | #include <linux/bootmem.h> | |
17 | ||
64909882 G |
18 | #include <asm/page.h> |
19 | #include <asm/pgtable.h> | |
20 | #include <asm/pgalloc.h> | |
7f8998c7 | 21 | #include <asm/sections.h> |
64909882 G |
22 | #include <asm/suspend.h> |
23 | ||
24 | #include "mach/pm.h" | |
25 | ||
26 | /* Pointer to the temporary resume page tables */ | |
27 | pgd_t *resume_pg_dir; | |
28 | ||
29 | struct swsusp_arch_regs swsusp_arch_regs_cpu0; | |
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 | pud = pud_offset(pgd, 0); | |
42 | pmd_table = pmd_offset(pud, 0); | |
43 | ||
44 | return pmd_table; | |
45 | } | |
46 | ||
47 | /* | |
48 | * Create a page table on a resume-safe page and place a pointer to it in | |
49 | * a middle page directory entry. | |
50 | */ | |
51 | static pte_t *resume_one_page_table_init(pmd_t *pmd) | |
52 | { | |
53 | if (pmd_none(*pmd)) { | |
54 | pte_t *page_table = (pte_t *)get_safe_page(GFP_ATOMIC); | |
55 | if (!page_table) | |
56 | return NULL; | |
57 | ||
58 | set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_KERNEL_TABLE)); | |
59 | ||
60 | BUG_ON(page_table != pte_offset_kernel(pmd, 0)); | |
61 | ||
62 | return page_table; | |
63 | } | |
64 | ||
65 | return pte_offset_kernel(pmd, 0); | |
66 | } | |
67 | ||
68 | /* | |
69 | * This maps the physical memory to kernel virtual address space, a total | |
70 | * of max_low_pfn pages, by creating page tables starting from address | |
71 | * PAGE_OFFSET. The page tables are allocated out of resume-safe pages. | |
72 | */ | |
73 | static int resume_physical_mapping_init(pgd_t *pgd_base) | |
74 | { | |
75 | unsigned long pfn; | |
76 | pgd_t *pgd; | |
77 | pmd_t *pmd; | |
78 | pte_t *pte; | |
79 | int pgd_idx, pmd_idx; | |
80 | ||
81 | pgd_idx = pgd_index(PAGE_OFFSET); | |
82 | pgd = pgd_base + pgd_idx; | |
83 | pfn = 0; | |
84 | ||
85 | for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { | |
86 | pmd = resume_one_md_table_init(pgd); | |
87 | if (!pmd) | |
88 | return -ENOMEM; | |
89 | ||
90 | if (pfn >= max_low_pfn) | |
91 | continue; | |
92 | ||
93 | for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD; pmd++, pmd_idx++) { | |
94 | pte_t *max_pte; | |
95 | ||
96 | if (pfn >= max_low_pfn) | |
97 | break; | |
98 | ||
99 | /* Map with normal page tables. | |
100 | * NOTE: We can mark everything as executable here | |
101 | */ | |
102 | pte = resume_one_page_table_init(pmd); | |
103 | if (!pte) | |
104 | return -ENOMEM; | |
105 | ||
106 | max_pte = pte + PTRS_PER_PTE; | |
107 | for (; pte < max_pte; pte++, pfn++) { | |
108 | if (pfn >= max_low_pfn) | |
109 | break; | |
110 | ||
111 | set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); | |
112 | } | |
113 | } | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | static inline void resume_init_first_level_page_table(pgd_t *pg_dir) | |
120 | { | |
121 | } | |
122 | ||
123 | int swsusp_arch_resume(void) | |
124 | { | |
125 | int error; | |
126 | ||
127 | resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC); | |
128 | if (!resume_pg_dir) | |
129 | return -ENOMEM; | |
130 | ||
131 | resume_init_first_level_page_table(resume_pg_dir); | |
132 | error = resume_physical_mapping_init(resume_pg_dir); | |
133 | if (error) | |
134 | return error; | |
135 | ||
136 | /* We have got enough memory and from now on we cannot recover */ | |
137 | restore_image(resume_pg_dir, restore_pblist); | |
138 | return 0; | |
139 | } | |
140 | ||
141 | /* | |
142 | * pfn_is_nosave - check if given pfn is in the 'nosave' section | |
143 | */ | |
144 | ||
145 | int pfn_is_nosave(unsigned long pfn) | |
146 | { | |
147 | unsigned long begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; | |
148 | unsigned long end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; | |
149 | ||
150 | return (pfn >= begin_pfn) && (pfn < end_pfn); | |
151 | } | |
152 | ||
153 | void save_processor_state(void) | |
154 | { | |
155 | } | |
156 | ||
157 | void restore_processor_state(void) | |
158 | { | |
159 | local_flush_tlb_all(); | |
160 | } |