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