Commit | Line | Data |
---|---|---|
cb18ef0d KC |
1 | /* |
2 | * Helper routines for building identity mapping page tables. This is | |
3 | * included by both the compressed kernel and the regular kernel. | |
4 | */ | |
cf4fb15b YL |
5 | |
6 | static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page, | |
7 | unsigned long addr, unsigned long end) | |
8 | { | |
9 | addr &= PMD_MASK; | |
10 | for (; addr < end; addr += PMD_SIZE) { | |
11 | pmd_t *pmd = pmd_page + pmd_index(addr); | |
12 | ||
13 | if (!pmd_present(*pmd)) | |
14 | set_pmd(pmd, __pmd(addr | pmd_flag)); | |
15 | } | |
16 | } | |
cb18ef0d | 17 | |
cf4fb15b YL |
18 | static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, |
19 | unsigned long addr, unsigned long end) | |
20 | { | |
21 | unsigned long next; | |
22 | ||
23 | for (; addr < end; addr = next) { | |
24 | pud_t *pud = pud_page + pud_index(addr); | |
25 | pmd_t *pmd; | |
26 | ||
27 | next = (addr & PUD_MASK) + PUD_SIZE; | |
28 | if (next > end) | |
29 | next = end; | |
30 | ||
31 | if (pud_present(*pud)) { | |
32 | pmd = pmd_offset(pud, 0); | |
33 | ident_pmd_init(info->pmd_flag, pmd, addr, next); | |
34 | continue; | |
35 | } | |
36 | pmd = (pmd_t *)info->alloc_pgt_page(info->context); | |
37 | if (!pmd) | |
38 | return -ENOMEM; | |
39 | ident_pmd_init(info->pmd_flag, pmd, addr, next); | |
40 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); | |
41 | } | |
42 | ||
43 | return 0; | |
44 | } | |
45 | ||
46 | int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, | |
47 | unsigned long addr, unsigned long end) | |
48 | { | |
49 | unsigned long next; | |
50 | int result; | |
51 | int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0; | |
52 | ||
53 | for (; addr < end; addr = next) { | |
54 | pgd_t *pgd = pgd_page + pgd_index(addr) + off; | |
55 | pud_t *pud; | |
56 | ||
57 | next = (addr & PGDIR_MASK) + PGDIR_SIZE; | |
58 | if (next > end) | |
59 | next = end; | |
60 | ||
61 | if (pgd_present(*pgd)) { | |
62 | pud = pud_offset(pgd, 0); | |
63 | result = ident_pud_init(info, pud, addr, next); | |
64 | if (result) | |
65 | return result; | |
66 | continue; | |
67 | } | |
68 | ||
69 | pud = (pud_t *)info->alloc_pgt_page(info->context); | |
70 | if (!pud) | |
71 | return -ENOMEM; | |
72 | result = ident_pud_init(info, pud, addr, next); | |
73 | if (result) | |
74 | return result; | |
75 | set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); | |
76 | } | |
77 | ||
78 | return 0; | |
79 | } |