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 | 5 | |
e4630fdd | 6 | static void ident_pmd_init(struct x86_mapping_info *info, pmd_t *pmd_page, |
cf4fb15b YL |
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 | ||
e4630fdd RW |
13 | if (pmd_present(*pmd)) |
14 | continue; | |
15 | ||
16 | set_pmd(pmd, __pmd((addr - info->offset) | info->pmd_flag)); | |
cf4fb15b YL |
17 | } |
18 | } | |
cb18ef0d | 19 | |
cf4fb15b YL |
20 | static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, |
21 | unsigned long addr, unsigned long end) | |
22 | { | |
23 | unsigned long next; | |
24 | ||
25 | for (; addr < end; addr = next) { | |
26 | pud_t *pud = pud_page + pud_index(addr); | |
27 | pmd_t *pmd; | |
28 | ||
29 | next = (addr & PUD_MASK) + PUD_SIZE; | |
30 | if (next > end) | |
31 | next = end; | |
32 | ||
33 | if (pud_present(*pud)) { | |
34 | pmd = pmd_offset(pud, 0); | |
e4630fdd | 35 | ident_pmd_init(info, pmd, addr, next); |
cf4fb15b YL |
36 | continue; |
37 | } | |
38 | pmd = (pmd_t *)info->alloc_pgt_page(info->context); | |
39 | if (!pmd) | |
40 | return -ENOMEM; | |
e4630fdd | 41 | ident_pmd_init(info, pmd, addr, next); |
cf4fb15b YL |
42 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); |
43 | } | |
44 | ||
45 | return 0; | |
46 | } | |
47 | ||
48 | int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, | |
e4630fdd | 49 | unsigned long pstart, unsigned long pend) |
cf4fb15b | 50 | { |
e4630fdd RW |
51 | unsigned long addr = pstart + info->offset; |
52 | unsigned long end = pend + info->offset; | |
cf4fb15b YL |
53 | unsigned long next; |
54 | int result; | |
cf4fb15b YL |
55 | |
56 | for (; addr < end; addr = next) { | |
e4630fdd | 57 | pgd_t *pgd = pgd_page + pgd_index(addr); |
cf4fb15b YL |
58 | pud_t *pud; |
59 | ||
60 | next = (addr & PGDIR_MASK) + PGDIR_SIZE; | |
61 | if (next > end) | |
62 | next = end; | |
63 | ||
64 | if (pgd_present(*pgd)) { | |
65 | pud = pud_offset(pgd, 0); | |
66 | result = ident_pud_init(info, pud, addr, next); | |
67 | if (result) | |
68 | return result; | |
69 | continue; | |
70 | } | |
71 | ||
72 | pud = (pud_t *)info->alloc_pgt_page(info->context); | |
73 | if (!pud) | |
74 | return -ENOMEM; | |
75 | result = ident_pud_init(info, pud, addr, next); | |
76 | if (result) | |
77 | return result; | |
78 | set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); | |
79 | } | |
80 | ||
81 | return 0; | |
82 | } |