blob: 4473cb4f8b906dcae083a4b29c38b72d9b7d56d3 [file] [log] [blame]
Kees Cookcb18ef02016-05-09 13:22:05 -07001/*
2 * Helper routines for building identity mapping page tables. This is
3 * included by both the compressed kernel and the regular kernel.
4 */
Yinghai Lucf4fb152016-05-06 15:01:34 -07005
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +02006static void ident_pmd_init(struct x86_mapping_info *info, pmd_t *pmd_page,
Yinghai Lucf4fb152016-05-06 15:01:34 -07007 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
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020013 if (pmd_present(*pmd))
14 continue;
15
16 set_pmd(pmd, __pmd((addr - info->offset) | info->pmd_flag));
Yinghai Lucf4fb152016-05-06 15:01:34 -070017 }
18}
Kees Cookcb18ef02016-05-09 13:22:05 -070019
Yinghai Lucf4fb152016-05-06 15:01:34 -070020static 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);
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020035 ident_pmd_init(info, pmd, addr, next);
Yinghai Lucf4fb152016-05-06 15:01:34 -070036 continue;
37 }
38 pmd = (pmd_t *)info->alloc_pgt_page(info->context);
39 if (!pmd)
40 return -ENOMEM;
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020041 ident_pmd_init(info, pmd, addr, next);
Yinghai Lucf4fb152016-05-06 15:01:34 -070042 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
43 }
44
45 return 0;
46}
47
48int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020049 unsigned long pstart, unsigned long pend)
Yinghai Lucf4fb152016-05-06 15:01:34 -070050{
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020051 unsigned long addr = pstart + info->offset;
52 unsigned long end = pend + info->offset;
Yinghai Lucf4fb152016-05-06 15:01:34 -070053 unsigned long next;
54 int result;
Yinghai Lucf4fb152016-05-06 15:01:34 -070055
56 for (; addr < end; addr = next) {
Rafael J. Wysockie4630fd2016-08-08 15:31:31 +020057 pgd_t *pgd = pgd_page + pgd_index(addr);
Yinghai Lucf4fb152016-05-06 15:01:34 -070058 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}