diff options
Diffstat (limited to 'arch/x86/mm/ident_map.c')
-rw-r--r-- | arch/x86/mm/ident_map.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c new file mode 100644 index 0000000..751ca92 --- /dev/null +++ b/arch/x86/mm/ident_map.c @@ -0,0 +1,74 @@ + +static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page, + unsigned long addr, unsigned long end) +{ + addr &= PMD_MASK; + for (; addr < end; addr += PMD_SIZE) { + pmd_t *pmd = pmd_page + pmd_index(addr); + + if (!pmd_present(*pmd)) + set_pmd(pmd, __pmd(addr | pmd_flag)); + } +} +static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, + unsigned long addr, unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next) { + pud_t *pud = pud_page + pud_index(addr); + pmd_t *pmd; + + next = (addr & PUD_MASK) + PUD_SIZE; + if (next > end) + next = end; + + if (pud_present(*pud)) { + pmd = pmd_offset(pud, 0); + ident_pmd_init(info->pmd_flag, pmd, addr, next); + continue; + } + pmd = (pmd_t *)info->alloc_pgt_page(info->context); + if (!pmd) + return -ENOMEM; + ident_pmd_init(info->pmd_flag, pmd, addr, next); + set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); + } + + return 0; +} + +int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, + unsigned long addr, unsigned long end) +{ + unsigned long next; + int result; + int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0; + + for (; addr < end; addr = next) { + pgd_t *pgd = pgd_page + pgd_index(addr) + off; + pud_t *pud; + + next = (addr & PGDIR_MASK) + PGDIR_SIZE; + if (next > end) + next = end; + + if (pgd_present(*pgd)) { + pud = pud_offset(pgd, 0); + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + continue; + } + + pud = (pud_t *)info->alloc_pgt_page(info->context); + if (!pud) + return -ENOMEM; + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); + } + + return 0; +} |