From 12f49643bc44c428919b210148a930496827dd26 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Fri, 20 May 2005 13:59:12 -0700 Subject: [PATCH] [PATCH] uml: fixrange_init 3-level page table support From: Al Viro - add three-level page table support to fixrange_init. Signed-off-by: Jeff Dike Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/mem.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c index f156661781cb..c22825f13e40 100644 --- a/arch/um/kernel/mem.c +++ b/arch/um/kernel/mem.c @@ -100,12 +100,37 @@ void mem_init(void) #endif } +/* + * Create a page table and place a pointer to it in a middle page + * directory entry. + */ +static void __init one_page_table_init(pmd_t *pmd) +{ + if (pmd_none(*pmd)) { + pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pmd(pmd, __pmd(_KERNPG_TABLE + + (unsigned long) __pa(pte))); + if (pte != pte_offset_kernel(pmd, 0)) + BUG(); + } +} + +static void __init one_md_table_init(pud_t *pud) +{ +#ifdef CONFIG_3_LEVEL_PGTABLES + pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); + if (pmd_table != pmd_offset(pud, 0)) + BUG(); +#endif +} + static void __init fixrange_init(unsigned long start, unsigned long end, pgd_t *pgd_base) { pgd_t *pgd; + pud_t *pud; pmd_t *pmd; - pte_t *pte; int i, j; unsigned long vaddr; @@ -115,15 +140,12 @@ static void __init fixrange_init(unsigned long start, unsigned long end, pgd = pgd_base + i; for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { - pmd = (pmd_t *)pgd; + pud = pud_offset(pgd, vaddr); + if (pud_none(*pud)) + one_md_table_init(pud); + pmd = pmd_offset(pud, vaddr); for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) { - if (pmd_none(*pmd)) { - pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); - set_pmd(pmd, __pmd(_KERNPG_TABLE + - (unsigned long) __pa(pte))); - if (pte != pte_offset_kernel(pmd, 0)) - BUG(); - } + one_page_table_init(pmd); vaddr += PMD_SIZE; } j = 0; -- 2.39.5