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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/arm/mm/pgd.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/arm/mm/pgd.c')
-rw-r--r-- | arch/arm/mm/pgd.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c new file mode 100644 index 00000000..b2027c15 --- /dev/null +++ b/arch/arm/mm/pgd.c @@ -0,0 +1,115 @@ +/* + * linux/arch/arm/mm/pgd.c + * + * Copyright (C) 1998-2005 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/mm.h> +#include <linux/gfp.h> +#include <linux/highmem.h> + +#include <asm/pgalloc.h> +#include <asm/page.h> +#include <asm/tlbflush.h> + +#include "mm.h" + +/* + * need to get a 16k page for level 1 + */ +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *new_pgd, *init_pgd; + pud_t *new_pud, *init_pud; + pmd_t *new_pmd, *init_pmd; + pte_t *new_pte, *init_pte; + + new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2); + if (!new_pgd) + goto no_pgd; + + memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); + + /* + * Copy over the kernel and IO PGD entries + */ + init_pgd = pgd_offset_k(0); + memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD, + (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); + + clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t)); + + if (!vectors_high()) { + /* + * On ARM, first page must always be allocated since it + * contains the machine vectors. + */ + new_pud = pud_alloc(mm, new_pgd, 0); + if (!new_pud) + goto no_pud; + + new_pmd = pmd_alloc(mm, new_pud, 0); + if (!new_pmd) + goto no_pmd; + + new_pte = pte_alloc_map(mm, NULL, new_pmd, 0); + if (!new_pte) + goto no_pte; + + init_pud = pud_offset(init_pgd, 0); + init_pmd = pmd_offset(init_pud, 0); + init_pte = pte_offset_map(init_pmd, 0); + set_pte_ext(new_pte, *init_pte, 0); + pte_unmap(init_pte); + pte_unmap(new_pte); + } + + return new_pgd; + +no_pte: + pmd_free(mm, new_pmd); +no_pmd: + pud_free(mm, new_pud); +no_pud: + free_pages((unsigned long)new_pgd, 2); +no_pgd: + return NULL; +} + +void pgd_free(struct mm_struct *mm, pgd_t *pgd_base) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pgtable_t pte; + + if (!pgd_base) + return; + + pgd = pgd_base + pgd_index(0); + if (pgd_none_or_clear_bad(pgd)) + goto no_pgd; + + pud = pud_offset(pgd, 0); + if (pud_none_or_clear_bad(pud)) + goto no_pud; + + pmd = pmd_offset(pud, 0); + if (pmd_none_or_clear_bad(pmd)) + goto no_pmd; + + pte = pmd_pgtable(*pmd); + pmd_clear(pmd); + pte_free(mm, pte); +no_pmd: + pud_clear(pud); + pmd_free(mm, pmd); +no_pud: + pgd_clear(pgd); + pud_free(mm, pud); +no_pgd: + free_pages((unsigned long) pgd_base, 2); +} |