/* * 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 <linux/slab.h> #include <asm/cp15.h> #include <asm/pgalloc.h> #include <asm/page.h> #include <asm/tlbflush.h> #include "mm.h" #ifdef CONFIG_ARM_LPAE #define __pgd_alloc() kmalloc_array(PTRS_PER_PGD, sizeof(pgd_t), GFP_KERNEL) #define __pgd_free(pgd) kfree(pgd) #else #define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2) #define __pgd_free(pgd) free_pages((unsigned long)pgd, 2) #endif /* * 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_alloc(); 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)); #ifdef CONFIG_ARM_LPAE /* * Allocate PMD table for modules and pkmap mappings. */ new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR), MODULES_VADDR); if (!new_pud) goto no_pud; new_pmd = pmd_alloc(mm, new_pud, 0); if (!new_pmd) goto no_pmd; #endif if (!vectors_high()) { /* * On ARM, first page must always be allocated since it * contains the machine vectors. The vectors are always high * with LPAE. */ 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, new_pmd, 0); if (!new_pte) goto no_pte; #ifndef CONFIG_ARM_LPAE /* * Modify the PTE pointer to have the correct domain. This * needs to be the vectors domain to avoid the low vectors * being unmapped. */ pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK; pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS); #endif 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 + 0, init_pte[0], 0); set_pte_ext(new_pte + 1, init_pte[1], 0); pte_unmap(init_pte); pte_unmap(new_pte); } return new_pgd; no_pte: pmd_free(mm, new_pmd); mm_dec_nr_pmds(mm); no_pmd: pud_free(mm, new_pud); no_pud: __pgd_free(new_pgd); 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); mm_dec_nr_ptes(mm); no_pmd: pud_clear(pud); pmd_free(mm, pmd); mm_dec_nr_pmds(mm); no_pud: pgd_clear(pgd); pud_free(mm, pud); no_pgd: #ifdef CONFIG_ARM_LPAE /* * Free modules/pkmap or identity pmd tables. */ for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) { if (pgd_none_or_clear_bad(pgd)) continue; if (pgd_val(*pgd) & L_PGD_SWAPPER) continue; pud = pud_offset(pgd, 0); if (pud_none_or_clear_bad(pud)) continue; pmd = pmd_offset(pud, 0); pud_clear(pud); pmd_free(mm, pmd); mm_dec_nr_pmds(mm); pgd_clear(pgd); pud_free(mm, pud); } #endif __pgd_free(pgd_base); }