2 * linux/arch/arm/mm/pgd.c
4 * Copyright (C) 1998-2005 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 #include <linux/gfp.h>
12 #include <linux/highmem.h>
13 #include <linux/slab.h>
16 #include <asm/pgalloc.h>
18 #include <asm/tlbflush.h>
22 #ifdef CONFIG_ARM_LPAE
23 #define __pgd_alloc() kmalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL)
24 #define __pgd_free(pgd) kfree(pgd)
26 #define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_REPEAT, 2)
27 #define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
31 * need to get a 16k page for level 1
33 pgd_t *pgd_alloc(struct mm_struct *mm)
35 pgd_t *new_pgd, *init_pgd;
36 pud_t *new_pud, *init_pud;
37 pmd_t *new_pmd, *init_pmd;
38 pte_t *new_pte, *init_pte;
40 new_pgd = __pgd_alloc();
44 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
47 * Copy over the kernel and IO PGD entries
49 init_pgd = pgd_offset_k(0);
50 memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
51 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
53 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
55 #ifdef CONFIG_ARM_LPAE
57 * Allocate PMD table for modules and pkmap mappings.
59 new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
64 new_pmd = pmd_alloc(mm, new_pud, 0);
69 if (!vectors_high()) {
71 * On ARM, first page must always be allocated since it
72 * contains the machine vectors. The vectors are always high
75 new_pud = pud_alloc(mm, new_pgd, 0);
79 new_pmd = pmd_alloc(mm, new_pud, 0);
83 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
87 #ifndef CONFIG_ARM_LPAE
89 * Modify the PTE pointer to have the correct domain. This
90 * needs to be the vectors domain to avoid the low vectors
93 pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
94 pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
97 init_pud = pud_offset(init_pgd, 0);
98 init_pmd = pmd_offset(init_pud, 0);
99 init_pte = pte_offset_map(init_pmd, 0);
100 set_pte_ext(new_pte + 0, init_pte[0], 0);
101 set_pte_ext(new_pte + 1, init_pte[1], 0);
109 pmd_free(mm, new_pmd);
112 pud_free(mm, new_pud);
119 void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
129 pgd = pgd_base + pgd_index(0);
130 if (pgd_none_or_clear_bad(pgd))
133 pud = pud_offset(pgd, 0);
134 if (pud_none_or_clear_bad(pud))
137 pmd = pmd_offset(pud, 0);
138 if (pmd_none_or_clear_bad(pmd))
141 pte = pmd_pgtable(*pmd);
144 atomic_long_dec(&mm->nr_ptes);
153 #ifdef CONFIG_ARM_LPAE
155 * Free modules/pkmap or identity pmd tables.
157 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
158 if (pgd_none_or_clear_bad(pgd))
160 if (pgd_val(*pgd) & L_PGD_SWAPPER)
162 pud = pud_offset(pgd, 0);
163 if (pud_none_or_clear_bad(pud))
165 pmd = pmd_offset(pud, 0);
173 __pgd_free(pgd_base);