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>
15 #include <asm/pgalloc.h>
17 #include <asm/tlbflush.h>
21 #ifdef CONFIG_ARM_LPAE
22 #define __pgd_alloc() kmalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL)
23 #define __pgd_free(pgd) kfree(pgd)
25 #define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2)
26 #define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
30 * need to get a 16k page for level 1
32 pgd_t *pgd_alloc(struct mm_struct *mm)
34 pgd_t *new_pgd, *init_pgd;
35 pud_t *new_pud, *init_pud;
36 pmd_t *new_pmd, *init_pmd;
37 pte_t *new_pte, *init_pte;
39 new_pgd = __pgd_alloc();
43 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
46 * Copy over the kernel and IO PGD entries
48 init_pgd = pgd_offset_k(0);
49 memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
50 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
52 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
54 #ifdef CONFIG_ARM_LPAE
56 * Allocate PMD table for modules and pkmap mappings.
58 new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
63 new_pmd = pmd_alloc(mm, new_pud, 0);
68 if (!vectors_high()) {
70 * On ARM, first page must always be allocated since it
71 * contains the machine vectors. The vectors are always high
74 new_pud = pud_alloc(mm, new_pgd, 0);
78 new_pmd = pmd_alloc(mm, new_pud, 0);
82 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
86 init_pud = pud_offset(init_pgd, 0);
87 init_pmd = pmd_offset(init_pud, 0);
88 init_pte = pte_offset_map(init_pmd, 0);
89 set_pte_ext(new_pte, *init_pte, 0);
97 pmd_free(mm, new_pmd);
99 pud_free(mm, new_pud);
106 void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
116 pgd = pgd_base + pgd_index(0);
117 if (pgd_none_or_clear_bad(pgd))
120 pud = pud_offset(pgd, 0);
121 if (pud_none_or_clear_bad(pud))
124 pmd = pmd_offset(pud, 0);
125 if (pmd_none_or_clear_bad(pmd))
128 pte = pmd_pgtable(*pmd);
138 #ifdef CONFIG_ARM_LPAE
140 * Free modules/pkmap or identity pmd tables.
142 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
143 if (pgd_none_or_clear_bad(pgd))
145 if (pgd_val(*pgd) & L_PGD_SWAPPER)
147 pud = pud_offset(pgd, 0);
148 if (pud_none_or_clear_bad(pud))
150 pmd = pmd_offset(pud, 0);
157 __pgd_free(pgd_base);