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1/*
2 * linux/arch/arm/mm/pgd.c
3 *
4 * Copyright (C) 1998-2005 Russell King
5 *
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.
9 */
10#include <linux/mm.h>
11#include <linux/gfp.h>
12#include <linux/highmem.h>
13
14#include <asm/pgalloc.h>
15#include <asm/page.h>
16#include <asm/tlbflush.h>
17
18#include "mm.h"
19
20/*
21 * need to get a 16k page for level 1
22 */
23pgd_t *pgd_alloc(struct mm_struct *mm)
24{
25 pgd_t *new_pgd, *init_pgd;
26 pud_t *new_pud, *init_pud;
27 pmd_t *new_pmd, *init_pmd;
28 pte_t *new_pte, *init_pte;
29
30 new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
31 if (!new_pgd)
32 goto no_pgd;
33
34 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
35
36 /*
37 * Copy over the kernel and IO PGD entries
38 */
39 init_pgd = pgd_offset_k(0);
40 memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
41 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
42
43 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
44
45 if (!vectors_high()) {
46 /*
47 * On ARM, first page must always be allocated since it
48 * contains the machine vectors.
49 */
50 new_pud = pud_alloc(mm, new_pgd, 0);
51 if (!new_pud)
52 goto no_pud;
53
54 new_pmd = pmd_alloc(mm, new_pud, 0);
55 if (!new_pmd)
56 goto no_pmd;
57
58 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
59 if (!new_pte)
60 goto no_pte;
61
62 init_pud = pud_offset(init_pgd, 0);
63 init_pmd = pmd_offset(init_pud, 0);
64 init_pte = pte_offset_map(init_pmd, 0);
65 set_pte_ext(new_pte, *init_pte, 0);
66 pte_unmap(init_pte);
67 pte_unmap(new_pte);
68 }
69
70 return new_pgd;
71
72no_pte:
73 pmd_free(mm, new_pmd);
74no_pmd:
75 pud_free(mm, new_pud);
76no_pud:
77 free_pages((unsigned long)new_pgd, 2);
78no_pgd:
79 return NULL;
80}
81
82void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
83{
84 pgd_t *pgd;
85 pud_t *pud;
86 pmd_t *pmd;
87 pgtable_t pte;
88
89 if (!pgd_base)
90 return;
91
92 pgd = pgd_base + pgd_index(0);
93 if (pgd_none_or_clear_bad(pgd))
94 goto no_pgd;
95
96 pud = pud_offset(pgd, 0);
97 if (pud_none_or_clear_bad(pud))
98 goto no_pud;
99
100 pmd = pmd_offset(pud, 0);
101 if (pmd_none_or_clear_bad(pmd))
102 goto no_pmd;
103
104 pte = pmd_pgtable(*pmd);
105 pmd_clear(pmd);
106 pte_free(mm, pte);
107no_pmd:
108 pud_clear(pud);
109 pmd_free(mm, pmd);
110no_pud:
111 pgd_clear(pgd);
112 pud_free(mm, pud);
113no_pgd:
114 free_pages((unsigned long) pgd_base, 2);
115}
1/*
2 * linux/arch/arm/mm/pgd.c
3 *
4 * Copyright (C) 1998-2005 Russell King
5 *
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.
9 */
10#include <linux/mm.h>
11#include <linux/gfp.h>
12#include <linux/highmem.h>
13#include <linux/slab.h>
14
15#include <asm/cp15.h>
16#include <asm/pgalloc.h>
17#include <asm/page.h>
18#include <asm/tlbflush.h>
19
20#include "mm.h"
21
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)
25#else
26#define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2)
27#define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
28#endif
29
30/*
31 * need to get a 16k page for level 1
32 */
33pgd_t *pgd_alloc(struct mm_struct *mm)
34{
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;
39
40 new_pgd = __pgd_alloc();
41 if (!new_pgd)
42 goto no_pgd;
43
44 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
45
46 /*
47 * Copy over the kernel and IO PGD entries
48 */
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));
52
53 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
54
55#ifdef CONFIG_ARM_LPAE
56 /*
57 * Allocate PMD table for modules and pkmap mappings.
58 */
59 new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
60 MODULES_VADDR);
61 if (!new_pud)
62 goto no_pud;
63
64 new_pmd = pmd_alloc(mm, new_pud, 0);
65 if (!new_pmd)
66 goto no_pmd;
67#endif
68
69 if (!vectors_high()) {
70 /*
71 * On ARM, first page must always be allocated since it
72 * contains the machine vectors. The vectors are always high
73 * with LPAE.
74 */
75 new_pud = pud_alloc(mm, new_pgd, 0);
76 if (!new_pud)
77 goto no_pud;
78
79 new_pmd = pmd_alloc(mm, new_pud, 0);
80 if (!new_pmd)
81 goto no_pmd;
82
83 new_pte = pte_alloc_map(mm, new_pmd, 0);
84 if (!new_pte)
85 goto no_pte;
86
87#ifndef CONFIG_ARM_LPAE
88 /*
89 * Modify the PTE pointer to have the correct domain. This
90 * needs to be the vectors domain to avoid the low vectors
91 * being unmapped.
92 */
93 pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
94 pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
95#endif
96
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);
102 pte_unmap(init_pte);
103 pte_unmap(new_pte);
104 }
105
106 return new_pgd;
107
108no_pte:
109 pmd_free(mm, new_pmd);
110 mm_dec_nr_pmds(mm);
111no_pmd:
112 pud_free(mm, new_pud);
113no_pud:
114 __pgd_free(new_pgd);
115no_pgd:
116 return NULL;
117}
118
119void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
120{
121 pgd_t *pgd;
122 pud_t *pud;
123 pmd_t *pmd;
124 pgtable_t pte;
125
126 if (!pgd_base)
127 return;
128
129 pgd = pgd_base + pgd_index(0);
130 if (pgd_none_or_clear_bad(pgd))
131 goto no_pgd;
132
133 pud = pud_offset(pgd, 0);
134 if (pud_none_or_clear_bad(pud))
135 goto no_pud;
136
137 pmd = pmd_offset(pud, 0);
138 if (pmd_none_or_clear_bad(pmd))
139 goto no_pmd;
140
141 pte = pmd_pgtable(*pmd);
142 pmd_clear(pmd);
143 pte_free(mm, pte);
144 mm_dec_nr_ptes(mm);
145no_pmd:
146 pud_clear(pud);
147 pmd_free(mm, pmd);
148 mm_dec_nr_pmds(mm);
149no_pud:
150 pgd_clear(pgd);
151 pud_free(mm, pud);
152no_pgd:
153#ifdef CONFIG_ARM_LPAE
154 /*
155 * Free modules/pkmap or identity pmd tables.
156 */
157 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
158 if (pgd_none_or_clear_bad(pgd))
159 continue;
160 if (pgd_val(*pgd) & L_PGD_SWAPPER)
161 continue;
162 pud = pud_offset(pgd, 0);
163 if (pud_none_or_clear_bad(pud))
164 continue;
165 pmd = pmd_offset(pud, 0);
166 pud_clear(pud);
167 pmd_free(mm, pmd);
168 mm_dec_nr_pmds(mm);
169 pgd_clear(pgd);
170 pud_free(mm, pud);
171 }
172#endif
173 __pgd_free(pgd_base);
174}