Commit | Line | Data |
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1da177e4 | 1 | /* |
0c668984 | 2 | * linux/arch/arm/mm/pgd.c |
1da177e4 | 3 | * |
90072059 | 4 | * Copyright (C) 1998-2005 Russell King |
1da177e4 LT |
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. | |
1da177e4 | 9 | */ |
1da177e4 | 10 | #include <linux/mm.h> |
5a0e3ad6 | 11 | #include <linux/gfp.h> |
1da177e4 | 12 | #include <linux/highmem.h> |
da028779 | 13 | #include <linux/slab.h> |
1da177e4 | 14 | |
15d07dc9 | 15 | #include <asm/cp15.h> |
1da177e4 LT |
16 | #include <asm/pgalloc.h> |
17 | #include <asm/page.h> | |
1da177e4 LT |
18 | #include <asm/tlbflush.h> |
19 | ||
1b2e2b73 RK |
20 | #include "mm.h" |
21 | ||
da028779 CM |
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 | ||
1da177e4 LT |
30 | /* |
31 | * need to get a 16k page for level 1 | |
32 | */ | |
b0d03745 | 33 | pgd_t *pgd_alloc(struct mm_struct *mm) |
1da177e4 LT |
34 | { |
35 | pgd_t *new_pgd, *init_pgd; | |
516295e5 | 36 | pud_t *new_pud, *init_pud; |
1da177e4 LT |
37 | pmd_t *new_pmd, *init_pmd; |
38 | pte_t *new_pte, *init_pte; | |
39 | ||
da028779 | 40 | new_pgd = __pgd_alloc(); |
1da177e4 LT |
41 | if (!new_pgd) |
42 | goto no_pgd; | |
43 | ||
e926f449 | 44 | memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); |
1da177e4 | 45 | |
a343e607 RK |
46 | /* |
47 | * Copy over the kernel and IO PGD entries | |
48 | */ | |
1da177e4 | 49 | init_pgd = pgd_offset_k(0); |
e926f449 RK |
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)); | |
a343e607 RK |
52 | |
53 | clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t)); | |
1da177e4 | 54 | |
da028779 CM |
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 | ||
1da177e4 | 69 | if (!vectors_high()) { |
1da177e4 LT |
70 | /* |
71 | * On ARM, first page must always be allocated since it | |
da028779 CM |
72 | * contains the machine vectors. The vectors are always high |
73 | * with LPAE. | |
1da177e4 | 74 | */ |
516295e5 RK |
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); | |
1da177e4 LT |
80 | if (!new_pmd) |
81 | goto no_pmd; | |
82 | ||
8ac1f832 | 83 | new_pte = pte_alloc_map(mm, NULL, new_pmd, 0); |
1da177e4 LT |
84 | if (!new_pte) |
85 | goto no_pte; | |
86 | ||
516295e5 RK |
87 | init_pud = pud_offset(init_pgd, 0); |
88 | init_pmd = pmd_offset(init_pud, 0); | |
ece0e2b6 | 89 | init_pte = pte_offset_map(init_pmd, 0); |
ad1ae2fe | 90 | set_pte_ext(new_pte, *init_pte, 0); |
ece0e2b6 | 91 | pte_unmap(init_pte); |
1da177e4 | 92 | pte_unmap(new_pte); |
1da177e4 LT |
93 | } |
94 | ||
1da177e4 LT |
95 | return new_pgd; |
96 | ||
97 | no_pte: | |
5e541973 | 98 | pmd_free(mm, new_pmd); |
1da177e4 | 99 | no_pmd: |
516295e5 RK |
100 | pud_free(mm, new_pud); |
101 | no_pud: | |
da028779 | 102 | __pgd_free(new_pgd); |
1da177e4 LT |
103 | no_pgd: |
104 | return NULL; | |
105 | } | |
106 | ||
6e4beb5e | 107 | void pgd_free(struct mm_struct *mm, pgd_t *pgd_base) |
1da177e4 | 108 | { |
6e4beb5e | 109 | pgd_t *pgd; |
516295e5 | 110 | pud_t *pud; |
1da177e4 | 111 | pmd_t *pmd; |
0c82d83c | 112 | pgtable_t pte; |
1da177e4 | 113 | |
6e4beb5e | 114 | if (!pgd_base) |
1da177e4 LT |
115 | return; |
116 | ||
6e4beb5e RK |
117 | pgd = pgd_base + pgd_index(0); |
118 | if (pgd_none_or_clear_bad(pgd)) | |
119 | goto no_pgd; | |
120 | ||
516295e5 RK |
121 | pud = pud_offset(pgd, 0); |
122 | if (pud_none_or_clear_bad(pud)) | |
123 | goto no_pud; | |
124 | ||
125 | pmd = pmd_offset(pud, 0); | |
6e4beb5e RK |
126 | if (pmd_none_or_clear_bad(pmd)) |
127 | goto no_pmd; | |
1da177e4 | 128 | |
0c82d83c | 129 | pte = pmd_pgtable(*pmd); |
1da177e4 | 130 | pmd_clear(pmd); |
5e541973 | 131 | pte_free(mm, pte); |
6e4beb5e | 132 | no_pmd: |
516295e5 | 133 | pud_clear(pud); |
5e541973 | 134 | pmd_free(mm, pmd); |
516295e5 RK |
135 | no_pud: |
136 | pgd_clear(pgd); | |
137 | pud_free(mm, pud); | |
6e4beb5e | 138 | no_pgd: |
da028779 CM |
139 | #ifdef CONFIG_ARM_LPAE |
140 | /* | |
141 | * Free modules/pkmap or identity pmd tables. | |
142 | */ | |
143 | for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) { | |
144 | if (pgd_none_or_clear_bad(pgd)) | |
145 | continue; | |
146 | if (pgd_val(*pgd) & L_PGD_SWAPPER) | |
147 | continue; | |
148 | pud = pud_offset(pgd, 0); | |
149 | if (pud_none_or_clear_bad(pud)) | |
150 | continue; | |
151 | pmd = pmd_offset(pud, 0); | |
152 | pud_clear(pud); | |
153 | pmd_free(mm, pmd); | |
154 | pgd_clear(pgd); | |
155 | pud_free(mm, pud); | |
156 | } | |
157 | #endif | |
158 | __pgd_free(pgd_base); | |
1da177e4 | 159 | } |