pgd.c
3.32 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
* 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(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 | __GFP_REPEAT, 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, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
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);
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);
no_pmd:
pud_clear(pud);
pmd_free(mm, pmd);
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);
pgd_clear(pgd);
pud_free(mm, pud);
}
#endif
__pgd_free(pgd_base);
}