x86/xen: resume timer irqs early
[linux/fpc-iii.git] / arch / arm / mm / pgd.c
blob1046b373d1aedb2823e3bb62f106681f9b63fc2a
1 /*
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.
9 */
10 #include <linux/mm.h>
11 #include <linux/gfp.h>
12 #include <linux/highmem.h>
13 #include <linux/slab.h>
15 #include <asm/cp15.h>
16 #include <asm/pgalloc.h>
17 #include <asm/page.h>
18 #include <asm/tlbflush.h>
20 #include "mm.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)
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
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();
41 if (!new_pgd)
42 goto no_pgd;
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),
60 MODULES_VADDR);
61 if (!new_pud)
62 goto no_pud;
64 new_pmd = pmd_alloc(mm, new_pud, 0);
65 if (!new_pmd)
66 goto no_pmd;
67 #endif
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
73 * with LPAE.
75 new_pud = pud_alloc(mm, new_pgd, 0);
76 if (!new_pud)
77 goto no_pud;
79 new_pmd = pmd_alloc(mm, new_pud, 0);
80 if (!new_pmd)
81 goto no_pmd;
83 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
84 if (!new_pte)
85 goto no_pte;
87 init_pud = pud_offset(init_pgd, 0);
88 init_pmd = pmd_offset(init_pud, 0);
89 init_pte = pte_offset_map(init_pmd, 0);
90 set_pte_ext(new_pte + 0, init_pte[0], 0);
91 set_pte_ext(new_pte + 1, init_pte[1], 0);
92 pte_unmap(init_pte);
93 pte_unmap(new_pte);
96 return new_pgd;
98 no_pte:
99 pmd_free(mm, new_pmd);
100 no_pmd:
101 pud_free(mm, new_pud);
102 no_pud:
103 __pgd_free(new_pgd);
104 no_pgd:
105 return NULL;
108 void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
110 pgd_t *pgd;
111 pud_t *pud;
112 pmd_t *pmd;
113 pgtable_t pte;
115 if (!pgd_base)
116 return;
118 pgd = pgd_base + pgd_index(0);
119 if (pgd_none_or_clear_bad(pgd))
120 goto no_pgd;
122 pud = pud_offset(pgd, 0);
123 if (pud_none_or_clear_bad(pud))
124 goto no_pud;
126 pmd = pmd_offset(pud, 0);
127 if (pmd_none_or_clear_bad(pmd))
128 goto no_pmd;
130 pte = pmd_pgtable(*pmd);
131 pmd_clear(pmd);
132 pte_free(mm, pte);
133 no_pmd:
134 pud_clear(pud);
135 pmd_free(mm, pmd);
136 no_pud:
137 pgd_clear(pgd);
138 pud_free(mm, pud);
139 no_pgd:
140 #ifdef CONFIG_ARM_LPAE
142 * Free modules/pkmap or identity pmd tables.
144 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
145 if (pgd_none_or_clear_bad(pgd))
146 continue;
147 if (pgd_val(*pgd) & L_PGD_SWAPPER)
148 continue;
149 pud = pud_offset(pgd, 0);
150 if (pud_none_or_clear_bad(pud))
151 continue;
152 pmd = pmd_offset(pud, 0);
153 pud_clear(pud);
154 pmd_free(mm, pmd);
155 pgd_clear(pgd);
156 pud_free(mm, pud);
158 #endif
159 __pgd_free(pgd_base);