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>
14 #include <asm/pgalloc.h>
16 #include <asm/tlbflush.h>
20 #define FIRST_KERNEL_PGD_NR (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD)
23 * need to get a 16k page for level 1
25 pgd_t
*get_pgd_slow(struct mm_struct
*mm
)
27 pgd_t
*new_pgd
, *init_pgd
;
28 pmd_t
*new_pmd
, *init_pmd
;
29 pte_t
*new_pte
, *init_pte
;
31 new_pgd
= (pgd_t
*)__get_free_pages(GFP_KERNEL
, 2);
35 memset(new_pgd
, 0, FIRST_KERNEL_PGD_NR
* sizeof(pgd_t
));
38 * Copy over the kernel and IO PGD entries
40 init_pgd
= pgd_offset_k(0);
41 memcpy(new_pgd
+ FIRST_KERNEL_PGD_NR
, init_pgd
+ FIRST_KERNEL_PGD_NR
,
42 (PTRS_PER_PGD
- FIRST_KERNEL_PGD_NR
) * sizeof(pgd_t
));
44 clean_dcache_area(new_pgd
, PTRS_PER_PGD
* sizeof(pgd_t
));
46 if (!vectors_high()) {
48 * On ARM, first page must always be allocated since it
49 * contains the machine vectors.
51 new_pmd
= pmd_alloc(mm
, new_pgd
, 0);
55 new_pte
= pte_alloc_map(mm
, new_pmd
, 0);
59 init_pmd
= pmd_offset(init_pgd
, 0);
60 init_pte
= pte_offset_map_nested(init_pmd
, 0);
61 set_pte_ext(new_pte
, *init_pte
, 0);
62 pte_unmap_nested(init_pte
);
69 pmd_free(mm
, new_pmd
);
71 free_pages((unsigned long)new_pgd
, 2);
76 void free_pgd_slow(struct mm_struct
*mm
, pgd_t
*pgd
)
84 /* pgd is always present and good */
85 pmd
= pmd_off(pgd
, 0);
94 pte
= pmd_pgtable(*pmd
);
99 free_pages((unsigned long) pgd
, 2);