blob: 61e24a25f71a7d9b59480ffe3f29831580097c17 [file] [log] [blame]
Ley Foon Tancbd15b32014-11-06 15:19:45 +08001/*
2 * Copyright (C) 2009 Wind River Systems Inc
3 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 */
9
10#include <linux/mm.h>
11#include <linux/sched.h>
12
13#include <asm/pgtable.h>
14#include <asm/cpuinfo.h>
15
16/* pteaddr:
17 * ptbase | vpn* | zero
18 * 31-22 | 21-2 | 1-0
19 *
20 * *vpn is preserved on double fault
21 *
22 * tlbacc:
23 * IG |*flags| pfn
24 * 31-25|24-20 | 19-0
25 *
26 * *crwxg
27 *
28 * tlbmisc:
29 * resv |way |rd | we|pid |dbl|bad|perm|d
30 * 31-24 |23-20 |19 | 20|17-4|3 |2 |1 |0
31 *
32 */
33
34/*
35 * Initialize a new pgd / pmd table with invalid pointers.
36 */
37static void pgd_init(pgd_t *pgd)
38{
39 unsigned long *p = (unsigned long *) pgd;
40 int i;
41
42 for (i = 0; i < USER_PTRS_PER_PGD; i += 8) {
43 p[i + 0] = (unsigned long) invalid_pte_table;
44 p[i + 1] = (unsigned long) invalid_pte_table;
45 p[i + 2] = (unsigned long) invalid_pte_table;
46 p[i + 3] = (unsigned long) invalid_pte_table;
47 p[i + 4] = (unsigned long) invalid_pte_table;
48 p[i + 5] = (unsigned long) invalid_pte_table;
49 p[i + 6] = (unsigned long) invalid_pte_table;
50 p[i + 7] = (unsigned long) invalid_pte_table;
51 }
52}
53
54pgd_t *pgd_alloc(struct mm_struct *mm)
55{
56 pgd_t *ret, *init;
57
58 ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
59 if (ret) {
60 init = pgd_offset(&init_mm, 0UL);
61 pgd_init(ret);
62 memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
63 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
64 }
65
66 return ret;
67}
68
69void __init pagetable_init(void)
70{
71 /* Initialize the entire pgd. */
72 pgd_init(swapper_pg_dir);
73 pgd_init(swapper_pg_dir + USER_PTRS_PER_PGD);
74}