1 | /* |
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/cpuinfo.h> |
14 | |
15 | /* pteaddr: |
16 | * ptbase | vpn* | zero |
17 | * 31-22 | 21-2 | 1-0 |
18 | * |
19 | * *vpn is preserved on double fault |
20 | * |
21 | * tlbacc: |
22 | * IG |*flags| pfn |
23 | * 31-25|24-20 | 19-0 |
24 | * |
25 | * *crwxg |
26 | * |
27 | * tlbmisc: |
28 | * resv |way |rd | we|pid |dbl|bad|perm|d |
29 | * 31-24 |23-20 |19 | 20|17-4|3 |2 |1 |0 |
30 | * |
31 | */ |
32 | |
33 | /* |
34 | * Initialize a new pgd / pmd table with invalid pointers. |
35 | */ |
36 | static void pgd_init(pgd_t *pgd) |
37 | { |
38 | unsigned long *p = (unsigned long *) pgd; |
39 | int i; |
40 | |
41 | for (i = 0; i < USER_PTRS_PER_PGD; i += 8) { |
42 | p[i + 0] = (unsigned long) invalid_pte_table; |
43 | p[i + 1] = (unsigned long) invalid_pte_table; |
44 | p[i + 2] = (unsigned long) invalid_pte_table; |
45 | p[i + 3] = (unsigned long) invalid_pte_table; |
46 | p[i + 4] = (unsigned long) invalid_pte_table; |
47 | p[i + 5] = (unsigned long) invalid_pte_table; |
48 | p[i + 6] = (unsigned long) invalid_pte_table; |
49 | p[i + 7] = (unsigned long) invalid_pte_table; |
50 | } |
51 | } |
52 | |
53 | pgd_t *pgd_alloc(struct mm_struct *mm) |
54 | { |
55 | pgd_t *ret, *init; |
56 | |
57 | ret = (pgd_t *) __get_free_page(GFP_KERNEL); |
58 | if (ret) { |
59 | init = pgd_offset(&init_mm, 0UL); |
60 | pgd_init(pgd: ret); |
61 | memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD, |
62 | (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); |
63 | } |
64 | |
65 | return ret; |
66 | } |
67 | |
68 | void __init pagetable_init(void) |
69 | { |
70 | /* Initialize the entire pgd. */ |
71 | pgd_init(swapper_pg_dir); |
72 | pgd_init(swapper_pg_dir + USER_PTRS_PER_PGD); |
73 | } |
74 | |