]>
Commit | Line | Data |
---|---|---|
9b081e10 CL |
1 | /* |
2 | * PowerPC version | |
3 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
4 | * | |
5 | * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) | |
6 | * and Cort Dougan (PReP) (cort@cs.nmt.edu) | |
7 | * Copyright (C) 1996 Paul Mackerras | |
8 | * | |
9 | * Derived from "arch/i386/mm/init.c" | |
10 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
11 | * | |
12 | * Dave Engebretsen <engebret@us.ibm.com> | |
13 | * Rework for PPC64 port. | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | */ | |
21 | ||
22 | #undef DEBUG | |
23 | ||
24 | #include <linux/string.h> | |
25 | #include <asm/pgalloc.h> | |
26 | #include <asm/pgtable.h> | |
27 | ||
28 | static void pgd_ctor(void *addr) | |
29 | { | |
30 | memset(addr, 0, PGD_TABLE_SIZE); | |
31 | } | |
32 | ||
33 | static void pud_ctor(void *addr) | |
34 | { | |
35 | memset(addr, 0, PUD_TABLE_SIZE); | |
36 | } | |
37 | ||
38 | static void pmd_ctor(void *addr) | |
39 | { | |
40 | memset(addr, 0, PMD_TABLE_SIZE); | |
41 | } | |
42 | ||
43 | struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; | |
44 | ||
45 | /* | |
46 | * Create a kmem_cache() for pagetables. This is not used for PTE | |
47 | * pages - they're linked to struct page, come from the normal free | |
48 | * pages pool and have a different entry size (see real_pte_t) to | |
49 | * everything else. Caches created by this function are used for all | |
50 | * the higher level pagetables, and for hugepage pagetables. | |
51 | */ | |
52 | void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) | |
53 | { | |
54 | char *name; | |
55 | unsigned long table_size = sizeof(void *) << shift; | |
56 | unsigned long align = table_size; | |
57 | ||
58 | /* When batching pgtable pointers for RCU freeing, we store | |
59 | * the index size in the low bits. Table alignment must be | |
60 | * big enough to fit it. | |
61 | * | |
62 | * Likewise, hugeapge pagetable pointers contain a (different) | |
63 | * shift value in the low bits. All tables must be aligned so | |
64 | * as to leave enough 0 bits in the address to contain it. */ | |
65 | unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, | |
66 | HUGEPD_SHIFT_MASK + 1); | |
67 | struct kmem_cache *new; | |
68 | ||
69 | /* It would be nice if this was a BUILD_BUG_ON(), but at the | |
70 | * moment, gcc doesn't seem to recognize is_power_of_2 as a | |
71 | * constant expression, so so much for that. */ | |
72 | BUG_ON(!is_power_of_2(minalign)); | |
73 | BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); | |
74 | ||
75 | if (PGT_CACHE(shift)) | |
76 | return; /* Already have a cache of this size */ | |
77 | ||
78 | align = max_t(unsigned long, align, minalign); | |
79 | name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); | |
80 | new = kmem_cache_create(name, table_size, align, 0, ctor); | |
bf5ca68d NP |
81 | if (!new) |
82 | panic("Could not allocate pgtable cache for order %d", shift); | |
83 | ||
9b081e10 CL |
84 | kfree(name); |
85 | pgtable_cache[shift - 1] = new; | |
bf5ca68d | 86 | |
9b081e10 CL |
87 | pr_debug("Allocated pgtable cache for order %d\n", shift); |
88 | } | |
89 | ||
90 | ||
91 | void pgtable_cache_init(void) | |
92 | { | |
93 | pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); | |
94 | ||
bf5ca68d | 95 | if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX)) |
9b081e10 CL |
96 | pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor); |
97 | /* | |
98 | * In all current configs, when the PUD index exists it's the | |
99 | * same size as either the pgd or pmd index except with THP enabled | |
100 | * on book3s 64 | |
101 | */ | |
102 | if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)) | |
103 | pgtable_cache_add(PUD_INDEX_SIZE, pud_ctor); | |
9b081e10 | 104 | } |