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1 | /* |
2 | * SPU local store allocation routines | |
3 | * | |
4 | * Copyright 2007 Benjamin Herrenschmidt, IBM Corp. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2, or (at your option) | |
9 | * any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
21 | #undef DEBUG | |
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/mm.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
f1fa74f4 BH |
26 | #include <linux/vmalloc.h> |
27 | ||
28 | #include <asm/spu.h> | |
29 | #include <asm/spu_csa.h> | |
30 | #include <asm/mmu.h> | |
31 | ||
7cd58e43 JK |
32 | #include "spufs.h" |
33 | ||
f1fa74f4 BH |
34 | static int spu_alloc_lscsa_std(struct spu_state *csa) |
35 | { | |
36 | struct spu_lscsa *lscsa; | |
37 | unsigned char *p; | |
38 | ||
467d93a7 | 39 | lscsa = vzalloc(sizeof(struct spu_lscsa)); |
f1fa74f4 BH |
40 | if (!lscsa) |
41 | return -ENOMEM; | |
f1fa74f4 BH |
42 | csa->lscsa = lscsa; |
43 | ||
44 | /* Set LS pages reserved to allow for user-space mapping. */ | |
45 | for (p = lscsa->ls; p < lscsa->ls + LS_SIZE; p += PAGE_SIZE) | |
46 | SetPageReserved(vmalloc_to_page(p)); | |
47 | ||
48 | return 0; | |
49 | } | |
50 | ||
51 | static void spu_free_lscsa_std(struct spu_state *csa) | |
52 | { | |
53 | /* Clear reserved bit before vfree. */ | |
54 | unsigned char *p; | |
55 | ||
56 | if (csa->lscsa == NULL) | |
57 | return; | |
58 | ||
59 | for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) | |
60 | ClearPageReserved(vmalloc_to_page(p)); | |
61 | ||
62 | vfree(csa->lscsa); | |
63 | } | |
64 | ||
65 | #ifdef CONFIG_SPU_FS_64K_LS | |
66 | ||
67 | #define SPU_64K_PAGE_SHIFT 16 | |
68 | #define SPU_64K_PAGE_ORDER (SPU_64K_PAGE_SHIFT - PAGE_SHIFT) | |
69 | #define SPU_64K_PAGE_COUNT (1ul << SPU_64K_PAGE_ORDER) | |
70 | ||
71 | int spu_alloc_lscsa(struct spu_state *csa) | |
72 | { | |
73 | struct page **pgarray; | |
74 | unsigned char *p; | |
75 | int i, j, n_4k; | |
76 | ||
77 | /* Check availability of 64K pages */ | |
f6eb7d7f | 78 | if (!spu_64k_pages_available()) |
f1fa74f4 BH |
79 | goto fail; |
80 | ||
81 | csa->use_big_pages = 1; | |
82 | ||
83 | pr_debug("spu_alloc_lscsa(csa=0x%p), trying to allocate 64K pages\n", | |
84 | csa); | |
85 | ||
86 | /* First try to allocate our 64K pages. We need 5 of them | |
87 | * with the current implementation. In the future, we should try | |
88 | * to separate the lscsa with the actual local store image, thus | |
89 | * allowing us to require only 4 64K pages per context | |
90 | */ | |
91 | for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) { | |
92 | /* XXX This is likely to fail, we should use a special pool | |
93 | * similiar to what hugetlbfs does. | |
94 | */ | |
95 | csa->lscsa_pages[i] = alloc_pages(GFP_KERNEL, | |
96 | SPU_64K_PAGE_ORDER); | |
97 | if (csa->lscsa_pages[i] == NULL) | |
98 | goto fail; | |
99 | } | |
100 | ||
101 | pr_debug(" success ! creating vmap...\n"); | |
102 | ||
103 | /* Now we need to create a vmalloc mapping of these for the kernel | |
104 | * and SPU context switch code to use. Currently, we stick to a | |
105 | * normal kernel vmalloc mapping, which in our case will be 4K | |
106 | */ | |
107 | n_4k = SPU_64K_PAGE_COUNT * SPU_LSCSA_NUM_BIG_PAGES; | |
108 | pgarray = kmalloc(sizeof(struct page *) * n_4k, GFP_KERNEL); | |
109 | if (pgarray == NULL) | |
110 | goto fail; | |
111 | for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) | |
112 | for (j = 0; j < SPU_64K_PAGE_COUNT; j++) | |
113 | /* We assume all the struct page's are contiguous | |
114 | * which should be hopefully the case for an order 4 | |
115 | * allocation.. | |
116 | */ | |
117 | pgarray[i * SPU_64K_PAGE_COUNT + j] = | |
118 | csa->lscsa_pages[i] + j; | |
119 | csa->lscsa = vmap(pgarray, n_4k, VM_USERMAP, PAGE_KERNEL); | |
120 | kfree(pgarray); | |
121 | if (csa->lscsa == NULL) | |
122 | goto fail; | |
123 | ||
124 | memset(csa->lscsa, 0, sizeof(struct spu_lscsa)); | |
125 | ||
126 | /* Set LS pages reserved to allow for user-space mapping. | |
127 | * | |
128 | * XXX isn't that a bit obsolete ? I think we should just | |
129 | * make sure the page count is high enough. Anyway, won't harm | |
130 | * for now | |
131 | */ | |
132 | for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) | |
133 | SetPageReserved(vmalloc_to_page(p)); | |
134 | ||
135 | pr_debug(" all good !\n"); | |
136 | ||
137 | return 0; | |
138 | fail: | |
139 | pr_debug("spufs: failed to allocate lscsa 64K pages, falling back\n"); | |
140 | spu_free_lscsa(csa); | |
141 | return spu_alloc_lscsa_std(csa); | |
142 | } | |
143 | ||
144 | void spu_free_lscsa(struct spu_state *csa) | |
145 | { | |
146 | unsigned char *p; | |
147 | int i; | |
148 | ||
149 | if (!csa->use_big_pages) { | |
150 | spu_free_lscsa_std(csa); | |
151 | return; | |
152 | } | |
153 | csa->use_big_pages = 0; | |
154 | ||
155 | if (csa->lscsa == NULL) | |
156 | goto free_pages; | |
157 | ||
158 | for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) | |
159 | ClearPageReserved(vmalloc_to_page(p)); | |
160 | ||
161 | vunmap(csa->lscsa); | |
162 | csa->lscsa = NULL; | |
163 | ||
164 | free_pages: | |
165 | ||
166 | for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) | |
167 | if (csa->lscsa_pages[i]) | |
168 | __free_pages(csa->lscsa_pages[i], SPU_64K_PAGE_ORDER); | |
169 | } | |
170 | ||
171 | #else /* CONFIG_SPU_FS_64K_LS */ | |
172 | ||
173 | int spu_alloc_lscsa(struct spu_state *csa) | |
174 | { | |
175 | return spu_alloc_lscsa_std(csa); | |
176 | } | |
177 | ||
178 | void spu_free_lscsa(struct spu_state *csa) | |
179 | { | |
180 | spu_free_lscsa_std(csa); | |
181 | } | |
182 | ||
183 | #endif /* !defined(CONFIG_SPU_FS_64K_LS) */ |