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> 25 #include <linux/slab.h> 26 #include <linux/vmalloc.h> 27 28 #include <asm/spu.h> 29 #include <asm/spu_csa.h> 30 #include <asm/mmu.h> 31 32 #include "spufs.h" 33 34 static int spu_alloc_lscsa_std(struct spu_state *csa) 35 { 36 struct spu_lscsa *lscsa; 37 unsigned char *p; 38 39 lscsa = vmalloc(sizeof(struct spu_lscsa)); 40 if (!lscsa) 41 return -ENOMEM; 42 memset(lscsa, 0, sizeof(struct spu_lscsa)); 43 csa->lscsa = lscsa; 44 45 /* Set LS pages reserved to allow for user-space mapping. */ 46 for (p = lscsa->ls; p < lscsa->ls + LS_SIZE; p += PAGE_SIZE) 47 SetPageReserved(vmalloc_to_page(p)); 48 49 return 0; 50 } 51 52 static void spu_free_lscsa_std(struct spu_state *csa) 53 { 54 /* Clear reserved bit before vfree. */ 55 unsigned char *p; 56 57 if (csa->lscsa == NULL) 58 return; 59 60 for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) 61 ClearPageReserved(vmalloc_to_page(p)); 62 63 vfree(csa->lscsa); 64 } 65 66 #ifdef CONFIG_SPU_FS_64K_LS 67 68 #define SPU_64K_PAGE_SHIFT 16 69 #define SPU_64K_PAGE_ORDER (SPU_64K_PAGE_SHIFT - PAGE_SHIFT) 70 #define SPU_64K_PAGE_COUNT (1ul << SPU_64K_PAGE_ORDER) 71 72 int spu_alloc_lscsa(struct spu_state *csa) 73 { 74 struct page **pgarray; 75 unsigned char *p; 76 int i, j, n_4k; 77 78 /* Check availability of 64K pages */ 79 if (!spu_64k_pages_available()) 80 goto fail; 81 82 csa->use_big_pages = 1; 83 84 pr_debug("spu_alloc_lscsa(csa=0x%p), trying to allocate 64K pages\n", 85 csa); 86 87 /* First try to allocate our 64K pages. We need 5 of them 88 * with the current implementation. In the future, we should try 89 * to separate the lscsa with the actual local store image, thus 90 * allowing us to require only 4 64K pages per context 91 */ 92 for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) { 93 /* XXX This is likely to fail, we should use a special pool 94 * similiar to what hugetlbfs does. 95 */ 96 csa->lscsa_pages[i] = alloc_pages(GFP_KERNEL, 97 SPU_64K_PAGE_ORDER); 98 if (csa->lscsa_pages[i] == NULL) 99 goto fail; 100 } 101 102 pr_debug(" success ! creating vmap...\n"); 103 104 /* Now we need to create a vmalloc mapping of these for the kernel 105 * and SPU context switch code to use. Currently, we stick to a 106 * normal kernel vmalloc mapping, which in our case will be 4K 107 */ 108 n_4k = SPU_64K_PAGE_COUNT * SPU_LSCSA_NUM_BIG_PAGES; 109 pgarray = kmalloc(sizeof(struct page *) * n_4k, GFP_KERNEL); 110 if (pgarray == NULL) 111 goto fail; 112 for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) 113 for (j = 0; j < SPU_64K_PAGE_COUNT; j++) 114 /* We assume all the struct page's are contiguous 115 * which should be hopefully the case for an order 4 116 * allocation.. 117 */ 118 pgarray[i * SPU_64K_PAGE_COUNT + j] = 119 csa->lscsa_pages[i] + j; 120 csa->lscsa = vmap(pgarray, n_4k, VM_USERMAP, PAGE_KERNEL); 121 kfree(pgarray); 122 if (csa->lscsa == NULL) 123 goto fail; 124 125 memset(csa->lscsa, 0, sizeof(struct spu_lscsa)); 126 127 /* Set LS pages reserved to allow for user-space mapping. 128 * 129 * XXX isn't that a bit obsolete ? I think we should just 130 * make sure the page count is high enough. Anyway, won't harm 131 * for now 132 */ 133 for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) 134 SetPageReserved(vmalloc_to_page(p)); 135 136 pr_debug(" all good !\n"); 137 138 return 0; 139 fail: 140 pr_debug("spufs: failed to allocate lscsa 64K pages, falling back\n"); 141 spu_free_lscsa(csa); 142 return spu_alloc_lscsa_std(csa); 143 } 144 145 void spu_free_lscsa(struct spu_state *csa) 146 { 147 unsigned char *p; 148 int i; 149 150 if (!csa->use_big_pages) { 151 spu_free_lscsa_std(csa); 152 return; 153 } 154 csa->use_big_pages = 0; 155 156 if (csa->lscsa == NULL) 157 goto free_pages; 158 159 for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE) 160 ClearPageReserved(vmalloc_to_page(p)); 161 162 vunmap(csa->lscsa); 163 csa->lscsa = NULL; 164 165 free_pages: 166 167 for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) 168 if (csa->lscsa_pages[i]) 169 __free_pages(csa->lscsa_pages[i], SPU_64K_PAGE_ORDER); 170 } 171 172 #else /* CONFIG_SPU_FS_64K_LS */ 173 174 int spu_alloc_lscsa(struct spu_state *csa) 175 { 176 return spu_alloc_lscsa_std(csa); 177 } 178 179 void spu_free_lscsa(struct spu_state *csa) 180 { 181 spu_free_lscsa_std(csa); 182 } 183 184 #endif /* !defined(CONFIG_SPU_FS_64K_LS) */ 185