1 /** 2 * \file drm_scatter.c 3 * IOCTLs to manage scatter/gather memory 4 * 5 * \author Gareth Hughes <gareth@valinux.com> 6 */ 7 8 /* 9 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com 10 * 11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 12 * All Rights Reserved. 13 * 14 * Permission is hereby granted, free of charge, to any person obtaining a 15 * copy of this software and associated documentation files (the "Software"), 16 * to deal in the Software without restriction, including without limitation 17 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 18 * and/or sell copies of the Software, and to permit persons to whom the 19 * Software is furnished to do so, subject to the following conditions: 20 * 21 * The above copyright notice and this permission notice (including the next 22 * paragraph) shall be included in all copies or substantial portions of the 23 * Software. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 28 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 31 * DEALINGS IN THE SOFTWARE. 32 */ 33 34 #include <linux/vmalloc.h> 35 #include "drmP.h" 36 37 #define DEBUG_SCATTER 0 38 39 static inline void *drm_vmalloc_dma(unsigned long size) 40 { 41 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) 42 return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE); 43 #else 44 return vmalloc_32(size); 45 #endif 46 } 47 48 void drm_sg_cleanup(struct drm_sg_mem * entry) 49 { 50 struct page *page; 51 int i; 52 53 for (i = 0; i < entry->pages; i++) { 54 page = entry->pagelist[i]; 55 if (page) 56 ClearPageReserved(page); 57 } 58 59 vfree(entry->virtual); 60 61 kfree(entry->busaddr); 62 kfree(entry->pagelist); 63 kfree(entry); 64 } 65 66 #ifdef _LP64 67 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1))) 68 #else 69 # define ScatterHandle(x) (unsigned int)(x) 70 #endif 71 72 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request) 73 { 74 struct drm_sg_mem *entry; 75 unsigned long pages, i, j; 76 77 DRM_DEBUG("\n"); 78 79 if (!drm_core_check_feature(dev, DRIVER_SG)) 80 return -EINVAL; 81 82 if (dev->sg) 83 return -EINVAL; 84 85 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 86 if (!entry) 87 return -ENOMEM; 88 89 memset(entry, 0, sizeof(*entry)); 90 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE; 91 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages); 92 93 entry->pages = pages; 94 entry->pagelist = kmalloc(pages * sizeof(*entry->pagelist), GFP_KERNEL); 95 if (!entry->pagelist) { 96 kfree(entry); 97 return -ENOMEM; 98 } 99 100 memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist)); 101 102 entry->busaddr = kmalloc(pages * sizeof(*entry->busaddr), GFP_KERNEL); 103 if (!entry->busaddr) { 104 kfree(entry->pagelist); 105 kfree(entry); 106 return -ENOMEM; 107 } 108 memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr)); 109 110 entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT); 111 if (!entry->virtual) { 112 kfree(entry->busaddr); 113 kfree(entry->pagelist); 114 kfree(entry); 115 return -ENOMEM; 116 } 117 118 /* This also forces the mapping of COW pages, so our page list 119 * will be valid. Please don't remove it... 120 */ 121 memset(entry->virtual, 0, pages << PAGE_SHIFT); 122 123 entry->handle = ScatterHandle((unsigned long)entry->virtual); 124 125 DRM_DEBUG("handle = %08lx\n", entry->handle); 126 DRM_DEBUG("virtual = %p\n", entry->virtual); 127 128 for (i = (unsigned long)entry->virtual, j = 0; j < pages; 129 i += PAGE_SIZE, j++) { 130 entry->pagelist[j] = vmalloc_to_page((void *)i); 131 if (!entry->pagelist[j]) 132 goto failed; 133 SetPageReserved(entry->pagelist[j]); 134 } 135 136 request->handle = entry->handle; 137 138 dev->sg = entry; 139 140 #if DEBUG_SCATTER 141 /* Verify that each page points to its virtual address, and vice 142 * versa. 143 */ 144 { 145 int error = 0; 146 147 for (i = 0; i < pages; i++) { 148 unsigned long *tmp; 149 150 tmp = page_address(entry->pagelist[i]); 151 for (j = 0; 152 j < PAGE_SIZE / sizeof(unsigned long); 153 j++, tmp++) { 154 *tmp = 0xcafebabe; 155 } 156 tmp = (unsigned long *)((u8 *) entry->virtual + 157 (PAGE_SIZE * i)); 158 for (j = 0; 159 j < PAGE_SIZE / sizeof(unsigned long); 160 j++, tmp++) { 161 if (*tmp != 0xcafebabe && error == 0) { 162 error = 1; 163 DRM_ERROR("Scatter allocation error, " 164 "pagelist does not match " 165 "virtual mapping\n"); 166 } 167 } 168 tmp = page_address(entry->pagelist[i]); 169 for (j = 0; 170 j < PAGE_SIZE / sizeof(unsigned long); 171 j++, tmp++) { 172 *tmp = 0; 173 } 174 } 175 if (error == 0) 176 DRM_ERROR("Scatter allocation matches pagelist\n"); 177 } 178 #endif 179 180 return 0; 181 182 failed: 183 drm_sg_cleanup(entry); 184 return -ENOMEM; 185 } 186 EXPORT_SYMBOL(drm_sg_alloc); 187 188 189 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data, 190 struct drm_file *file_priv) 191 { 192 struct drm_scatter_gather *request = data; 193 194 return drm_sg_alloc(dev, request); 195 196 } 197 198 int drm_sg_free(struct drm_device *dev, void *data, 199 struct drm_file *file_priv) 200 { 201 struct drm_scatter_gather *request = data; 202 struct drm_sg_mem *entry; 203 204 if (!drm_core_check_feature(dev, DRIVER_SG)) 205 return -EINVAL; 206 207 entry = dev->sg; 208 dev->sg = NULL; 209 210 if (!entry || entry->handle != request->handle) 211 return -EINVAL; 212 213 DRM_DEBUG("virtual = %p\n", entry->virtual); 214 215 drm_sg_cleanup(entry); 216 217 return 0; 218 } 219