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/mm.h> 35 #include <linux/slab.h> 36 #include <linux/vmalloc.h> 37 38 #include <drm/drm.h> 39 #include <drm/drm_drv.h> 40 #include <drm/drm_print.h> 41 42 #include "drm_legacy.h" 43 44 #define DEBUG_SCATTER 0 45 46 static void drm_sg_cleanup(struct drm_sg_mem * entry) 47 { 48 struct page *page; 49 int i; 50 51 for (i = 0; i < entry->pages; i++) { 52 page = entry->pagelist[i]; 53 if (page) 54 ClearPageReserved(page); 55 } 56 57 vfree(entry->virtual); 58 59 kfree(entry->busaddr); 60 kfree(entry->pagelist); 61 kfree(entry); 62 } 63 64 void drm_legacy_sg_cleanup(struct drm_device *dev) 65 { 66 if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg && 67 drm_core_check_feature(dev, DRIVER_LEGACY)) { 68 drm_sg_cleanup(dev->sg); 69 dev->sg = NULL; 70 } 71 } 72 #ifdef _LP64 73 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1))) 74 #else 75 # define ScatterHandle(x) (unsigned int)(x) 76 #endif 77 78 int drm_legacy_sg_alloc(struct drm_device *dev, void *data, 79 struct drm_file *file_priv) 80 { 81 struct drm_scatter_gather *request = data; 82 struct drm_sg_mem *entry; 83 unsigned long pages, i, j; 84 85 DRM_DEBUG("\n"); 86 87 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 88 return -EOPNOTSUPP; 89 90 if (!drm_core_check_feature(dev, DRIVER_SG)) 91 return -EOPNOTSUPP; 92 93 if (request->size > SIZE_MAX - PAGE_SIZE) 94 return -EINVAL; 95 96 if (dev->sg) 97 return -EINVAL; 98 99 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 100 if (!entry) 101 return -ENOMEM; 102 103 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE; 104 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages); 105 106 entry->pages = pages; 107 entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL); 108 if (!entry->pagelist) { 109 kfree(entry); 110 return -ENOMEM; 111 } 112 113 entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL); 114 if (!entry->busaddr) { 115 kfree(entry->pagelist); 116 kfree(entry); 117 return -ENOMEM; 118 } 119 120 entry->virtual = vmalloc_32(pages << PAGE_SHIFT); 121 if (!entry->virtual) { 122 kfree(entry->busaddr); 123 kfree(entry->pagelist); 124 kfree(entry); 125 return -ENOMEM; 126 } 127 128 /* This also forces the mapping of COW pages, so our page list 129 * will be valid. Please don't remove it... 130 */ 131 memset(entry->virtual, 0, pages << PAGE_SHIFT); 132 133 entry->handle = ScatterHandle((unsigned long)entry->virtual); 134 135 DRM_DEBUG("handle = %08lx\n", entry->handle); 136 DRM_DEBUG("virtual = %p\n", entry->virtual); 137 138 for (i = (unsigned long)entry->virtual, j = 0; j < pages; 139 i += PAGE_SIZE, j++) { 140 entry->pagelist[j] = vmalloc_to_page((void *)i); 141 if (!entry->pagelist[j]) 142 goto failed; 143 SetPageReserved(entry->pagelist[j]); 144 } 145 146 request->handle = entry->handle; 147 148 dev->sg = entry; 149 150 #if DEBUG_SCATTER 151 /* Verify that each page points to its virtual address, and vice 152 * versa. 153 */ 154 { 155 int error = 0; 156 157 for (i = 0; i < pages; i++) { 158 unsigned long *tmp; 159 160 tmp = page_address(entry->pagelist[i]); 161 for (j = 0; 162 j < PAGE_SIZE / sizeof(unsigned long); 163 j++, tmp++) { 164 *tmp = 0xcafebabe; 165 } 166 tmp = (unsigned long *)((u8 *) entry->virtual + 167 (PAGE_SIZE * i)); 168 for (j = 0; 169 j < PAGE_SIZE / sizeof(unsigned long); 170 j++, tmp++) { 171 if (*tmp != 0xcafebabe && error == 0) { 172 error = 1; 173 DRM_ERROR("Scatter allocation error, " 174 "pagelist does not match " 175 "virtual mapping\n"); 176 } 177 } 178 tmp = page_address(entry->pagelist[i]); 179 for (j = 0; 180 j < PAGE_SIZE / sizeof(unsigned long); 181 j++, tmp++) { 182 *tmp = 0; 183 } 184 } 185 if (error == 0) 186 DRM_ERROR("Scatter allocation matches pagelist\n"); 187 } 188 #endif 189 190 return 0; 191 192 failed: 193 drm_sg_cleanup(entry); 194 return -ENOMEM; 195 } 196 197 int drm_legacy_sg_free(struct drm_device *dev, void *data, 198 struct drm_file *file_priv) 199 { 200 struct drm_scatter_gather *request = data; 201 struct drm_sg_mem *entry; 202 203 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 204 return -EOPNOTSUPP; 205 206 if (!drm_core_check_feature(dev, DRIVER_SG)) 207 return -EOPNOTSUPP; 208 209 entry = dev->sg; 210 dev->sg = NULL; 211 212 if (!entry || entry->handle != request->handle) 213 return -EINVAL; 214 215 DRM_DEBUG("virtual = %p\n", entry->virtual); 216 217 drm_sg_cleanup(entry); 218 219 return 0; 220 } 221