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