1 /* $NetBSD: drm_scatter.c,v 1.2 2018/08/27 04:58:19 riastradh Exp $ */ 2 3 /** 4 * \file drm_scatter.c 5 * IOCTLs to manage scatter/gather memory 6 * 7 * \author Gareth Hughes <gareth@valinux.com> 8 */ 9 10 /* 11 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com 12 * 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 14 * All Rights Reserved. 15 * 16 * Permission is hereby granted, free of charge, to any person obtaining a 17 * copy of this software and associated documentation files (the "Software"), 18 * to deal in the Software without restriction, including without limitation 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 20 * and/or sell copies of the Software, and to permit persons to whom the 21 * Software is furnished to do so, subject to the following conditions: 22 * 23 * The above copyright notice and this permission notice (including the next 24 * paragraph) shall be included in all copies or substantial portions of the 25 * Software. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 30 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 33 * DEALINGS IN THE SOFTWARE. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: drm_scatter.c,v 1.2 2018/08/27 04:58:19 riastradh Exp $"); 38 39 #include <linux/vmalloc.h> 40 #include <linux/slab.h> 41 #include <drm/drmP.h> 42 #include "drm_legacy.h" 43 44 #define DEBUG_SCATTER 0 45 46 static inline void *drm_vmalloc_dma(unsigned long size) 47 { 48 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) 49 return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE); 50 #else 51 return vmalloc_32(size); 52 #endif 53 } 54 55 static void drm_sg_cleanup(struct drm_sg_mem * entry) 56 { 57 struct page *page; 58 int i; 59 60 for (i = 0; i < entry->pages; i++) { 61 page = entry->pagelist[i]; 62 if (page) 63 ClearPageReserved(page); 64 } 65 66 vfree(entry->virtual); 67 68 kfree(entry->busaddr); 69 kfree(entry->pagelist); 70 kfree(entry); 71 } 72 73 void drm_legacy_sg_cleanup(struct drm_device *dev) 74 { 75 if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg && 76 !drm_core_check_feature(dev, DRIVER_MODESET)) { 77 drm_sg_cleanup(dev->sg); 78 dev->sg = NULL; 79 } 80 } 81 #ifdef _LP64 82 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1))) 83 #else 84 # define ScatterHandle(x) (unsigned int)(x) 85 #endif 86 87 int drm_legacy_sg_alloc(struct drm_device *dev, void *data, 88 struct drm_file *file_priv) 89 { 90 struct drm_scatter_gather *request = data; 91 struct drm_sg_mem *entry; 92 unsigned long pages, i, j; 93 94 DRM_DEBUG("\n"); 95 96 if (drm_core_check_feature(dev, DRIVER_MODESET)) 97 return -EINVAL; 98 99 if (!drm_core_check_feature(dev, DRIVER_SG)) 100 return -EINVAL; 101 102 if (dev->sg) 103 return -EINVAL; 104 105 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 106 if (!entry) 107 return -ENOMEM; 108 109 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE; 110 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages); 111 112 entry->pages = pages; 113 entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL); 114 if (!entry->pagelist) { 115 kfree(entry); 116 return -ENOMEM; 117 } 118 119 entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL); 120 if (!entry->busaddr) { 121 kfree(entry->pagelist); 122 kfree(entry); 123 return -ENOMEM; 124 } 125 126 entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT); 127 if (!entry->virtual) { 128 kfree(entry->busaddr); 129 kfree(entry->pagelist); 130 kfree(entry); 131 return -ENOMEM; 132 } 133 134 /* This also forces the mapping of COW pages, so our page list 135 * will be valid. Please don't remove it... 136 */ 137 memset(entry->virtual, 0, pages << PAGE_SHIFT); 138 139 entry->handle = ScatterHandle((unsigned long)entry->virtual); 140 141 DRM_DEBUG("handle = %08lx\n", entry->handle); 142 DRM_DEBUG("virtual = %p\n", entry->virtual); 143 144 for (i = (unsigned long)entry->virtual, j = 0; j < pages; 145 i += PAGE_SIZE, j++) { 146 entry->pagelist[j] = vmalloc_to_page((void *)i); 147 if (!entry->pagelist[j]) 148 goto failed; 149 SetPageReserved(entry->pagelist[j]); 150 } 151 152 request->handle = entry->handle; 153 154 dev->sg = entry; 155 156 #if DEBUG_SCATTER 157 /* Verify that each page points to its virtual address, and vice 158 * versa. 159 */ 160 { 161 int error = 0; 162 163 for (i = 0; i < pages; i++) { 164 unsigned long *tmp; 165 166 tmp = page_address(entry->pagelist[i]); 167 for (j = 0; 168 j < PAGE_SIZE / sizeof(unsigned long); 169 j++, tmp++) { 170 *tmp = 0xcafebabe; 171 } 172 tmp = (unsigned long *)((u8 *) entry->virtual + 173 (PAGE_SIZE * i)); 174 for (j = 0; 175 j < PAGE_SIZE / sizeof(unsigned long); 176 j++, tmp++) { 177 if (*tmp != 0xcafebabe && error == 0) { 178 error = 1; 179 DRM_ERROR("Scatter allocation error, " 180 "pagelist does not match " 181 "virtual mapping\n"); 182 } 183 } 184 tmp = page_address(entry->pagelist[i]); 185 for (j = 0; 186 j < PAGE_SIZE / sizeof(unsigned long); 187 j++, tmp++) { 188 *tmp = 0; 189 } 190 } 191 if (error == 0) 192 DRM_ERROR("Scatter allocation matches pagelist\n"); 193 } 194 #endif 195 196 return 0; 197 198 failed: 199 drm_sg_cleanup(entry); 200 return -ENOMEM; 201 } 202 203 int drm_legacy_sg_free(struct drm_device *dev, void *data, 204 struct drm_file *file_priv) 205 { 206 struct drm_scatter_gather *request = data; 207 struct drm_sg_mem *entry; 208 209 if (drm_core_check_feature(dev, DRIVER_MODESET)) 210 return -EINVAL; 211 212 if (!drm_core_check_feature(dev, DRIVER_SG)) 213 return -EINVAL; 214 215 entry = dev->sg; 216 dev->sg = NULL; 217 218 if (!entry || entry->handle != request->handle) 219 return -EINVAL; 220 221 DRM_DEBUG("virtual = %p\n", entry->virtual); 222 223 drm_sg_cleanup(entry); 224 225 return 0; 226 } 227