Dave Airlie | 3248877 | 2011-11-25 15:21:02 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright © 2012 Red Hat |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 5 | * copy of this software and associated documentation files (the "Software"), |
| 6 | * to deal in the Software without restriction, including without limitation |
| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 8 | * and/or sell copies of the Software, and to permit persons to whom the |
| 9 | * Software is furnished to do so, subject to the following conditions: |
| 10 | * |
| 11 | * The above copyright notice and this permission notice (including the next |
| 12 | * paragraph) shall be included in all copies or substantial portions of the |
| 13 | * Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 21 | * IN THE SOFTWARE. |
| 22 | * |
| 23 | * Authors: |
| 24 | * Dave Airlie <airlied@redhat.com> |
| 25 | * Rob Clark <rob.clark@linaro.org> |
| 26 | * |
| 27 | */ |
| 28 | |
| 29 | #include <linux/export.h> |
| 30 | #include <linux/dma-buf.h> |
| 31 | #include "drmP.h" |
| 32 | |
| 33 | /* |
| 34 | * DMA-BUF/GEM Object references and lifetime overview: |
| 35 | * |
| 36 | * On the export the dma_buf holds a reference to the exporting GEM |
| 37 | * object. It takes this reference in handle_to_fd_ioctl, when it |
| 38 | * first calls .prime_export and stores the exporting GEM object in |
| 39 | * the dma_buf priv. This reference is released when the dma_buf |
| 40 | * object goes away in the driver .release function. |
| 41 | * |
| 42 | * On the import the importing GEM object holds a reference to the |
| 43 | * dma_buf (which in turn holds a ref to the exporting GEM object). |
| 44 | * It takes that reference in the fd_to_handle ioctl. |
| 45 | * It calls dma_buf_get, creates an attachment to it and stores the |
| 46 | * attachment in the GEM object. When this attachment is destroyed |
| 47 | * when the imported object is destroyed, we remove the attachment |
| 48 | * and drop the reference to the dma_buf. |
| 49 | * |
| 50 | * Thus the chain of references always flows in one direction |
| 51 | * (avoiding loops): importing_gem -> dmabuf -> exporting_gem |
| 52 | * |
| 53 | * Self-importing: if userspace is using PRIME as a replacement for flink |
| 54 | * then it will get a fd->handle request for a GEM object that it created. |
| 55 | * Drivers should detect this situation and return back the gem object |
| 56 | * from the dma-buf private. |
| 57 | */ |
| 58 | |
| 59 | struct drm_prime_member { |
| 60 | struct list_head entry; |
| 61 | struct dma_buf *dma_buf; |
| 62 | uint32_t handle; |
| 63 | }; |
| 64 | |
| 65 | int drm_gem_prime_handle_to_fd(struct drm_device *dev, |
| 66 | struct drm_file *file_priv, uint32_t handle, uint32_t flags, |
| 67 | int *prime_fd) |
| 68 | { |
| 69 | struct drm_gem_object *obj; |
| 70 | void *buf; |
Dave Airlie | 0ff926c | 2012-05-20 17:31:16 +0100 | [diff] [blame] | 71 | int ret; |
Dave Airlie | 3248877 | 2011-11-25 15:21:02 +0000 | [diff] [blame] | 72 | |
| 73 | obj = drm_gem_object_lookup(dev, file_priv, handle); |
| 74 | if (!obj) |
| 75 | return -ENOENT; |
| 76 | |
| 77 | mutex_lock(&file_priv->prime.lock); |
| 78 | /* re-export the original imported object */ |
| 79 | if (obj->import_attach) { |
| 80 | get_dma_buf(obj->import_attach->dmabuf); |
| 81 | *prime_fd = dma_buf_fd(obj->import_attach->dmabuf, flags); |
| 82 | drm_gem_object_unreference_unlocked(obj); |
| 83 | mutex_unlock(&file_priv->prime.lock); |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | if (obj->export_dma_buf) { |
| 88 | get_dma_buf(obj->export_dma_buf); |
| 89 | *prime_fd = dma_buf_fd(obj->export_dma_buf, flags); |
| 90 | drm_gem_object_unreference_unlocked(obj); |
| 91 | } else { |
| 92 | buf = dev->driver->gem_prime_export(dev, obj, flags); |
| 93 | if (IS_ERR(buf)) { |
| 94 | /* normally the created dma-buf takes ownership of the ref, |
| 95 | * but if that fails then drop the ref |
| 96 | */ |
| 97 | drm_gem_object_unreference_unlocked(obj); |
| 98 | mutex_unlock(&file_priv->prime.lock); |
| 99 | return PTR_ERR(buf); |
| 100 | } |
| 101 | obj->export_dma_buf = buf; |
| 102 | *prime_fd = dma_buf_fd(buf, flags); |
| 103 | } |
Dave Airlie | 0ff926c | 2012-05-20 17:31:16 +0100 | [diff] [blame] | 104 | /* if we've exported this buffer the cheat and add it to the import list |
| 105 | * so we get the correct handle back |
| 106 | */ |
| 107 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, |
| 108 | obj->export_dma_buf, handle); |
| 109 | if (ret) { |
| 110 | drm_gem_object_unreference_unlocked(obj); |
| 111 | mutex_unlock(&file_priv->prime.lock); |
| 112 | return ret; |
| 113 | } |
| 114 | |
Dave Airlie | 3248877 | 2011-11-25 15:21:02 +0000 | [diff] [blame] | 115 | mutex_unlock(&file_priv->prime.lock); |
| 116 | return 0; |
| 117 | } |
| 118 | EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); |
| 119 | |
| 120 | int drm_gem_prime_fd_to_handle(struct drm_device *dev, |
| 121 | struct drm_file *file_priv, int prime_fd, uint32_t *handle) |
| 122 | { |
| 123 | struct dma_buf *dma_buf; |
| 124 | struct drm_gem_object *obj; |
| 125 | int ret; |
| 126 | |
| 127 | dma_buf = dma_buf_get(prime_fd); |
| 128 | if (IS_ERR(dma_buf)) |
| 129 | return PTR_ERR(dma_buf); |
| 130 | |
| 131 | mutex_lock(&file_priv->prime.lock); |
| 132 | |
| 133 | ret = drm_prime_lookup_imported_buf_handle(&file_priv->prime, |
| 134 | dma_buf, handle); |
| 135 | if (!ret) { |
| 136 | ret = 0; |
| 137 | goto out_put; |
| 138 | } |
| 139 | |
| 140 | /* never seen this one, need to import */ |
| 141 | obj = dev->driver->gem_prime_import(dev, dma_buf); |
| 142 | if (IS_ERR(obj)) { |
| 143 | ret = PTR_ERR(obj); |
| 144 | goto out_put; |
| 145 | } |
| 146 | |
| 147 | ret = drm_gem_handle_create(file_priv, obj, handle); |
| 148 | drm_gem_object_unreference_unlocked(obj); |
| 149 | if (ret) |
| 150 | goto out_put; |
| 151 | |
| 152 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, |
| 153 | dma_buf, *handle); |
| 154 | if (ret) |
| 155 | goto fail; |
| 156 | |
| 157 | mutex_unlock(&file_priv->prime.lock); |
| 158 | return 0; |
| 159 | |
| 160 | fail: |
| 161 | /* hmm, if driver attached, we are relying on the free-object path |
| 162 | * to detach.. which seems ok.. |
| 163 | */ |
| 164 | drm_gem_object_handle_unreference_unlocked(obj); |
| 165 | out_put: |
| 166 | dma_buf_put(dma_buf); |
| 167 | mutex_unlock(&file_priv->prime.lock); |
| 168 | return ret; |
| 169 | } |
| 170 | EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); |
| 171 | |
| 172 | int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, |
| 173 | struct drm_file *file_priv) |
| 174 | { |
| 175 | struct drm_prime_handle *args = data; |
| 176 | uint32_t flags; |
| 177 | |
| 178 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) |
| 179 | return -EINVAL; |
| 180 | |
| 181 | if (!dev->driver->prime_handle_to_fd) |
| 182 | return -ENOSYS; |
| 183 | |
| 184 | /* check flags are valid */ |
| 185 | if (args->flags & ~DRM_CLOEXEC) |
| 186 | return -EINVAL; |
| 187 | |
| 188 | /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ |
| 189 | flags = args->flags & DRM_CLOEXEC; |
| 190 | |
| 191 | return dev->driver->prime_handle_to_fd(dev, file_priv, |
| 192 | args->handle, flags, &args->fd); |
| 193 | } |
| 194 | |
| 195 | int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, |
| 196 | struct drm_file *file_priv) |
| 197 | { |
| 198 | struct drm_prime_handle *args = data; |
| 199 | |
| 200 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) |
| 201 | return -EINVAL; |
| 202 | |
| 203 | if (!dev->driver->prime_fd_to_handle) |
| 204 | return -ENOSYS; |
| 205 | |
| 206 | return dev->driver->prime_fd_to_handle(dev, file_priv, |
| 207 | args->fd, &args->handle); |
| 208 | } |
| 209 | |
| 210 | /* |
| 211 | * drm_prime_pages_to_sg |
| 212 | * |
| 213 | * this helper creates an sg table object from a set of pages |
| 214 | * the driver is responsible for mapping the pages into the |
| 215 | * importers address space |
| 216 | */ |
| 217 | struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) |
| 218 | { |
| 219 | struct sg_table *sg = NULL; |
| 220 | struct scatterlist *iter; |
| 221 | int i; |
| 222 | int ret; |
| 223 | |
| 224 | sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); |
| 225 | if (!sg) |
| 226 | goto out; |
| 227 | |
| 228 | ret = sg_alloc_table(sg, nr_pages, GFP_KERNEL); |
| 229 | if (ret) |
| 230 | goto out; |
| 231 | |
| 232 | for_each_sg(sg->sgl, iter, nr_pages, i) |
| 233 | sg_set_page(iter, pages[i], PAGE_SIZE, 0); |
| 234 | |
| 235 | return sg; |
| 236 | out: |
| 237 | kfree(sg); |
| 238 | return NULL; |
| 239 | } |
| 240 | EXPORT_SYMBOL(drm_prime_pages_to_sg); |
| 241 | |
Dave Airlie | 51ab7ba | 2012-05-18 15:40:33 +0100 | [diff] [blame] | 242 | /* export an sg table into an array of pages and addresses |
| 243 | this is currently required by the TTM driver in order to do correct fault |
| 244 | handling */ |
| 245 | int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, |
| 246 | dma_addr_t *addrs, int max_pages) |
| 247 | { |
| 248 | unsigned count; |
| 249 | struct scatterlist *sg; |
| 250 | struct page *page; |
| 251 | u32 len, offset; |
| 252 | int pg_index; |
| 253 | dma_addr_t addr; |
| 254 | |
| 255 | pg_index = 0; |
| 256 | for_each_sg(sgt->sgl, sg, sgt->nents, count) { |
| 257 | len = sg->length; |
| 258 | offset = sg->offset; |
| 259 | page = sg_page(sg); |
| 260 | addr = sg_dma_address(sg); |
| 261 | |
| 262 | while (len > 0) { |
| 263 | if (WARN_ON(pg_index >= max_pages)) |
| 264 | return -1; |
| 265 | pages[pg_index] = page; |
| 266 | if (addrs) |
| 267 | addrs[pg_index] = addr; |
| 268 | |
| 269 | page++; |
| 270 | addr += PAGE_SIZE; |
| 271 | len -= PAGE_SIZE; |
| 272 | pg_index++; |
| 273 | } |
| 274 | } |
| 275 | return 0; |
| 276 | } |
| 277 | EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); |
Dave Airlie | 3248877 | 2011-11-25 15:21:02 +0000 | [diff] [blame] | 278 | /* helper function to cleanup a GEM/prime object */ |
| 279 | void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) |
| 280 | { |
| 281 | struct dma_buf_attachment *attach; |
| 282 | struct dma_buf *dma_buf; |
| 283 | attach = obj->import_attach; |
| 284 | if (sg) |
| 285 | dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); |
| 286 | dma_buf = attach->dmabuf; |
| 287 | dma_buf_detach(attach->dmabuf, attach); |
| 288 | /* remove the reference */ |
| 289 | dma_buf_put(dma_buf); |
| 290 | } |
| 291 | EXPORT_SYMBOL(drm_prime_gem_destroy); |
| 292 | |
| 293 | void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) |
| 294 | { |
| 295 | INIT_LIST_HEAD(&prime_fpriv->head); |
| 296 | mutex_init(&prime_fpriv->lock); |
| 297 | } |
| 298 | EXPORT_SYMBOL(drm_prime_init_file_private); |
| 299 | |
| 300 | void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) |
| 301 | { |
| 302 | struct drm_prime_member *member, *safe; |
| 303 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { |
| 304 | list_del(&member->entry); |
| 305 | kfree(member); |
| 306 | } |
| 307 | } |
| 308 | EXPORT_SYMBOL(drm_prime_destroy_file_private); |
| 309 | |
| 310 | int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle) |
| 311 | { |
| 312 | struct drm_prime_member *member; |
| 313 | |
| 314 | member = kmalloc(sizeof(*member), GFP_KERNEL); |
| 315 | if (!member) |
| 316 | return -ENOMEM; |
| 317 | |
| 318 | member->dma_buf = dma_buf; |
| 319 | member->handle = handle; |
| 320 | list_add(&member->entry, &prime_fpriv->head); |
| 321 | return 0; |
| 322 | } |
| 323 | EXPORT_SYMBOL(drm_prime_add_imported_buf_handle); |
| 324 | |
| 325 | int drm_prime_lookup_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle) |
| 326 | { |
| 327 | struct drm_prime_member *member; |
| 328 | |
| 329 | list_for_each_entry(member, &prime_fpriv->head, entry) { |
| 330 | if (member->dma_buf == dma_buf) { |
| 331 | *handle = member->handle; |
| 332 | return 0; |
| 333 | } |
| 334 | } |
| 335 | return -ENOENT; |
| 336 | } |
| 337 | EXPORT_SYMBOL(drm_prime_lookup_imported_buf_handle); |
| 338 | |
| 339 | void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) |
| 340 | { |
| 341 | struct drm_prime_member *member, *safe; |
| 342 | |
| 343 | mutex_lock(&prime_fpriv->lock); |
| 344 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { |
| 345 | if (member->dma_buf == dma_buf) { |
| 346 | list_del(&member->entry); |
| 347 | kfree(member); |
| 348 | } |
| 349 | } |
| 350 | mutex_unlock(&prime_fpriv->lock); |
| 351 | } |
| 352 | EXPORT_SYMBOL(drm_prime_remove_imported_buf_handle); |