Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Framework for buffer objects that can be shared across devices/subsystems. |
| 3 | * |
| 4 | * Copyright(C) 2011 Linaro Limited. All rights reserved. |
| 5 | * Author: Sumit Semwal <sumit.semwal@ti.com> |
| 6 | * |
| 7 | * Many thanks to linaro-mm-sig list, and specially |
| 8 | * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and |
| 9 | * Daniel Vetter <daniel@ffwll.ch> for their support in creation and |
| 10 | * refining of this idea. |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify it |
| 13 | * under the terms of the GNU General Public License version 2 as published by |
| 14 | * the Free Software Foundation. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 17 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 19 | * more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License along with |
| 22 | * this program. If not, see <http://www.gnu.org/licenses/>. |
| 23 | */ |
| 24 | |
| 25 | #include <linux/fs.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/dma-buf.h> |
| 28 | #include <linux/anon_inodes.h> |
| 29 | #include <linux/export.h> |
| 30 | |
| 31 | static inline int is_dma_buf_file(struct file *); |
| 32 | |
| 33 | static int dma_buf_release(struct inode *inode, struct file *file) |
| 34 | { |
| 35 | struct dma_buf *dmabuf; |
| 36 | |
| 37 | if (!is_dma_buf_file(file)) |
| 38 | return -EINVAL; |
| 39 | |
| 40 | dmabuf = file->private_data; |
| 41 | |
| 42 | dmabuf->ops->release(dmabuf); |
| 43 | kfree(dmabuf); |
| 44 | return 0; |
| 45 | } |
| 46 | |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 47 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
| 48 | { |
| 49 | struct dma_buf *dmabuf; |
| 50 | |
| 51 | if (!is_dma_buf_file(file)) |
| 52 | return -EINVAL; |
| 53 | |
| 54 | dmabuf = file->private_data; |
| 55 | |
| 56 | /* check for overflowing the buffer's size */ |
| 57 | if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > |
| 58 | dmabuf->size >> PAGE_SHIFT) |
| 59 | return -EINVAL; |
| 60 | |
| 61 | return dmabuf->ops->mmap(dmabuf, vma); |
| 62 | } |
| 63 | |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 64 | static const struct file_operations dma_buf_fops = { |
| 65 | .release = dma_buf_release, |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 66 | .mmap = dma_buf_mmap_internal, |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 67 | }; |
| 68 | |
| 69 | /* |
| 70 | * is_dma_buf_file - Check if struct file* is associated with dma_buf |
| 71 | */ |
| 72 | static inline int is_dma_buf_file(struct file *file) |
| 73 | { |
| 74 | return file->f_op == &dma_buf_fops; |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
| 79 | * with this buffer, so it can be exported. |
| 80 | * Also connect the allocator specific data and ops to the buffer. |
| 81 | * |
| 82 | * @priv: [in] Attach private data of allocator to this buffer |
| 83 | * @ops: [in] Attach allocator-defined dma buf ops to the new buffer. |
| 84 | * @size: [in] Size of the buffer |
| 85 | * @flags: [in] mode flags for the file. |
| 86 | * |
| 87 | * Returns, on success, a newly created dma_buf object, which wraps the |
| 88 | * supplied private data and operations for dma_buf_ops. On either missing |
| 89 | * ops, or error in allocating struct dma_buf, will return negative error. |
| 90 | * |
| 91 | */ |
Laurent Pinchart | 5375764 | 2012-01-26 12:27:22 +0100 | [diff] [blame] | 92 | struct dma_buf *dma_buf_export(void *priv, const struct dma_buf_ops *ops, |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 93 | size_t size, int flags) |
| 94 | { |
| 95 | struct dma_buf *dmabuf; |
| 96 | struct file *file; |
| 97 | |
| 98 | if (WARN_ON(!priv || !ops |
| 99 | || !ops->map_dma_buf |
| 100 | || !ops->unmap_dma_buf |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 101 | || !ops->release |
| 102 | || !ops->kmap_atomic |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 103 | || !ops->kmap |
| 104 | || !ops->mmap)) { |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 105 | return ERR_PTR(-EINVAL); |
| 106 | } |
| 107 | |
| 108 | dmabuf = kzalloc(sizeof(struct dma_buf), GFP_KERNEL); |
| 109 | if (dmabuf == NULL) |
| 110 | return ERR_PTR(-ENOMEM); |
| 111 | |
| 112 | dmabuf->priv = priv; |
| 113 | dmabuf->ops = ops; |
| 114 | dmabuf->size = size; |
| 115 | |
| 116 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags); |
| 117 | |
| 118 | dmabuf->file = file; |
| 119 | |
| 120 | mutex_init(&dmabuf->lock); |
| 121 | INIT_LIST_HEAD(&dmabuf->attachments); |
| 122 | |
| 123 | return dmabuf; |
| 124 | } |
| 125 | EXPORT_SYMBOL_GPL(dma_buf_export); |
| 126 | |
| 127 | |
| 128 | /** |
| 129 | * dma_buf_fd - returns a file descriptor for the given dma_buf |
| 130 | * @dmabuf: [in] pointer to dma_buf for which fd is required. |
Dave Airlie | 55c1c4c | 2012-03-16 10:34:02 +0000 | [diff] [blame] | 131 | * @flags: [in] flags to give to fd |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 132 | * |
| 133 | * On success, returns an associated 'fd'. Else, returns error. |
| 134 | */ |
Dave Airlie | 55c1c4c | 2012-03-16 10:34:02 +0000 | [diff] [blame] | 135 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 136 | { |
| 137 | int error, fd; |
| 138 | |
| 139 | if (!dmabuf || !dmabuf->file) |
| 140 | return -EINVAL; |
| 141 | |
Dave Airlie | 55c1c4c | 2012-03-16 10:34:02 +0000 | [diff] [blame] | 142 | error = get_unused_fd_flags(flags); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 143 | if (error < 0) |
| 144 | return error; |
| 145 | fd = error; |
| 146 | |
| 147 | fd_install(fd, dmabuf->file); |
| 148 | |
| 149 | return fd; |
| 150 | } |
| 151 | EXPORT_SYMBOL_GPL(dma_buf_fd); |
| 152 | |
| 153 | /** |
| 154 | * dma_buf_get - returns the dma_buf structure related to an fd |
| 155 | * @fd: [in] fd associated with the dma_buf to be returned |
| 156 | * |
| 157 | * On success, returns the dma_buf structure associated with an fd; uses |
| 158 | * file's refcounting done by fget to increase refcount. returns ERR_PTR |
| 159 | * otherwise. |
| 160 | */ |
| 161 | struct dma_buf *dma_buf_get(int fd) |
| 162 | { |
| 163 | struct file *file; |
| 164 | |
| 165 | file = fget(fd); |
| 166 | |
| 167 | if (!file) |
| 168 | return ERR_PTR(-EBADF); |
| 169 | |
| 170 | if (!is_dma_buf_file(file)) { |
| 171 | fput(file); |
| 172 | return ERR_PTR(-EINVAL); |
| 173 | } |
| 174 | |
| 175 | return file->private_data; |
| 176 | } |
| 177 | EXPORT_SYMBOL_GPL(dma_buf_get); |
| 178 | |
| 179 | /** |
| 180 | * dma_buf_put - decreases refcount of the buffer |
| 181 | * @dmabuf: [in] buffer to reduce refcount of |
| 182 | * |
| 183 | * Uses file's refcounting done implicitly by fput() |
| 184 | */ |
| 185 | void dma_buf_put(struct dma_buf *dmabuf) |
| 186 | { |
| 187 | if (WARN_ON(!dmabuf || !dmabuf->file)) |
| 188 | return; |
| 189 | |
| 190 | fput(dmabuf->file); |
| 191 | } |
| 192 | EXPORT_SYMBOL_GPL(dma_buf_put); |
| 193 | |
| 194 | /** |
| 195 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, |
| 196 | * calls attach() of dma_buf_ops to allow device-specific attach functionality |
| 197 | * @dmabuf: [in] buffer to attach device to. |
| 198 | * @dev: [in] device to be attached. |
| 199 | * |
| 200 | * Returns struct dma_buf_attachment * for this attachment; may return negative |
| 201 | * error codes. |
| 202 | * |
| 203 | */ |
| 204 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, |
| 205 | struct device *dev) |
| 206 | { |
| 207 | struct dma_buf_attachment *attach; |
| 208 | int ret; |
| 209 | |
Laurent Pinchart | d1aa06a | 2012-01-26 12:27:23 +0100 | [diff] [blame] | 210 | if (WARN_ON(!dmabuf || !dev)) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 211 | return ERR_PTR(-EINVAL); |
| 212 | |
| 213 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); |
| 214 | if (attach == NULL) |
Laurent Pinchart | a9fbc3b | 2012-01-26 12:27:24 +0100 | [diff] [blame] | 215 | return ERR_PTR(-ENOMEM); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 216 | |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 217 | attach->dev = dev; |
| 218 | attach->dmabuf = dmabuf; |
Laurent Pinchart | 2ed9201 | 2012-01-26 12:27:25 +0100 | [diff] [blame] | 219 | |
| 220 | mutex_lock(&dmabuf->lock); |
| 221 | |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 222 | if (dmabuf->ops->attach) { |
| 223 | ret = dmabuf->ops->attach(dmabuf, dev, attach); |
| 224 | if (ret) |
| 225 | goto err_attach; |
| 226 | } |
| 227 | list_add(&attach->node, &dmabuf->attachments); |
| 228 | |
| 229 | mutex_unlock(&dmabuf->lock); |
| 230 | return attach; |
| 231 | |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 232 | err_attach: |
| 233 | kfree(attach); |
| 234 | mutex_unlock(&dmabuf->lock); |
| 235 | return ERR_PTR(ret); |
| 236 | } |
| 237 | EXPORT_SYMBOL_GPL(dma_buf_attach); |
| 238 | |
| 239 | /** |
| 240 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; |
| 241 | * optionally calls detach() of dma_buf_ops for device-specific detach |
| 242 | * @dmabuf: [in] buffer to detach from. |
| 243 | * @attach: [in] attachment to be detached; is free'd after this call. |
| 244 | * |
| 245 | */ |
| 246 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) |
| 247 | { |
Laurent Pinchart | d1aa06a | 2012-01-26 12:27:23 +0100 | [diff] [blame] | 248 | if (WARN_ON(!dmabuf || !attach)) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 249 | return; |
| 250 | |
| 251 | mutex_lock(&dmabuf->lock); |
| 252 | list_del(&attach->node); |
| 253 | if (dmabuf->ops->detach) |
| 254 | dmabuf->ops->detach(dmabuf, attach); |
| 255 | |
| 256 | mutex_unlock(&dmabuf->lock); |
| 257 | kfree(attach); |
| 258 | } |
| 259 | EXPORT_SYMBOL_GPL(dma_buf_detach); |
| 260 | |
| 261 | /** |
| 262 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; |
| 263 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the |
| 264 | * dma_buf_ops. |
| 265 | * @attach: [in] attachment whose scatterlist is to be returned |
| 266 | * @direction: [in] direction of DMA transfer |
| 267 | * |
| 268 | * Returns sg_table containing the scatterlist to be returned; may return NULL |
| 269 | * or ERR_PTR. |
| 270 | * |
| 271 | */ |
| 272 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, |
| 273 | enum dma_data_direction direction) |
| 274 | { |
| 275 | struct sg_table *sg_table = ERR_PTR(-EINVAL); |
| 276 | |
| 277 | might_sleep(); |
| 278 | |
Laurent Pinchart | d1aa06a | 2012-01-26 12:27:23 +0100 | [diff] [blame] | 279 | if (WARN_ON(!attach || !attach->dmabuf)) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 280 | return ERR_PTR(-EINVAL); |
| 281 | |
Laurent Pinchart | d1aa06a | 2012-01-26 12:27:23 +0100 | [diff] [blame] | 282 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 283 | |
| 284 | return sg_table; |
| 285 | } |
| 286 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); |
| 287 | |
| 288 | /** |
| 289 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might |
| 290 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of |
| 291 | * dma_buf_ops. |
| 292 | * @attach: [in] attachment to unmap buffer from |
| 293 | * @sg_table: [in] scatterlist info of the buffer to unmap |
Sumit Semwal | 33ea2dc | 2012-01-27 15:09:27 +0530 | [diff] [blame] | 294 | * @direction: [in] direction of DMA transfer |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 295 | * |
| 296 | */ |
| 297 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, |
Sumit Semwal | 33ea2dc | 2012-01-27 15:09:27 +0530 | [diff] [blame] | 298 | struct sg_table *sg_table, |
| 299 | enum dma_data_direction direction) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 300 | { |
Laurent Pinchart | d1aa06a | 2012-01-26 12:27:23 +0100 | [diff] [blame] | 301 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 302 | return; |
| 303 | |
Sumit Semwal | 33ea2dc | 2012-01-27 15:09:27 +0530 | [diff] [blame] | 304 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
| 305 | direction); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 306 | } |
| 307 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 308 | |
| 309 | |
| 310 | /** |
| 311 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the |
| 312 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific |
| 313 | * preparations. Coherency is only guaranteed in the specified range for the |
| 314 | * specified access direction. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 315 | * @dmabuf: [in] buffer to prepare cpu access for. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 316 | * @start: [in] start of range for cpu access. |
| 317 | * @len: [in] length of range for cpu access. |
| 318 | * @direction: [in] length of range for cpu access. |
| 319 | * |
| 320 | * Can return negative error values, returns 0 on success. |
| 321 | */ |
| 322 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, |
| 323 | enum dma_data_direction direction) |
| 324 | { |
| 325 | int ret = 0; |
| 326 | |
| 327 | if (WARN_ON(!dmabuf)) |
| 328 | return -EINVAL; |
| 329 | |
| 330 | if (dmabuf->ops->begin_cpu_access) |
| 331 | ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); |
| 332 | |
| 333 | return ret; |
| 334 | } |
| 335 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); |
| 336 | |
| 337 | /** |
| 338 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the |
| 339 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific |
| 340 | * actions. Coherency is only guaranteed in the specified range for the |
| 341 | * specified access direction. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 342 | * @dmabuf: [in] buffer to complete cpu access for. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 343 | * @start: [in] start of range for cpu access. |
| 344 | * @len: [in] length of range for cpu access. |
| 345 | * @direction: [in] length of range for cpu access. |
| 346 | * |
| 347 | * This call must always succeed. |
| 348 | */ |
| 349 | void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, |
| 350 | enum dma_data_direction direction) |
| 351 | { |
| 352 | WARN_ON(!dmabuf); |
| 353 | |
| 354 | if (dmabuf->ops->end_cpu_access) |
| 355 | dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); |
| 356 | } |
| 357 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); |
| 358 | |
| 359 | /** |
| 360 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address |
| 361 | * space. The same restrictions as for kmap_atomic and friends apply. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 362 | * @dmabuf: [in] buffer to map page from. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 363 | * @page_num: [in] page in PAGE_SIZE units to map. |
| 364 | * |
| 365 | * This call must always succeed, any necessary preparations that might fail |
| 366 | * need to be done in begin_cpu_access. |
| 367 | */ |
| 368 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) |
| 369 | { |
| 370 | WARN_ON(!dmabuf); |
| 371 | |
| 372 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); |
| 373 | } |
| 374 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); |
| 375 | |
| 376 | /** |
| 377 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 378 | * @dmabuf: [in] buffer to unmap page from. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 379 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
| 380 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. |
| 381 | * |
| 382 | * This call must always succeed. |
| 383 | */ |
| 384 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, |
| 385 | void *vaddr) |
| 386 | { |
| 387 | WARN_ON(!dmabuf); |
| 388 | |
| 389 | if (dmabuf->ops->kunmap_atomic) |
| 390 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); |
| 391 | } |
| 392 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); |
| 393 | |
| 394 | /** |
| 395 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The |
| 396 | * same restrictions as for kmap and friends apply. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 397 | * @dmabuf: [in] buffer to map page from. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 398 | * @page_num: [in] page in PAGE_SIZE units to map. |
| 399 | * |
| 400 | * This call must always succeed, any necessary preparations that might fail |
| 401 | * need to be done in begin_cpu_access. |
| 402 | */ |
| 403 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) |
| 404 | { |
| 405 | WARN_ON(!dmabuf); |
| 406 | |
| 407 | return dmabuf->ops->kmap(dmabuf, page_num); |
| 408 | } |
| 409 | EXPORT_SYMBOL_GPL(dma_buf_kmap); |
| 410 | |
| 411 | /** |
| 412 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. |
Randy Dunlap | efb4df82 | 2012-04-17 17:03:30 -0700 | [diff] [blame] | 413 | * @dmabuf: [in] buffer to unmap page from. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 414 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
| 415 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. |
| 416 | * |
| 417 | * This call must always succeed. |
| 418 | */ |
| 419 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, |
| 420 | void *vaddr) |
| 421 | { |
| 422 | WARN_ON(!dmabuf); |
| 423 | |
| 424 | if (dmabuf->ops->kunmap) |
| 425 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); |
| 426 | } |
| 427 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 428 | |
| 429 | |
| 430 | /** |
| 431 | * dma_buf_mmap - Setup up a userspace mmap with the given vma |
Sumit Semwal | 12c4727 | 2012-05-23 15:27:40 +0530 | [diff] [blame] | 432 | * @dmabuf: [in] buffer that should back the vma |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 433 | * @vma: [in] vma for the mmap |
| 434 | * @pgoff: [in] offset in pages where this mmap should start within the |
| 435 | * dma-buf buffer. |
| 436 | * |
| 437 | * This function adjusts the passed in vma so that it points at the file of the |
| 438 | * dma_buf operation. It alsog adjusts the starting pgoff and does bounds |
| 439 | * checking on the size of the vma. Then it calls the exporters mmap function to |
| 440 | * set up the mapping. |
| 441 | * |
| 442 | * Can return negative error values, returns 0 on success. |
| 443 | */ |
| 444 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, |
| 445 | unsigned long pgoff) |
| 446 | { |
| 447 | if (WARN_ON(!dmabuf || !vma)) |
| 448 | return -EINVAL; |
| 449 | |
| 450 | /* check for offset overflow */ |
| 451 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) |
| 452 | return -EOVERFLOW; |
| 453 | |
| 454 | /* check for overflowing the buffer's size */ |
| 455 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > |
| 456 | dmabuf->size >> PAGE_SHIFT) |
| 457 | return -EINVAL; |
| 458 | |
| 459 | /* readjust the vma */ |
| 460 | if (vma->vm_file) |
| 461 | fput(vma->vm_file); |
| 462 | |
| 463 | vma->vm_file = dmabuf->file; |
| 464 | get_file(vma->vm_file); |
| 465 | |
| 466 | vma->vm_pgoff = pgoff; |
| 467 | |
| 468 | return dmabuf->ops->mmap(dmabuf, vma); |
| 469 | } |
| 470 | EXPORT_SYMBOL_GPL(dma_buf_mmap); |
Dave Airlie | 98f86c9 | 2012-05-20 12:33:56 +0530 | [diff] [blame] | 471 | |
| 472 | /** |
Sumit Semwal | 12c4727 | 2012-05-23 15:27:40 +0530 | [diff] [blame] | 473 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
| 474 | * address space. Same restrictions as for vmap and friends apply. |
| 475 | * @dmabuf: [in] buffer to vmap |
Dave Airlie | 98f86c9 | 2012-05-20 12:33:56 +0530 | [diff] [blame] | 476 | * |
| 477 | * This call may fail due to lack of virtual mapping address space. |
| 478 | * These calls are optional in drivers. The intended use for them |
| 479 | * is for mapping objects linear in kernel space for high use objects. |
| 480 | * Please attempt to use kmap/kunmap before thinking about these interfaces. |
| 481 | */ |
| 482 | void *dma_buf_vmap(struct dma_buf *dmabuf) |
| 483 | { |
| 484 | if (WARN_ON(!dmabuf)) |
| 485 | return NULL; |
| 486 | |
| 487 | if (dmabuf->ops->vmap) |
| 488 | return dmabuf->ops->vmap(dmabuf); |
| 489 | return NULL; |
| 490 | } |
| 491 | EXPORT_SYMBOL_GPL(dma_buf_vmap); |
| 492 | |
| 493 | /** |
| 494 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. |
Sumit Semwal | 12c4727 | 2012-05-23 15:27:40 +0530 | [diff] [blame] | 495 | * @dmabuf: [in] buffer to vunmap |
Randy Dunlap | 6e7b4a5 | 2012-06-09 15:02:59 -0700 | [diff] [blame] | 496 | * @vaddr: [in] vmap to vunmap |
Dave Airlie | 98f86c9 | 2012-05-20 12:33:56 +0530 | [diff] [blame] | 497 | */ |
| 498 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) |
| 499 | { |
| 500 | if (WARN_ON(!dmabuf)) |
| 501 | return; |
| 502 | |
| 503 | if (dmabuf->ops->vunmap) |
| 504 | dmabuf->ops->vunmap(dmabuf, vaddr); |
| 505 | } |
| 506 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); |