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d15bd7ee SS |
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> | |
3aac4502 | 28 | #include <linux/fence.h> |
d15bd7ee SS |
29 | #include <linux/anon_inodes.h> |
30 | #include <linux/export.h> | |
b89e3563 SS |
31 | #include <linux/debugfs.h> |
32 | #include <linux/seq_file.h> | |
9b495a58 | 33 | #include <linux/poll.h> |
3aac4502 | 34 | #include <linux/reservation.h> |
d15bd7ee SS |
35 | |
36 | static inline int is_dma_buf_file(struct file *); | |
37 | ||
b89e3563 SS |
38 | struct dma_buf_list { |
39 | struct list_head head; | |
40 | struct mutex lock; | |
41 | }; | |
42 | ||
43 | static struct dma_buf_list db_list; | |
44 | ||
d15bd7ee SS |
45 | static int dma_buf_release(struct inode *inode, struct file *file) |
46 | { | |
47 | struct dma_buf *dmabuf; | |
48 | ||
49 | if (!is_dma_buf_file(file)) | |
50 | return -EINVAL; | |
51 | ||
52 | dmabuf = file->private_data; | |
53 | ||
f00b4dad DV |
54 | BUG_ON(dmabuf->vmapping_counter); |
55 | ||
9b495a58 ML |
56 | /* |
57 | * Any fences that a dma-buf poll can wait on should be signaled | |
58 | * before releasing dma-buf. This is the responsibility of each | |
59 | * driver that uses the reservation objects. | |
60 | * | |
61 | * If you hit this BUG() it means someone dropped their ref to the | |
62 | * dma-buf while still having pending operation to the buffer. | |
63 | */ | |
64 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
65 | ||
d15bd7ee | 66 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
67 | |
68 | mutex_lock(&db_list.lock); | |
69 | list_del(&dmabuf->list_node); | |
70 | mutex_unlock(&db_list.lock); | |
71 | ||
3aac4502 ML |
72 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
73 | reservation_object_fini(dmabuf->resv); | |
74 | ||
d15bd7ee SS |
75 | kfree(dmabuf); |
76 | return 0; | |
77 | } | |
78 | ||
4c78513e DV |
79 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
80 | { | |
81 | struct dma_buf *dmabuf; | |
82 | ||
83 | if (!is_dma_buf_file(file)) | |
84 | return -EINVAL; | |
85 | ||
86 | dmabuf = file->private_data; | |
87 | ||
88 | /* check for overflowing the buffer's size */ | |
89 | if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
90 | dmabuf->size >> PAGE_SHIFT) | |
91 | return -EINVAL; | |
92 | ||
93 | return dmabuf->ops->mmap(dmabuf, vma); | |
94 | } | |
95 | ||
19e8697b CJHR |
96 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
97 | { | |
98 | struct dma_buf *dmabuf; | |
99 | loff_t base; | |
100 | ||
101 | if (!is_dma_buf_file(file)) | |
102 | return -EBADF; | |
103 | ||
104 | dmabuf = file->private_data; | |
105 | ||
106 | /* only support discovering the end of the buffer, | |
107 | but also allow SEEK_SET to maintain the idiomatic | |
108 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
109 | if (whence == SEEK_END) | |
110 | base = dmabuf->size; | |
111 | else if (whence == SEEK_SET) | |
112 | base = 0; | |
113 | else | |
114 | return -EINVAL; | |
115 | ||
116 | if (offset != 0) | |
117 | return -EINVAL; | |
118 | ||
119 | return base + offset; | |
120 | } | |
121 | ||
9b495a58 ML |
122 | static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) |
123 | { | |
124 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
125 | unsigned long flags; | |
126 | ||
127 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
128 | wake_up_locked_poll(dcb->poll, dcb->active); | |
129 | dcb->active = 0; | |
130 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
131 | } | |
132 | ||
133 | static unsigned int dma_buf_poll(struct file *file, poll_table *poll) | |
134 | { | |
135 | struct dma_buf *dmabuf; | |
136 | struct reservation_object *resv; | |
04a5faa8 ML |
137 | struct reservation_object_list *fobj; |
138 | struct fence *fence_excl; | |
9b495a58 | 139 | unsigned long events; |
04a5faa8 | 140 | unsigned shared_count; |
9b495a58 ML |
141 | |
142 | dmabuf = file->private_data; | |
143 | if (!dmabuf || !dmabuf->resv) | |
144 | return POLLERR; | |
145 | ||
146 | resv = dmabuf->resv; | |
147 | ||
148 | poll_wait(file, &dmabuf->poll, poll); | |
149 | ||
150 | events = poll_requested_events(poll) & (POLLIN | POLLOUT); | |
151 | if (!events) | |
152 | return 0; | |
153 | ||
154 | ww_mutex_lock(&resv->lock, NULL); | |
155 | ||
04a5faa8 ML |
156 | fobj = resv->fence; |
157 | if (!fobj) | |
158 | goto out; | |
159 | ||
160 | shared_count = fobj->shared_count; | |
161 | fence_excl = resv->fence_excl; | |
162 | ||
163 | if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { | |
9b495a58 ML |
164 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
165 | unsigned long pevents = POLLIN; | |
166 | ||
04a5faa8 | 167 | if (shared_count == 0) |
9b495a58 ML |
168 | pevents |= POLLOUT; |
169 | ||
170 | spin_lock_irq(&dmabuf->poll.lock); | |
171 | if (dcb->active) { | |
172 | dcb->active |= pevents; | |
173 | events &= ~pevents; | |
174 | } else | |
175 | dcb->active = pevents; | |
176 | spin_unlock_irq(&dmabuf->poll.lock); | |
177 | ||
178 | if (events & pevents) { | |
04a5faa8 ML |
179 | if (!fence_add_callback(fence_excl, &dcb->cb, |
180 | dma_buf_poll_cb)) { | |
9b495a58 | 181 | events &= ~pevents; |
04a5faa8 | 182 | } else { |
9b495a58 ML |
183 | /* |
184 | * No callback queued, wake up any additional | |
185 | * waiters. | |
186 | */ | |
187 | dma_buf_poll_cb(NULL, &dcb->cb); | |
04a5faa8 | 188 | } |
9b495a58 ML |
189 | } |
190 | } | |
191 | ||
04a5faa8 | 192 | if ((events & POLLOUT) && shared_count > 0) { |
9b495a58 ML |
193 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
194 | int i; | |
195 | ||
196 | /* Only queue a new callback if no event has fired yet */ | |
197 | spin_lock_irq(&dmabuf->poll.lock); | |
198 | if (dcb->active) | |
199 | events &= ~POLLOUT; | |
200 | else | |
201 | dcb->active = POLLOUT; | |
202 | spin_unlock_irq(&dmabuf->poll.lock); | |
203 | ||
204 | if (!(events & POLLOUT)) | |
205 | goto out; | |
206 | ||
04a5faa8 ML |
207 | for (i = 0; i < shared_count; ++i) { |
208 | struct fence *fence = fobj->shared[i]; | |
209 | ||
210 | if (!fence_add_callback(fence, &dcb->cb, | |
211 | dma_buf_poll_cb)) { | |
9b495a58 ML |
212 | events &= ~POLLOUT; |
213 | break; | |
214 | } | |
04a5faa8 | 215 | } |
9b495a58 ML |
216 | |
217 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 218 | if (i == shared_count) |
9b495a58 ML |
219 | dma_buf_poll_cb(NULL, &dcb->cb); |
220 | } | |
221 | ||
222 | out: | |
223 | ww_mutex_unlock(&resv->lock); | |
224 | return events; | |
225 | } | |
226 | ||
d15bd7ee SS |
227 | static const struct file_operations dma_buf_fops = { |
228 | .release = dma_buf_release, | |
4c78513e | 229 | .mmap = dma_buf_mmap_internal, |
19e8697b | 230 | .llseek = dma_buf_llseek, |
9b495a58 | 231 | .poll = dma_buf_poll, |
d15bd7ee SS |
232 | }; |
233 | ||
234 | /* | |
235 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
236 | */ | |
237 | static inline int is_dma_buf_file(struct file *file) | |
238 | { | |
239 | return file->f_op == &dma_buf_fops; | |
240 | } | |
241 | ||
242 | /** | |
78df9695 | 243 | * dma_buf_export_named - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
244 | * with this buffer, so it can be exported. |
245 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 246 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee SS |
247 | * |
248 | * @priv: [in] Attach private data of allocator to this buffer | |
249 | * @ops: [in] Attach allocator-defined dma buf ops to the new buffer. | |
250 | * @size: [in] Size of the buffer | |
251 | * @flags: [in] mode flags for the file. | |
78df9695 | 252 | * @exp_name: [in] name of the exporting module - useful for debugging. |
3aac4502 | 253 | * @resv: [in] reservation-object, NULL to allocate default one. |
d15bd7ee SS |
254 | * |
255 | * Returns, on success, a newly created dma_buf object, which wraps the | |
256 | * supplied private data and operations for dma_buf_ops. On either missing | |
257 | * ops, or error in allocating struct dma_buf, will return negative error. | |
258 | * | |
259 | */ | |
78df9695 | 260 | struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, |
3aac4502 ML |
261 | size_t size, int flags, const char *exp_name, |
262 | struct reservation_object *resv) | |
d15bd7ee SS |
263 | { |
264 | struct dma_buf *dmabuf; | |
265 | struct file *file; | |
3aac4502 ML |
266 | size_t alloc_size = sizeof(struct dma_buf); |
267 | if (!resv) | |
268 | alloc_size += sizeof(struct reservation_object); | |
269 | else | |
270 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
271 | alloc_size += 1; | |
d15bd7ee SS |
272 | |
273 | if (WARN_ON(!priv || !ops | |
274 | || !ops->map_dma_buf | |
275 | || !ops->unmap_dma_buf | |
fc13020e DV |
276 | || !ops->release |
277 | || !ops->kmap_atomic | |
4c78513e DV |
278 | || !ops->kmap |
279 | || !ops->mmap)) { | |
d15bd7ee SS |
280 | return ERR_PTR(-EINVAL); |
281 | } | |
282 | ||
3aac4502 | 283 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
d15bd7ee SS |
284 | if (dmabuf == NULL) |
285 | return ERR_PTR(-ENOMEM); | |
286 | ||
287 | dmabuf->priv = priv; | |
288 | dmabuf->ops = ops; | |
289 | dmabuf->size = size; | |
78df9695 | 290 | dmabuf->exp_name = exp_name; |
9b495a58 ML |
291 | init_waitqueue_head(&dmabuf->poll); |
292 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
293 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
294 | ||
3aac4502 ML |
295 | if (!resv) { |
296 | resv = (struct reservation_object *)&dmabuf[1]; | |
297 | reservation_object_init(resv); | |
298 | } | |
299 | dmabuf->resv = resv; | |
d15bd7ee SS |
300 | |
301 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags); | |
9022e24e TT |
302 | if (IS_ERR(file)) { |
303 | kfree(dmabuf); | |
304 | return ERR_CAST(file); | |
305 | } | |
19e8697b CJHR |
306 | |
307 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
308 | dmabuf->file = file; |
309 | ||
310 | mutex_init(&dmabuf->lock); | |
311 | INIT_LIST_HEAD(&dmabuf->attachments); | |
312 | ||
b89e3563 SS |
313 | mutex_lock(&db_list.lock); |
314 | list_add(&dmabuf->list_node, &db_list.head); | |
315 | mutex_unlock(&db_list.lock); | |
316 | ||
d15bd7ee SS |
317 | return dmabuf; |
318 | } | |
78df9695 | 319 | EXPORT_SYMBOL_GPL(dma_buf_export_named); |
d15bd7ee SS |
320 | |
321 | ||
322 | /** | |
323 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
324 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 325 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
326 | * |
327 | * On success, returns an associated 'fd'. Else, returns error. | |
328 | */ | |
55c1c4ca | 329 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 330 | { |
f5e097f0 | 331 | int fd; |
d15bd7ee SS |
332 | |
333 | if (!dmabuf || !dmabuf->file) | |
334 | return -EINVAL; | |
335 | ||
f5e097f0 BP |
336 | fd = get_unused_fd_flags(flags); |
337 | if (fd < 0) | |
338 | return fd; | |
d15bd7ee SS |
339 | |
340 | fd_install(fd, dmabuf->file); | |
341 | ||
342 | return fd; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
345 | ||
346 | /** | |
347 | * dma_buf_get - returns the dma_buf structure related to an fd | |
348 | * @fd: [in] fd associated with the dma_buf to be returned | |
349 | * | |
350 | * On success, returns the dma_buf structure associated with an fd; uses | |
351 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
352 | * otherwise. | |
353 | */ | |
354 | struct dma_buf *dma_buf_get(int fd) | |
355 | { | |
356 | struct file *file; | |
357 | ||
358 | file = fget(fd); | |
359 | ||
360 | if (!file) | |
361 | return ERR_PTR(-EBADF); | |
362 | ||
363 | if (!is_dma_buf_file(file)) { | |
364 | fput(file); | |
365 | return ERR_PTR(-EINVAL); | |
366 | } | |
367 | ||
368 | return file->private_data; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
371 | ||
372 | /** | |
373 | * dma_buf_put - decreases refcount of the buffer | |
374 | * @dmabuf: [in] buffer to reduce refcount of | |
375 | * | |
376 | * Uses file's refcounting done implicitly by fput() | |
377 | */ | |
378 | void dma_buf_put(struct dma_buf *dmabuf) | |
379 | { | |
380 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
381 | return; | |
382 | ||
383 | fput(dmabuf->file); | |
384 | } | |
385 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
386 | ||
387 | /** | |
388 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
389 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
390 | * @dmabuf: [in] buffer to attach device to. | |
391 | * @dev: [in] device to be attached. | |
392 | * | |
fee0c54e CC |
393 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
394 | * error. | |
d15bd7ee SS |
395 | */ |
396 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
397 | struct device *dev) | |
398 | { | |
399 | struct dma_buf_attachment *attach; | |
400 | int ret; | |
401 | ||
d1aa06a1 | 402 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
403 | return ERR_PTR(-EINVAL); |
404 | ||
405 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
406 | if (attach == NULL) | |
a9fbc3b7 | 407 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 408 | |
d15bd7ee SS |
409 | attach->dev = dev; |
410 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
411 | |
412 | mutex_lock(&dmabuf->lock); | |
413 | ||
d15bd7ee SS |
414 | if (dmabuf->ops->attach) { |
415 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
416 | if (ret) | |
417 | goto err_attach; | |
418 | } | |
419 | list_add(&attach->node, &dmabuf->attachments); | |
420 | ||
421 | mutex_unlock(&dmabuf->lock); | |
422 | return attach; | |
423 | ||
d15bd7ee SS |
424 | err_attach: |
425 | kfree(attach); | |
426 | mutex_unlock(&dmabuf->lock); | |
427 | return ERR_PTR(ret); | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
430 | ||
431 | /** | |
432 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
433 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
434 | * @dmabuf: [in] buffer to detach from. | |
435 | * @attach: [in] attachment to be detached; is free'd after this call. | |
436 | * | |
437 | */ | |
438 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
439 | { | |
d1aa06a1 | 440 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
441 | return; |
442 | ||
443 | mutex_lock(&dmabuf->lock); | |
444 | list_del(&attach->node); | |
445 | if (dmabuf->ops->detach) | |
446 | dmabuf->ops->detach(dmabuf, attach); | |
447 | ||
448 | mutex_unlock(&dmabuf->lock); | |
449 | kfree(attach); | |
450 | } | |
451 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
452 | ||
453 | /** | |
454 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
455 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
456 | * dma_buf_ops. | |
457 | * @attach: [in] attachment whose scatterlist is to be returned | |
458 | * @direction: [in] direction of DMA transfer | |
459 | * | |
fee0c54e CC |
460 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
461 | * on error. | |
d15bd7ee SS |
462 | */ |
463 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
464 | enum dma_data_direction direction) | |
465 | { | |
466 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
467 | ||
468 | might_sleep(); | |
469 | ||
d1aa06a1 | 470 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
471 | return ERR_PTR(-EINVAL); |
472 | ||
d1aa06a1 | 473 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
474 | if (!sg_table) |
475 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
476 | |
477 | return sg_table; | |
478 | } | |
479 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
480 | ||
481 | /** | |
482 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
483 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
484 | * dma_buf_ops. | |
485 | * @attach: [in] attachment to unmap buffer from | |
486 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 487 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
488 | * |
489 | */ | |
490 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
491 | struct sg_table *sg_table, |
492 | enum dma_data_direction direction) | |
d15bd7ee | 493 | { |
b6fa0cd6 RC |
494 | might_sleep(); |
495 | ||
d1aa06a1 | 496 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
497 | return; |
498 | ||
33ea2dcb SS |
499 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
500 | direction); | |
d15bd7ee SS |
501 | } |
502 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
503 | |
504 | ||
505 | /** | |
506 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
507 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
508 | * preparations. Coherency is only guaranteed in the specified range for the | |
509 | * specified access direction. | |
efb4df82 | 510 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
511 | * @start: [in] start of range for cpu access. |
512 | * @len: [in] length of range for cpu access. | |
513 | * @direction: [in] length of range for cpu access. | |
514 | * | |
515 | * Can return negative error values, returns 0 on success. | |
516 | */ | |
517 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
518 | enum dma_data_direction direction) | |
519 | { | |
520 | int ret = 0; | |
521 | ||
522 | if (WARN_ON(!dmabuf)) | |
523 | return -EINVAL; | |
524 | ||
525 | if (dmabuf->ops->begin_cpu_access) | |
526 | ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); | |
527 | ||
528 | return ret; | |
529 | } | |
530 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
531 | ||
532 | /** | |
533 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
534 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
535 | * actions. Coherency is only guaranteed in the specified range for the | |
536 | * specified access direction. | |
efb4df82 | 537 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
538 | * @start: [in] start of range for cpu access. |
539 | * @len: [in] length of range for cpu access. | |
540 | * @direction: [in] length of range for cpu access. | |
541 | * | |
542 | * This call must always succeed. | |
543 | */ | |
544 | void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
545 | enum dma_data_direction direction) | |
546 | { | |
547 | WARN_ON(!dmabuf); | |
548 | ||
549 | if (dmabuf->ops->end_cpu_access) | |
550 | dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); | |
551 | } | |
552 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
553 | ||
554 | /** | |
555 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
556 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 557 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
558 | * @page_num: [in] page in PAGE_SIZE units to map. |
559 | * | |
560 | * This call must always succeed, any necessary preparations that might fail | |
561 | * need to be done in begin_cpu_access. | |
562 | */ | |
563 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
564 | { | |
565 | WARN_ON(!dmabuf); | |
566 | ||
567 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
568 | } | |
569 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
570 | ||
571 | /** | |
572 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 573 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
574 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
575 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
576 | * | |
577 | * This call must always succeed. | |
578 | */ | |
579 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
580 | void *vaddr) | |
581 | { | |
582 | WARN_ON(!dmabuf); | |
583 | ||
584 | if (dmabuf->ops->kunmap_atomic) | |
585 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
586 | } | |
587 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
588 | ||
589 | /** | |
590 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
591 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 592 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
593 | * @page_num: [in] page in PAGE_SIZE units to map. |
594 | * | |
595 | * This call must always succeed, any necessary preparations that might fail | |
596 | * need to be done in begin_cpu_access. | |
597 | */ | |
598 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
599 | { | |
600 | WARN_ON(!dmabuf); | |
601 | ||
602 | return dmabuf->ops->kmap(dmabuf, page_num); | |
603 | } | |
604 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
605 | ||
606 | /** | |
607 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 608 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
609 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
610 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
611 | * | |
612 | * This call must always succeed. | |
613 | */ | |
614 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
615 | void *vaddr) | |
616 | { | |
617 | WARN_ON(!dmabuf); | |
618 | ||
619 | if (dmabuf->ops->kunmap) | |
620 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
621 | } | |
622 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
623 | |
624 | ||
625 | /** | |
626 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 627 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
628 | * @vma: [in] vma for the mmap |
629 | * @pgoff: [in] offset in pages where this mmap should start within the | |
630 | * dma-buf buffer. | |
631 | * | |
632 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 633 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
634 | * checking on the size of the vma. Then it calls the exporters mmap function to |
635 | * set up the mapping. | |
636 | * | |
637 | * Can return negative error values, returns 0 on success. | |
638 | */ | |
639 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
640 | unsigned long pgoff) | |
641 | { | |
495c10cc JS |
642 | struct file *oldfile; |
643 | int ret; | |
644 | ||
4c78513e DV |
645 | if (WARN_ON(!dmabuf || !vma)) |
646 | return -EINVAL; | |
647 | ||
648 | /* check for offset overflow */ | |
649 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) | |
650 | return -EOVERFLOW; | |
651 | ||
652 | /* check for overflowing the buffer's size */ | |
653 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
654 | dmabuf->size >> PAGE_SHIFT) | |
655 | return -EINVAL; | |
656 | ||
657 | /* readjust the vma */ | |
495c10cc JS |
658 | get_file(dmabuf->file); |
659 | oldfile = vma->vm_file; | |
660 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
661 | vma->vm_pgoff = pgoff; |
662 | ||
495c10cc JS |
663 | ret = dmabuf->ops->mmap(dmabuf, vma); |
664 | if (ret) { | |
665 | /* restore old parameters on failure */ | |
666 | vma->vm_file = oldfile; | |
667 | fput(dmabuf->file); | |
668 | } else { | |
669 | if (oldfile) | |
670 | fput(oldfile); | |
671 | } | |
672 | return ret; | |
673 | ||
4c78513e DV |
674 | } |
675 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
676 | |
677 | /** | |
12c4727e SS |
678 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
679 | * address space. Same restrictions as for vmap and friends apply. | |
680 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
681 | * |
682 | * This call may fail due to lack of virtual mapping address space. | |
683 | * These calls are optional in drivers. The intended use for them | |
684 | * is for mapping objects linear in kernel space for high use objects. | |
685 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
686 | * |
687 | * Returns NULL on error. | |
98f86c9e DA |
688 | */ |
689 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
690 | { | |
f00b4dad DV |
691 | void *ptr; |
692 | ||
98f86c9e DA |
693 | if (WARN_ON(!dmabuf)) |
694 | return NULL; | |
695 | ||
f00b4dad DV |
696 | if (!dmabuf->ops->vmap) |
697 | return NULL; | |
698 | ||
699 | mutex_lock(&dmabuf->lock); | |
700 | if (dmabuf->vmapping_counter) { | |
701 | dmabuf->vmapping_counter++; | |
702 | BUG_ON(!dmabuf->vmap_ptr); | |
703 | ptr = dmabuf->vmap_ptr; | |
704 | goto out_unlock; | |
705 | } | |
706 | ||
707 | BUG_ON(dmabuf->vmap_ptr); | |
708 | ||
709 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
710 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
711 | ptr = NULL; | |
712 | if (!ptr) | |
f00b4dad DV |
713 | goto out_unlock; |
714 | ||
715 | dmabuf->vmap_ptr = ptr; | |
716 | dmabuf->vmapping_counter = 1; | |
717 | ||
718 | out_unlock: | |
719 | mutex_unlock(&dmabuf->lock); | |
720 | return ptr; | |
98f86c9e DA |
721 | } |
722 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
723 | ||
724 | /** | |
725 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 726 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 727 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
728 | */ |
729 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
730 | { | |
731 | if (WARN_ON(!dmabuf)) | |
732 | return; | |
733 | ||
f00b4dad DV |
734 | BUG_ON(!dmabuf->vmap_ptr); |
735 | BUG_ON(dmabuf->vmapping_counter == 0); | |
736 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
737 | ||
738 | mutex_lock(&dmabuf->lock); | |
739 | if (--dmabuf->vmapping_counter == 0) { | |
740 | if (dmabuf->ops->vunmap) | |
741 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
742 | dmabuf->vmap_ptr = NULL; | |
743 | } | |
744 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
745 | } |
746 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
747 | |
748 | #ifdef CONFIG_DEBUG_FS | |
749 | static int dma_buf_describe(struct seq_file *s) | |
750 | { | |
751 | int ret; | |
752 | struct dma_buf *buf_obj; | |
753 | struct dma_buf_attachment *attach_obj; | |
754 | int count = 0, attach_count; | |
755 | size_t size = 0; | |
756 | ||
757 | ret = mutex_lock_interruptible(&db_list.lock); | |
758 | ||
759 | if (ret) | |
760 | return ret; | |
761 | ||
c0b00a52 SS |
762 | seq_puts(s, "\nDma-buf Objects:\n"); |
763 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
764 | |
765 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
766 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
767 | ||
768 | if (ret) { | |
c0b00a52 SS |
769 | seq_puts(s, |
770 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
771 | continue; |
772 | } | |
773 | ||
c0b00a52 SS |
774 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
775 | buf_obj->size, | |
b89e3563 | 776 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
c0b00a52 SS |
777 | (long)(buf_obj->file->f_count.counter), |
778 | buf_obj->exp_name); | |
b89e3563 | 779 | |
c0b00a52 | 780 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
781 | attach_count = 0; |
782 | ||
783 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 784 | seq_puts(s, "\t"); |
b89e3563 | 785 | |
c0b00a52 | 786 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
787 | attach_count++; |
788 | } | |
789 | ||
c0b00a52 | 790 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
791 | attach_count); |
792 | ||
793 | count++; | |
794 | size += buf_obj->size; | |
795 | mutex_unlock(&buf_obj->lock); | |
796 | } | |
797 | ||
798 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
799 | ||
800 | mutex_unlock(&db_list.lock); | |
801 | return 0; | |
802 | } | |
803 | ||
804 | static int dma_buf_show(struct seq_file *s, void *unused) | |
805 | { | |
806 | void (*func)(struct seq_file *) = s->private; | |
807 | func(s); | |
808 | return 0; | |
809 | } | |
810 | ||
811 | static int dma_buf_debug_open(struct inode *inode, struct file *file) | |
812 | { | |
813 | return single_open(file, dma_buf_show, inode->i_private); | |
814 | } | |
815 | ||
816 | static const struct file_operations dma_buf_debug_fops = { | |
817 | .open = dma_buf_debug_open, | |
818 | .read = seq_read, | |
819 | .llseek = seq_lseek, | |
820 | .release = single_release, | |
821 | }; | |
822 | ||
823 | static struct dentry *dma_buf_debugfs_dir; | |
824 | ||
825 | static int dma_buf_init_debugfs(void) | |
826 | { | |
827 | int err = 0; | |
828 | dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); | |
829 | if (IS_ERR(dma_buf_debugfs_dir)) { | |
830 | err = PTR_ERR(dma_buf_debugfs_dir); | |
831 | dma_buf_debugfs_dir = NULL; | |
832 | return err; | |
833 | } | |
834 | ||
835 | err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); | |
836 | ||
837 | if (err) | |
838 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); | |
839 | ||
840 | return err; | |
841 | } | |
842 | ||
843 | static void dma_buf_uninit_debugfs(void) | |
844 | { | |
845 | if (dma_buf_debugfs_dir) | |
846 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
847 | } | |
848 | ||
849 | int dma_buf_debugfs_create_file(const char *name, | |
850 | int (*write)(struct seq_file *)) | |
851 | { | |
852 | struct dentry *d; | |
853 | ||
854 | d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, | |
855 | write, &dma_buf_debug_fops); | |
856 | ||
28ce4201 | 857 | return PTR_ERR_OR_ZERO(d); |
b89e3563 SS |
858 | } |
859 | #else | |
860 | static inline int dma_buf_init_debugfs(void) | |
861 | { | |
862 | return 0; | |
863 | } | |
864 | static inline void dma_buf_uninit_debugfs(void) | |
865 | { | |
866 | } | |
867 | #endif | |
868 | ||
869 | static int __init dma_buf_init(void) | |
870 | { | |
871 | mutex_init(&db_list.lock); | |
872 | INIT_LIST_HEAD(&db_list.head); | |
873 | dma_buf_init_debugfs(); | |
874 | return 0; | |
875 | } | |
876 | subsys_initcall(dma_buf_init); | |
877 | ||
878 | static void __exit dma_buf_deinit(void) | |
879 | { | |
880 | dma_buf_uninit_debugfs(); | |
881 | } | |
882 | __exitcall(dma_buf_deinit); |