Commit | Line | Data |
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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; |
3c3b177a | 140 | unsigned shared_count, seq; |
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 | ||
3c3b177a ML |
154 | retry: |
155 | seq = read_seqcount_begin(&resv->seq); | |
156 | rcu_read_lock(); | |
9b495a58 | 157 | |
3c3b177a ML |
158 | fobj = rcu_dereference(resv->fence); |
159 | if (fobj) | |
160 | shared_count = fobj->shared_count; | |
161 | else | |
162 | shared_count = 0; | |
163 | fence_excl = rcu_dereference(resv->fence_excl); | |
164 | if (read_seqcount_retry(&resv->seq, seq)) { | |
165 | rcu_read_unlock(); | |
166 | goto retry; | |
167 | } | |
04a5faa8 ML |
168 | |
169 | if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { | |
9b495a58 ML |
170 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
171 | unsigned long pevents = POLLIN; | |
172 | ||
04a5faa8 | 173 | if (shared_count == 0) |
9b495a58 ML |
174 | pevents |= POLLOUT; |
175 | ||
176 | spin_lock_irq(&dmabuf->poll.lock); | |
177 | if (dcb->active) { | |
178 | dcb->active |= pevents; | |
179 | events &= ~pevents; | |
180 | } else | |
181 | dcb->active = pevents; | |
182 | spin_unlock_irq(&dmabuf->poll.lock); | |
183 | ||
184 | if (events & pevents) { | |
3c3b177a ML |
185 | if (!fence_get_rcu(fence_excl)) { |
186 | /* force a recheck */ | |
187 | events &= ~pevents; | |
188 | dma_buf_poll_cb(NULL, &dcb->cb); | |
189 | } else if (!fence_add_callback(fence_excl, &dcb->cb, | |
04a5faa8 | 190 | dma_buf_poll_cb)) { |
9b495a58 | 191 | events &= ~pevents; |
3c3b177a | 192 | fence_put(fence_excl); |
04a5faa8 | 193 | } else { |
9b495a58 ML |
194 | /* |
195 | * No callback queued, wake up any additional | |
196 | * waiters. | |
197 | */ | |
3c3b177a | 198 | fence_put(fence_excl); |
9b495a58 | 199 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 200 | } |
9b495a58 ML |
201 | } |
202 | } | |
203 | ||
04a5faa8 | 204 | if ((events & POLLOUT) && shared_count > 0) { |
9b495a58 ML |
205 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
206 | int i; | |
207 | ||
208 | /* Only queue a new callback if no event has fired yet */ | |
209 | spin_lock_irq(&dmabuf->poll.lock); | |
210 | if (dcb->active) | |
211 | events &= ~POLLOUT; | |
212 | else | |
213 | dcb->active = POLLOUT; | |
214 | spin_unlock_irq(&dmabuf->poll.lock); | |
215 | ||
216 | if (!(events & POLLOUT)) | |
217 | goto out; | |
218 | ||
04a5faa8 | 219 | for (i = 0; i < shared_count; ++i) { |
3c3b177a | 220 | struct fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 221 | |
3c3b177a ML |
222 | if (!fence_get_rcu(fence)) { |
223 | /* | |
224 | * fence refcount dropped to zero, this means | |
225 | * that fobj has been freed | |
226 | * | |
227 | * call dma_buf_poll_cb and force a recheck! | |
228 | */ | |
229 | events &= ~POLLOUT; | |
230 | dma_buf_poll_cb(NULL, &dcb->cb); | |
231 | break; | |
232 | } | |
04a5faa8 ML |
233 | if (!fence_add_callback(fence, &dcb->cb, |
234 | dma_buf_poll_cb)) { | |
3c3b177a | 235 | fence_put(fence); |
9b495a58 ML |
236 | events &= ~POLLOUT; |
237 | break; | |
238 | } | |
3c3b177a | 239 | fence_put(fence); |
04a5faa8 | 240 | } |
9b495a58 ML |
241 | |
242 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 243 | if (i == shared_count) |
9b495a58 ML |
244 | dma_buf_poll_cb(NULL, &dcb->cb); |
245 | } | |
246 | ||
247 | out: | |
3c3b177a | 248 | rcu_read_unlock(); |
9b495a58 ML |
249 | return events; |
250 | } | |
251 | ||
d15bd7ee SS |
252 | static const struct file_operations dma_buf_fops = { |
253 | .release = dma_buf_release, | |
4c78513e | 254 | .mmap = dma_buf_mmap_internal, |
19e8697b | 255 | .llseek = dma_buf_llseek, |
9b495a58 | 256 | .poll = dma_buf_poll, |
d15bd7ee SS |
257 | }; |
258 | ||
259 | /* | |
260 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
261 | */ | |
262 | static inline int is_dma_buf_file(struct file *file) | |
263 | { | |
264 | return file->f_op == &dma_buf_fops; | |
265 | } | |
266 | ||
267 | /** | |
d8fbe341 | 268 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
269 | * with this buffer, so it can be exported. |
270 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 271 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 272 | * |
d8fbe341 SS |
273 | * @exp_info: [in] holds all the export related information provided |
274 | * by the exporter. see struct dma_buf_export_info | |
275 | * for further details. | |
d15bd7ee SS |
276 | * |
277 | * Returns, on success, a newly created dma_buf object, which wraps the | |
278 | * supplied private data and operations for dma_buf_ops. On either missing | |
279 | * ops, or error in allocating struct dma_buf, will return negative error. | |
280 | * | |
281 | */ | |
d8fbe341 | 282 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
283 | { |
284 | struct dma_buf *dmabuf; | |
d8fbe341 | 285 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 286 | struct file *file; |
3aac4502 | 287 | size_t alloc_size = sizeof(struct dma_buf); |
d8fbe341 | 288 | if (!exp_info->resv) |
3aac4502 ML |
289 | alloc_size += sizeof(struct reservation_object); |
290 | else | |
291 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
292 | alloc_size += 1; | |
d15bd7ee | 293 | |
d8fbe341 SS |
294 | if (WARN_ON(!exp_info->priv |
295 | || !exp_info->ops | |
296 | || !exp_info->ops->map_dma_buf | |
297 | || !exp_info->ops->unmap_dma_buf | |
298 | || !exp_info->ops->release | |
299 | || !exp_info->ops->kmap_atomic | |
300 | || !exp_info->ops->kmap | |
301 | || !exp_info->ops->mmap)) { | |
d15bd7ee SS |
302 | return ERR_PTR(-EINVAL); |
303 | } | |
304 | ||
3aac4502 | 305 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
d15bd7ee SS |
306 | if (dmabuf == NULL) |
307 | return ERR_PTR(-ENOMEM); | |
308 | ||
d8fbe341 SS |
309 | dmabuf->priv = exp_info->priv; |
310 | dmabuf->ops = exp_info->ops; | |
311 | dmabuf->size = exp_info->size; | |
312 | dmabuf->exp_name = exp_info->exp_name; | |
9b495a58 ML |
313 | init_waitqueue_head(&dmabuf->poll); |
314 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
315 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
316 | ||
3aac4502 ML |
317 | if (!resv) { |
318 | resv = (struct reservation_object *)&dmabuf[1]; | |
319 | reservation_object_init(resv); | |
320 | } | |
321 | dmabuf->resv = resv; | |
d15bd7ee | 322 | |
d8fbe341 SS |
323 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
324 | exp_info->flags); | |
9022e24e TT |
325 | if (IS_ERR(file)) { |
326 | kfree(dmabuf); | |
327 | return ERR_CAST(file); | |
328 | } | |
19e8697b CJHR |
329 | |
330 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
331 | dmabuf->file = file; |
332 | ||
333 | mutex_init(&dmabuf->lock); | |
334 | INIT_LIST_HEAD(&dmabuf->attachments); | |
335 | ||
b89e3563 SS |
336 | mutex_lock(&db_list.lock); |
337 | list_add(&dmabuf->list_node, &db_list.head); | |
338 | mutex_unlock(&db_list.lock); | |
339 | ||
d15bd7ee SS |
340 | return dmabuf; |
341 | } | |
d8fbe341 | 342 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
343 | |
344 | /** | |
345 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
346 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 347 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
348 | * |
349 | * On success, returns an associated 'fd'. Else, returns error. | |
350 | */ | |
55c1c4ca | 351 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 352 | { |
f5e097f0 | 353 | int fd; |
d15bd7ee SS |
354 | |
355 | if (!dmabuf || !dmabuf->file) | |
356 | return -EINVAL; | |
357 | ||
f5e097f0 BP |
358 | fd = get_unused_fd_flags(flags); |
359 | if (fd < 0) | |
360 | return fd; | |
d15bd7ee SS |
361 | |
362 | fd_install(fd, dmabuf->file); | |
363 | ||
364 | return fd; | |
365 | } | |
366 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
367 | ||
368 | /** | |
369 | * dma_buf_get - returns the dma_buf structure related to an fd | |
370 | * @fd: [in] fd associated with the dma_buf to be returned | |
371 | * | |
372 | * On success, returns the dma_buf structure associated with an fd; uses | |
373 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
374 | * otherwise. | |
375 | */ | |
376 | struct dma_buf *dma_buf_get(int fd) | |
377 | { | |
378 | struct file *file; | |
379 | ||
380 | file = fget(fd); | |
381 | ||
382 | if (!file) | |
383 | return ERR_PTR(-EBADF); | |
384 | ||
385 | if (!is_dma_buf_file(file)) { | |
386 | fput(file); | |
387 | return ERR_PTR(-EINVAL); | |
388 | } | |
389 | ||
390 | return file->private_data; | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
393 | ||
394 | /** | |
395 | * dma_buf_put - decreases refcount of the buffer | |
396 | * @dmabuf: [in] buffer to reduce refcount of | |
397 | * | |
398 | * Uses file's refcounting done implicitly by fput() | |
399 | */ | |
400 | void dma_buf_put(struct dma_buf *dmabuf) | |
401 | { | |
402 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
403 | return; | |
404 | ||
405 | fput(dmabuf->file); | |
406 | } | |
407 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
408 | ||
409 | /** | |
410 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
411 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
412 | * @dmabuf: [in] buffer to attach device to. | |
413 | * @dev: [in] device to be attached. | |
414 | * | |
fee0c54e CC |
415 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
416 | * error. | |
d15bd7ee SS |
417 | */ |
418 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
419 | struct device *dev) | |
420 | { | |
421 | struct dma_buf_attachment *attach; | |
422 | int ret; | |
423 | ||
d1aa06a1 | 424 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
425 | return ERR_PTR(-EINVAL); |
426 | ||
427 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
428 | if (attach == NULL) | |
a9fbc3b7 | 429 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 430 | |
d15bd7ee SS |
431 | attach->dev = dev; |
432 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
433 | |
434 | mutex_lock(&dmabuf->lock); | |
435 | ||
d15bd7ee SS |
436 | if (dmabuf->ops->attach) { |
437 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
438 | if (ret) | |
439 | goto err_attach; | |
440 | } | |
441 | list_add(&attach->node, &dmabuf->attachments); | |
442 | ||
443 | mutex_unlock(&dmabuf->lock); | |
444 | return attach; | |
445 | ||
d15bd7ee SS |
446 | err_attach: |
447 | kfree(attach); | |
448 | mutex_unlock(&dmabuf->lock); | |
449 | return ERR_PTR(ret); | |
450 | } | |
451 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
452 | ||
453 | /** | |
454 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
455 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
456 | * @dmabuf: [in] buffer to detach from. | |
457 | * @attach: [in] attachment to be detached; is free'd after this call. | |
458 | * | |
459 | */ | |
460 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
461 | { | |
d1aa06a1 | 462 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
463 | return; |
464 | ||
465 | mutex_lock(&dmabuf->lock); | |
466 | list_del(&attach->node); | |
467 | if (dmabuf->ops->detach) | |
468 | dmabuf->ops->detach(dmabuf, attach); | |
469 | ||
470 | mutex_unlock(&dmabuf->lock); | |
471 | kfree(attach); | |
472 | } | |
473 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
474 | ||
475 | /** | |
476 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
477 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
478 | * dma_buf_ops. | |
479 | * @attach: [in] attachment whose scatterlist is to be returned | |
480 | * @direction: [in] direction of DMA transfer | |
481 | * | |
fee0c54e CC |
482 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
483 | * on error. | |
d15bd7ee SS |
484 | */ |
485 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
486 | enum dma_data_direction direction) | |
487 | { | |
488 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
489 | ||
490 | might_sleep(); | |
491 | ||
d1aa06a1 | 492 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
493 | return ERR_PTR(-EINVAL); |
494 | ||
d1aa06a1 | 495 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
496 | if (!sg_table) |
497 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
498 | |
499 | return sg_table; | |
500 | } | |
501 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
502 | ||
503 | /** | |
504 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
505 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
506 | * dma_buf_ops. | |
507 | * @attach: [in] attachment to unmap buffer from | |
508 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 509 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
510 | * |
511 | */ | |
512 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
513 | struct sg_table *sg_table, |
514 | enum dma_data_direction direction) | |
d15bd7ee | 515 | { |
b6fa0cd6 RC |
516 | might_sleep(); |
517 | ||
d1aa06a1 | 518 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
519 | return; |
520 | ||
33ea2dcb SS |
521 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
522 | direction); | |
d15bd7ee SS |
523 | } |
524 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
525 | |
526 | ||
527 | /** | |
528 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
529 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
530 | * preparations. Coherency is only guaranteed in the specified range for the | |
531 | * specified access direction. | |
efb4df82 | 532 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
533 | * @start: [in] start of range for cpu access. |
534 | * @len: [in] length of range for cpu access. | |
535 | * @direction: [in] length of range for cpu access. | |
536 | * | |
537 | * Can return negative error values, returns 0 on success. | |
538 | */ | |
539 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
540 | enum dma_data_direction direction) | |
541 | { | |
542 | int ret = 0; | |
543 | ||
544 | if (WARN_ON(!dmabuf)) | |
545 | return -EINVAL; | |
546 | ||
547 | if (dmabuf->ops->begin_cpu_access) | |
548 | ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); | |
549 | ||
550 | return ret; | |
551 | } | |
552 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
553 | ||
554 | /** | |
555 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
556 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
557 | * actions. Coherency is only guaranteed in the specified range for the | |
558 | * specified access direction. | |
efb4df82 | 559 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
560 | * @start: [in] start of range for cpu access. |
561 | * @len: [in] length of range for cpu access. | |
562 | * @direction: [in] length of range for cpu access. | |
563 | * | |
564 | * This call must always succeed. | |
565 | */ | |
566 | void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
567 | enum dma_data_direction direction) | |
568 | { | |
569 | WARN_ON(!dmabuf); | |
570 | ||
571 | if (dmabuf->ops->end_cpu_access) | |
572 | dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); | |
573 | } | |
574 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
575 | ||
576 | /** | |
577 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
578 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 579 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
580 | * @page_num: [in] page in PAGE_SIZE units to map. |
581 | * | |
582 | * This call must always succeed, any necessary preparations that might fail | |
583 | * need to be done in begin_cpu_access. | |
584 | */ | |
585 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
586 | { | |
587 | WARN_ON(!dmabuf); | |
588 | ||
589 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
590 | } | |
591 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
592 | ||
593 | /** | |
594 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 595 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
596 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
597 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
598 | * | |
599 | * This call must always succeed. | |
600 | */ | |
601 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
602 | void *vaddr) | |
603 | { | |
604 | WARN_ON(!dmabuf); | |
605 | ||
606 | if (dmabuf->ops->kunmap_atomic) | |
607 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
608 | } | |
609 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
610 | ||
611 | /** | |
612 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
613 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 614 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
615 | * @page_num: [in] page in PAGE_SIZE units to map. |
616 | * | |
617 | * This call must always succeed, any necessary preparations that might fail | |
618 | * need to be done in begin_cpu_access. | |
619 | */ | |
620 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
621 | { | |
622 | WARN_ON(!dmabuf); | |
623 | ||
624 | return dmabuf->ops->kmap(dmabuf, page_num); | |
625 | } | |
626 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
627 | ||
628 | /** | |
629 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 630 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
631 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
632 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
633 | * | |
634 | * This call must always succeed. | |
635 | */ | |
636 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
637 | void *vaddr) | |
638 | { | |
639 | WARN_ON(!dmabuf); | |
640 | ||
641 | if (dmabuf->ops->kunmap) | |
642 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
645 | |
646 | ||
647 | /** | |
648 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 649 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
650 | * @vma: [in] vma for the mmap |
651 | * @pgoff: [in] offset in pages where this mmap should start within the | |
652 | * dma-buf buffer. | |
653 | * | |
654 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 655 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
656 | * checking on the size of the vma. Then it calls the exporters mmap function to |
657 | * set up the mapping. | |
658 | * | |
659 | * Can return negative error values, returns 0 on success. | |
660 | */ | |
661 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
662 | unsigned long pgoff) | |
663 | { | |
495c10cc JS |
664 | struct file *oldfile; |
665 | int ret; | |
666 | ||
4c78513e DV |
667 | if (WARN_ON(!dmabuf || !vma)) |
668 | return -EINVAL; | |
669 | ||
670 | /* check for offset overflow */ | |
671 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) | |
672 | return -EOVERFLOW; | |
673 | ||
674 | /* check for overflowing the buffer's size */ | |
675 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
676 | dmabuf->size >> PAGE_SHIFT) | |
677 | return -EINVAL; | |
678 | ||
679 | /* readjust the vma */ | |
495c10cc JS |
680 | get_file(dmabuf->file); |
681 | oldfile = vma->vm_file; | |
682 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
683 | vma->vm_pgoff = pgoff; |
684 | ||
495c10cc JS |
685 | ret = dmabuf->ops->mmap(dmabuf, vma); |
686 | if (ret) { | |
687 | /* restore old parameters on failure */ | |
688 | vma->vm_file = oldfile; | |
689 | fput(dmabuf->file); | |
690 | } else { | |
691 | if (oldfile) | |
692 | fput(oldfile); | |
693 | } | |
694 | return ret; | |
695 | ||
4c78513e DV |
696 | } |
697 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
698 | |
699 | /** | |
12c4727e SS |
700 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
701 | * address space. Same restrictions as for vmap and friends apply. | |
702 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
703 | * |
704 | * This call may fail due to lack of virtual mapping address space. | |
705 | * These calls are optional in drivers. The intended use for them | |
706 | * is for mapping objects linear in kernel space for high use objects. | |
707 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
708 | * |
709 | * Returns NULL on error. | |
98f86c9e DA |
710 | */ |
711 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
712 | { | |
f00b4dad DV |
713 | void *ptr; |
714 | ||
98f86c9e DA |
715 | if (WARN_ON(!dmabuf)) |
716 | return NULL; | |
717 | ||
f00b4dad DV |
718 | if (!dmabuf->ops->vmap) |
719 | return NULL; | |
720 | ||
721 | mutex_lock(&dmabuf->lock); | |
722 | if (dmabuf->vmapping_counter) { | |
723 | dmabuf->vmapping_counter++; | |
724 | BUG_ON(!dmabuf->vmap_ptr); | |
725 | ptr = dmabuf->vmap_ptr; | |
726 | goto out_unlock; | |
727 | } | |
728 | ||
729 | BUG_ON(dmabuf->vmap_ptr); | |
730 | ||
731 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
732 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
733 | ptr = NULL; | |
734 | if (!ptr) | |
f00b4dad DV |
735 | goto out_unlock; |
736 | ||
737 | dmabuf->vmap_ptr = ptr; | |
738 | dmabuf->vmapping_counter = 1; | |
739 | ||
740 | out_unlock: | |
741 | mutex_unlock(&dmabuf->lock); | |
742 | return ptr; | |
98f86c9e DA |
743 | } |
744 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
745 | ||
746 | /** | |
747 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 748 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 749 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
750 | */ |
751 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
752 | { | |
753 | if (WARN_ON(!dmabuf)) | |
754 | return; | |
755 | ||
f00b4dad DV |
756 | BUG_ON(!dmabuf->vmap_ptr); |
757 | BUG_ON(dmabuf->vmapping_counter == 0); | |
758 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
759 | ||
760 | mutex_lock(&dmabuf->lock); | |
761 | if (--dmabuf->vmapping_counter == 0) { | |
762 | if (dmabuf->ops->vunmap) | |
763 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
764 | dmabuf->vmap_ptr = NULL; | |
765 | } | |
766 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
767 | } |
768 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
769 | |
770 | #ifdef CONFIG_DEBUG_FS | |
771 | static int dma_buf_describe(struct seq_file *s) | |
772 | { | |
773 | int ret; | |
774 | struct dma_buf *buf_obj; | |
775 | struct dma_buf_attachment *attach_obj; | |
776 | int count = 0, attach_count; | |
777 | size_t size = 0; | |
778 | ||
779 | ret = mutex_lock_interruptible(&db_list.lock); | |
780 | ||
781 | if (ret) | |
782 | return ret; | |
783 | ||
c0b00a52 SS |
784 | seq_puts(s, "\nDma-buf Objects:\n"); |
785 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
786 | |
787 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
788 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
789 | ||
790 | if (ret) { | |
c0b00a52 SS |
791 | seq_puts(s, |
792 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
793 | continue; |
794 | } | |
795 | ||
c0b00a52 SS |
796 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
797 | buf_obj->size, | |
b89e3563 | 798 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 799 | file_count(buf_obj->file), |
c0b00a52 | 800 | buf_obj->exp_name); |
b89e3563 | 801 | |
c0b00a52 | 802 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
803 | attach_count = 0; |
804 | ||
805 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 806 | seq_puts(s, "\t"); |
b89e3563 | 807 | |
c0b00a52 | 808 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
809 | attach_count++; |
810 | } | |
811 | ||
c0b00a52 | 812 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
813 | attach_count); |
814 | ||
815 | count++; | |
816 | size += buf_obj->size; | |
817 | mutex_unlock(&buf_obj->lock); | |
818 | } | |
819 | ||
820 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
821 | ||
822 | mutex_unlock(&db_list.lock); | |
823 | return 0; | |
824 | } | |
825 | ||
826 | static int dma_buf_show(struct seq_file *s, void *unused) | |
827 | { | |
828 | void (*func)(struct seq_file *) = s->private; | |
829 | func(s); | |
830 | return 0; | |
831 | } | |
832 | ||
833 | static int dma_buf_debug_open(struct inode *inode, struct file *file) | |
834 | { | |
835 | return single_open(file, dma_buf_show, inode->i_private); | |
836 | } | |
837 | ||
838 | static const struct file_operations dma_buf_debug_fops = { | |
839 | .open = dma_buf_debug_open, | |
840 | .read = seq_read, | |
841 | .llseek = seq_lseek, | |
842 | .release = single_release, | |
843 | }; | |
844 | ||
845 | static struct dentry *dma_buf_debugfs_dir; | |
846 | ||
847 | static int dma_buf_init_debugfs(void) | |
848 | { | |
849 | int err = 0; | |
850 | dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); | |
851 | if (IS_ERR(dma_buf_debugfs_dir)) { | |
852 | err = PTR_ERR(dma_buf_debugfs_dir); | |
853 | dma_buf_debugfs_dir = NULL; | |
854 | return err; | |
855 | } | |
856 | ||
857 | err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); | |
858 | ||
859 | if (err) | |
860 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); | |
861 | ||
862 | return err; | |
863 | } | |
864 | ||
865 | static void dma_buf_uninit_debugfs(void) | |
866 | { | |
867 | if (dma_buf_debugfs_dir) | |
868 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
869 | } | |
870 | ||
871 | int dma_buf_debugfs_create_file(const char *name, | |
872 | int (*write)(struct seq_file *)) | |
873 | { | |
874 | struct dentry *d; | |
875 | ||
876 | d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, | |
877 | write, &dma_buf_debug_fops); | |
878 | ||
28ce4201 | 879 | return PTR_ERR_OR_ZERO(d); |
b89e3563 SS |
880 | } |
881 | #else | |
882 | static inline int dma_buf_init_debugfs(void) | |
883 | { | |
884 | return 0; | |
885 | } | |
886 | static inline void dma_buf_uninit_debugfs(void) | |
887 | { | |
888 | } | |
889 | #endif | |
890 | ||
891 | static int __init dma_buf_init(void) | |
892 | { | |
893 | mutex_init(&db_list.lock); | |
894 | INIT_LIST_HEAD(&db_list.head); | |
895 | dma_buf_init_debugfs(); | |
896 | return 0; | |
897 | } | |
898 | subsys_initcall(dma_buf_init); | |
899 | ||
900 | static void __exit dma_buf_deinit(void) | |
901 | { | |
902 | dma_buf_uninit_debugfs(); | |
903 | } | |
904 | __exitcall(dma_buf_deinit); |