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 | /** | |
78df9695 | 268 | * dma_buf_export_named - 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 SS |
272 | * |
273 | * @priv: [in] Attach private data of allocator to this buffer | |
274 | * @ops: [in] Attach allocator-defined dma buf ops to the new buffer. | |
275 | * @size: [in] Size of the buffer | |
276 | * @flags: [in] mode flags for the file. | |
78df9695 | 277 | * @exp_name: [in] name of the exporting module - useful for debugging. |
3aac4502 | 278 | * @resv: [in] reservation-object, NULL to allocate default one. |
d15bd7ee SS |
279 | * |
280 | * Returns, on success, a newly created dma_buf object, which wraps the | |
281 | * supplied private data and operations for dma_buf_ops. On either missing | |
282 | * ops, or error in allocating struct dma_buf, will return negative error. | |
283 | * | |
284 | */ | |
78df9695 | 285 | struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, |
3aac4502 ML |
286 | size_t size, int flags, const char *exp_name, |
287 | struct reservation_object *resv) | |
d15bd7ee SS |
288 | { |
289 | struct dma_buf *dmabuf; | |
290 | struct file *file; | |
3aac4502 ML |
291 | size_t alloc_size = sizeof(struct dma_buf); |
292 | if (!resv) | |
293 | alloc_size += sizeof(struct reservation_object); | |
294 | else | |
295 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
296 | alloc_size += 1; | |
d15bd7ee SS |
297 | |
298 | if (WARN_ON(!priv || !ops | |
299 | || !ops->map_dma_buf | |
300 | || !ops->unmap_dma_buf | |
fc13020e DV |
301 | || !ops->release |
302 | || !ops->kmap_atomic | |
4c78513e DV |
303 | || !ops->kmap |
304 | || !ops->mmap)) { | |
d15bd7ee SS |
305 | return ERR_PTR(-EINVAL); |
306 | } | |
307 | ||
3aac4502 | 308 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
d15bd7ee SS |
309 | if (dmabuf == NULL) |
310 | return ERR_PTR(-ENOMEM); | |
311 | ||
312 | dmabuf->priv = priv; | |
313 | dmabuf->ops = ops; | |
314 | dmabuf->size = size; | |
78df9695 | 315 | dmabuf->exp_name = exp_name; |
9b495a58 ML |
316 | init_waitqueue_head(&dmabuf->poll); |
317 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
318 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
319 | ||
3aac4502 ML |
320 | if (!resv) { |
321 | resv = (struct reservation_object *)&dmabuf[1]; | |
322 | reservation_object_init(resv); | |
323 | } | |
324 | dmabuf->resv = resv; | |
d15bd7ee SS |
325 | |
326 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags); | |
9022e24e TT |
327 | if (IS_ERR(file)) { |
328 | kfree(dmabuf); | |
329 | return ERR_CAST(file); | |
330 | } | |
19e8697b CJHR |
331 | |
332 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
333 | dmabuf->file = file; |
334 | ||
335 | mutex_init(&dmabuf->lock); | |
336 | INIT_LIST_HEAD(&dmabuf->attachments); | |
337 | ||
b89e3563 SS |
338 | mutex_lock(&db_list.lock); |
339 | list_add(&dmabuf->list_node, &db_list.head); | |
340 | mutex_unlock(&db_list.lock); | |
341 | ||
d15bd7ee SS |
342 | return dmabuf; |
343 | } | |
78df9695 | 344 | EXPORT_SYMBOL_GPL(dma_buf_export_named); |
d15bd7ee SS |
345 | |
346 | ||
347 | /** | |
348 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
349 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 350 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
351 | * |
352 | * On success, returns an associated 'fd'. Else, returns error. | |
353 | */ | |
55c1c4ca | 354 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 355 | { |
f5e097f0 | 356 | int fd; |
d15bd7ee SS |
357 | |
358 | if (!dmabuf || !dmabuf->file) | |
359 | return -EINVAL; | |
360 | ||
f5e097f0 BP |
361 | fd = get_unused_fd_flags(flags); |
362 | if (fd < 0) | |
363 | return fd; | |
d15bd7ee SS |
364 | |
365 | fd_install(fd, dmabuf->file); | |
366 | ||
367 | return fd; | |
368 | } | |
369 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
370 | ||
371 | /** | |
372 | * dma_buf_get - returns the dma_buf structure related to an fd | |
373 | * @fd: [in] fd associated with the dma_buf to be returned | |
374 | * | |
375 | * On success, returns the dma_buf structure associated with an fd; uses | |
376 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
377 | * otherwise. | |
378 | */ | |
379 | struct dma_buf *dma_buf_get(int fd) | |
380 | { | |
381 | struct file *file; | |
382 | ||
383 | file = fget(fd); | |
384 | ||
385 | if (!file) | |
386 | return ERR_PTR(-EBADF); | |
387 | ||
388 | if (!is_dma_buf_file(file)) { | |
389 | fput(file); | |
390 | return ERR_PTR(-EINVAL); | |
391 | } | |
392 | ||
393 | return file->private_data; | |
394 | } | |
395 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
396 | ||
397 | /** | |
398 | * dma_buf_put - decreases refcount of the buffer | |
399 | * @dmabuf: [in] buffer to reduce refcount of | |
400 | * | |
401 | * Uses file's refcounting done implicitly by fput() | |
402 | */ | |
403 | void dma_buf_put(struct dma_buf *dmabuf) | |
404 | { | |
405 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
406 | return; | |
407 | ||
408 | fput(dmabuf->file); | |
409 | } | |
410 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
411 | ||
412 | /** | |
413 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
414 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
415 | * @dmabuf: [in] buffer to attach device to. | |
416 | * @dev: [in] device to be attached. | |
417 | * | |
fee0c54e CC |
418 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
419 | * error. | |
d15bd7ee SS |
420 | */ |
421 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
422 | struct device *dev) | |
423 | { | |
424 | struct dma_buf_attachment *attach; | |
425 | int ret; | |
426 | ||
d1aa06a1 | 427 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
428 | return ERR_PTR(-EINVAL); |
429 | ||
430 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
431 | if (attach == NULL) | |
a9fbc3b7 | 432 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 433 | |
d15bd7ee SS |
434 | attach->dev = dev; |
435 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
436 | |
437 | mutex_lock(&dmabuf->lock); | |
438 | ||
d15bd7ee SS |
439 | if (dmabuf->ops->attach) { |
440 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
441 | if (ret) | |
442 | goto err_attach; | |
443 | } | |
444 | list_add(&attach->node, &dmabuf->attachments); | |
445 | ||
446 | mutex_unlock(&dmabuf->lock); | |
447 | return attach; | |
448 | ||
d15bd7ee SS |
449 | err_attach: |
450 | kfree(attach); | |
451 | mutex_unlock(&dmabuf->lock); | |
452 | return ERR_PTR(ret); | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
455 | ||
456 | /** | |
457 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
458 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
459 | * @dmabuf: [in] buffer to detach from. | |
460 | * @attach: [in] attachment to be detached; is free'd after this call. | |
461 | * | |
462 | */ | |
463 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
464 | { | |
d1aa06a1 | 465 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
466 | return; |
467 | ||
468 | mutex_lock(&dmabuf->lock); | |
469 | list_del(&attach->node); | |
470 | if (dmabuf->ops->detach) | |
471 | dmabuf->ops->detach(dmabuf, attach); | |
472 | ||
473 | mutex_unlock(&dmabuf->lock); | |
474 | kfree(attach); | |
475 | } | |
476 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
477 | ||
478 | /** | |
479 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
480 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
481 | * dma_buf_ops. | |
482 | * @attach: [in] attachment whose scatterlist is to be returned | |
483 | * @direction: [in] direction of DMA transfer | |
484 | * | |
fee0c54e CC |
485 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
486 | * on error. | |
d15bd7ee SS |
487 | */ |
488 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
489 | enum dma_data_direction direction) | |
490 | { | |
491 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
492 | ||
493 | might_sleep(); | |
494 | ||
d1aa06a1 | 495 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
496 | return ERR_PTR(-EINVAL); |
497 | ||
d1aa06a1 | 498 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
499 | if (!sg_table) |
500 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
501 | |
502 | return sg_table; | |
503 | } | |
504 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
505 | ||
506 | /** | |
507 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
508 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
509 | * dma_buf_ops. | |
510 | * @attach: [in] attachment to unmap buffer from | |
511 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 512 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
513 | * |
514 | */ | |
515 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
516 | struct sg_table *sg_table, |
517 | enum dma_data_direction direction) | |
d15bd7ee | 518 | { |
b6fa0cd6 RC |
519 | might_sleep(); |
520 | ||
d1aa06a1 | 521 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
522 | return; |
523 | ||
33ea2dcb SS |
524 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
525 | direction); | |
d15bd7ee SS |
526 | } |
527 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
528 | |
529 | ||
530 | /** | |
531 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
532 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
533 | * preparations. Coherency is only guaranteed in the specified range for the | |
534 | * specified access direction. | |
efb4df82 | 535 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
536 | * @start: [in] start of range for cpu access. |
537 | * @len: [in] length of range for cpu access. | |
538 | * @direction: [in] length of range for cpu access. | |
539 | * | |
540 | * Can return negative error values, returns 0 on success. | |
541 | */ | |
542 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
543 | enum dma_data_direction direction) | |
544 | { | |
545 | int ret = 0; | |
546 | ||
547 | if (WARN_ON(!dmabuf)) | |
548 | return -EINVAL; | |
549 | ||
550 | if (dmabuf->ops->begin_cpu_access) | |
551 | ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); | |
552 | ||
553 | return ret; | |
554 | } | |
555 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
556 | ||
557 | /** | |
558 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
559 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
560 | * actions. Coherency is only guaranteed in the specified range for the | |
561 | * specified access direction. | |
efb4df82 | 562 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
563 | * @start: [in] start of range for cpu access. |
564 | * @len: [in] length of range for cpu access. | |
565 | * @direction: [in] length of range for cpu access. | |
566 | * | |
567 | * This call must always succeed. | |
568 | */ | |
569 | void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
570 | enum dma_data_direction direction) | |
571 | { | |
572 | WARN_ON(!dmabuf); | |
573 | ||
574 | if (dmabuf->ops->end_cpu_access) | |
575 | dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); | |
576 | } | |
577 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
578 | ||
579 | /** | |
580 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
581 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 582 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
583 | * @page_num: [in] page in PAGE_SIZE units to map. |
584 | * | |
585 | * This call must always succeed, any necessary preparations that might fail | |
586 | * need to be done in begin_cpu_access. | |
587 | */ | |
588 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
589 | { | |
590 | WARN_ON(!dmabuf); | |
591 | ||
592 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
593 | } | |
594 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
595 | ||
596 | /** | |
597 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 598 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
599 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
600 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
601 | * | |
602 | * This call must always succeed. | |
603 | */ | |
604 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
605 | void *vaddr) | |
606 | { | |
607 | WARN_ON(!dmabuf); | |
608 | ||
609 | if (dmabuf->ops->kunmap_atomic) | |
610 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
611 | } | |
612 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
613 | ||
614 | /** | |
615 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
616 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 617 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
618 | * @page_num: [in] page in PAGE_SIZE units to map. |
619 | * | |
620 | * This call must always succeed, any necessary preparations that might fail | |
621 | * need to be done in begin_cpu_access. | |
622 | */ | |
623 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
624 | { | |
625 | WARN_ON(!dmabuf); | |
626 | ||
627 | return dmabuf->ops->kmap(dmabuf, page_num); | |
628 | } | |
629 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
630 | ||
631 | /** | |
632 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 633 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
634 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
635 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
636 | * | |
637 | * This call must always succeed. | |
638 | */ | |
639 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
640 | void *vaddr) | |
641 | { | |
642 | WARN_ON(!dmabuf); | |
643 | ||
644 | if (dmabuf->ops->kunmap) | |
645 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
646 | } | |
647 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
648 | |
649 | ||
650 | /** | |
651 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 652 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
653 | * @vma: [in] vma for the mmap |
654 | * @pgoff: [in] offset in pages where this mmap should start within the | |
655 | * dma-buf buffer. | |
656 | * | |
657 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 658 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
659 | * checking on the size of the vma. Then it calls the exporters mmap function to |
660 | * set up the mapping. | |
661 | * | |
662 | * Can return negative error values, returns 0 on success. | |
663 | */ | |
664 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
665 | unsigned long pgoff) | |
666 | { | |
495c10cc JS |
667 | struct file *oldfile; |
668 | int ret; | |
669 | ||
4c78513e DV |
670 | if (WARN_ON(!dmabuf || !vma)) |
671 | return -EINVAL; | |
672 | ||
673 | /* check for offset overflow */ | |
674 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) | |
675 | return -EOVERFLOW; | |
676 | ||
677 | /* check for overflowing the buffer's size */ | |
678 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
679 | dmabuf->size >> PAGE_SHIFT) | |
680 | return -EINVAL; | |
681 | ||
682 | /* readjust the vma */ | |
495c10cc JS |
683 | get_file(dmabuf->file); |
684 | oldfile = vma->vm_file; | |
685 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
686 | vma->vm_pgoff = pgoff; |
687 | ||
495c10cc JS |
688 | ret = dmabuf->ops->mmap(dmabuf, vma); |
689 | if (ret) { | |
690 | /* restore old parameters on failure */ | |
691 | vma->vm_file = oldfile; | |
692 | fput(dmabuf->file); | |
693 | } else { | |
694 | if (oldfile) | |
695 | fput(oldfile); | |
696 | } | |
697 | return ret; | |
698 | ||
4c78513e DV |
699 | } |
700 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
701 | |
702 | /** | |
12c4727e SS |
703 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
704 | * address space. Same restrictions as for vmap and friends apply. | |
705 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
706 | * |
707 | * This call may fail due to lack of virtual mapping address space. | |
708 | * These calls are optional in drivers. The intended use for them | |
709 | * is for mapping objects linear in kernel space for high use objects. | |
710 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
711 | * |
712 | * Returns NULL on error. | |
98f86c9e DA |
713 | */ |
714 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
715 | { | |
f00b4dad DV |
716 | void *ptr; |
717 | ||
98f86c9e DA |
718 | if (WARN_ON(!dmabuf)) |
719 | return NULL; | |
720 | ||
f00b4dad DV |
721 | if (!dmabuf->ops->vmap) |
722 | return NULL; | |
723 | ||
724 | mutex_lock(&dmabuf->lock); | |
725 | if (dmabuf->vmapping_counter) { | |
726 | dmabuf->vmapping_counter++; | |
727 | BUG_ON(!dmabuf->vmap_ptr); | |
728 | ptr = dmabuf->vmap_ptr; | |
729 | goto out_unlock; | |
730 | } | |
731 | ||
732 | BUG_ON(dmabuf->vmap_ptr); | |
733 | ||
734 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
735 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
736 | ptr = NULL; | |
737 | if (!ptr) | |
f00b4dad DV |
738 | goto out_unlock; |
739 | ||
740 | dmabuf->vmap_ptr = ptr; | |
741 | dmabuf->vmapping_counter = 1; | |
742 | ||
743 | out_unlock: | |
744 | mutex_unlock(&dmabuf->lock); | |
745 | return ptr; | |
98f86c9e DA |
746 | } |
747 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
748 | ||
749 | /** | |
750 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 751 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 752 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
753 | */ |
754 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
755 | { | |
756 | if (WARN_ON(!dmabuf)) | |
757 | return; | |
758 | ||
f00b4dad DV |
759 | BUG_ON(!dmabuf->vmap_ptr); |
760 | BUG_ON(dmabuf->vmapping_counter == 0); | |
761 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
762 | ||
763 | mutex_lock(&dmabuf->lock); | |
764 | if (--dmabuf->vmapping_counter == 0) { | |
765 | if (dmabuf->ops->vunmap) | |
766 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
767 | dmabuf->vmap_ptr = NULL; | |
768 | } | |
769 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
770 | } |
771 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
772 | |
773 | #ifdef CONFIG_DEBUG_FS | |
774 | static int dma_buf_describe(struct seq_file *s) | |
775 | { | |
776 | int ret; | |
777 | struct dma_buf *buf_obj; | |
778 | struct dma_buf_attachment *attach_obj; | |
779 | int count = 0, attach_count; | |
780 | size_t size = 0; | |
781 | ||
782 | ret = mutex_lock_interruptible(&db_list.lock); | |
783 | ||
784 | if (ret) | |
785 | return ret; | |
786 | ||
c0b00a52 SS |
787 | seq_puts(s, "\nDma-buf Objects:\n"); |
788 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
789 | |
790 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
791 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
792 | ||
793 | if (ret) { | |
c0b00a52 SS |
794 | seq_puts(s, |
795 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
796 | continue; |
797 | } | |
798 | ||
c0b00a52 SS |
799 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
800 | buf_obj->size, | |
b89e3563 | 801 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 802 | file_count(buf_obj->file), |
c0b00a52 | 803 | buf_obj->exp_name); |
b89e3563 | 804 | |
c0b00a52 | 805 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
806 | attach_count = 0; |
807 | ||
808 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 809 | seq_puts(s, "\t"); |
b89e3563 | 810 | |
c0b00a52 | 811 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
812 | attach_count++; |
813 | } | |
814 | ||
c0b00a52 | 815 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
816 | attach_count); |
817 | ||
818 | count++; | |
819 | size += buf_obj->size; | |
820 | mutex_unlock(&buf_obj->lock); | |
821 | } | |
822 | ||
823 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
824 | ||
825 | mutex_unlock(&db_list.lock); | |
826 | return 0; | |
827 | } | |
828 | ||
829 | static int dma_buf_show(struct seq_file *s, void *unused) | |
830 | { | |
831 | void (*func)(struct seq_file *) = s->private; | |
832 | func(s); | |
833 | return 0; | |
834 | } | |
835 | ||
836 | static int dma_buf_debug_open(struct inode *inode, struct file *file) | |
837 | { | |
838 | return single_open(file, dma_buf_show, inode->i_private); | |
839 | } | |
840 | ||
841 | static const struct file_operations dma_buf_debug_fops = { | |
842 | .open = dma_buf_debug_open, | |
843 | .read = seq_read, | |
844 | .llseek = seq_lseek, | |
845 | .release = single_release, | |
846 | }; | |
847 | ||
848 | static struct dentry *dma_buf_debugfs_dir; | |
849 | ||
850 | static int dma_buf_init_debugfs(void) | |
851 | { | |
852 | int err = 0; | |
853 | dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); | |
854 | if (IS_ERR(dma_buf_debugfs_dir)) { | |
855 | err = PTR_ERR(dma_buf_debugfs_dir); | |
856 | dma_buf_debugfs_dir = NULL; | |
857 | return err; | |
858 | } | |
859 | ||
860 | err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); | |
861 | ||
862 | if (err) | |
863 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); | |
864 | ||
865 | return err; | |
866 | } | |
867 | ||
868 | static void dma_buf_uninit_debugfs(void) | |
869 | { | |
870 | if (dma_buf_debugfs_dir) | |
871 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
872 | } | |
873 | ||
874 | int dma_buf_debugfs_create_file(const char *name, | |
875 | int (*write)(struct seq_file *)) | |
876 | { | |
877 | struct dentry *d; | |
878 | ||
879 | d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, | |
880 | write, &dma_buf_debug_fops); | |
881 | ||
28ce4201 | 882 | return PTR_ERR_OR_ZERO(d); |
b89e3563 SS |
883 | } |
884 | #else | |
885 | static inline int dma_buf_init_debugfs(void) | |
886 | { | |
887 | return 0; | |
888 | } | |
889 | static inline void dma_buf_uninit_debugfs(void) | |
890 | { | |
891 | } | |
892 | #endif | |
893 | ||
894 | static int __init dma_buf_init(void) | |
895 | { | |
896 | mutex_init(&db_list.lock); | |
897 | INIT_LIST_HEAD(&db_list.head); | |
898 | dma_buf_init_debugfs(); | |
899 | return 0; | |
900 | } | |
901 | subsys_initcall(dma_buf_init); | |
902 | ||
903 | static void __exit dma_buf_deinit(void) | |
904 | { | |
905 | dma_buf_uninit_debugfs(); | |
906 | } | |
907 | __exitcall(dma_buf_deinit); |