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 | 31 | #include <linux/debugfs.h> |
9abdffe2 | 32 | #include <linux/module.h> |
b89e3563 | 33 | #include <linux/seq_file.h> |
9b495a58 | 34 | #include <linux/poll.h> |
3aac4502 | 35 | #include <linux/reservation.h> |
d15bd7ee SS |
36 | |
37 | static inline int is_dma_buf_file(struct file *); | |
38 | ||
b89e3563 SS |
39 | struct dma_buf_list { |
40 | struct list_head head; | |
41 | struct mutex lock; | |
42 | }; | |
43 | ||
44 | static struct dma_buf_list db_list; | |
45 | ||
d15bd7ee SS |
46 | static int dma_buf_release(struct inode *inode, struct file *file) |
47 | { | |
48 | struct dma_buf *dmabuf; | |
49 | ||
50 | if (!is_dma_buf_file(file)) | |
51 | return -EINVAL; | |
52 | ||
53 | dmabuf = file->private_data; | |
54 | ||
f00b4dad DV |
55 | BUG_ON(dmabuf->vmapping_counter); |
56 | ||
9b495a58 ML |
57 | /* |
58 | * Any fences that a dma-buf poll can wait on should be signaled | |
59 | * before releasing dma-buf. This is the responsibility of each | |
60 | * driver that uses the reservation objects. | |
61 | * | |
62 | * If you hit this BUG() it means someone dropped their ref to the | |
63 | * dma-buf while still having pending operation to the buffer. | |
64 | */ | |
65 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
66 | ||
d15bd7ee | 67 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
68 | |
69 | mutex_lock(&db_list.lock); | |
70 | list_del(&dmabuf->list_node); | |
71 | mutex_unlock(&db_list.lock); | |
72 | ||
3aac4502 ML |
73 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
74 | reservation_object_fini(dmabuf->resv); | |
75 | ||
9abdffe2 | 76 | module_put(dmabuf->owner); |
d15bd7ee SS |
77 | kfree(dmabuf); |
78 | return 0; | |
79 | } | |
80 | ||
4c78513e DV |
81 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
82 | { | |
83 | struct dma_buf *dmabuf; | |
84 | ||
85 | if (!is_dma_buf_file(file)) | |
86 | return -EINVAL; | |
87 | ||
88 | dmabuf = file->private_data; | |
89 | ||
90 | /* check for overflowing the buffer's size */ | |
91 | if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
92 | dmabuf->size >> PAGE_SHIFT) | |
93 | return -EINVAL; | |
94 | ||
95 | return dmabuf->ops->mmap(dmabuf, vma); | |
96 | } | |
97 | ||
19e8697b CJHR |
98 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
99 | { | |
100 | struct dma_buf *dmabuf; | |
101 | loff_t base; | |
102 | ||
103 | if (!is_dma_buf_file(file)) | |
104 | return -EBADF; | |
105 | ||
106 | dmabuf = file->private_data; | |
107 | ||
108 | /* only support discovering the end of the buffer, | |
109 | but also allow SEEK_SET to maintain the idiomatic | |
110 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
111 | if (whence == SEEK_END) | |
112 | base = dmabuf->size; | |
113 | else if (whence == SEEK_SET) | |
114 | base = 0; | |
115 | else | |
116 | return -EINVAL; | |
117 | ||
118 | if (offset != 0) | |
119 | return -EINVAL; | |
120 | ||
121 | return base + offset; | |
122 | } | |
123 | ||
9b495a58 ML |
124 | static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) |
125 | { | |
126 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
127 | unsigned long flags; | |
128 | ||
129 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
130 | wake_up_locked_poll(dcb->poll, dcb->active); | |
131 | dcb->active = 0; | |
132 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
133 | } | |
134 | ||
135 | static unsigned int dma_buf_poll(struct file *file, poll_table *poll) | |
136 | { | |
137 | struct dma_buf *dmabuf; | |
138 | struct reservation_object *resv; | |
04a5faa8 ML |
139 | struct reservation_object_list *fobj; |
140 | struct fence *fence_excl; | |
9b495a58 | 141 | unsigned long events; |
3c3b177a | 142 | unsigned shared_count, seq; |
9b495a58 ML |
143 | |
144 | dmabuf = file->private_data; | |
145 | if (!dmabuf || !dmabuf->resv) | |
146 | return POLLERR; | |
147 | ||
148 | resv = dmabuf->resv; | |
149 | ||
150 | poll_wait(file, &dmabuf->poll, poll); | |
151 | ||
152 | events = poll_requested_events(poll) & (POLLIN | POLLOUT); | |
153 | if (!events) | |
154 | return 0; | |
155 | ||
3c3b177a ML |
156 | retry: |
157 | seq = read_seqcount_begin(&resv->seq); | |
158 | rcu_read_lock(); | |
9b495a58 | 159 | |
3c3b177a ML |
160 | fobj = rcu_dereference(resv->fence); |
161 | if (fobj) | |
162 | shared_count = fobj->shared_count; | |
163 | else | |
164 | shared_count = 0; | |
165 | fence_excl = rcu_dereference(resv->fence_excl); | |
166 | if (read_seqcount_retry(&resv->seq, seq)) { | |
167 | rcu_read_unlock(); | |
168 | goto retry; | |
169 | } | |
04a5faa8 ML |
170 | |
171 | if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { | |
9b495a58 ML |
172 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
173 | unsigned long pevents = POLLIN; | |
174 | ||
04a5faa8 | 175 | if (shared_count == 0) |
9b495a58 ML |
176 | pevents |= POLLOUT; |
177 | ||
178 | spin_lock_irq(&dmabuf->poll.lock); | |
179 | if (dcb->active) { | |
180 | dcb->active |= pevents; | |
181 | events &= ~pevents; | |
182 | } else | |
183 | dcb->active = pevents; | |
184 | spin_unlock_irq(&dmabuf->poll.lock); | |
185 | ||
186 | if (events & pevents) { | |
3c3b177a ML |
187 | if (!fence_get_rcu(fence_excl)) { |
188 | /* force a recheck */ | |
189 | events &= ~pevents; | |
190 | dma_buf_poll_cb(NULL, &dcb->cb); | |
191 | } else if (!fence_add_callback(fence_excl, &dcb->cb, | |
04a5faa8 | 192 | dma_buf_poll_cb)) { |
9b495a58 | 193 | events &= ~pevents; |
3c3b177a | 194 | fence_put(fence_excl); |
04a5faa8 | 195 | } else { |
9b495a58 ML |
196 | /* |
197 | * No callback queued, wake up any additional | |
198 | * waiters. | |
199 | */ | |
3c3b177a | 200 | fence_put(fence_excl); |
9b495a58 | 201 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 202 | } |
9b495a58 ML |
203 | } |
204 | } | |
205 | ||
04a5faa8 | 206 | if ((events & POLLOUT) && shared_count > 0) { |
9b495a58 ML |
207 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
208 | int i; | |
209 | ||
210 | /* Only queue a new callback if no event has fired yet */ | |
211 | spin_lock_irq(&dmabuf->poll.lock); | |
212 | if (dcb->active) | |
213 | events &= ~POLLOUT; | |
214 | else | |
215 | dcb->active = POLLOUT; | |
216 | spin_unlock_irq(&dmabuf->poll.lock); | |
217 | ||
218 | if (!(events & POLLOUT)) | |
219 | goto out; | |
220 | ||
04a5faa8 | 221 | for (i = 0; i < shared_count; ++i) { |
3c3b177a | 222 | struct fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 223 | |
3c3b177a ML |
224 | if (!fence_get_rcu(fence)) { |
225 | /* | |
226 | * fence refcount dropped to zero, this means | |
227 | * that fobj has been freed | |
228 | * | |
229 | * call dma_buf_poll_cb and force a recheck! | |
230 | */ | |
231 | events &= ~POLLOUT; | |
232 | dma_buf_poll_cb(NULL, &dcb->cb); | |
233 | break; | |
234 | } | |
04a5faa8 ML |
235 | if (!fence_add_callback(fence, &dcb->cb, |
236 | dma_buf_poll_cb)) { | |
3c3b177a | 237 | fence_put(fence); |
9b495a58 ML |
238 | events &= ~POLLOUT; |
239 | break; | |
240 | } | |
3c3b177a | 241 | fence_put(fence); |
04a5faa8 | 242 | } |
9b495a58 ML |
243 | |
244 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 245 | if (i == shared_count) |
9b495a58 ML |
246 | dma_buf_poll_cb(NULL, &dcb->cb); |
247 | } | |
248 | ||
249 | out: | |
3c3b177a | 250 | rcu_read_unlock(); |
9b495a58 ML |
251 | return events; |
252 | } | |
253 | ||
d15bd7ee SS |
254 | static const struct file_operations dma_buf_fops = { |
255 | .release = dma_buf_release, | |
4c78513e | 256 | .mmap = dma_buf_mmap_internal, |
19e8697b | 257 | .llseek = dma_buf_llseek, |
9b495a58 | 258 | .poll = dma_buf_poll, |
d15bd7ee SS |
259 | }; |
260 | ||
261 | /* | |
262 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
263 | */ | |
264 | static inline int is_dma_buf_file(struct file *file) | |
265 | { | |
266 | return file->f_op == &dma_buf_fops; | |
267 | } | |
268 | ||
269 | /** | |
d8fbe341 | 270 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
271 | * with this buffer, so it can be exported. |
272 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 273 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 274 | * |
d8fbe341 SS |
275 | * @exp_info: [in] holds all the export related information provided |
276 | * by the exporter. see struct dma_buf_export_info | |
277 | * for further details. | |
d15bd7ee SS |
278 | * |
279 | * Returns, on success, a newly created dma_buf object, which wraps the | |
280 | * supplied private data and operations for dma_buf_ops. On either missing | |
281 | * ops, or error in allocating struct dma_buf, will return negative error. | |
282 | * | |
283 | */ | |
d8fbe341 | 284 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
285 | { |
286 | struct dma_buf *dmabuf; | |
d8fbe341 | 287 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 288 | struct file *file; |
3aac4502 | 289 | size_t alloc_size = sizeof(struct dma_buf); |
d8fbe341 | 290 | if (!exp_info->resv) |
3aac4502 ML |
291 | alloc_size += sizeof(struct reservation_object); |
292 | else | |
293 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
294 | alloc_size += 1; | |
d15bd7ee | 295 | |
d8fbe341 SS |
296 | if (WARN_ON(!exp_info->priv |
297 | || !exp_info->ops | |
298 | || !exp_info->ops->map_dma_buf | |
299 | || !exp_info->ops->unmap_dma_buf | |
300 | || !exp_info->ops->release | |
301 | || !exp_info->ops->kmap_atomic | |
302 | || !exp_info->ops->kmap | |
303 | || !exp_info->ops->mmap)) { | |
d15bd7ee SS |
304 | return ERR_PTR(-EINVAL); |
305 | } | |
306 | ||
9abdffe2 SS |
307 | if (!try_module_get(exp_info->owner)) |
308 | return ERR_PTR(-ENOENT); | |
309 | ||
3aac4502 | 310 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 SS |
311 | if (!dmabuf) { |
312 | module_put(exp_info->owner); | |
d15bd7ee | 313 | return ERR_PTR(-ENOMEM); |
9abdffe2 | 314 | } |
d15bd7ee | 315 | |
d8fbe341 SS |
316 | dmabuf->priv = exp_info->priv; |
317 | dmabuf->ops = exp_info->ops; | |
318 | dmabuf->size = exp_info->size; | |
319 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 320 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
321 | init_waitqueue_head(&dmabuf->poll); |
322 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
323 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
324 | ||
3aac4502 ML |
325 | if (!resv) { |
326 | resv = (struct reservation_object *)&dmabuf[1]; | |
327 | reservation_object_init(resv); | |
328 | } | |
329 | dmabuf->resv = resv; | |
d15bd7ee | 330 | |
d8fbe341 SS |
331 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
332 | exp_info->flags); | |
9022e24e TT |
333 | if (IS_ERR(file)) { |
334 | kfree(dmabuf); | |
335 | return ERR_CAST(file); | |
336 | } | |
19e8697b CJHR |
337 | |
338 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
339 | dmabuf->file = file; |
340 | ||
341 | mutex_init(&dmabuf->lock); | |
342 | INIT_LIST_HEAD(&dmabuf->attachments); | |
343 | ||
b89e3563 SS |
344 | mutex_lock(&db_list.lock); |
345 | list_add(&dmabuf->list_node, &db_list.head); | |
346 | mutex_unlock(&db_list.lock); | |
347 | ||
d15bd7ee SS |
348 | return dmabuf; |
349 | } | |
d8fbe341 | 350 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
351 | |
352 | /** | |
353 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
354 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 355 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
356 | * |
357 | * On success, returns an associated 'fd'. Else, returns error. | |
358 | */ | |
55c1c4ca | 359 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 360 | { |
f5e097f0 | 361 | int fd; |
d15bd7ee SS |
362 | |
363 | if (!dmabuf || !dmabuf->file) | |
364 | return -EINVAL; | |
365 | ||
f5e097f0 BP |
366 | fd = get_unused_fd_flags(flags); |
367 | if (fd < 0) | |
368 | return fd; | |
d15bd7ee SS |
369 | |
370 | fd_install(fd, dmabuf->file); | |
371 | ||
372 | return fd; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
375 | ||
376 | /** | |
377 | * dma_buf_get - returns the dma_buf structure related to an fd | |
378 | * @fd: [in] fd associated with the dma_buf to be returned | |
379 | * | |
380 | * On success, returns the dma_buf structure associated with an fd; uses | |
381 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
382 | * otherwise. | |
383 | */ | |
384 | struct dma_buf *dma_buf_get(int fd) | |
385 | { | |
386 | struct file *file; | |
387 | ||
388 | file = fget(fd); | |
389 | ||
390 | if (!file) | |
391 | return ERR_PTR(-EBADF); | |
392 | ||
393 | if (!is_dma_buf_file(file)) { | |
394 | fput(file); | |
395 | return ERR_PTR(-EINVAL); | |
396 | } | |
397 | ||
398 | return file->private_data; | |
399 | } | |
400 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
401 | ||
402 | /** | |
403 | * dma_buf_put - decreases refcount of the buffer | |
404 | * @dmabuf: [in] buffer to reduce refcount of | |
405 | * | |
406 | * Uses file's refcounting done implicitly by fput() | |
407 | */ | |
408 | void dma_buf_put(struct dma_buf *dmabuf) | |
409 | { | |
410 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
411 | return; | |
412 | ||
413 | fput(dmabuf->file); | |
414 | } | |
415 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
416 | ||
417 | /** | |
418 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
419 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
420 | * @dmabuf: [in] buffer to attach device to. | |
421 | * @dev: [in] device to be attached. | |
422 | * | |
fee0c54e CC |
423 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
424 | * error. | |
d15bd7ee SS |
425 | */ |
426 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
427 | struct device *dev) | |
428 | { | |
429 | struct dma_buf_attachment *attach; | |
430 | int ret; | |
431 | ||
d1aa06a1 | 432 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
433 | return ERR_PTR(-EINVAL); |
434 | ||
435 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
436 | if (attach == NULL) | |
a9fbc3b7 | 437 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 438 | |
d15bd7ee SS |
439 | attach->dev = dev; |
440 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
441 | |
442 | mutex_lock(&dmabuf->lock); | |
443 | ||
d15bd7ee SS |
444 | if (dmabuf->ops->attach) { |
445 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
446 | if (ret) | |
447 | goto err_attach; | |
448 | } | |
449 | list_add(&attach->node, &dmabuf->attachments); | |
450 | ||
451 | mutex_unlock(&dmabuf->lock); | |
452 | return attach; | |
453 | ||
d15bd7ee SS |
454 | err_attach: |
455 | kfree(attach); | |
456 | mutex_unlock(&dmabuf->lock); | |
457 | return ERR_PTR(ret); | |
458 | } | |
459 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
460 | ||
461 | /** | |
462 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
463 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
464 | * @dmabuf: [in] buffer to detach from. | |
465 | * @attach: [in] attachment to be detached; is free'd after this call. | |
466 | * | |
467 | */ | |
468 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
469 | { | |
d1aa06a1 | 470 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
471 | return; |
472 | ||
473 | mutex_lock(&dmabuf->lock); | |
474 | list_del(&attach->node); | |
475 | if (dmabuf->ops->detach) | |
476 | dmabuf->ops->detach(dmabuf, attach); | |
477 | ||
478 | mutex_unlock(&dmabuf->lock); | |
479 | kfree(attach); | |
480 | } | |
481 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
482 | ||
483 | /** | |
484 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
485 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
486 | * dma_buf_ops. | |
487 | * @attach: [in] attachment whose scatterlist is to be returned | |
488 | * @direction: [in] direction of DMA transfer | |
489 | * | |
fee0c54e CC |
490 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
491 | * on error. | |
d15bd7ee SS |
492 | */ |
493 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
494 | enum dma_data_direction direction) | |
495 | { | |
496 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
497 | ||
498 | might_sleep(); | |
499 | ||
d1aa06a1 | 500 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
501 | return ERR_PTR(-EINVAL); |
502 | ||
d1aa06a1 | 503 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
504 | if (!sg_table) |
505 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
506 | |
507 | return sg_table; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
510 | ||
511 | /** | |
512 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
513 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
514 | * dma_buf_ops. | |
515 | * @attach: [in] attachment to unmap buffer from | |
516 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 517 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
518 | * |
519 | */ | |
520 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
521 | struct sg_table *sg_table, |
522 | enum dma_data_direction direction) | |
d15bd7ee | 523 | { |
b6fa0cd6 RC |
524 | might_sleep(); |
525 | ||
d1aa06a1 | 526 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
527 | return; |
528 | ||
33ea2dcb SS |
529 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
530 | direction); | |
d15bd7ee SS |
531 | } |
532 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
533 | |
534 | ||
535 | /** | |
536 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
537 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
538 | * preparations. Coherency is only guaranteed in the specified range for the | |
539 | * specified access direction. | |
efb4df82 | 540 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
541 | * @start: [in] start of range for cpu access. |
542 | * @len: [in] length of range for cpu access. | |
543 | * @direction: [in] length of range for cpu access. | |
544 | * | |
545 | * Can return negative error values, returns 0 on success. | |
546 | */ | |
547 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
548 | enum dma_data_direction direction) | |
549 | { | |
550 | int ret = 0; | |
551 | ||
552 | if (WARN_ON(!dmabuf)) | |
553 | return -EINVAL; | |
554 | ||
555 | if (dmabuf->ops->begin_cpu_access) | |
556 | ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); | |
557 | ||
558 | return ret; | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
561 | ||
562 | /** | |
563 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
564 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
565 | * actions. Coherency is only guaranteed in the specified range for the | |
566 | * specified access direction. | |
efb4df82 | 567 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
568 | * @start: [in] start of range for cpu access. |
569 | * @len: [in] length of range for cpu access. | |
570 | * @direction: [in] length of range for cpu access. | |
571 | * | |
572 | * This call must always succeed. | |
573 | */ | |
574 | void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, | |
575 | enum dma_data_direction direction) | |
576 | { | |
577 | WARN_ON(!dmabuf); | |
578 | ||
579 | if (dmabuf->ops->end_cpu_access) | |
580 | dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); | |
581 | } | |
582 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
583 | ||
584 | /** | |
585 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
586 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 587 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
588 | * @page_num: [in] page in PAGE_SIZE units to map. |
589 | * | |
590 | * This call must always succeed, any necessary preparations that might fail | |
591 | * need to be done in begin_cpu_access. | |
592 | */ | |
593 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
594 | { | |
595 | WARN_ON(!dmabuf); | |
596 | ||
597 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
598 | } | |
599 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
600 | ||
601 | /** | |
602 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 603 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
604 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
605 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
606 | * | |
607 | * This call must always succeed. | |
608 | */ | |
609 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
610 | void *vaddr) | |
611 | { | |
612 | WARN_ON(!dmabuf); | |
613 | ||
614 | if (dmabuf->ops->kunmap_atomic) | |
615 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
616 | } | |
617 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
618 | ||
619 | /** | |
620 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
621 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 622 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
623 | * @page_num: [in] page in PAGE_SIZE units to map. |
624 | * | |
625 | * This call must always succeed, any necessary preparations that might fail | |
626 | * need to be done in begin_cpu_access. | |
627 | */ | |
628 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
629 | { | |
630 | WARN_ON(!dmabuf); | |
631 | ||
632 | return dmabuf->ops->kmap(dmabuf, page_num); | |
633 | } | |
634 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
635 | ||
636 | /** | |
637 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 638 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
639 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
640 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
641 | * | |
642 | * This call must always succeed. | |
643 | */ | |
644 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
645 | void *vaddr) | |
646 | { | |
647 | WARN_ON(!dmabuf); | |
648 | ||
649 | if (dmabuf->ops->kunmap) | |
650 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
651 | } | |
652 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
653 | |
654 | ||
655 | /** | |
656 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 657 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
658 | * @vma: [in] vma for the mmap |
659 | * @pgoff: [in] offset in pages where this mmap should start within the | |
660 | * dma-buf buffer. | |
661 | * | |
662 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 663 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
664 | * checking on the size of the vma. Then it calls the exporters mmap function to |
665 | * set up the mapping. | |
666 | * | |
667 | * Can return negative error values, returns 0 on success. | |
668 | */ | |
669 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
670 | unsigned long pgoff) | |
671 | { | |
495c10cc JS |
672 | struct file *oldfile; |
673 | int ret; | |
674 | ||
4c78513e DV |
675 | if (WARN_ON(!dmabuf || !vma)) |
676 | return -EINVAL; | |
677 | ||
678 | /* check for offset overflow */ | |
679 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) | |
680 | return -EOVERFLOW; | |
681 | ||
682 | /* check for overflowing the buffer's size */ | |
683 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
684 | dmabuf->size >> PAGE_SHIFT) | |
685 | return -EINVAL; | |
686 | ||
687 | /* readjust the vma */ | |
495c10cc JS |
688 | get_file(dmabuf->file); |
689 | oldfile = vma->vm_file; | |
690 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
691 | vma->vm_pgoff = pgoff; |
692 | ||
495c10cc JS |
693 | ret = dmabuf->ops->mmap(dmabuf, vma); |
694 | if (ret) { | |
695 | /* restore old parameters on failure */ | |
696 | vma->vm_file = oldfile; | |
697 | fput(dmabuf->file); | |
698 | } else { | |
699 | if (oldfile) | |
700 | fput(oldfile); | |
701 | } | |
702 | return ret; | |
703 | ||
4c78513e DV |
704 | } |
705 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
706 | |
707 | /** | |
12c4727e SS |
708 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
709 | * address space. Same restrictions as for vmap and friends apply. | |
710 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
711 | * |
712 | * This call may fail due to lack of virtual mapping address space. | |
713 | * These calls are optional in drivers. The intended use for them | |
714 | * is for mapping objects linear in kernel space for high use objects. | |
715 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
716 | * |
717 | * Returns NULL on error. | |
98f86c9e DA |
718 | */ |
719 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
720 | { | |
f00b4dad DV |
721 | void *ptr; |
722 | ||
98f86c9e DA |
723 | if (WARN_ON(!dmabuf)) |
724 | return NULL; | |
725 | ||
f00b4dad DV |
726 | if (!dmabuf->ops->vmap) |
727 | return NULL; | |
728 | ||
729 | mutex_lock(&dmabuf->lock); | |
730 | if (dmabuf->vmapping_counter) { | |
731 | dmabuf->vmapping_counter++; | |
732 | BUG_ON(!dmabuf->vmap_ptr); | |
733 | ptr = dmabuf->vmap_ptr; | |
734 | goto out_unlock; | |
735 | } | |
736 | ||
737 | BUG_ON(dmabuf->vmap_ptr); | |
738 | ||
739 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
740 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
741 | ptr = NULL; | |
742 | if (!ptr) | |
f00b4dad DV |
743 | goto out_unlock; |
744 | ||
745 | dmabuf->vmap_ptr = ptr; | |
746 | dmabuf->vmapping_counter = 1; | |
747 | ||
748 | out_unlock: | |
749 | mutex_unlock(&dmabuf->lock); | |
750 | return ptr; | |
98f86c9e DA |
751 | } |
752 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
753 | ||
754 | /** | |
755 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 756 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 757 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
758 | */ |
759 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
760 | { | |
761 | if (WARN_ON(!dmabuf)) | |
762 | return; | |
763 | ||
f00b4dad DV |
764 | BUG_ON(!dmabuf->vmap_ptr); |
765 | BUG_ON(dmabuf->vmapping_counter == 0); | |
766 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
767 | ||
768 | mutex_lock(&dmabuf->lock); | |
769 | if (--dmabuf->vmapping_counter == 0) { | |
770 | if (dmabuf->ops->vunmap) | |
771 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
772 | dmabuf->vmap_ptr = NULL; | |
773 | } | |
774 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
775 | } |
776 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
777 | |
778 | #ifdef CONFIG_DEBUG_FS | |
779 | static int dma_buf_describe(struct seq_file *s) | |
780 | { | |
781 | int ret; | |
782 | struct dma_buf *buf_obj; | |
783 | struct dma_buf_attachment *attach_obj; | |
784 | int count = 0, attach_count; | |
785 | size_t size = 0; | |
786 | ||
787 | ret = mutex_lock_interruptible(&db_list.lock); | |
788 | ||
789 | if (ret) | |
790 | return ret; | |
791 | ||
c0b00a52 SS |
792 | seq_puts(s, "\nDma-buf Objects:\n"); |
793 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
794 | |
795 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
796 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
797 | ||
798 | if (ret) { | |
c0b00a52 SS |
799 | seq_puts(s, |
800 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
801 | continue; |
802 | } | |
803 | ||
c0b00a52 SS |
804 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
805 | buf_obj->size, | |
b89e3563 | 806 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 807 | file_count(buf_obj->file), |
c0b00a52 | 808 | buf_obj->exp_name); |
b89e3563 | 809 | |
c0b00a52 | 810 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
811 | attach_count = 0; |
812 | ||
813 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 814 | seq_puts(s, "\t"); |
b89e3563 | 815 | |
c0b00a52 | 816 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
817 | attach_count++; |
818 | } | |
819 | ||
c0b00a52 | 820 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
821 | attach_count); |
822 | ||
823 | count++; | |
824 | size += buf_obj->size; | |
825 | mutex_unlock(&buf_obj->lock); | |
826 | } | |
827 | ||
828 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
829 | ||
830 | mutex_unlock(&db_list.lock); | |
831 | return 0; | |
832 | } | |
833 | ||
834 | static int dma_buf_show(struct seq_file *s, void *unused) | |
835 | { | |
836 | void (*func)(struct seq_file *) = s->private; | |
837 | func(s); | |
838 | return 0; | |
839 | } | |
840 | ||
841 | static int dma_buf_debug_open(struct inode *inode, struct file *file) | |
842 | { | |
843 | return single_open(file, dma_buf_show, inode->i_private); | |
844 | } | |
845 | ||
846 | static const struct file_operations dma_buf_debug_fops = { | |
847 | .open = dma_buf_debug_open, | |
848 | .read = seq_read, | |
849 | .llseek = seq_lseek, | |
850 | .release = single_release, | |
851 | }; | |
852 | ||
853 | static struct dentry *dma_buf_debugfs_dir; | |
854 | ||
855 | static int dma_buf_init_debugfs(void) | |
856 | { | |
857 | int err = 0; | |
858 | dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); | |
859 | if (IS_ERR(dma_buf_debugfs_dir)) { | |
860 | err = PTR_ERR(dma_buf_debugfs_dir); | |
861 | dma_buf_debugfs_dir = NULL; | |
862 | return err; | |
863 | } | |
864 | ||
865 | err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); | |
866 | ||
867 | if (err) | |
868 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); | |
869 | ||
870 | return err; | |
871 | } | |
872 | ||
873 | static void dma_buf_uninit_debugfs(void) | |
874 | { | |
875 | if (dma_buf_debugfs_dir) | |
876 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
877 | } | |
878 | ||
879 | int dma_buf_debugfs_create_file(const char *name, | |
880 | int (*write)(struct seq_file *)) | |
881 | { | |
882 | struct dentry *d; | |
883 | ||
884 | d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, | |
885 | write, &dma_buf_debug_fops); | |
886 | ||
28ce4201 | 887 | return PTR_ERR_OR_ZERO(d); |
b89e3563 SS |
888 | } |
889 | #else | |
890 | static inline int dma_buf_init_debugfs(void) | |
891 | { | |
892 | return 0; | |
893 | } | |
894 | static inline void dma_buf_uninit_debugfs(void) | |
895 | { | |
896 | } | |
897 | #endif | |
898 | ||
899 | static int __init dma_buf_init(void) | |
900 | { | |
901 | mutex_init(&db_list.lock); | |
902 | INIT_LIST_HEAD(&db_list.head); | |
903 | dma_buf_init_debugfs(); | |
904 | return 0; | |
905 | } | |
906 | subsys_initcall(dma_buf_init); | |
907 | ||
908 | static void __exit dma_buf_deinit(void) | |
909 | { | |
910 | dma_buf_uninit_debugfs(); | |
911 | } | |
912 | __exitcall(dma_buf_deinit); |