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 | 36 | |
c11e391d DV |
37 | #include <uapi/linux/dma-buf.h> |
38 | ||
d15bd7ee SS |
39 | static inline int is_dma_buf_file(struct file *); |
40 | ||
b89e3563 SS |
41 | struct dma_buf_list { |
42 | struct list_head head; | |
43 | struct mutex lock; | |
44 | }; | |
45 | ||
46 | static struct dma_buf_list db_list; | |
47 | ||
d15bd7ee SS |
48 | static int dma_buf_release(struct inode *inode, struct file *file) |
49 | { | |
50 | struct dma_buf *dmabuf; | |
51 | ||
52 | if (!is_dma_buf_file(file)) | |
53 | return -EINVAL; | |
54 | ||
55 | dmabuf = file->private_data; | |
56 | ||
f00b4dad DV |
57 | BUG_ON(dmabuf->vmapping_counter); |
58 | ||
9b495a58 ML |
59 | /* |
60 | * Any fences that a dma-buf poll can wait on should be signaled | |
61 | * before releasing dma-buf. This is the responsibility of each | |
62 | * driver that uses the reservation objects. | |
63 | * | |
64 | * If you hit this BUG() it means someone dropped their ref to the | |
65 | * dma-buf while still having pending operation to the buffer. | |
66 | */ | |
67 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
68 | ||
d15bd7ee | 69 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
70 | |
71 | mutex_lock(&db_list.lock); | |
72 | list_del(&dmabuf->list_node); | |
73 | mutex_unlock(&db_list.lock); | |
74 | ||
3aac4502 ML |
75 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
76 | reservation_object_fini(dmabuf->resv); | |
77 | ||
9abdffe2 | 78 | module_put(dmabuf->owner); |
d15bd7ee SS |
79 | kfree(dmabuf); |
80 | return 0; | |
81 | } | |
82 | ||
4c78513e DV |
83 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
84 | { | |
85 | struct dma_buf *dmabuf; | |
86 | ||
87 | if (!is_dma_buf_file(file)) | |
88 | return -EINVAL; | |
89 | ||
90 | dmabuf = file->private_data; | |
91 | ||
92 | /* check for overflowing the buffer's size */ | |
93 | if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
94 | dmabuf->size >> PAGE_SHIFT) | |
95 | return -EINVAL; | |
96 | ||
97 | return dmabuf->ops->mmap(dmabuf, vma); | |
98 | } | |
99 | ||
19e8697b CJHR |
100 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
101 | { | |
102 | struct dma_buf *dmabuf; | |
103 | loff_t base; | |
104 | ||
105 | if (!is_dma_buf_file(file)) | |
106 | return -EBADF; | |
107 | ||
108 | dmabuf = file->private_data; | |
109 | ||
110 | /* only support discovering the end of the buffer, | |
111 | but also allow SEEK_SET to maintain the idiomatic | |
112 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
113 | if (whence == SEEK_END) | |
114 | base = dmabuf->size; | |
115 | else if (whence == SEEK_SET) | |
116 | base = 0; | |
117 | else | |
118 | return -EINVAL; | |
119 | ||
120 | if (offset != 0) | |
121 | return -EINVAL; | |
122 | ||
123 | return base + offset; | |
124 | } | |
125 | ||
9b495a58 ML |
126 | static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) |
127 | { | |
128 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
129 | unsigned long flags; | |
130 | ||
131 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
132 | wake_up_locked_poll(dcb->poll, dcb->active); | |
133 | dcb->active = 0; | |
134 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
135 | } | |
136 | ||
137 | static unsigned int dma_buf_poll(struct file *file, poll_table *poll) | |
138 | { | |
139 | struct dma_buf *dmabuf; | |
140 | struct reservation_object *resv; | |
04a5faa8 ML |
141 | struct reservation_object_list *fobj; |
142 | struct fence *fence_excl; | |
9b495a58 | 143 | unsigned long events; |
3c3b177a | 144 | unsigned shared_count, seq; |
9b495a58 ML |
145 | |
146 | dmabuf = file->private_data; | |
147 | if (!dmabuf || !dmabuf->resv) | |
148 | return POLLERR; | |
149 | ||
150 | resv = dmabuf->resv; | |
151 | ||
152 | poll_wait(file, &dmabuf->poll, poll); | |
153 | ||
154 | events = poll_requested_events(poll) & (POLLIN | POLLOUT); | |
155 | if (!events) | |
156 | return 0; | |
157 | ||
3c3b177a ML |
158 | retry: |
159 | seq = read_seqcount_begin(&resv->seq); | |
160 | rcu_read_lock(); | |
9b495a58 | 161 | |
3c3b177a ML |
162 | fobj = rcu_dereference(resv->fence); |
163 | if (fobj) | |
164 | shared_count = fobj->shared_count; | |
165 | else | |
166 | shared_count = 0; | |
167 | fence_excl = rcu_dereference(resv->fence_excl); | |
168 | if (read_seqcount_retry(&resv->seq, seq)) { | |
169 | rcu_read_unlock(); | |
170 | goto retry; | |
171 | } | |
04a5faa8 ML |
172 | |
173 | if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { | |
9b495a58 ML |
174 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
175 | unsigned long pevents = POLLIN; | |
176 | ||
04a5faa8 | 177 | if (shared_count == 0) |
9b495a58 ML |
178 | pevents |= POLLOUT; |
179 | ||
180 | spin_lock_irq(&dmabuf->poll.lock); | |
181 | if (dcb->active) { | |
182 | dcb->active |= pevents; | |
183 | events &= ~pevents; | |
184 | } else | |
185 | dcb->active = pevents; | |
186 | spin_unlock_irq(&dmabuf->poll.lock); | |
187 | ||
188 | if (events & pevents) { | |
3c3b177a ML |
189 | if (!fence_get_rcu(fence_excl)) { |
190 | /* force a recheck */ | |
191 | events &= ~pevents; | |
192 | dma_buf_poll_cb(NULL, &dcb->cb); | |
193 | } else if (!fence_add_callback(fence_excl, &dcb->cb, | |
04a5faa8 | 194 | dma_buf_poll_cb)) { |
9b495a58 | 195 | events &= ~pevents; |
3c3b177a | 196 | fence_put(fence_excl); |
04a5faa8 | 197 | } else { |
9b495a58 ML |
198 | /* |
199 | * No callback queued, wake up any additional | |
200 | * waiters. | |
201 | */ | |
3c3b177a | 202 | fence_put(fence_excl); |
9b495a58 | 203 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 204 | } |
9b495a58 ML |
205 | } |
206 | } | |
207 | ||
04a5faa8 | 208 | if ((events & POLLOUT) && shared_count > 0) { |
9b495a58 ML |
209 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
210 | int i; | |
211 | ||
212 | /* Only queue a new callback if no event has fired yet */ | |
213 | spin_lock_irq(&dmabuf->poll.lock); | |
214 | if (dcb->active) | |
215 | events &= ~POLLOUT; | |
216 | else | |
217 | dcb->active = POLLOUT; | |
218 | spin_unlock_irq(&dmabuf->poll.lock); | |
219 | ||
220 | if (!(events & POLLOUT)) | |
221 | goto out; | |
222 | ||
04a5faa8 | 223 | for (i = 0; i < shared_count; ++i) { |
3c3b177a | 224 | struct fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 225 | |
3c3b177a ML |
226 | if (!fence_get_rcu(fence)) { |
227 | /* | |
228 | * fence refcount dropped to zero, this means | |
229 | * that fobj has been freed | |
230 | * | |
231 | * call dma_buf_poll_cb and force a recheck! | |
232 | */ | |
233 | events &= ~POLLOUT; | |
234 | dma_buf_poll_cb(NULL, &dcb->cb); | |
235 | break; | |
236 | } | |
04a5faa8 ML |
237 | if (!fence_add_callback(fence, &dcb->cb, |
238 | dma_buf_poll_cb)) { | |
3c3b177a | 239 | fence_put(fence); |
9b495a58 ML |
240 | events &= ~POLLOUT; |
241 | break; | |
242 | } | |
3c3b177a | 243 | fence_put(fence); |
04a5faa8 | 244 | } |
9b495a58 ML |
245 | |
246 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 247 | if (i == shared_count) |
9b495a58 ML |
248 | dma_buf_poll_cb(NULL, &dcb->cb); |
249 | } | |
250 | ||
251 | out: | |
3c3b177a | 252 | rcu_read_unlock(); |
9b495a58 ML |
253 | return events; |
254 | } | |
255 | ||
c11e391d DV |
256 | static long dma_buf_ioctl(struct file *file, |
257 | unsigned int cmd, unsigned long arg) | |
258 | { | |
259 | struct dma_buf *dmabuf; | |
260 | struct dma_buf_sync sync; | |
261 | enum dma_data_direction direction; | |
18b862dc | 262 | int ret; |
c11e391d DV |
263 | |
264 | dmabuf = file->private_data; | |
265 | ||
266 | switch (cmd) { | |
267 | case DMA_BUF_IOCTL_SYNC: | |
268 | if (copy_from_user(&sync, (void __user *) arg, sizeof(sync))) | |
269 | return -EFAULT; | |
270 | ||
271 | if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK) | |
272 | return -EINVAL; | |
273 | ||
274 | switch (sync.flags & DMA_BUF_SYNC_RW) { | |
275 | case DMA_BUF_SYNC_READ: | |
276 | direction = DMA_FROM_DEVICE; | |
277 | break; | |
278 | case DMA_BUF_SYNC_WRITE: | |
279 | direction = DMA_TO_DEVICE; | |
280 | break; | |
281 | case DMA_BUF_SYNC_RW: | |
282 | direction = DMA_BIDIRECTIONAL; | |
283 | break; | |
284 | default: | |
285 | return -EINVAL; | |
286 | } | |
287 | ||
288 | if (sync.flags & DMA_BUF_SYNC_END) | |
18b862dc | 289 | ret = dma_buf_end_cpu_access(dmabuf, direction); |
c11e391d | 290 | else |
18b862dc | 291 | ret = dma_buf_begin_cpu_access(dmabuf, direction); |
c11e391d | 292 | |
18b862dc | 293 | return ret; |
c11e391d DV |
294 | default: |
295 | return -ENOTTY; | |
296 | } | |
297 | } | |
298 | ||
d15bd7ee SS |
299 | static const struct file_operations dma_buf_fops = { |
300 | .release = dma_buf_release, | |
4c78513e | 301 | .mmap = dma_buf_mmap_internal, |
19e8697b | 302 | .llseek = dma_buf_llseek, |
9b495a58 | 303 | .poll = dma_buf_poll, |
c11e391d | 304 | .unlocked_ioctl = dma_buf_ioctl, |
d15bd7ee SS |
305 | }; |
306 | ||
307 | /* | |
308 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
309 | */ | |
310 | static inline int is_dma_buf_file(struct file *file) | |
311 | { | |
312 | return file->f_op == &dma_buf_fops; | |
313 | } | |
314 | ||
315 | /** | |
d8fbe341 | 316 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
317 | * with this buffer, so it can be exported. |
318 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 319 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 320 | * |
d8fbe341 SS |
321 | * @exp_info: [in] holds all the export related information provided |
322 | * by the exporter. see struct dma_buf_export_info | |
323 | * for further details. | |
d15bd7ee SS |
324 | * |
325 | * Returns, on success, a newly created dma_buf object, which wraps the | |
326 | * supplied private data and operations for dma_buf_ops. On either missing | |
327 | * ops, or error in allocating struct dma_buf, will return negative error. | |
328 | * | |
329 | */ | |
d8fbe341 | 330 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
331 | { |
332 | struct dma_buf *dmabuf; | |
d8fbe341 | 333 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 334 | struct file *file; |
3aac4502 | 335 | size_t alloc_size = sizeof(struct dma_buf); |
5136629d | 336 | |
d8fbe341 | 337 | if (!exp_info->resv) |
3aac4502 ML |
338 | alloc_size += sizeof(struct reservation_object); |
339 | else | |
340 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
341 | alloc_size += 1; | |
d15bd7ee | 342 | |
d8fbe341 SS |
343 | if (WARN_ON(!exp_info->priv |
344 | || !exp_info->ops | |
345 | || !exp_info->ops->map_dma_buf | |
346 | || !exp_info->ops->unmap_dma_buf | |
347 | || !exp_info->ops->release | |
348 | || !exp_info->ops->kmap_atomic | |
349 | || !exp_info->ops->kmap | |
350 | || !exp_info->ops->mmap)) { | |
d15bd7ee SS |
351 | return ERR_PTR(-EINVAL); |
352 | } | |
353 | ||
9abdffe2 SS |
354 | if (!try_module_get(exp_info->owner)) |
355 | return ERR_PTR(-ENOENT); | |
356 | ||
3aac4502 | 357 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 SS |
358 | if (!dmabuf) { |
359 | module_put(exp_info->owner); | |
d15bd7ee | 360 | return ERR_PTR(-ENOMEM); |
9abdffe2 | 361 | } |
d15bd7ee | 362 | |
d8fbe341 SS |
363 | dmabuf->priv = exp_info->priv; |
364 | dmabuf->ops = exp_info->ops; | |
365 | dmabuf->size = exp_info->size; | |
366 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 367 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
368 | init_waitqueue_head(&dmabuf->poll); |
369 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
370 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
371 | ||
3aac4502 ML |
372 | if (!resv) { |
373 | resv = (struct reservation_object *)&dmabuf[1]; | |
374 | reservation_object_init(resv); | |
375 | } | |
376 | dmabuf->resv = resv; | |
d15bd7ee | 377 | |
d8fbe341 SS |
378 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
379 | exp_info->flags); | |
9022e24e TT |
380 | if (IS_ERR(file)) { |
381 | kfree(dmabuf); | |
382 | return ERR_CAST(file); | |
383 | } | |
19e8697b CJHR |
384 | |
385 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
386 | dmabuf->file = file; |
387 | ||
388 | mutex_init(&dmabuf->lock); | |
389 | INIT_LIST_HEAD(&dmabuf->attachments); | |
390 | ||
b89e3563 SS |
391 | mutex_lock(&db_list.lock); |
392 | list_add(&dmabuf->list_node, &db_list.head); | |
393 | mutex_unlock(&db_list.lock); | |
394 | ||
d15bd7ee SS |
395 | return dmabuf; |
396 | } | |
d8fbe341 | 397 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
398 | |
399 | /** | |
400 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
401 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 402 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
403 | * |
404 | * On success, returns an associated 'fd'. Else, returns error. | |
405 | */ | |
55c1c4ca | 406 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 407 | { |
f5e097f0 | 408 | int fd; |
d15bd7ee SS |
409 | |
410 | if (!dmabuf || !dmabuf->file) | |
411 | return -EINVAL; | |
412 | ||
f5e097f0 BP |
413 | fd = get_unused_fd_flags(flags); |
414 | if (fd < 0) | |
415 | return fd; | |
d15bd7ee SS |
416 | |
417 | fd_install(fd, dmabuf->file); | |
418 | ||
419 | return fd; | |
420 | } | |
421 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
422 | ||
423 | /** | |
424 | * dma_buf_get - returns the dma_buf structure related to an fd | |
425 | * @fd: [in] fd associated with the dma_buf to be returned | |
426 | * | |
427 | * On success, returns the dma_buf structure associated with an fd; uses | |
428 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
429 | * otherwise. | |
430 | */ | |
431 | struct dma_buf *dma_buf_get(int fd) | |
432 | { | |
433 | struct file *file; | |
434 | ||
435 | file = fget(fd); | |
436 | ||
437 | if (!file) | |
438 | return ERR_PTR(-EBADF); | |
439 | ||
440 | if (!is_dma_buf_file(file)) { | |
441 | fput(file); | |
442 | return ERR_PTR(-EINVAL); | |
443 | } | |
444 | ||
445 | return file->private_data; | |
446 | } | |
447 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
448 | ||
449 | /** | |
450 | * dma_buf_put - decreases refcount of the buffer | |
451 | * @dmabuf: [in] buffer to reduce refcount of | |
452 | * | |
453 | * Uses file's refcounting done implicitly by fput() | |
454 | */ | |
455 | void dma_buf_put(struct dma_buf *dmabuf) | |
456 | { | |
457 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
458 | return; | |
459 | ||
460 | fput(dmabuf->file); | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
463 | ||
464 | /** | |
465 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
466 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
467 | * @dmabuf: [in] buffer to attach device to. | |
468 | * @dev: [in] device to be attached. | |
469 | * | |
fee0c54e CC |
470 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
471 | * error. | |
d15bd7ee SS |
472 | */ |
473 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
474 | struct device *dev) | |
475 | { | |
476 | struct dma_buf_attachment *attach; | |
477 | int ret; | |
478 | ||
d1aa06a1 | 479 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
480 | return ERR_PTR(-EINVAL); |
481 | ||
482 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
483 | if (attach == NULL) | |
a9fbc3b7 | 484 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 485 | |
d15bd7ee SS |
486 | attach->dev = dev; |
487 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
488 | |
489 | mutex_lock(&dmabuf->lock); | |
490 | ||
d15bd7ee SS |
491 | if (dmabuf->ops->attach) { |
492 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
493 | if (ret) | |
494 | goto err_attach; | |
495 | } | |
496 | list_add(&attach->node, &dmabuf->attachments); | |
497 | ||
498 | mutex_unlock(&dmabuf->lock); | |
499 | return attach; | |
500 | ||
d15bd7ee SS |
501 | err_attach: |
502 | kfree(attach); | |
503 | mutex_unlock(&dmabuf->lock); | |
504 | return ERR_PTR(ret); | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
507 | ||
508 | /** | |
509 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
510 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
511 | * @dmabuf: [in] buffer to detach from. | |
512 | * @attach: [in] attachment to be detached; is free'd after this call. | |
513 | * | |
514 | */ | |
515 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
516 | { | |
d1aa06a1 | 517 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
518 | return; |
519 | ||
520 | mutex_lock(&dmabuf->lock); | |
521 | list_del(&attach->node); | |
522 | if (dmabuf->ops->detach) | |
523 | dmabuf->ops->detach(dmabuf, attach); | |
524 | ||
525 | mutex_unlock(&dmabuf->lock); | |
526 | kfree(attach); | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
529 | ||
530 | /** | |
531 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
532 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
533 | * dma_buf_ops. | |
534 | * @attach: [in] attachment whose scatterlist is to be returned | |
535 | * @direction: [in] direction of DMA transfer | |
536 | * | |
fee0c54e CC |
537 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
538 | * on error. | |
d15bd7ee SS |
539 | */ |
540 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
541 | enum dma_data_direction direction) | |
542 | { | |
543 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
544 | ||
545 | might_sleep(); | |
546 | ||
d1aa06a1 | 547 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
548 | return ERR_PTR(-EINVAL); |
549 | ||
d1aa06a1 | 550 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
551 | if (!sg_table) |
552 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
553 | |
554 | return sg_table; | |
555 | } | |
556 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
557 | ||
558 | /** | |
559 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
560 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
561 | * dma_buf_ops. | |
562 | * @attach: [in] attachment to unmap buffer from | |
563 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 564 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
565 | * |
566 | */ | |
567 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
568 | struct sg_table *sg_table, |
569 | enum dma_data_direction direction) | |
d15bd7ee | 570 | { |
b6fa0cd6 RC |
571 | might_sleep(); |
572 | ||
d1aa06a1 | 573 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
574 | return; |
575 | ||
33ea2dcb SS |
576 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
577 | direction); | |
d15bd7ee SS |
578 | } |
579 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
580 | |
581 | ||
582 | /** | |
583 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
584 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
585 | * preparations. Coherency is only guaranteed in the specified range for the | |
586 | * specified access direction. | |
efb4df82 | 587 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
588 | * @direction: [in] length of range for cpu access. |
589 | * | |
590 | * Can return negative error values, returns 0 on success. | |
591 | */ | |
831e9da7 | 592 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
593 | enum dma_data_direction direction) |
594 | { | |
595 | int ret = 0; | |
596 | ||
597 | if (WARN_ON(!dmabuf)) | |
598 | return -EINVAL; | |
599 | ||
600 | if (dmabuf->ops->begin_cpu_access) | |
831e9da7 | 601 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e DV |
602 | |
603 | return ret; | |
604 | } | |
605 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
606 | ||
607 | /** | |
608 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
609 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
610 | * actions. Coherency is only guaranteed in the specified range for the | |
611 | * specified access direction. | |
efb4df82 | 612 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
613 | * @direction: [in] length of range for cpu access. |
614 | * | |
87e332d5 | 615 | * Can return negative error values, returns 0 on success. |
fc13020e | 616 | */ |
18b862dc CW |
617 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
618 | enum dma_data_direction direction) | |
fc13020e | 619 | { |
18b862dc CW |
620 | int ret = 0; |
621 | ||
fc13020e DV |
622 | WARN_ON(!dmabuf); |
623 | ||
624 | if (dmabuf->ops->end_cpu_access) | |
18b862dc CW |
625 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
626 | ||
627 | return ret; | |
fc13020e DV |
628 | } |
629 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
630 | ||
631 | /** | |
632 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
633 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 634 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
635 | * @page_num: [in] page in PAGE_SIZE units to map. |
636 | * | |
637 | * This call must always succeed, any necessary preparations that might fail | |
638 | * need to be done in begin_cpu_access. | |
639 | */ | |
640 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
641 | { | |
642 | WARN_ON(!dmabuf); | |
643 | ||
644 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
645 | } | |
646 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
647 | ||
648 | /** | |
649 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 650 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
651 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
652 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
653 | * | |
654 | * This call must always succeed. | |
655 | */ | |
656 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
657 | void *vaddr) | |
658 | { | |
659 | WARN_ON(!dmabuf); | |
660 | ||
661 | if (dmabuf->ops->kunmap_atomic) | |
662 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
663 | } | |
664 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
665 | ||
666 | /** | |
667 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
668 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 669 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
670 | * @page_num: [in] page in PAGE_SIZE units to map. |
671 | * | |
672 | * This call must always succeed, any necessary preparations that might fail | |
673 | * need to be done in begin_cpu_access. | |
674 | */ | |
675 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
676 | { | |
677 | WARN_ON(!dmabuf); | |
678 | ||
679 | return dmabuf->ops->kmap(dmabuf, page_num); | |
680 | } | |
681 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
682 | ||
683 | /** | |
684 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 685 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
686 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
687 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
688 | * | |
689 | * This call must always succeed. | |
690 | */ | |
691 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
692 | void *vaddr) | |
693 | { | |
694 | WARN_ON(!dmabuf); | |
695 | ||
696 | if (dmabuf->ops->kunmap) | |
697 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
698 | } | |
699 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
700 | |
701 | ||
702 | /** | |
703 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 704 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
705 | * @vma: [in] vma for the mmap |
706 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 707 | * dma-buf buffer. |
4c78513e DV |
708 | * |
709 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 710 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
711 | * checking on the size of the vma. Then it calls the exporters mmap function to |
712 | * set up the mapping. | |
713 | * | |
714 | * Can return negative error values, returns 0 on success. | |
715 | */ | |
716 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
717 | unsigned long pgoff) | |
718 | { | |
495c10cc JS |
719 | struct file *oldfile; |
720 | int ret; | |
721 | ||
4c78513e DV |
722 | if (WARN_ON(!dmabuf || !vma)) |
723 | return -EINVAL; | |
724 | ||
725 | /* check for offset overflow */ | |
726 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) | |
727 | return -EOVERFLOW; | |
728 | ||
729 | /* check for overflowing the buffer's size */ | |
730 | if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > | |
731 | dmabuf->size >> PAGE_SHIFT) | |
732 | return -EINVAL; | |
733 | ||
734 | /* readjust the vma */ | |
495c10cc JS |
735 | get_file(dmabuf->file); |
736 | oldfile = vma->vm_file; | |
737 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
738 | vma->vm_pgoff = pgoff; |
739 | ||
495c10cc JS |
740 | ret = dmabuf->ops->mmap(dmabuf, vma); |
741 | if (ret) { | |
742 | /* restore old parameters on failure */ | |
743 | vma->vm_file = oldfile; | |
744 | fput(dmabuf->file); | |
745 | } else { | |
746 | if (oldfile) | |
747 | fput(oldfile); | |
748 | } | |
749 | return ret; | |
750 | ||
4c78513e DV |
751 | } |
752 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
753 | |
754 | /** | |
12c4727e SS |
755 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
756 | * address space. Same restrictions as for vmap and friends apply. | |
757 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
758 | * |
759 | * This call may fail due to lack of virtual mapping address space. | |
760 | * These calls are optional in drivers. The intended use for them | |
761 | * is for mapping objects linear in kernel space for high use objects. | |
762 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
763 | * |
764 | * Returns NULL on error. | |
98f86c9e DA |
765 | */ |
766 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
767 | { | |
f00b4dad DV |
768 | void *ptr; |
769 | ||
98f86c9e DA |
770 | if (WARN_ON(!dmabuf)) |
771 | return NULL; | |
772 | ||
f00b4dad DV |
773 | if (!dmabuf->ops->vmap) |
774 | return NULL; | |
775 | ||
776 | mutex_lock(&dmabuf->lock); | |
777 | if (dmabuf->vmapping_counter) { | |
778 | dmabuf->vmapping_counter++; | |
779 | BUG_ON(!dmabuf->vmap_ptr); | |
780 | ptr = dmabuf->vmap_ptr; | |
781 | goto out_unlock; | |
782 | } | |
783 | ||
784 | BUG_ON(dmabuf->vmap_ptr); | |
785 | ||
786 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
787 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
788 | ptr = NULL; | |
789 | if (!ptr) | |
f00b4dad DV |
790 | goto out_unlock; |
791 | ||
792 | dmabuf->vmap_ptr = ptr; | |
793 | dmabuf->vmapping_counter = 1; | |
794 | ||
795 | out_unlock: | |
796 | mutex_unlock(&dmabuf->lock); | |
797 | return ptr; | |
98f86c9e DA |
798 | } |
799 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
800 | ||
801 | /** | |
802 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 803 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 804 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
805 | */ |
806 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
807 | { | |
808 | if (WARN_ON(!dmabuf)) | |
809 | return; | |
810 | ||
f00b4dad DV |
811 | BUG_ON(!dmabuf->vmap_ptr); |
812 | BUG_ON(dmabuf->vmapping_counter == 0); | |
813 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
814 | ||
815 | mutex_lock(&dmabuf->lock); | |
816 | if (--dmabuf->vmapping_counter == 0) { | |
817 | if (dmabuf->ops->vunmap) | |
818 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
819 | dmabuf->vmap_ptr = NULL; | |
820 | } | |
821 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
822 | } |
823 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
824 | |
825 | #ifdef CONFIG_DEBUG_FS | |
826 | static int dma_buf_describe(struct seq_file *s) | |
827 | { | |
828 | int ret; | |
829 | struct dma_buf *buf_obj; | |
830 | struct dma_buf_attachment *attach_obj; | |
831 | int count = 0, attach_count; | |
832 | size_t size = 0; | |
833 | ||
834 | ret = mutex_lock_interruptible(&db_list.lock); | |
835 | ||
836 | if (ret) | |
837 | return ret; | |
838 | ||
c0b00a52 SS |
839 | seq_puts(s, "\nDma-buf Objects:\n"); |
840 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
841 | |
842 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
843 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
844 | ||
845 | if (ret) { | |
c0b00a52 SS |
846 | seq_puts(s, |
847 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
848 | continue; |
849 | } | |
850 | ||
c0b00a52 SS |
851 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
852 | buf_obj->size, | |
b89e3563 | 853 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 854 | file_count(buf_obj->file), |
c0b00a52 | 855 | buf_obj->exp_name); |
b89e3563 | 856 | |
c0b00a52 | 857 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
858 | attach_count = 0; |
859 | ||
860 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 861 | seq_puts(s, "\t"); |
b89e3563 | 862 | |
c0b00a52 | 863 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
864 | attach_count++; |
865 | } | |
866 | ||
c0b00a52 | 867 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
868 | attach_count); |
869 | ||
870 | count++; | |
871 | size += buf_obj->size; | |
872 | mutex_unlock(&buf_obj->lock); | |
873 | } | |
874 | ||
875 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
876 | ||
877 | mutex_unlock(&db_list.lock); | |
878 | return 0; | |
879 | } | |
880 | ||
881 | static int dma_buf_show(struct seq_file *s, void *unused) | |
882 | { | |
883 | void (*func)(struct seq_file *) = s->private; | |
5136629d | 884 | |
b89e3563 SS |
885 | func(s); |
886 | return 0; | |
887 | } | |
888 | ||
889 | static int dma_buf_debug_open(struct inode *inode, struct file *file) | |
890 | { | |
891 | return single_open(file, dma_buf_show, inode->i_private); | |
892 | } | |
893 | ||
894 | static const struct file_operations dma_buf_debug_fops = { | |
895 | .open = dma_buf_debug_open, | |
896 | .read = seq_read, | |
897 | .llseek = seq_lseek, | |
898 | .release = single_release, | |
899 | }; | |
900 | ||
901 | static struct dentry *dma_buf_debugfs_dir; | |
902 | ||
903 | static int dma_buf_init_debugfs(void) | |
904 | { | |
905 | int err = 0; | |
5136629d | 906 | |
b89e3563 | 907 | dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); |
5136629d | 908 | |
b89e3563 SS |
909 | if (IS_ERR(dma_buf_debugfs_dir)) { |
910 | err = PTR_ERR(dma_buf_debugfs_dir); | |
911 | dma_buf_debugfs_dir = NULL; | |
912 | return err; | |
913 | } | |
914 | ||
915 | err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); | |
916 | ||
917 | if (err) | |
918 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); | |
919 | ||
920 | return err; | |
921 | } | |
922 | ||
923 | static void dma_buf_uninit_debugfs(void) | |
924 | { | |
925 | if (dma_buf_debugfs_dir) | |
926 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
927 | } | |
928 | ||
929 | int dma_buf_debugfs_create_file(const char *name, | |
930 | int (*write)(struct seq_file *)) | |
931 | { | |
932 | struct dentry *d; | |
933 | ||
934 | d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, | |
935 | write, &dma_buf_debug_fops); | |
936 | ||
28ce4201 | 937 | return PTR_ERR_OR_ZERO(d); |
b89e3563 SS |
938 | } |
939 | #else | |
940 | static inline int dma_buf_init_debugfs(void) | |
941 | { | |
942 | return 0; | |
943 | } | |
944 | static inline void dma_buf_uninit_debugfs(void) | |
945 | { | |
946 | } | |
947 | #endif | |
948 | ||
949 | static int __init dma_buf_init(void) | |
950 | { | |
951 | mutex_init(&db_list.lock); | |
952 | INIT_LIST_HEAD(&db_list.head); | |
953 | dma_buf_init_debugfs(); | |
954 | return 0; | |
955 | } | |
956 | subsys_initcall(dma_buf_init); | |
957 | ||
958 | static void __exit dma_buf_deinit(void) | |
959 | { | |
960 | dma_buf_uninit_debugfs(); | |
961 | } | |
962 | __exitcall(dma_buf_deinit); |