Commit | Line | Data |
---|---|---|
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> |
b02da6f8 | 36 | #include <linux/mm.h> |
d15bd7ee | 37 | |
c11e391d DV |
38 | #include <uapi/linux/dma-buf.h> |
39 | ||
d15bd7ee SS |
40 | static inline int is_dma_buf_file(struct file *); |
41 | ||
b89e3563 SS |
42 | struct dma_buf_list { |
43 | struct list_head head; | |
44 | struct mutex lock; | |
45 | }; | |
46 | ||
47 | static struct dma_buf_list db_list; | |
48 | ||
d15bd7ee SS |
49 | static int dma_buf_release(struct inode *inode, struct file *file) |
50 | { | |
51 | struct dma_buf *dmabuf; | |
52 | ||
53 | if (!is_dma_buf_file(file)) | |
54 | return -EINVAL; | |
55 | ||
56 | dmabuf = file->private_data; | |
57 | ||
f00b4dad DV |
58 | BUG_ON(dmabuf->vmapping_counter); |
59 | ||
9b495a58 ML |
60 | /* |
61 | * Any fences that a dma-buf poll can wait on should be signaled | |
62 | * before releasing dma-buf. This is the responsibility of each | |
63 | * driver that uses the reservation objects. | |
64 | * | |
65 | * If you hit this BUG() it means someone dropped their ref to the | |
66 | * dma-buf while still having pending operation to the buffer. | |
67 | */ | |
68 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
69 | ||
d15bd7ee | 70 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
71 | |
72 | mutex_lock(&db_list.lock); | |
73 | list_del(&dmabuf->list_node); | |
74 | mutex_unlock(&db_list.lock); | |
75 | ||
3aac4502 ML |
76 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
77 | reservation_object_fini(dmabuf->resv); | |
78 | ||
9abdffe2 | 79 | module_put(dmabuf->owner); |
d15bd7ee SS |
80 | kfree(dmabuf); |
81 | return 0; | |
82 | } | |
83 | ||
4c78513e DV |
84 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
85 | { | |
86 | struct dma_buf *dmabuf; | |
87 | ||
88 | if (!is_dma_buf_file(file)) | |
89 | return -EINVAL; | |
90 | ||
91 | dmabuf = file->private_data; | |
92 | ||
93 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 94 | if (vma->vm_pgoff + vma_pages(vma) > |
4c78513e DV |
95 | dmabuf->size >> PAGE_SHIFT) |
96 | return -EINVAL; | |
97 | ||
98 | return dmabuf->ops->mmap(dmabuf, vma); | |
99 | } | |
100 | ||
19e8697b CJHR |
101 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
102 | { | |
103 | struct dma_buf *dmabuf; | |
104 | loff_t base; | |
105 | ||
106 | if (!is_dma_buf_file(file)) | |
107 | return -EBADF; | |
108 | ||
109 | dmabuf = file->private_data; | |
110 | ||
111 | /* only support discovering the end of the buffer, | |
112 | but also allow SEEK_SET to maintain the idiomatic | |
113 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
114 | if (whence == SEEK_END) | |
115 | base = dmabuf->size; | |
116 | else if (whence == SEEK_SET) | |
117 | base = 0; | |
118 | else | |
119 | return -EINVAL; | |
120 | ||
121 | if (offset != 0) | |
122 | return -EINVAL; | |
123 | ||
124 | return base + offset; | |
125 | } | |
126 | ||
9b495a58 ML |
127 | static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) |
128 | { | |
129 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
130 | unsigned long flags; | |
131 | ||
132 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
133 | wake_up_locked_poll(dcb->poll, dcb->active); | |
134 | dcb->active = 0; | |
135 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
136 | } | |
137 | ||
138 | static unsigned int dma_buf_poll(struct file *file, poll_table *poll) | |
139 | { | |
140 | struct dma_buf *dmabuf; | |
141 | struct reservation_object *resv; | |
04a5faa8 ML |
142 | struct reservation_object_list *fobj; |
143 | struct fence *fence_excl; | |
9b495a58 | 144 | unsigned long events; |
3c3b177a | 145 | unsigned shared_count, seq; |
9b495a58 ML |
146 | |
147 | dmabuf = file->private_data; | |
148 | if (!dmabuf || !dmabuf->resv) | |
149 | return POLLERR; | |
150 | ||
151 | resv = dmabuf->resv; | |
152 | ||
153 | poll_wait(file, &dmabuf->poll, poll); | |
154 | ||
155 | events = poll_requested_events(poll) & (POLLIN | POLLOUT); | |
156 | if (!events) | |
157 | return 0; | |
158 | ||
3c3b177a ML |
159 | retry: |
160 | seq = read_seqcount_begin(&resv->seq); | |
161 | rcu_read_lock(); | |
9b495a58 | 162 | |
3c3b177a ML |
163 | fobj = rcu_dereference(resv->fence); |
164 | if (fobj) | |
165 | shared_count = fobj->shared_count; | |
166 | else | |
167 | shared_count = 0; | |
168 | fence_excl = rcu_dereference(resv->fence_excl); | |
169 | if (read_seqcount_retry(&resv->seq, seq)) { | |
170 | rcu_read_unlock(); | |
171 | goto retry; | |
172 | } | |
04a5faa8 ML |
173 | |
174 | if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { | |
9b495a58 ML |
175 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
176 | unsigned long pevents = POLLIN; | |
177 | ||
04a5faa8 | 178 | if (shared_count == 0) |
9b495a58 ML |
179 | pevents |= POLLOUT; |
180 | ||
181 | spin_lock_irq(&dmabuf->poll.lock); | |
182 | if (dcb->active) { | |
183 | dcb->active |= pevents; | |
184 | events &= ~pevents; | |
185 | } else | |
186 | dcb->active = pevents; | |
187 | spin_unlock_irq(&dmabuf->poll.lock); | |
188 | ||
189 | if (events & pevents) { | |
3c3b177a ML |
190 | if (!fence_get_rcu(fence_excl)) { |
191 | /* force a recheck */ | |
192 | events &= ~pevents; | |
193 | dma_buf_poll_cb(NULL, &dcb->cb); | |
194 | } else if (!fence_add_callback(fence_excl, &dcb->cb, | |
04a5faa8 | 195 | dma_buf_poll_cb)) { |
9b495a58 | 196 | events &= ~pevents; |
3c3b177a | 197 | fence_put(fence_excl); |
04a5faa8 | 198 | } else { |
9b495a58 ML |
199 | /* |
200 | * No callback queued, wake up any additional | |
201 | * waiters. | |
202 | */ | |
3c3b177a | 203 | fence_put(fence_excl); |
9b495a58 | 204 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 205 | } |
9b495a58 ML |
206 | } |
207 | } | |
208 | ||
04a5faa8 | 209 | if ((events & POLLOUT) && shared_count > 0) { |
9b495a58 ML |
210 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
211 | int i; | |
212 | ||
213 | /* Only queue a new callback if no event has fired yet */ | |
214 | spin_lock_irq(&dmabuf->poll.lock); | |
215 | if (dcb->active) | |
216 | events &= ~POLLOUT; | |
217 | else | |
218 | dcb->active = POLLOUT; | |
219 | spin_unlock_irq(&dmabuf->poll.lock); | |
220 | ||
221 | if (!(events & POLLOUT)) | |
222 | goto out; | |
223 | ||
04a5faa8 | 224 | for (i = 0; i < shared_count; ++i) { |
3c3b177a | 225 | struct fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 226 | |
3c3b177a ML |
227 | if (!fence_get_rcu(fence)) { |
228 | /* | |
229 | * fence refcount dropped to zero, this means | |
230 | * that fobj has been freed | |
231 | * | |
232 | * call dma_buf_poll_cb and force a recheck! | |
233 | */ | |
234 | events &= ~POLLOUT; | |
235 | dma_buf_poll_cb(NULL, &dcb->cb); | |
236 | break; | |
237 | } | |
04a5faa8 ML |
238 | if (!fence_add_callback(fence, &dcb->cb, |
239 | dma_buf_poll_cb)) { | |
3c3b177a | 240 | fence_put(fence); |
9b495a58 ML |
241 | events &= ~POLLOUT; |
242 | break; | |
243 | } | |
3c3b177a | 244 | fence_put(fence); |
04a5faa8 | 245 | } |
9b495a58 ML |
246 | |
247 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 248 | if (i == shared_count) |
9b495a58 ML |
249 | dma_buf_poll_cb(NULL, &dcb->cb); |
250 | } | |
251 | ||
252 | out: | |
3c3b177a | 253 | rcu_read_unlock(); |
9b495a58 ML |
254 | return events; |
255 | } | |
256 | ||
c11e391d DV |
257 | static long dma_buf_ioctl(struct file *file, |
258 | unsigned int cmd, unsigned long arg) | |
259 | { | |
260 | struct dma_buf *dmabuf; | |
261 | struct dma_buf_sync sync; | |
262 | enum dma_data_direction direction; | |
18b862dc | 263 | int ret; |
c11e391d DV |
264 | |
265 | dmabuf = file->private_data; | |
266 | ||
267 | switch (cmd) { | |
268 | case DMA_BUF_IOCTL_SYNC: | |
269 | if (copy_from_user(&sync, (void __user *) arg, sizeof(sync))) | |
270 | return -EFAULT; | |
271 | ||
272 | if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK) | |
273 | return -EINVAL; | |
274 | ||
275 | switch (sync.flags & DMA_BUF_SYNC_RW) { | |
276 | case DMA_BUF_SYNC_READ: | |
277 | direction = DMA_FROM_DEVICE; | |
278 | break; | |
279 | case DMA_BUF_SYNC_WRITE: | |
280 | direction = DMA_TO_DEVICE; | |
281 | break; | |
282 | case DMA_BUF_SYNC_RW: | |
283 | direction = DMA_BIDIRECTIONAL; | |
284 | break; | |
285 | default: | |
286 | return -EINVAL; | |
287 | } | |
288 | ||
289 | if (sync.flags & DMA_BUF_SYNC_END) | |
18b862dc | 290 | ret = dma_buf_end_cpu_access(dmabuf, direction); |
c11e391d | 291 | else |
18b862dc | 292 | ret = dma_buf_begin_cpu_access(dmabuf, direction); |
c11e391d | 293 | |
18b862dc | 294 | return ret; |
c11e391d DV |
295 | default: |
296 | return -ENOTTY; | |
297 | } | |
298 | } | |
299 | ||
d15bd7ee SS |
300 | static const struct file_operations dma_buf_fops = { |
301 | .release = dma_buf_release, | |
4c78513e | 302 | .mmap = dma_buf_mmap_internal, |
19e8697b | 303 | .llseek = dma_buf_llseek, |
9b495a58 | 304 | .poll = dma_buf_poll, |
c11e391d | 305 | .unlocked_ioctl = dma_buf_ioctl, |
d15bd7ee SS |
306 | }; |
307 | ||
308 | /* | |
309 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
310 | */ | |
311 | static inline int is_dma_buf_file(struct file *file) | |
312 | { | |
313 | return file->f_op == &dma_buf_fops; | |
314 | } | |
315 | ||
316 | /** | |
d8fbe341 | 317 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
318 | * with this buffer, so it can be exported. |
319 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 320 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 321 | * |
d8fbe341 SS |
322 | * @exp_info: [in] holds all the export related information provided |
323 | * by the exporter. see struct dma_buf_export_info | |
324 | * for further details. | |
d15bd7ee SS |
325 | * |
326 | * Returns, on success, a newly created dma_buf object, which wraps the | |
327 | * supplied private data and operations for dma_buf_ops. On either missing | |
328 | * ops, or error in allocating struct dma_buf, will return negative error. | |
329 | * | |
330 | */ | |
d8fbe341 | 331 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
332 | { |
333 | struct dma_buf *dmabuf; | |
d8fbe341 | 334 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 335 | struct file *file; |
3aac4502 | 336 | size_t alloc_size = sizeof(struct dma_buf); |
a026df4c | 337 | int ret; |
5136629d | 338 | |
d8fbe341 | 339 | if (!exp_info->resv) |
3aac4502 ML |
340 | alloc_size += sizeof(struct reservation_object); |
341 | else | |
342 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
343 | alloc_size += 1; | |
d15bd7ee | 344 | |
d8fbe341 SS |
345 | if (WARN_ON(!exp_info->priv |
346 | || !exp_info->ops | |
347 | || !exp_info->ops->map_dma_buf | |
348 | || !exp_info->ops->unmap_dma_buf | |
349 | || !exp_info->ops->release | |
350 | || !exp_info->ops->kmap_atomic | |
351 | || !exp_info->ops->kmap | |
352 | || !exp_info->ops->mmap)) { | |
d15bd7ee SS |
353 | return ERR_PTR(-EINVAL); |
354 | } | |
355 | ||
9abdffe2 SS |
356 | if (!try_module_get(exp_info->owner)) |
357 | return ERR_PTR(-ENOENT); | |
358 | ||
3aac4502 | 359 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 | 360 | if (!dmabuf) { |
a026df4c CW |
361 | ret = -ENOMEM; |
362 | goto err_module; | |
9abdffe2 | 363 | } |
d15bd7ee | 364 | |
d8fbe341 SS |
365 | dmabuf->priv = exp_info->priv; |
366 | dmabuf->ops = exp_info->ops; | |
367 | dmabuf->size = exp_info->size; | |
368 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 369 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
370 | init_waitqueue_head(&dmabuf->poll); |
371 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
372 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
373 | ||
3aac4502 ML |
374 | if (!resv) { |
375 | resv = (struct reservation_object *)&dmabuf[1]; | |
376 | reservation_object_init(resv); | |
377 | } | |
378 | dmabuf->resv = resv; | |
d15bd7ee | 379 | |
d8fbe341 SS |
380 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
381 | exp_info->flags); | |
9022e24e | 382 | if (IS_ERR(file)) { |
a026df4c CW |
383 | ret = PTR_ERR(file); |
384 | goto err_dmabuf; | |
9022e24e | 385 | } |
19e8697b CJHR |
386 | |
387 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
388 | dmabuf->file = file; |
389 | ||
390 | mutex_init(&dmabuf->lock); | |
391 | INIT_LIST_HEAD(&dmabuf->attachments); | |
392 | ||
b89e3563 SS |
393 | mutex_lock(&db_list.lock); |
394 | list_add(&dmabuf->list_node, &db_list.head); | |
395 | mutex_unlock(&db_list.lock); | |
396 | ||
d15bd7ee | 397 | return dmabuf; |
a026df4c CW |
398 | |
399 | err_dmabuf: | |
400 | kfree(dmabuf); | |
401 | err_module: | |
402 | module_put(exp_info->owner); | |
403 | return ERR_PTR(ret); | |
d15bd7ee | 404 | } |
d8fbe341 | 405 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
406 | |
407 | /** | |
408 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
409 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 410 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
411 | * |
412 | * On success, returns an associated 'fd'. Else, returns error. | |
413 | */ | |
55c1c4ca | 414 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 415 | { |
f5e097f0 | 416 | int fd; |
d15bd7ee SS |
417 | |
418 | if (!dmabuf || !dmabuf->file) | |
419 | return -EINVAL; | |
420 | ||
f5e097f0 BP |
421 | fd = get_unused_fd_flags(flags); |
422 | if (fd < 0) | |
423 | return fd; | |
d15bd7ee SS |
424 | |
425 | fd_install(fd, dmabuf->file); | |
426 | ||
427 | return fd; | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
430 | ||
431 | /** | |
432 | * dma_buf_get - returns the dma_buf structure related to an fd | |
433 | * @fd: [in] fd associated with the dma_buf to be returned | |
434 | * | |
435 | * On success, returns the dma_buf structure associated with an fd; uses | |
436 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
437 | * otherwise. | |
438 | */ | |
439 | struct dma_buf *dma_buf_get(int fd) | |
440 | { | |
441 | struct file *file; | |
442 | ||
443 | file = fget(fd); | |
444 | ||
445 | if (!file) | |
446 | return ERR_PTR(-EBADF); | |
447 | ||
448 | if (!is_dma_buf_file(file)) { | |
449 | fput(file); | |
450 | return ERR_PTR(-EINVAL); | |
451 | } | |
452 | ||
453 | return file->private_data; | |
454 | } | |
455 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
456 | ||
457 | /** | |
458 | * dma_buf_put - decreases refcount of the buffer | |
459 | * @dmabuf: [in] buffer to reduce refcount of | |
460 | * | |
461 | * Uses file's refcounting done implicitly by fput() | |
462 | */ | |
463 | void dma_buf_put(struct dma_buf *dmabuf) | |
464 | { | |
465 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
466 | return; | |
467 | ||
468 | fput(dmabuf->file); | |
469 | } | |
470 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
471 | ||
472 | /** | |
473 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
474 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
475 | * @dmabuf: [in] buffer to attach device to. | |
476 | * @dev: [in] device to be attached. | |
477 | * | |
fee0c54e CC |
478 | * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on |
479 | * error. | |
d15bd7ee SS |
480 | */ |
481 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
482 | struct device *dev) | |
483 | { | |
484 | struct dma_buf_attachment *attach; | |
485 | int ret; | |
486 | ||
d1aa06a1 | 487 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
488 | return ERR_PTR(-EINVAL); |
489 | ||
490 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
491 | if (attach == NULL) | |
a9fbc3b7 | 492 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 493 | |
d15bd7ee SS |
494 | attach->dev = dev; |
495 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
496 | |
497 | mutex_lock(&dmabuf->lock); | |
498 | ||
d15bd7ee SS |
499 | if (dmabuf->ops->attach) { |
500 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
501 | if (ret) | |
502 | goto err_attach; | |
503 | } | |
504 | list_add(&attach->node, &dmabuf->attachments); | |
505 | ||
506 | mutex_unlock(&dmabuf->lock); | |
507 | return attach; | |
508 | ||
d15bd7ee SS |
509 | err_attach: |
510 | kfree(attach); | |
511 | mutex_unlock(&dmabuf->lock); | |
512 | return ERR_PTR(ret); | |
513 | } | |
514 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
515 | ||
516 | /** | |
517 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
518 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
519 | * @dmabuf: [in] buffer to detach from. | |
520 | * @attach: [in] attachment to be detached; is free'd after this call. | |
521 | * | |
522 | */ | |
523 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
524 | { | |
d1aa06a1 | 525 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
526 | return; |
527 | ||
528 | mutex_lock(&dmabuf->lock); | |
529 | list_del(&attach->node); | |
530 | if (dmabuf->ops->detach) | |
531 | dmabuf->ops->detach(dmabuf, attach); | |
532 | ||
533 | mutex_unlock(&dmabuf->lock); | |
534 | kfree(attach); | |
535 | } | |
536 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
537 | ||
538 | /** | |
539 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
540 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
541 | * dma_buf_ops. | |
542 | * @attach: [in] attachment whose scatterlist is to be returned | |
543 | * @direction: [in] direction of DMA transfer | |
544 | * | |
fee0c54e CC |
545 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
546 | * on error. | |
d15bd7ee SS |
547 | */ |
548 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
549 | enum dma_data_direction direction) | |
550 | { | |
551 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
552 | ||
553 | might_sleep(); | |
554 | ||
d1aa06a1 | 555 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
556 | return ERR_PTR(-EINVAL); |
557 | ||
d1aa06a1 | 558 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
559 | if (!sg_table) |
560 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
561 | |
562 | return sg_table; | |
563 | } | |
564 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
565 | ||
566 | /** | |
567 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
568 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
569 | * dma_buf_ops. | |
570 | * @attach: [in] attachment to unmap buffer from | |
571 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 572 | * @direction: [in] direction of DMA transfer |
d15bd7ee SS |
573 | * |
574 | */ | |
575 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
576 | struct sg_table *sg_table, |
577 | enum dma_data_direction direction) | |
d15bd7ee | 578 | { |
b6fa0cd6 RC |
579 | might_sleep(); |
580 | ||
d1aa06a1 | 581 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
582 | return; |
583 | ||
33ea2dcb SS |
584 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
585 | direction); | |
d15bd7ee SS |
586 | } |
587 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e DV |
588 | |
589 | ||
590 | /** | |
591 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
592 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
593 | * preparations. Coherency is only guaranteed in the specified range for the | |
594 | * specified access direction. | |
efb4df82 | 595 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
596 | * @direction: [in] length of range for cpu access. |
597 | * | |
598 | * Can return negative error values, returns 0 on success. | |
599 | */ | |
831e9da7 | 600 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
601 | enum dma_data_direction direction) |
602 | { | |
603 | int ret = 0; | |
604 | ||
605 | if (WARN_ON(!dmabuf)) | |
606 | return -EINVAL; | |
607 | ||
608 | if (dmabuf->ops->begin_cpu_access) | |
831e9da7 | 609 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e DV |
610 | |
611 | return ret; | |
612 | } | |
613 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
614 | ||
615 | /** | |
616 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
617 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
618 | * actions. Coherency is only guaranteed in the specified range for the | |
619 | * specified access direction. | |
efb4df82 | 620 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
621 | * @direction: [in] length of range for cpu access. |
622 | * | |
87e332d5 | 623 | * Can return negative error values, returns 0 on success. |
fc13020e | 624 | */ |
18b862dc CW |
625 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
626 | enum dma_data_direction direction) | |
fc13020e | 627 | { |
18b862dc CW |
628 | int ret = 0; |
629 | ||
fc13020e DV |
630 | WARN_ON(!dmabuf); |
631 | ||
632 | if (dmabuf->ops->end_cpu_access) | |
18b862dc CW |
633 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
634 | ||
635 | return ret; | |
fc13020e DV |
636 | } |
637 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
638 | ||
639 | /** | |
640 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
641 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 642 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
643 | * @page_num: [in] page in PAGE_SIZE units to map. |
644 | * | |
645 | * This call must always succeed, any necessary preparations that might fail | |
646 | * need to be done in begin_cpu_access. | |
647 | */ | |
648 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
649 | { | |
650 | WARN_ON(!dmabuf); | |
651 | ||
652 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
653 | } | |
654 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
655 | ||
656 | /** | |
657 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 658 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
659 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
660 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
661 | * | |
662 | * This call must always succeed. | |
663 | */ | |
664 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
665 | void *vaddr) | |
666 | { | |
667 | WARN_ON(!dmabuf); | |
668 | ||
669 | if (dmabuf->ops->kunmap_atomic) | |
670 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
671 | } | |
672 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
673 | ||
674 | /** | |
675 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
676 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 677 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
678 | * @page_num: [in] page in PAGE_SIZE units to map. |
679 | * | |
680 | * This call must always succeed, any necessary preparations that might fail | |
681 | * need to be done in begin_cpu_access. | |
682 | */ | |
683 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
684 | { | |
685 | WARN_ON(!dmabuf); | |
686 | ||
687 | return dmabuf->ops->kmap(dmabuf, page_num); | |
688 | } | |
689 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
690 | ||
691 | /** | |
692 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 693 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
694 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
695 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
696 | * | |
697 | * This call must always succeed. | |
698 | */ | |
699 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
700 | void *vaddr) | |
701 | { | |
702 | WARN_ON(!dmabuf); | |
703 | ||
704 | if (dmabuf->ops->kunmap) | |
705 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
706 | } | |
707 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
708 | |
709 | ||
710 | /** | |
711 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 712 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
713 | * @vma: [in] vma for the mmap |
714 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 715 | * dma-buf buffer. |
4c78513e DV |
716 | * |
717 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 718 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
719 | * checking on the size of the vma. Then it calls the exporters mmap function to |
720 | * set up the mapping. | |
721 | * | |
722 | * Can return negative error values, returns 0 on success. | |
723 | */ | |
724 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
725 | unsigned long pgoff) | |
726 | { | |
495c10cc JS |
727 | struct file *oldfile; |
728 | int ret; | |
729 | ||
4c78513e DV |
730 | if (WARN_ON(!dmabuf || !vma)) |
731 | return -EINVAL; | |
732 | ||
733 | /* check for offset overflow */ | |
b02da6f8 | 734 | if (pgoff + vma_pages(vma) < pgoff) |
4c78513e DV |
735 | return -EOVERFLOW; |
736 | ||
737 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 738 | if (pgoff + vma_pages(vma) > |
4c78513e DV |
739 | dmabuf->size >> PAGE_SHIFT) |
740 | return -EINVAL; | |
741 | ||
742 | /* readjust the vma */ | |
495c10cc JS |
743 | get_file(dmabuf->file); |
744 | oldfile = vma->vm_file; | |
745 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
746 | vma->vm_pgoff = pgoff; |
747 | ||
495c10cc JS |
748 | ret = dmabuf->ops->mmap(dmabuf, vma); |
749 | if (ret) { | |
750 | /* restore old parameters on failure */ | |
751 | vma->vm_file = oldfile; | |
752 | fput(dmabuf->file); | |
753 | } else { | |
754 | if (oldfile) | |
755 | fput(oldfile); | |
756 | } | |
757 | return ret; | |
758 | ||
4c78513e DV |
759 | } |
760 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
761 | |
762 | /** | |
12c4727e SS |
763 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
764 | * address space. Same restrictions as for vmap and friends apply. | |
765 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
766 | * |
767 | * This call may fail due to lack of virtual mapping address space. | |
768 | * These calls are optional in drivers. The intended use for them | |
769 | * is for mapping objects linear in kernel space for high use objects. | |
770 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
771 | * |
772 | * Returns NULL on error. | |
98f86c9e DA |
773 | */ |
774 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
775 | { | |
f00b4dad DV |
776 | void *ptr; |
777 | ||
98f86c9e DA |
778 | if (WARN_ON(!dmabuf)) |
779 | return NULL; | |
780 | ||
f00b4dad DV |
781 | if (!dmabuf->ops->vmap) |
782 | return NULL; | |
783 | ||
784 | mutex_lock(&dmabuf->lock); | |
785 | if (dmabuf->vmapping_counter) { | |
786 | dmabuf->vmapping_counter++; | |
787 | BUG_ON(!dmabuf->vmap_ptr); | |
788 | ptr = dmabuf->vmap_ptr; | |
789 | goto out_unlock; | |
790 | } | |
791 | ||
792 | BUG_ON(dmabuf->vmap_ptr); | |
793 | ||
794 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
795 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
796 | ptr = NULL; | |
797 | if (!ptr) | |
f00b4dad DV |
798 | goto out_unlock; |
799 | ||
800 | dmabuf->vmap_ptr = ptr; | |
801 | dmabuf->vmapping_counter = 1; | |
802 | ||
803 | out_unlock: | |
804 | mutex_unlock(&dmabuf->lock); | |
805 | return ptr; | |
98f86c9e DA |
806 | } |
807 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
808 | ||
809 | /** | |
810 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 811 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 812 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
813 | */ |
814 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
815 | { | |
816 | if (WARN_ON(!dmabuf)) | |
817 | return; | |
818 | ||
f00b4dad DV |
819 | BUG_ON(!dmabuf->vmap_ptr); |
820 | BUG_ON(dmabuf->vmapping_counter == 0); | |
821 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
822 | ||
823 | mutex_lock(&dmabuf->lock); | |
824 | if (--dmabuf->vmapping_counter == 0) { | |
825 | if (dmabuf->ops->vunmap) | |
826 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
827 | dmabuf->vmap_ptr = NULL; | |
828 | } | |
829 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
830 | } |
831 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
832 | |
833 | #ifdef CONFIG_DEBUG_FS | |
eb0b947e | 834 | static int dma_buf_debug_show(struct seq_file *s, void *unused) |
b89e3563 SS |
835 | { |
836 | int ret; | |
837 | struct dma_buf *buf_obj; | |
838 | struct dma_buf_attachment *attach_obj; | |
839 | int count = 0, attach_count; | |
840 | size_t size = 0; | |
841 | ||
842 | ret = mutex_lock_interruptible(&db_list.lock); | |
843 | ||
844 | if (ret) | |
845 | return ret; | |
846 | ||
c0b00a52 SS |
847 | seq_puts(s, "\nDma-buf Objects:\n"); |
848 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
849 | |
850 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
851 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
852 | ||
853 | if (ret) { | |
c0b00a52 SS |
854 | seq_puts(s, |
855 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
856 | continue; |
857 | } | |
858 | ||
c0b00a52 SS |
859 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
860 | buf_obj->size, | |
b89e3563 | 861 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 862 | file_count(buf_obj->file), |
c0b00a52 | 863 | buf_obj->exp_name); |
b89e3563 | 864 | |
c0b00a52 | 865 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
866 | attach_count = 0; |
867 | ||
868 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 869 | seq_puts(s, "\t"); |
b89e3563 | 870 | |
c0b00a52 | 871 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
872 | attach_count++; |
873 | } | |
874 | ||
c0b00a52 | 875 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
876 | attach_count); |
877 | ||
878 | count++; | |
879 | size += buf_obj->size; | |
880 | mutex_unlock(&buf_obj->lock); | |
881 | } | |
882 | ||
883 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
884 | ||
885 | mutex_unlock(&db_list.lock); | |
886 | return 0; | |
887 | } | |
888 | ||
b89e3563 SS |
889 | static int dma_buf_debug_open(struct inode *inode, struct file *file) |
890 | { | |
eb0b947e | 891 | return single_open(file, dma_buf_debug_show, NULL); |
b89e3563 SS |
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 | { | |
bd3e2208 | 905 | struct dentry *d; |
b89e3563 | 906 | int err = 0; |
5136629d | 907 | |
bd3e2208 MK |
908 | d = debugfs_create_dir("dma_buf", NULL); |
909 | if (IS_ERR(d)) | |
910 | return PTR_ERR(d); | |
5136629d | 911 | |
bd3e2208 | 912 | dma_buf_debugfs_dir = d; |
b89e3563 | 913 | |
bd3e2208 MK |
914 | d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, |
915 | NULL, &dma_buf_debug_fops); | |
916 | if (IS_ERR(d)) { | |
b89e3563 | 917 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); |
b7479990 MK |
918 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
919 | dma_buf_debugfs_dir = NULL; | |
bd3e2208 | 920 | err = PTR_ERR(d); |
b7479990 | 921 | } |
b89e3563 SS |
922 | |
923 | return err; | |
924 | } | |
925 | ||
926 | static void dma_buf_uninit_debugfs(void) | |
927 | { | |
928 | if (dma_buf_debugfs_dir) | |
929 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
930 | } | |
b89e3563 SS |
931 | #else |
932 | static inline int dma_buf_init_debugfs(void) | |
933 | { | |
934 | return 0; | |
935 | } | |
936 | static inline void dma_buf_uninit_debugfs(void) | |
937 | { | |
938 | } | |
939 | #endif | |
940 | ||
941 | static int __init dma_buf_init(void) | |
942 | { | |
943 | mutex_init(&db_list.lock); | |
944 | INIT_LIST_HEAD(&db_list.head); | |
945 | dma_buf_init_debugfs(); | |
946 | return 0; | |
947 | } | |
948 | subsys_initcall(dma_buf_init); | |
949 | ||
950 | static void __exit dma_buf_deinit(void) | |
951 | { | |
952 | dma_buf_uninit_debugfs(); | |
953 | } | |
954 | __exitcall(dma_buf_deinit); |