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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> | |
f54d1867 | 28 | #include <linux/dma-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 | ||
f54d1867 | 127 | static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb) |
9b495a58 ML |
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 | 142 | struct reservation_object_list *fobj; |
f54d1867 | 143 | struct dma_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) { | |
f54d1867 | 190 | if (!dma_fence_get_rcu(fence_excl)) { |
3c3b177a ML |
191 | /* force a recheck */ |
192 | events &= ~pevents; | |
193 | dma_buf_poll_cb(NULL, &dcb->cb); | |
f54d1867 CW |
194 | } else if (!dma_fence_add_callback(fence_excl, &dcb->cb, |
195 | dma_buf_poll_cb)) { | |
9b495a58 | 196 | events &= ~pevents; |
f54d1867 | 197 | dma_fence_put(fence_excl); |
04a5faa8 | 198 | } else { |
9b495a58 ML |
199 | /* |
200 | * No callback queued, wake up any additional | |
201 | * waiters. | |
202 | */ | |
f54d1867 | 203 | dma_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) { |
f54d1867 | 225 | struct dma_fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 226 | |
f54d1867 | 227 | if (!dma_fence_get_rcu(fence)) { |
3c3b177a ML |
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 | } | |
f54d1867 CW |
238 | if (!dma_fence_add_callback(fence, &dcb->cb, |
239 | dma_buf_poll_cb)) { | |
240 | dma_fence_put(fence); | |
9b495a58 ML |
241 | events &= ~POLLOUT; |
242 | break; | |
243 | } | |
f54d1867 | 244 | dma_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 | ||
2904a8c1 DV |
316 | /** |
317 | * DOC: dma buf device access | |
318 | * | |
319 | * For device DMA access to a shared DMA buffer the usual sequence of operations | |
320 | * is fairly simple: | |
321 | * | |
322 | * 1. The exporter defines his exporter instance using | |
323 | * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private | |
324 | * buffer object into a &dma_buf. It then exports that &dma_buf to userspace | |
325 | * as a file descriptor by calling dma_buf_fd(). | |
326 | * | |
327 | * 2. Userspace passes this file-descriptors to all drivers it wants this buffer | |
328 | * to share with: First the filedescriptor is converted to a &dma_buf using | |
329 | * dma_buf_get(). The the buffer is attached to the device using | |
330 | * dma_buf_attach(). | |
331 | * | |
332 | * Up to this stage the exporter is still free to migrate or reallocate the | |
333 | * backing storage. | |
334 | * | |
335 | * 3. Once the buffer is attached to all devices userspace can inniate DMA | |
336 | * access to the shared buffer. In the kernel this is done by calling | |
337 | * dma_buf_map_attachment() and dma_buf_unmap_attachment(). | |
338 | * | |
339 | * 4. Once a driver is done with a shared buffer it needs to call | |
340 | * dma_buf_detach() (after cleaning up any mappings) and then release the | |
341 | * reference acquired with dma_buf_get by calling dma_buf_put(). | |
342 | * | |
343 | * For the detailed semantics exporters are expected to implement see | |
344 | * &dma_buf_ops. | |
345 | */ | |
346 | ||
d15bd7ee | 347 | /** |
d8fbe341 | 348 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
349 | * with this buffer, so it can be exported. |
350 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 351 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 352 | * |
d8fbe341 | 353 | * @exp_info: [in] holds all the export related information provided |
2904a8c1 | 354 | * by the exporter. see struct &dma_buf_export_info |
d8fbe341 | 355 | * for further details. |
d15bd7ee SS |
356 | * |
357 | * Returns, on success, a newly created dma_buf object, which wraps the | |
358 | * supplied private data and operations for dma_buf_ops. On either missing | |
359 | * ops, or error in allocating struct dma_buf, will return negative error. | |
360 | * | |
2904a8c1 DV |
361 | * For most cases the easiest way to create @exp_info is through the |
362 | * %DEFINE_DMA_BUF_EXPORT_INFO macro. | |
d15bd7ee | 363 | */ |
d8fbe341 | 364 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
365 | { |
366 | struct dma_buf *dmabuf; | |
d8fbe341 | 367 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 368 | struct file *file; |
3aac4502 | 369 | size_t alloc_size = sizeof(struct dma_buf); |
a026df4c | 370 | int ret; |
5136629d | 371 | |
d8fbe341 | 372 | if (!exp_info->resv) |
3aac4502 ML |
373 | alloc_size += sizeof(struct reservation_object); |
374 | else | |
375 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
376 | alloc_size += 1; | |
d15bd7ee | 377 | |
d8fbe341 SS |
378 | if (WARN_ON(!exp_info->priv |
379 | || !exp_info->ops | |
380 | || !exp_info->ops->map_dma_buf | |
381 | || !exp_info->ops->unmap_dma_buf | |
382 | || !exp_info->ops->release | |
383 | || !exp_info->ops->kmap_atomic | |
384 | || !exp_info->ops->kmap | |
385 | || !exp_info->ops->mmap)) { | |
d15bd7ee SS |
386 | return ERR_PTR(-EINVAL); |
387 | } | |
388 | ||
9abdffe2 SS |
389 | if (!try_module_get(exp_info->owner)) |
390 | return ERR_PTR(-ENOENT); | |
391 | ||
3aac4502 | 392 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 | 393 | if (!dmabuf) { |
a026df4c CW |
394 | ret = -ENOMEM; |
395 | goto err_module; | |
9abdffe2 | 396 | } |
d15bd7ee | 397 | |
d8fbe341 SS |
398 | dmabuf->priv = exp_info->priv; |
399 | dmabuf->ops = exp_info->ops; | |
400 | dmabuf->size = exp_info->size; | |
401 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 402 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
403 | init_waitqueue_head(&dmabuf->poll); |
404 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
405 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
406 | ||
3aac4502 ML |
407 | if (!resv) { |
408 | resv = (struct reservation_object *)&dmabuf[1]; | |
409 | reservation_object_init(resv); | |
410 | } | |
411 | dmabuf->resv = resv; | |
d15bd7ee | 412 | |
d8fbe341 SS |
413 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
414 | exp_info->flags); | |
9022e24e | 415 | if (IS_ERR(file)) { |
a026df4c CW |
416 | ret = PTR_ERR(file); |
417 | goto err_dmabuf; | |
9022e24e | 418 | } |
19e8697b CJHR |
419 | |
420 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
421 | dmabuf->file = file; |
422 | ||
423 | mutex_init(&dmabuf->lock); | |
424 | INIT_LIST_HEAD(&dmabuf->attachments); | |
425 | ||
b89e3563 SS |
426 | mutex_lock(&db_list.lock); |
427 | list_add(&dmabuf->list_node, &db_list.head); | |
428 | mutex_unlock(&db_list.lock); | |
429 | ||
d15bd7ee | 430 | return dmabuf; |
a026df4c CW |
431 | |
432 | err_dmabuf: | |
433 | kfree(dmabuf); | |
434 | err_module: | |
435 | module_put(exp_info->owner); | |
436 | return ERR_PTR(ret); | |
d15bd7ee | 437 | } |
d8fbe341 | 438 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
439 | |
440 | /** | |
441 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
442 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 443 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
444 | * |
445 | * On success, returns an associated 'fd'. Else, returns error. | |
446 | */ | |
55c1c4ca | 447 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 448 | { |
f5e097f0 | 449 | int fd; |
d15bd7ee SS |
450 | |
451 | if (!dmabuf || !dmabuf->file) | |
452 | return -EINVAL; | |
453 | ||
f5e097f0 BP |
454 | fd = get_unused_fd_flags(flags); |
455 | if (fd < 0) | |
456 | return fd; | |
d15bd7ee SS |
457 | |
458 | fd_install(fd, dmabuf->file); | |
459 | ||
460 | return fd; | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
463 | ||
464 | /** | |
465 | * dma_buf_get - returns the dma_buf structure related to an fd | |
466 | * @fd: [in] fd associated with the dma_buf to be returned | |
467 | * | |
468 | * On success, returns the dma_buf structure associated with an fd; uses | |
469 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
470 | * otherwise. | |
471 | */ | |
472 | struct dma_buf *dma_buf_get(int fd) | |
473 | { | |
474 | struct file *file; | |
475 | ||
476 | file = fget(fd); | |
477 | ||
478 | if (!file) | |
479 | return ERR_PTR(-EBADF); | |
480 | ||
481 | if (!is_dma_buf_file(file)) { | |
482 | fput(file); | |
483 | return ERR_PTR(-EINVAL); | |
484 | } | |
485 | ||
486 | return file->private_data; | |
487 | } | |
488 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
489 | ||
490 | /** | |
491 | * dma_buf_put - decreases refcount of the buffer | |
492 | * @dmabuf: [in] buffer to reduce refcount of | |
493 | * | |
2904a8c1 DV |
494 | * Uses file's refcounting done implicitly by fput(). |
495 | * | |
496 | * If, as a result of this call, the refcount becomes 0, the 'release' file | |
497 | * operation related to this fd is called. It calls the release operation of | |
498 | * struct &dma_buf_ops in turn, and frees the memory allocated for dmabuf when | |
499 | * exported. | |
d15bd7ee SS |
500 | */ |
501 | void dma_buf_put(struct dma_buf *dmabuf) | |
502 | { | |
503 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
504 | return; | |
505 | ||
506 | fput(dmabuf->file); | |
507 | } | |
508 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
509 | ||
510 | /** | |
511 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
512 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
513 | * @dmabuf: [in] buffer to attach device to. | |
514 | * @dev: [in] device to be attached. | |
515 | * | |
2904a8c1 DV |
516 | * Returns struct dma_buf_attachment pointer for this attachment. Attachments |
517 | * must be cleaned up by calling dma_buf_detach(). | |
518 | * | |
519 | * Returns: | |
520 | * | |
521 | * A pointer to newly created &dma_buf_attachment on success, or a negative | |
522 | * error code wrapped into a pointer on failure. | |
523 | * | |
524 | * Note that this can fail if the backing storage of @dmabuf is in a place not | |
525 | * accessible to @dev, and cannot be moved to a more suitable place. This is | |
526 | * indicated with the error code -EBUSY. | |
d15bd7ee SS |
527 | */ |
528 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
529 | struct device *dev) | |
530 | { | |
531 | struct dma_buf_attachment *attach; | |
532 | int ret; | |
533 | ||
d1aa06a1 | 534 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
535 | return ERR_PTR(-EINVAL); |
536 | ||
537 | attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); | |
538 | if (attach == NULL) | |
a9fbc3b7 | 539 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 540 | |
d15bd7ee SS |
541 | attach->dev = dev; |
542 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
543 | |
544 | mutex_lock(&dmabuf->lock); | |
545 | ||
d15bd7ee SS |
546 | if (dmabuf->ops->attach) { |
547 | ret = dmabuf->ops->attach(dmabuf, dev, attach); | |
548 | if (ret) | |
549 | goto err_attach; | |
550 | } | |
551 | list_add(&attach->node, &dmabuf->attachments); | |
552 | ||
553 | mutex_unlock(&dmabuf->lock); | |
554 | return attach; | |
555 | ||
d15bd7ee SS |
556 | err_attach: |
557 | kfree(attach); | |
558 | mutex_unlock(&dmabuf->lock); | |
559 | return ERR_PTR(ret); | |
560 | } | |
561 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
562 | ||
563 | /** | |
564 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
565 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
566 | * @dmabuf: [in] buffer to detach from. | |
567 | * @attach: [in] attachment to be detached; is free'd after this call. | |
568 | * | |
2904a8c1 | 569 | * Clean up a device attachment obtained by calling dma_buf_attach(). |
d15bd7ee SS |
570 | */ |
571 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
572 | { | |
d1aa06a1 | 573 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
574 | return; |
575 | ||
576 | mutex_lock(&dmabuf->lock); | |
577 | list_del(&attach->node); | |
578 | if (dmabuf->ops->detach) | |
579 | dmabuf->ops->detach(dmabuf, attach); | |
580 | ||
581 | mutex_unlock(&dmabuf->lock); | |
582 | kfree(attach); | |
583 | } | |
584 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
585 | ||
586 | /** | |
587 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
588 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
589 | * dma_buf_ops. | |
590 | * @attach: [in] attachment whose scatterlist is to be returned | |
591 | * @direction: [in] direction of DMA transfer | |
592 | * | |
fee0c54e | 593 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
2904a8c1 DV |
594 | * on error. May return -EINTR if it is interrupted by a signal. |
595 | * | |
596 | * A mapping must be unmapped again using dma_buf_map_attachment(). Note that | |
597 | * the underlying backing storage is pinned for as long as a mapping exists, | |
598 | * therefore users/importers should not hold onto a mapping for undue amounts of | |
599 | * time. | |
d15bd7ee SS |
600 | */ |
601 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
602 | enum dma_data_direction direction) | |
603 | { | |
604 | struct sg_table *sg_table = ERR_PTR(-EINVAL); | |
605 | ||
606 | might_sleep(); | |
607 | ||
d1aa06a1 | 608 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
609 | return ERR_PTR(-EINVAL); |
610 | ||
d1aa06a1 | 611 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
612 | if (!sg_table) |
613 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
614 | |
615 | return sg_table; | |
616 | } | |
617 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
618 | ||
619 | /** | |
620 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
621 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
622 | * dma_buf_ops. | |
623 | * @attach: [in] attachment to unmap buffer from | |
624 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 625 | * @direction: [in] direction of DMA transfer |
d15bd7ee | 626 | * |
2904a8c1 | 627 | * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). |
d15bd7ee SS |
628 | */ |
629 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
630 | struct sg_table *sg_table, |
631 | enum dma_data_direction direction) | |
d15bd7ee | 632 | { |
b6fa0cd6 RC |
633 | might_sleep(); |
634 | ||
d1aa06a1 | 635 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
636 | return; |
637 | ||
33ea2dcb SS |
638 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
639 | direction); | |
d15bd7ee SS |
640 | } |
641 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e | 642 | |
0959a168 DV |
643 | /** |
644 | * DOC: cpu access | |
645 | * | |
646 | * There are mutliple reasons for supporting CPU access to a dma buffer object: | |
647 | * | |
648 | * - Fallback operations in the kernel, for example when a device is connected | |
649 | * over USB and the kernel needs to shuffle the data around first before | |
650 | * sending it away. Cache coherency is handled by braketing any transactions | |
651 | * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access() | |
652 | * access. | |
653 | * | |
654 | * To support dma_buf objects residing in highmem cpu access is page-based | |
655 | * using an api similar to kmap. Accessing a dma_buf is done in aligned chunks | |
656 | * of PAGE_SIZE size. Before accessing a chunk it needs to be mapped, which | |
657 | * returns a pointer in kernel virtual address space. Afterwards the chunk | |
658 | * needs to be unmapped again. There is no limit on how often a given chunk | |
659 | * can be mapped and unmapped, i.e. the importer does not need to call | |
660 | * begin_cpu_access again before mapping the same chunk again. | |
661 | * | |
662 | * Interfaces:: | |
663 | * void \*dma_buf_kmap(struct dma_buf \*, unsigned long); | |
664 | * void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*); | |
665 | * | |
666 | * There are also atomic variants of these interfaces. Like for kmap they | |
667 | * facilitate non-blocking fast-paths. Neither the importer nor the exporter | |
668 | * (in the callback) is allowed to block when using these. | |
669 | * | |
670 | * Interfaces:: | |
671 | * void \*dma_buf_kmap_atomic(struct dma_buf \*, unsigned long); | |
672 | * void dma_buf_kunmap_atomic(struct dma_buf \*, unsigned long, void \*); | |
673 | * | |
674 | * For importers all the restrictions of using kmap apply, like the limited | |
675 | * supply of kmap_atomic slots. Hence an importer shall only hold onto at | |
676 | * max 2 atomic dma_buf kmaps at the same time (in any given process context). | |
677 | * | |
678 | * dma_buf kmap calls outside of the range specified in begin_cpu_access are | |
679 | * undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on | |
680 | * the partial chunks at the beginning and end but may return stale or bogus | |
681 | * data outside of the range (in these partial chunks). | |
682 | * | |
683 | * Note that these calls need to always succeed. The exporter needs to | |
684 | * complete any preparations that might fail in begin_cpu_access. | |
685 | * | |
686 | * For some cases the overhead of kmap can be too high, a vmap interface | |
687 | * is introduced. This interface should be used very carefully, as vmalloc | |
688 | * space is a limited resources on many architectures. | |
689 | * | |
690 | * Interfaces:: | |
691 | * void \*dma_buf_vmap(struct dma_buf \*dmabuf) | |
692 | * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr) | |
693 | * | |
694 | * The vmap call can fail if there is no vmap support in the exporter, or if | |
695 | * it runs out of vmalloc space. Fallback to kmap should be implemented. Note | |
696 | * that the dma-buf layer keeps a reference count for all vmap access and | |
697 | * calls down into the exporter's vmap function only when no vmapping exists, | |
698 | * and only unmaps it once. Protection against concurrent vmap/vunmap calls is | |
699 | * provided by taking the dma_buf->lock mutex. | |
700 | * | |
701 | * - For full compatibility on the importer side with existing userspace | |
702 | * interfaces, which might already support mmap'ing buffers. This is needed in | |
703 | * many processing pipelines (e.g. feeding a software rendered image into a | |
704 | * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION | |
705 | * framework already supported this and for DMA buffer file descriptors to | |
706 | * replace ION buffers mmap support was needed. | |
707 | * | |
708 | * There is no special interfaces, userspace simply calls mmap on the dma-buf | |
709 | * fd. But like for CPU access there's a need to braket the actual access, | |
710 | * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that | |
711 | * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must | |
712 | * be restarted. | |
713 | * | |
714 | * Some systems might need some sort of cache coherency management e.g. when | |
715 | * CPU and GPU domains are being accessed through dma-buf at the same time. | |
716 | * To circumvent this problem there are begin/end coherency markers, that | |
717 | * forward directly to existing dma-buf device drivers vfunc hooks. Userspace | |
718 | * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The | |
719 | * sequence would be used like following: | |
720 | * | |
721 | * - mmap dma-buf fd | |
722 | * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write | |
723 | * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you | |
724 | * want (with the new data being consumed by say the GPU or the scanout | |
725 | * device) | |
726 | * - munmap once you don't need the buffer any more | |
727 | * | |
728 | * For correctness and optimal performance, it is always required to use | |
729 | * SYNC_START and SYNC_END before and after, respectively, when accessing the | |
730 | * mapped address. Userspace cannot rely on coherent access, even when there | |
731 | * are systems where it just works without calling these ioctls. | |
732 | * | |
733 | * - And as a CPU fallback in userspace processing pipelines. | |
734 | * | |
735 | * Similar to the motivation for kernel cpu access it is again important that | |
736 | * the userspace code of a given importing subsystem can use the same | |
737 | * interfaces with a imported dma-buf buffer object as with a native buffer | |
738 | * object. This is especially important for drm where the userspace part of | |
739 | * contemporary OpenGL, X, and other drivers is huge, and reworking them to | |
740 | * use a different way to mmap a buffer rather invasive. | |
741 | * | |
742 | * The assumption in the current dma-buf interfaces is that redirecting the | |
743 | * initial mmap is all that's needed. A survey of some of the existing | |
744 | * subsystems shows that no driver seems to do any nefarious thing like | |
745 | * syncing up with outstanding asynchronous processing on the device or | |
746 | * allocating special resources at fault time. So hopefully this is good | |
747 | * enough, since adding interfaces to intercept pagefaults and allow pte | |
748 | * shootdowns would increase the complexity quite a bit. | |
749 | * | |
750 | * Interface:: | |
751 | * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*, | |
752 | * unsigned long); | |
753 | * | |
754 | * If the importing subsystem simply provides a special-purpose mmap call to | |
755 | * set up a mapping in userspace, calling do_mmap with dma_buf->file will | |
756 | * equally achieve that for a dma-buf object. | |
757 | */ | |
758 | ||
ae4e46b1 CW |
759 | static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
760 | enum dma_data_direction direction) | |
761 | { | |
762 | bool write = (direction == DMA_BIDIRECTIONAL || | |
763 | direction == DMA_TO_DEVICE); | |
764 | struct reservation_object *resv = dmabuf->resv; | |
765 | long ret; | |
766 | ||
767 | /* Wait on any implicit rendering fences */ | |
768 | ret = reservation_object_wait_timeout_rcu(resv, write, true, | |
769 | MAX_SCHEDULE_TIMEOUT); | |
770 | if (ret < 0) | |
771 | return ret; | |
772 | ||
773 | return 0; | |
774 | } | |
fc13020e DV |
775 | |
776 | /** | |
777 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
778 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
779 | * preparations. Coherency is only guaranteed in the specified range for the | |
780 | * specified access direction. | |
efb4df82 | 781 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
782 | * @direction: [in] length of range for cpu access. |
783 | * | |
0959a168 DV |
784 | * After the cpu access is complete the caller should call |
785 | * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is | |
786 | * it guaranteed to be coherent with other DMA access. | |
787 | * | |
fc13020e DV |
788 | * Can return negative error values, returns 0 on success. |
789 | */ | |
831e9da7 | 790 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
791 | enum dma_data_direction direction) |
792 | { | |
793 | int ret = 0; | |
794 | ||
795 | if (WARN_ON(!dmabuf)) | |
796 | return -EINVAL; | |
797 | ||
798 | if (dmabuf->ops->begin_cpu_access) | |
831e9da7 | 799 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e | 800 | |
ae4e46b1 CW |
801 | /* Ensure that all fences are waited upon - but we first allow |
802 | * the native handler the chance to do so more efficiently if it | |
803 | * chooses. A double invocation here will be reasonably cheap no-op. | |
804 | */ | |
805 | if (ret == 0) | |
806 | ret = __dma_buf_begin_cpu_access(dmabuf, direction); | |
807 | ||
fc13020e DV |
808 | return ret; |
809 | } | |
810 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
811 | ||
812 | /** | |
813 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
814 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
815 | * actions. Coherency is only guaranteed in the specified range for the | |
816 | * specified access direction. | |
efb4df82 | 817 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
818 | * @direction: [in] length of range for cpu access. |
819 | * | |
0959a168 DV |
820 | * This terminates CPU access started with dma_buf_begin_cpu_access(). |
821 | * | |
87e332d5 | 822 | * Can return negative error values, returns 0 on success. |
fc13020e | 823 | */ |
18b862dc CW |
824 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
825 | enum dma_data_direction direction) | |
fc13020e | 826 | { |
18b862dc CW |
827 | int ret = 0; |
828 | ||
fc13020e DV |
829 | WARN_ON(!dmabuf); |
830 | ||
831 | if (dmabuf->ops->end_cpu_access) | |
18b862dc CW |
832 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
833 | ||
834 | return ret; | |
fc13020e DV |
835 | } |
836 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
837 | ||
838 | /** | |
839 | * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address | |
840 | * space. The same restrictions as for kmap_atomic and friends apply. | |
efb4df82 | 841 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
842 | * @page_num: [in] page in PAGE_SIZE units to map. |
843 | * | |
844 | * This call must always succeed, any necessary preparations that might fail | |
845 | * need to be done in begin_cpu_access. | |
846 | */ | |
847 | void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) | |
848 | { | |
849 | WARN_ON(!dmabuf); | |
850 | ||
851 | return dmabuf->ops->kmap_atomic(dmabuf, page_num); | |
852 | } | |
853 | EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); | |
854 | ||
855 | /** | |
856 | * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. | |
efb4df82 | 857 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
858 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
859 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. | |
860 | * | |
861 | * This call must always succeed. | |
862 | */ | |
863 | void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, | |
864 | void *vaddr) | |
865 | { | |
866 | WARN_ON(!dmabuf); | |
867 | ||
868 | if (dmabuf->ops->kunmap_atomic) | |
869 | dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); | |
870 | } | |
871 | EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); | |
872 | ||
873 | /** | |
874 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
875 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 876 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
877 | * @page_num: [in] page in PAGE_SIZE units to map. |
878 | * | |
879 | * This call must always succeed, any necessary preparations that might fail | |
880 | * need to be done in begin_cpu_access. | |
881 | */ | |
882 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
883 | { | |
884 | WARN_ON(!dmabuf); | |
885 | ||
886 | return dmabuf->ops->kmap(dmabuf, page_num); | |
887 | } | |
888 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
889 | ||
890 | /** | |
891 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 892 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
893 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
894 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
895 | * | |
896 | * This call must always succeed. | |
897 | */ | |
898 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
899 | void *vaddr) | |
900 | { | |
901 | WARN_ON(!dmabuf); | |
902 | ||
903 | if (dmabuf->ops->kunmap) | |
904 | dmabuf->ops->kunmap(dmabuf, page_num, vaddr); | |
905 | } | |
906 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
907 | |
908 | ||
909 | /** | |
910 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 911 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
912 | * @vma: [in] vma for the mmap |
913 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 914 | * dma-buf buffer. |
4c78513e DV |
915 | * |
916 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 917 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
918 | * checking on the size of the vma. Then it calls the exporters mmap function to |
919 | * set up the mapping. | |
920 | * | |
921 | * Can return negative error values, returns 0 on success. | |
922 | */ | |
923 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
924 | unsigned long pgoff) | |
925 | { | |
495c10cc JS |
926 | struct file *oldfile; |
927 | int ret; | |
928 | ||
4c78513e DV |
929 | if (WARN_ON(!dmabuf || !vma)) |
930 | return -EINVAL; | |
931 | ||
932 | /* check for offset overflow */ | |
b02da6f8 | 933 | if (pgoff + vma_pages(vma) < pgoff) |
4c78513e DV |
934 | return -EOVERFLOW; |
935 | ||
936 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 937 | if (pgoff + vma_pages(vma) > |
4c78513e DV |
938 | dmabuf->size >> PAGE_SHIFT) |
939 | return -EINVAL; | |
940 | ||
941 | /* readjust the vma */ | |
495c10cc JS |
942 | get_file(dmabuf->file); |
943 | oldfile = vma->vm_file; | |
944 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
945 | vma->vm_pgoff = pgoff; |
946 | ||
495c10cc JS |
947 | ret = dmabuf->ops->mmap(dmabuf, vma); |
948 | if (ret) { | |
949 | /* restore old parameters on failure */ | |
950 | vma->vm_file = oldfile; | |
951 | fput(dmabuf->file); | |
952 | } else { | |
953 | if (oldfile) | |
954 | fput(oldfile); | |
955 | } | |
956 | return ret; | |
957 | ||
4c78513e DV |
958 | } |
959 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
960 | |
961 | /** | |
12c4727e SS |
962 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
963 | * address space. Same restrictions as for vmap and friends apply. | |
964 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
965 | * |
966 | * This call may fail due to lack of virtual mapping address space. | |
967 | * These calls are optional in drivers. The intended use for them | |
968 | * is for mapping objects linear in kernel space for high use objects. | |
969 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
970 | * |
971 | * Returns NULL on error. | |
98f86c9e DA |
972 | */ |
973 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
974 | { | |
f00b4dad DV |
975 | void *ptr; |
976 | ||
98f86c9e DA |
977 | if (WARN_ON(!dmabuf)) |
978 | return NULL; | |
979 | ||
f00b4dad DV |
980 | if (!dmabuf->ops->vmap) |
981 | return NULL; | |
982 | ||
983 | mutex_lock(&dmabuf->lock); | |
984 | if (dmabuf->vmapping_counter) { | |
985 | dmabuf->vmapping_counter++; | |
986 | BUG_ON(!dmabuf->vmap_ptr); | |
987 | ptr = dmabuf->vmap_ptr; | |
988 | goto out_unlock; | |
989 | } | |
990 | ||
991 | BUG_ON(dmabuf->vmap_ptr); | |
992 | ||
993 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
994 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
995 | ptr = NULL; | |
996 | if (!ptr) | |
f00b4dad DV |
997 | goto out_unlock; |
998 | ||
999 | dmabuf->vmap_ptr = ptr; | |
1000 | dmabuf->vmapping_counter = 1; | |
1001 | ||
1002 | out_unlock: | |
1003 | mutex_unlock(&dmabuf->lock); | |
1004 | return ptr; | |
98f86c9e DA |
1005 | } |
1006 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
1007 | ||
1008 | /** | |
1009 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 1010 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 1011 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
1012 | */ |
1013 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
1014 | { | |
1015 | if (WARN_ON(!dmabuf)) | |
1016 | return; | |
1017 | ||
f00b4dad DV |
1018 | BUG_ON(!dmabuf->vmap_ptr); |
1019 | BUG_ON(dmabuf->vmapping_counter == 0); | |
1020 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
1021 | ||
1022 | mutex_lock(&dmabuf->lock); | |
1023 | if (--dmabuf->vmapping_counter == 0) { | |
1024 | if (dmabuf->ops->vunmap) | |
1025 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
1026 | dmabuf->vmap_ptr = NULL; | |
1027 | } | |
1028 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
1029 | } |
1030 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
1031 | |
1032 | #ifdef CONFIG_DEBUG_FS | |
eb0b947e | 1033 | static int dma_buf_debug_show(struct seq_file *s, void *unused) |
b89e3563 SS |
1034 | { |
1035 | int ret; | |
1036 | struct dma_buf *buf_obj; | |
1037 | struct dma_buf_attachment *attach_obj; | |
1038 | int count = 0, attach_count; | |
1039 | size_t size = 0; | |
1040 | ||
1041 | ret = mutex_lock_interruptible(&db_list.lock); | |
1042 | ||
1043 | if (ret) | |
1044 | return ret; | |
1045 | ||
c0b00a52 SS |
1046 | seq_puts(s, "\nDma-buf Objects:\n"); |
1047 | seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); | |
b89e3563 SS |
1048 | |
1049 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
1050 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
1051 | ||
1052 | if (ret) { | |
c0b00a52 SS |
1053 | seq_puts(s, |
1054 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
1055 | continue; |
1056 | } | |
1057 | ||
c0b00a52 SS |
1058 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
1059 | buf_obj->size, | |
b89e3563 | 1060 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 1061 | file_count(buf_obj->file), |
c0b00a52 | 1062 | buf_obj->exp_name); |
b89e3563 | 1063 | |
c0b00a52 | 1064 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
1065 | attach_count = 0; |
1066 | ||
1067 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
c0b00a52 | 1068 | seq_puts(s, "\t"); |
b89e3563 | 1069 | |
c0b00a52 | 1070 | seq_printf(s, "%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
1071 | attach_count++; |
1072 | } | |
1073 | ||
c0b00a52 | 1074 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
1075 | attach_count); |
1076 | ||
1077 | count++; | |
1078 | size += buf_obj->size; | |
1079 | mutex_unlock(&buf_obj->lock); | |
1080 | } | |
1081 | ||
1082 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
1083 | ||
1084 | mutex_unlock(&db_list.lock); | |
1085 | return 0; | |
1086 | } | |
1087 | ||
b89e3563 SS |
1088 | static int dma_buf_debug_open(struct inode *inode, struct file *file) |
1089 | { | |
eb0b947e | 1090 | return single_open(file, dma_buf_debug_show, NULL); |
b89e3563 SS |
1091 | } |
1092 | ||
1093 | static const struct file_operations dma_buf_debug_fops = { | |
1094 | .open = dma_buf_debug_open, | |
1095 | .read = seq_read, | |
1096 | .llseek = seq_lseek, | |
1097 | .release = single_release, | |
1098 | }; | |
1099 | ||
1100 | static struct dentry *dma_buf_debugfs_dir; | |
1101 | ||
1102 | static int dma_buf_init_debugfs(void) | |
1103 | { | |
bd3e2208 | 1104 | struct dentry *d; |
b89e3563 | 1105 | int err = 0; |
5136629d | 1106 | |
bd3e2208 MK |
1107 | d = debugfs_create_dir("dma_buf", NULL); |
1108 | if (IS_ERR(d)) | |
1109 | return PTR_ERR(d); | |
5136629d | 1110 | |
bd3e2208 | 1111 | dma_buf_debugfs_dir = d; |
b89e3563 | 1112 | |
bd3e2208 MK |
1113 | d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, |
1114 | NULL, &dma_buf_debug_fops); | |
1115 | if (IS_ERR(d)) { | |
b89e3563 | 1116 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); |
b7479990 MK |
1117 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
1118 | dma_buf_debugfs_dir = NULL; | |
bd3e2208 | 1119 | err = PTR_ERR(d); |
b7479990 | 1120 | } |
b89e3563 SS |
1121 | |
1122 | return err; | |
1123 | } | |
1124 | ||
1125 | static void dma_buf_uninit_debugfs(void) | |
1126 | { | |
1127 | if (dma_buf_debugfs_dir) | |
1128 | debugfs_remove_recursive(dma_buf_debugfs_dir); | |
1129 | } | |
b89e3563 SS |
1130 | #else |
1131 | static inline int dma_buf_init_debugfs(void) | |
1132 | { | |
1133 | return 0; | |
1134 | } | |
1135 | static inline void dma_buf_uninit_debugfs(void) | |
1136 | { | |
1137 | } | |
1138 | #endif | |
1139 | ||
1140 | static int __init dma_buf_init(void) | |
1141 | { | |
1142 | mutex_init(&db_list.lock); | |
1143 | INIT_LIST_HEAD(&db_list.head); | |
1144 | dma_buf_init_debugfs(); | |
1145 | return 0; | |
1146 | } | |
1147 | subsys_initcall(dma_buf_init); | |
1148 | ||
1149 | static void __exit dma_buf_deinit(void) | |
1150 | { | |
1151 | dma_buf_uninit_debugfs(); | |
1152 | } | |
1153 | __exitcall(dma_buf_deinit); |