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caab277b | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d15bd7ee SS |
2 | /* |
3 | * Framework for buffer objects that can be shared across devices/subsystems. | |
4 | * | |
5 | * Copyright(C) 2011 Linaro Limited. All rights reserved. | |
6 | * Author: Sumit Semwal <sumit.semwal@ti.com> | |
7 | * | |
8 | * Many thanks to linaro-mm-sig list, and specially | |
9 | * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and | |
10 | * Daniel Vetter <daniel@ffwll.ch> for their support in creation and | |
11 | * refining of this idea. | |
d15bd7ee SS |
12 | */ |
13 | ||
14 | #include <linux/fs.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/dma-buf.h> | |
f54d1867 | 17 | #include <linux/dma-fence.h> |
d15bd7ee SS |
18 | #include <linux/anon_inodes.h> |
19 | #include <linux/export.h> | |
b89e3563 | 20 | #include <linux/debugfs.h> |
9abdffe2 | 21 | #include <linux/module.h> |
b89e3563 | 22 | #include <linux/seq_file.h> |
9b495a58 | 23 | #include <linux/poll.h> |
3aac4502 | 24 | #include <linux/reservation.h> |
b02da6f8 | 25 | #include <linux/mm.h> |
d15bd7ee | 26 | |
c11e391d DV |
27 | #include <uapi/linux/dma-buf.h> |
28 | ||
d15bd7ee SS |
29 | static inline int is_dma_buf_file(struct file *); |
30 | ||
b89e3563 SS |
31 | struct dma_buf_list { |
32 | struct list_head head; | |
33 | struct mutex lock; | |
34 | }; | |
35 | ||
36 | static struct dma_buf_list db_list; | |
37 | ||
d15bd7ee SS |
38 | static int dma_buf_release(struct inode *inode, struct file *file) |
39 | { | |
40 | struct dma_buf *dmabuf; | |
41 | ||
42 | if (!is_dma_buf_file(file)) | |
43 | return -EINVAL; | |
44 | ||
45 | dmabuf = file->private_data; | |
46 | ||
f00b4dad DV |
47 | BUG_ON(dmabuf->vmapping_counter); |
48 | ||
9b495a58 ML |
49 | /* |
50 | * Any fences that a dma-buf poll can wait on should be signaled | |
51 | * before releasing dma-buf. This is the responsibility of each | |
52 | * driver that uses the reservation objects. | |
53 | * | |
54 | * If you hit this BUG() it means someone dropped their ref to the | |
55 | * dma-buf while still having pending operation to the buffer. | |
56 | */ | |
57 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
58 | ||
d15bd7ee | 59 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
60 | |
61 | mutex_lock(&db_list.lock); | |
62 | list_del(&dmabuf->list_node); | |
63 | mutex_unlock(&db_list.lock); | |
64 | ||
3aac4502 ML |
65 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
66 | reservation_object_fini(dmabuf->resv); | |
67 | ||
9abdffe2 | 68 | module_put(dmabuf->owner); |
d15bd7ee SS |
69 | kfree(dmabuf); |
70 | return 0; | |
71 | } | |
72 | ||
4c78513e DV |
73 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
74 | { | |
75 | struct dma_buf *dmabuf; | |
76 | ||
77 | if (!is_dma_buf_file(file)) | |
78 | return -EINVAL; | |
79 | ||
80 | dmabuf = file->private_data; | |
81 | ||
82 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 83 | if (vma->vm_pgoff + vma_pages(vma) > |
4c78513e DV |
84 | dmabuf->size >> PAGE_SHIFT) |
85 | return -EINVAL; | |
86 | ||
87 | return dmabuf->ops->mmap(dmabuf, vma); | |
88 | } | |
89 | ||
19e8697b CJHR |
90 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
91 | { | |
92 | struct dma_buf *dmabuf; | |
93 | loff_t base; | |
94 | ||
95 | if (!is_dma_buf_file(file)) | |
96 | return -EBADF; | |
97 | ||
98 | dmabuf = file->private_data; | |
99 | ||
100 | /* only support discovering the end of the buffer, | |
101 | but also allow SEEK_SET to maintain the idiomatic | |
102 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
103 | if (whence == SEEK_END) | |
104 | base = dmabuf->size; | |
105 | else if (whence == SEEK_SET) | |
106 | base = 0; | |
107 | else | |
108 | return -EINVAL; | |
109 | ||
110 | if (offset != 0) | |
111 | return -EINVAL; | |
112 | ||
113 | return base + offset; | |
114 | } | |
115 | ||
e7e21c72 DV |
116 | /** |
117 | * DOC: fence polling | |
118 | * | |
119 | * To support cross-device and cross-driver synchronization of buffer access | |
f641d3b5 | 120 | * implicit fences (represented internally in the kernel with &struct fence) can |
e7e21c72 DV |
121 | * be attached to a &dma_buf. The glue for that and a few related things are |
122 | * provided in the &reservation_object structure. | |
123 | * | |
124 | * Userspace can query the state of these implicitly tracked fences using poll() | |
125 | * and related system calls: | |
126 | * | |
a9a08845 | 127 | * - Checking for EPOLLIN, i.e. read access, can be use to query the state of the |
e7e21c72 DV |
128 | * most recent write or exclusive fence. |
129 | * | |
a9a08845 | 130 | * - Checking for EPOLLOUT, i.e. write access, can be used to query the state of |
e7e21c72 DV |
131 | * all attached fences, shared and exclusive ones. |
132 | * | |
133 | * Note that this only signals the completion of the respective fences, i.e. the | |
134 | * DMA transfers are complete. Cache flushing and any other necessary | |
135 | * preparations before CPU access can begin still need to happen. | |
136 | */ | |
137 | ||
f54d1867 | 138 | static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb) |
9b495a58 ML |
139 | { |
140 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
141 | unsigned long flags; | |
142 | ||
143 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
144 | wake_up_locked_poll(dcb->poll, dcb->active); | |
145 | dcb->active = 0; | |
146 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
147 | } | |
148 | ||
afc9a42b | 149 | static __poll_t dma_buf_poll(struct file *file, poll_table *poll) |
9b495a58 ML |
150 | { |
151 | struct dma_buf *dmabuf; | |
152 | struct reservation_object *resv; | |
04a5faa8 | 153 | struct reservation_object_list *fobj; |
f54d1867 | 154 | struct dma_fence *fence_excl; |
01699437 | 155 | __poll_t events; |
3c3b177a | 156 | unsigned shared_count, seq; |
9b495a58 ML |
157 | |
158 | dmabuf = file->private_data; | |
159 | if (!dmabuf || !dmabuf->resv) | |
a9a08845 | 160 | return EPOLLERR; |
9b495a58 ML |
161 | |
162 | resv = dmabuf->resv; | |
163 | ||
164 | poll_wait(file, &dmabuf->poll, poll); | |
165 | ||
a9a08845 | 166 | events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT); |
9b495a58 ML |
167 | if (!events) |
168 | return 0; | |
169 | ||
3c3b177a ML |
170 | retry: |
171 | seq = read_seqcount_begin(&resv->seq); | |
172 | rcu_read_lock(); | |
9b495a58 | 173 | |
3c3b177a ML |
174 | fobj = rcu_dereference(resv->fence); |
175 | if (fobj) | |
176 | shared_count = fobj->shared_count; | |
177 | else | |
178 | shared_count = 0; | |
179 | fence_excl = rcu_dereference(resv->fence_excl); | |
180 | if (read_seqcount_retry(&resv->seq, seq)) { | |
181 | rcu_read_unlock(); | |
182 | goto retry; | |
183 | } | |
04a5faa8 | 184 | |
a9a08845 | 185 | if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) { |
9b495a58 | 186 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
a9a08845 | 187 | __poll_t pevents = EPOLLIN; |
9b495a58 | 188 | |
04a5faa8 | 189 | if (shared_count == 0) |
a9a08845 | 190 | pevents |= EPOLLOUT; |
9b495a58 ML |
191 | |
192 | spin_lock_irq(&dmabuf->poll.lock); | |
193 | if (dcb->active) { | |
194 | dcb->active |= pevents; | |
195 | events &= ~pevents; | |
196 | } else | |
197 | dcb->active = pevents; | |
198 | spin_unlock_irq(&dmabuf->poll.lock); | |
199 | ||
200 | if (events & pevents) { | |
f54d1867 | 201 | if (!dma_fence_get_rcu(fence_excl)) { |
3c3b177a ML |
202 | /* force a recheck */ |
203 | events &= ~pevents; | |
204 | dma_buf_poll_cb(NULL, &dcb->cb); | |
f54d1867 CW |
205 | } else if (!dma_fence_add_callback(fence_excl, &dcb->cb, |
206 | dma_buf_poll_cb)) { | |
9b495a58 | 207 | events &= ~pevents; |
f54d1867 | 208 | dma_fence_put(fence_excl); |
04a5faa8 | 209 | } else { |
9b495a58 ML |
210 | /* |
211 | * No callback queued, wake up any additional | |
212 | * waiters. | |
213 | */ | |
f54d1867 | 214 | dma_fence_put(fence_excl); |
9b495a58 | 215 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 216 | } |
9b495a58 ML |
217 | } |
218 | } | |
219 | ||
a9a08845 | 220 | if ((events & EPOLLOUT) && shared_count > 0) { |
9b495a58 ML |
221 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
222 | int i; | |
223 | ||
224 | /* Only queue a new callback if no event has fired yet */ | |
225 | spin_lock_irq(&dmabuf->poll.lock); | |
226 | if (dcb->active) | |
a9a08845 | 227 | events &= ~EPOLLOUT; |
9b495a58 | 228 | else |
a9a08845 | 229 | dcb->active = EPOLLOUT; |
9b495a58 ML |
230 | spin_unlock_irq(&dmabuf->poll.lock); |
231 | ||
a9a08845 | 232 | if (!(events & EPOLLOUT)) |
9b495a58 ML |
233 | goto out; |
234 | ||
04a5faa8 | 235 | for (i = 0; i < shared_count; ++i) { |
f54d1867 | 236 | struct dma_fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 237 | |
f54d1867 | 238 | if (!dma_fence_get_rcu(fence)) { |
3c3b177a ML |
239 | /* |
240 | * fence refcount dropped to zero, this means | |
241 | * that fobj has been freed | |
242 | * | |
243 | * call dma_buf_poll_cb and force a recheck! | |
244 | */ | |
a9a08845 | 245 | events &= ~EPOLLOUT; |
3c3b177a ML |
246 | dma_buf_poll_cb(NULL, &dcb->cb); |
247 | break; | |
248 | } | |
f54d1867 CW |
249 | if (!dma_fence_add_callback(fence, &dcb->cb, |
250 | dma_buf_poll_cb)) { | |
251 | dma_fence_put(fence); | |
a9a08845 | 252 | events &= ~EPOLLOUT; |
9b495a58 ML |
253 | break; |
254 | } | |
f54d1867 | 255 | dma_fence_put(fence); |
04a5faa8 | 256 | } |
9b495a58 ML |
257 | |
258 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 259 | if (i == shared_count) |
9b495a58 ML |
260 | dma_buf_poll_cb(NULL, &dcb->cb); |
261 | } | |
262 | ||
263 | out: | |
3c3b177a | 264 | rcu_read_unlock(); |
9b495a58 ML |
265 | return events; |
266 | } | |
267 | ||
c11e391d DV |
268 | static long dma_buf_ioctl(struct file *file, |
269 | unsigned int cmd, unsigned long arg) | |
270 | { | |
271 | struct dma_buf *dmabuf; | |
272 | struct dma_buf_sync sync; | |
273 | enum dma_data_direction direction; | |
18b862dc | 274 | int ret; |
c11e391d DV |
275 | |
276 | dmabuf = file->private_data; | |
277 | ||
278 | switch (cmd) { | |
279 | case DMA_BUF_IOCTL_SYNC: | |
280 | if (copy_from_user(&sync, (void __user *) arg, sizeof(sync))) | |
281 | return -EFAULT; | |
282 | ||
283 | if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK) | |
284 | return -EINVAL; | |
285 | ||
286 | switch (sync.flags & DMA_BUF_SYNC_RW) { | |
287 | case DMA_BUF_SYNC_READ: | |
288 | direction = DMA_FROM_DEVICE; | |
289 | break; | |
290 | case DMA_BUF_SYNC_WRITE: | |
291 | direction = DMA_TO_DEVICE; | |
292 | break; | |
293 | case DMA_BUF_SYNC_RW: | |
294 | direction = DMA_BIDIRECTIONAL; | |
295 | break; | |
296 | default: | |
297 | return -EINVAL; | |
298 | } | |
299 | ||
300 | if (sync.flags & DMA_BUF_SYNC_END) | |
18b862dc | 301 | ret = dma_buf_end_cpu_access(dmabuf, direction); |
c11e391d | 302 | else |
18b862dc | 303 | ret = dma_buf_begin_cpu_access(dmabuf, direction); |
c11e391d | 304 | |
18b862dc | 305 | return ret; |
c11e391d DV |
306 | default: |
307 | return -ENOTTY; | |
308 | } | |
309 | } | |
310 | ||
d15bd7ee SS |
311 | static const struct file_operations dma_buf_fops = { |
312 | .release = dma_buf_release, | |
4c78513e | 313 | .mmap = dma_buf_mmap_internal, |
19e8697b | 314 | .llseek = dma_buf_llseek, |
9b495a58 | 315 | .poll = dma_buf_poll, |
c11e391d | 316 | .unlocked_ioctl = dma_buf_ioctl, |
888022c0 MS |
317 | #ifdef CONFIG_COMPAT |
318 | .compat_ioctl = dma_buf_ioctl, | |
319 | #endif | |
d15bd7ee SS |
320 | }; |
321 | ||
322 | /* | |
323 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
324 | */ | |
325 | static inline int is_dma_buf_file(struct file *file) | |
326 | { | |
327 | return file->f_op == &dma_buf_fops; | |
328 | } | |
329 | ||
2904a8c1 DV |
330 | /** |
331 | * DOC: dma buf device access | |
332 | * | |
333 | * For device DMA access to a shared DMA buffer the usual sequence of operations | |
334 | * is fairly simple: | |
335 | * | |
336 | * 1. The exporter defines his exporter instance using | |
337 | * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private | |
338 | * buffer object into a &dma_buf. It then exports that &dma_buf to userspace | |
339 | * as a file descriptor by calling dma_buf_fd(). | |
340 | * | |
341 | * 2. Userspace passes this file-descriptors to all drivers it wants this buffer | |
342 | * to share with: First the filedescriptor is converted to a &dma_buf using | |
c138782d | 343 | * dma_buf_get(). Then the buffer is attached to the device using |
2904a8c1 DV |
344 | * dma_buf_attach(). |
345 | * | |
346 | * Up to this stage the exporter is still free to migrate or reallocate the | |
347 | * backing storage. | |
348 | * | |
c138782d | 349 | * 3. Once the buffer is attached to all devices userspace can initiate DMA |
2904a8c1 DV |
350 | * access to the shared buffer. In the kernel this is done by calling |
351 | * dma_buf_map_attachment() and dma_buf_unmap_attachment(). | |
352 | * | |
353 | * 4. Once a driver is done with a shared buffer it needs to call | |
354 | * dma_buf_detach() (after cleaning up any mappings) and then release the | |
355 | * reference acquired with dma_buf_get by calling dma_buf_put(). | |
356 | * | |
357 | * For the detailed semantics exporters are expected to implement see | |
358 | * &dma_buf_ops. | |
359 | */ | |
360 | ||
d15bd7ee | 361 | /** |
d8fbe341 | 362 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
363 | * with this buffer, so it can be exported. |
364 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 365 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 366 | * |
d8fbe341 | 367 | * @exp_info: [in] holds all the export related information provided |
f641d3b5 | 368 | * by the exporter. see &struct dma_buf_export_info |
d8fbe341 | 369 | * for further details. |
d15bd7ee SS |
370 | * |
371 | * Returns, on success, a newly created dma_buf object, which wraps the | |
372 | * supplied private data and operations for dma_buf_ops. On either missing | |
373 | * ops, or error in allocating struct dma_buf, will return negative error. | |
374 | * | |
2904a8c1 DV |
375 | * For most cases the easiest way to create @exp_info is through the |
376 | * %DEFINE_DMA_BUF_EXPORT_INFO macro. | |
d15bd7ee | 377 | */ |
d8fbe341 | 378 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
379 | { |
380 | struct dma_buf *dmabuf; | |
d8fbe341 | 381 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 382 | struct file *file; |
3aac4502 | 383 | size_t alloc_size = sizeof(struct dma_buf); |
a026df4c | 384 | int ret; |
5136629d | 385 | |
d8fbe341 | 386 | if (!exp_info->resv) |
3aac4502 ML |
387 | alloc_size += sizeof(struct reservation_object); |
388 | else | |
389 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
390 | alloc_size += 1; | |
d15bd7ee | 391 | |
d8fbe341 SS |
392 | if (WARN_ON(!exp_info->priv |
393 | || !exp_info->ops | |
394 | || !exp_info->ops->map_dma_buf | |
395 | || !exp_info->ops->unmap_dma_buf | |
396 | || !exp_info->ops->release | |
d8fbe341 | 397 | || !exp_info->ops->mmap)) { |
d15bd7ee SS |
398 | return ERR_PTR(-EINVAL); |
399 | } | |
400 | ||
9abdffe2 SS |
401 | if (!try_module_get(exp_info->owner)) |
402 | return ERR_PTR(-ENOENT); | |
403 | ||
3aac4502 | 404 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 | 405 | if (!dmabuf) { |
a026df4c CW |
406 | ret = -ENOMEM; |
407 | goto err_module; | |
9abdffe2 | 408 | } |
d15bd7ee | 409 | |
d8fbe341 SS |
410 | dmabuf->priv = exp_info->priv; |
411 | dmabuf->ops = exp_info->ops; | |
412 | dmabuf->size = exp_info->size; | |
413 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 414 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
415 | init_waitqueue_head(&dmabuf->poll); |
416 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
417 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
418 | ||
3aac4502 ML |
419 | if (!resv) { |
420 | resv = (struct reservation_object *)&dmabuf[1]; | |
421 | reservation_object_init(resv); | |
422 | } | |
423 | dmabuf->resv = resv; | |
d15bd7ee | 424 | |
d8fbe341 SS |
425 | file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, |
426 | exp_info->flags); | |
9022e24e | 427 | if (IS_ERR(file)) { |
a026df4c CW |
428 | ret = PTR_ERR(file); |
429 | goto err_dmabuf; | |
9022e24e | 430 | } |
19e8697b CJHR |
431 | |
432 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
433 | dmabuf->file = file; |
434 | ||
435 | mutex_init(&dmabuf->lock); | |
436 | INIT_LIST_HEAD(&dmabuf->attachments); | |
437 | ||
b89e3563 SS |
438 | mutex_lock(&db_list.lock); |
439 | list_add(&dmabuf->list_node, &db_list.head); | |
440 | mutex_unlock(&db_list.lock); | |
441 | ||
d15bd7ee | 442 | return dmabuf; |
a026df4c CW |
443 | |
444 | err_dmabuf: | |
445 | kfree(dmabuf); | |
446 | err_module: | |
447 | module_put(exp_info->owner); | |
448 | return ERR_PTR(ret); | |
d15bd7ee | 449 | } |
d8fbe341 | 450 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
451 | |
452 | /** | |
453 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
454 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 455 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
456 | * |
457 | * On success, returns an associated 'fd'. Else, returns error. | |
458 | */ | |
55c1c4ca | 459 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 460 | { |
f5e097f0 | 461 | int fd; |
d15bd7ee SS |
462 | |
463 | if (!dmabuf || !dmabuf->file) | |
464 | return -EINVAL; | |
465 | ||
f5e097f0 BP |
466 | fd = get_unused_fd_flags(flags); |
467 | if (fd < 0) | |
468 | return fd; | |
d15bd7ee SS |
469 | |
470 | fd_install(fd, dmabuf->file); | |
471 | ||
472 | return fd; | |
473 | } | |
474 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
475 | ||
476 | /** | |
477 | * dma_buf_get - returns the dma_buf structure related to an fd | |
478 | * @fd: [in] fd associated with the dma_buf to be returned | |
479 | * | |
480 | * On success, returns the dma_buf structure associated with an fd; uses | |
481 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
482 | * otherwise. | |
483 | */ | |
484 | struct dma_buf *dma_buf_get(int fd) | |
485 | { | |
486 | struct file *file; | |
487 | ||
488 | file = fget(fd); | |
489 | ||
490 | if (!file) | |
491 | return ERR_PTR(-EBADF); | |
492 | ||
493 | if (!is_dma_buf_file(file)) { | |
494 | fput(file); | |
495 | return ERR_PTR(-EINVAL); | |
496 | } | |
497 | ||
498 | return file->private_data; | |
499 | } | |
500 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
501 | ||
502 | /** | |
503 | * dma_buf_put - decreases refcount of the buffer | |
504 | * @dmabuf: [in] buffer to reduce refcount of | |
505 | * | |
2904a8c1 DV |
506 | * Uses file's refcounting done implicitly by fput(). |
507 | * | |
508 | * If, as a result of this call, the refcount becomes 0, the 'release' file | |
e9b4d7b5 DV |
509 | * operation related to this fd is called. It calls &dma_buf_ops.release vfunc |
510 | * in turn, and frees the memory allocated for dmabuf when exported. | |
d15bd7ee SS |
511 | */ |
512 | void dma_buf_put(struct dma_buf *dmabuf) | |
513 | { | |
514 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
515 | return; | |
516 | ||
517 | fput(dmabuf->file); | |
518 | } | |
519 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
520 | ||
521 | /** | |
522 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
523 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
524 | * @dmabuf: [in] buffer to attach device to. | |
525 | * @dev: [in] device to be attached. | |
526 | * | |
2904a8c1 DV |
527 | * Returns struct dma_buf_attachment pointer for this attachment. Attachments |
528 | * must be cleaned up by calling dma_buf_detach(). | |
529 | * | |
530 | * Returns: | |
531 | * | |
532 | * A pointer to newly created &dma_buf_attachment on success, or a negative | |
533 | * error code wrapped into a pointer on failure. | |
534 | * | |
535 | * Note that this can fail if the backing storage of @dmabuf is in a place not | |
536 | * accessible to @dev, and cannot be moved to a more suitable place. This is | |
537 | * indicated with the error code -EBUSY. | |
d15bd7ee SS |
538 | */ |
539 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
540 | struct device *dev) | |
541 | { | |
542 | struct dma_buf_attachment *attach; | |
543 | int ret; | |
544 | ||
d1aa06a1 | 545 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
546 | return ERR_PTR(-EINVAL); |
547 | ||
db7942b6 | 548 | attach = kzalloc(sizeof(*attach), GFP_KERNEL); |
34d84ec4 | 549 | if (!attach) |
a9fbc3b7 | 550 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 551 | |
d15bd7ee SS |
552 | attach->dev = dev; |
553 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
554 | |
555 | mutex_lock(&dmabuf->lock); | |
556 | ||
d15bd7ee | 557 | if (dmabuf->ops->attach) { |
a19741e5 | 558 | ret = dmabuf->ops->attach(dmabuf, attach); |
d15bd7ee SS |
559 | if (ret) |
560 | goto err_attach; | |
561 | } | |
562 | list_add(&attach->node, &dmabuf->attachments); | |
563 | ||
564 | mutex_unlock(&dmabuf->lock); | |
565 | return attach; | |
566 | ||
d15bd7ee SS |
567 | err_attach: |
568 | kfree(attach); | |
569 | mutex_unlock(&dmabuf->lock); | |
570 | return ERR_PTR(ret); | |
571 | } | |
572 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
573 | ||
574 | /** | |
575 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
576 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
577 | * @dmabuf: [in] buffer to detach from. | |
578 | * @attach: [in] attachment to be detached; is free'd after this call. | |
579 | * | |
2904a8c1 | 580 | * Clean up a device attachment obtained by calling dma_buf_attach(). |
d15bd7ee SS |
581 | */ |
582 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
583 | { | |
d1aa06a1 | 584 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
585 | return; |
586 | ||
587 | mutex_lock(&dmabuf->lock); | |
588 | list_del(&attach->node); | |
589 | if (dmabuf->ops->detach) | |
590 | dmabuf->ops->detach(dmabuf, attach); | |
591 | ||
592 | mutex_unlock(&dmabuf->lock); | |
593 | kfree(attach); | |
594 | } | |
595 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
596 | ||
597 | /** | |
598 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
599 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
600 | * dma_buf_ops. | |
601 | * @attach: [in] attachment whose scatterlist is to be returned | |
602 | * @direction: [in] direction of DMA transfer | |
603 | * | |
fee0c54e | 604 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
2904a8c1 DV |
605 | * on error. May return -EINTR if it is interrupted by a signal. |
606 | * | |
c138782d | 607 | * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that |
2904a8c1 DV |
608 | * the underlying backing storage is pinned for as long as a mapping exists, |
609 | * therefore users/importers should not hold onto a mapping for undue amounts of | |
610 | * time. | |
d15bd7ee SS |
611 | */ |
612 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
613 | enum dma_data_direction direction) | |
614 | { | |
531beb06 | 615 | struct sg_table *sg_table; |
d15bd7ee SS |
616 | |
617 | might_sleep(); | |
618 | ||
d1aa06a1 | 619 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
620 | return ERR_PTR(-EINVAL); |
621 | ||
d1aa06a1 | 622 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
623 | if (!sg_table) |
624 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee SS |
625 | |
626 | return sg_table; | |
627 | } | |
628 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
629 | ||
630 | /** | |
631 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
632 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
633 | * dma_buf_ops. | |
634 | * @attach: [in] attachment to unmap buffer from | |
635 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 636 | * @direction: [in] direction of DMA transfer |
d15bd7ee | 637 | * |
2904a8c1 | 638 | * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). |
d15bd7ee SS |
639 | */ |
640 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
641 | struct sg_table *sg_table, |
642 | enum dma_data_direction direction) | |
d15bd7ee | 643 | { |
b6fa0cd6 RC |
644 | might_sleep(); |
645 | ||
d1aa06a1 | 646 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
647 | return; |
648 | ||
33ea2dcb SS |
649 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, |
650 | direction); | |
d15bd7ee SS |
651 | } |
652 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e | 653 | |
0959a168 DV |
654 | /** |
655 | * DOC: cpu access | |
656 | * | |
657 | * There are mutliple reasons for supporting CPU access to a dma buffer object: | |
658 | * | |
659 | * - Fallback operations in the kernel, for example when a device is connected | |
660 | * over USB and the kernel needs to shuffle the data around first before | |
661 | * sending it away. Cache coherency is handled by braketing any transactions | |
662 | * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access() | |
663 | * access. | |
664 | * | |
665 | * To support dma_buf objects residing in highmem cpu access is page-based | |
666 | * using an api similar to kmap. Accessing a dma_buf is done in aligned chunks | |
667 | * of PAGE_SIZE size. Before accessing a chunk it needs to be mapped, which | |
668 | * returns a pointer in kernel virtual address space. Afterwards the chunk | |
669 | * needs to be unmapped again. There is no limit on how often a given chunk | |
670 | * can be mapped and unmapped, i.e. the importer does not need to call | |
671 | * begin_cpu_access again before mapping the same chunk again. | |
672 | * | |
673 | * Interfaces:: | |
674 | * void \*dma_buf_kmap(struct dma_buf \*, unsigned long); | |
675 | * void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*); | |
676 | * | |
f664a526 CK |
677 | * Implementing the functions is optional for exporters and for importers all |
678 | * the restrictions of using kmap apply. | |
0959a168 DV |
679 | * |
680 | * dma_buf kmap calls outside of the range specified in begin_cpu_access are | |
681 | * undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on | |
682 | * the partial chunks at the beginning and end but may return stale or bogus | |
683 | * data outside of the range (in these partial chunks). | |
684 | * | |
0959a168 DV |
685 | * For some cases the overhead of kmap can be too high, a vmap interface |
686 | * is introduced. This interface should be used very carefully, as vmalloc | |
687 | * space is a limited resources on many architectures. | |
688 | * | |
689 | * Interfaces:: | |
690 | * void \*dma_buf_vmap(struct dma_buf \*dmabuf) | |
691 | * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr) | |
692 | * | |
693 | * The vmap call can fail if there is no vmap support in the exporter, or if | |
694 | * it runs out of vmalloc space. Fallback to kmap should be implemented. Note | |
695 | * that the dma-buf layer keeps a reference count for all vmap access and | |
696 | * calls down into the exporter's vmap function only when no vmapping exists, | |
697 | * and only unmaps it once. Protection against concurrent vmap/vunmap calls is | |
698 | * provided by taking the dma_buf->lock mutex. | |
699 | * | |
700 | * - For full compatibility on the importer side with existing userspace | |
701 | * interfaces, which might already support mmap'ing buffers. This is needed in | |
702 | * many processing pipelines (e.g. feeding a software rendered image into a | |
703 | * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION | |
704 | * framework already supported this and for DMA buffer file descriptors to | |
705 | * replace ION buffers mmap support was needed. | |
706 | * | |
707 | * There is no special interfaces, userspace simply calls mmap on the dma-buf | |
708 | * fd. But like for CPU access there's a need to braket the actual access, | |
709 | * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that | |
710 | * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must | |
711 | * be restarted. | |
712 | * | |
713 | * Some systems might need some sort of cache coherency management e.g. when | |
714 | * CPU and GPU domains are being accessed through dma-buf at the same time. | |
715 | * To circumvent this problem there are begin/end coherency markers, that | |
716 | * forward directly to existing dma-buf device drivers vfunc hooks. Userspace | |
717 | * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The | |
718 | * sequence would be used like following: | |
719 | * | |
720 | * - mmap dma-buf fd | |
721 | * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write | |
722 | * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you | |
723 | * want (with the new data being consumed by say the GPU or the scanout | |
724 | * device) | |
725 | * - munmap once you don't need the buffer any more | |
726 | * | |
727 | * For correctness and optimal performance, it is always required to use | |
728 | * SYNC_START and SYNC_END before and after, respectively, when accessing the | |
729 | * mapped address. Userspace cannot rely on coherent access, even when there | |
730 | * are systems where it just works without calling these ioctls. | |
731 | * | |
732 | * - And as a CPU fallback in userspace processing pipelines. | |
733 | * | |
734 | * Similar to the motivation for kernel cpu access it is again important that | |
735 | * the userspace code of a given importing subsystem can use the same | |
736 | * interfaces with a imported dma-buf buffer object as with a native buffer | |
737 | * object. This is especially important for drm where the userspace part of | |
738 | * contemporary OpenGL, X, and other drivers is huge, and reworking them to | |
739 | * use a different way to mmap a buffer rather invasive. | |
740 | * | |
741 | * The assumption in the current dma-buf interfaces is that redirecting the | |
742 | * initial mmap is all that's needed. A survey of some of the existing | |
743 | * subsystems shows that no driver seems to do any nefarious thing like | |
744 | * syncing up with outstanding asynchronous processing on the device or | |
745 | * allocating special resources at fault time. So hopefully this is good | |
746 | * enough, since adding interfaces to intercept pagefaults and allow pte | |
747 | * shootdowns would increase the complexity quite a bit. | |
748 | * | |
749 | * Interface:: | |
750 | * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*, | |
751 | * unsigned long); | |
752 | * | |
753 | * If the importing subsystem simply provides a special-purpose mmap call to | |
754 | * set up a mapping in userspace, calling do_mmap with dma_buf->file will | |
755 | * equally achieve that for a dma-buf object. | |
756 | */ | |
757 | ||
ae4e46b1 CW |
758 | static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
759 | enum dma_data_direction direction) | |
760 | { | |
761 | bool write = (direction == DMA_BIDIRECTIONAL || | |
762 | direction == DMA_TO_DEVICE); | |
763 | struct reservation_object *resv = dmabuf->resv; | |
764 | long ret; | |
765 | ||
766 | /* Wait on any implicit rendering fences */ | |
767 | ret = reservation_object_wait_timeout_rcu(resv, write, true, | |
768 | MAX_SCHEDULE_TIMEOUT); | |
769 | if (ret < 0) | |
770 | return ret; | |
771 | ||
772 | return 0; | |
773 | } | |
fc13020e DV |
774 | |
775 | /** | |
776 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
777 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
778 | * preparations. Coherency is only guaranteed in the specified range for the | |
779 | * specified access direction. | |
efb4df82 | 780 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
781 | * @direction: [in] length of range for cpu access. |
782 | * | |
0959a168 DV |
783 | * After the cpu access is complete the caller should call |
784 | * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is | |
785 | * it guaranteed to be coherent with other DMA access. | |
786 | * | |
fc13020e DV |
787 | * Can return negative error values, returns 0 on success. |
788 | */ | |
831e9da7 | 789 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
790 | enum dma_data_direction direction) |
791 | { | |
792 | int ret = 0; | |
793 | ||
794 | if (WARN_ON(!dmabuf)) | |
795 | return -EINVAL; | |
796 | ||
797 | if (dmabuf->ops->begin_cpu_access) | |
831e9da7 | 798 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e | 799 | |
ae4e46b1 CW |
800 | /* Ensure that all fences are waited upon - but we first allow |
801 | * the native handler the chance to do so more efficiently if it | |
802 | * chooses. A double invocation here will be reasonably cheap no-op. | |
803 | */ | |
804 | if (ret == 0) | |
805 | ret = __dma_buf_begin_cpu_access(dmabuf, direction); | |
806 | ||
fc13020e DV |
807 | return ret; |
808 | } | |
809 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
810 | ||
811 | /** | |
812 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
813 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
814 | * actions. Coherency is only guaranteed in the specified range for the | |
815 | * specified access direction. | |
efb4df82 | 816 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
817 | * @direction: [in] length of range for cpu access. |
818 | * | |
0959a168 DV |
819 | * This terminates CPU access started with dma_buf_begin_cpu_access(). |
820 | * | |
87e332d5 | 821 | * Can return negative error values, returns 0 on success. |
fc13020e | 822 | */ |
18b862dc CW |
823 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
824 | enum dma_data_direction direction) | |
fc13020e | 825 | { |
18b862dc CW |
826 | int ret = 0; |
827 | ||
fc13020e DV |
828 | WARN_ON(!dmabuf); |
829 | ||
830 | if (dmabuf->ops->end_cpu_access) | |
18b862dc CW |
831 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
832 | ||
833 | return ret; | |
fc13020e DV |
834 | } |
835 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
836 | ||
fc13020e DV |
837 | /** |
838 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
839 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 840 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
841 | * @page_num: [in] page in PAGE_SIZE units to map. |
842 | * | |
843 | * This call must always succeed, any necessary preparations that might fail | |
844 | * need to be done in begin_cpu_access. | |
845 | */ | |
846 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
847 | { | |
848 | WARN_ON(!dmabuf); | |
849 | ||
09ea0dfb GH |
850 | if (!dmabuf->ops->map) |
851 | return NULL; | |
f9b67f00 | 852 | return dmabuf->ops->map(dmabuf, page_num); |
fc13020e DV |
853 | } |
854 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
855 | ||
856 | /** | |
857 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 858 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
859 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
860 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
861 | * | |
862 | * This call must always succeed. | |
863 | */ | |
864 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
865 | void *vaddr) | |
866 | { | |
867 | WARN_ON(!dmabuf); | |
868 | ||
f9b67f00 LG |
869 | if (dmabuf->ops->unmap) |
870 | dmabuf->ops->unmap(dmabuf, page_num, vaddr); | |
fc13020e DV |
871 | } |
872 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
873 | |
874 | ||
875 | /** | |
876 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 877 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
878 | * @vma: [in] vma for the mmap |
879 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 880 | * dma-buf buffer. |
4c78513e DV |
881 | * |
882 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 883 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
884 | * checking on the size of the vma. Then it calls the exporters mmap function to |
885 | * set up the mapping. | |
886 | * | |
887 | * Can return negative error values, returns 0 on success. | |
888 | */ | |
889 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
890 | unsigned long pgoff) | |
891 | { | |
495c10cc JS |
892 | struct file *oldfile; |
893 | int ret; | |
894 | ||
4c78513e DV |
895 | if (WARN_ON(!dmabuf || !vma)) |
896 | return -EINVAL; | |
897 | ||
898 | /* check for offset overflow */ | |
b02da6f8 | 899 | if (pgoff + vma_pages(vma) < pgoff) |
4c78513e DV |
900 | return -EOVERFLOW; |
901 | ||
902 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 903 | if (pgoff + vma_pages(vma) > |
4c78513e DV |
904 | dmabuf->size >> PAGE_SHIFT) |
905 | return -EINVAL; | |
906 | ||
907 | /* readjust the vma */ | |
495c10cc JS |
908 | get_file(dmabuf->file); |
909 | oldfile = vma->vm_file; | |
910 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
911 | vma->vm_pgoff = pgoff; |
912 | ||
495c10cc JS |
913 | ret = dmabuf->ops->mmap(dmabuf, vma); |
914 | if (ret) { | |
915 | /* restore old parameters on failure */ | |
916 | vma->vm_file = oldfile; | |
917 | fput(dmabuf->file); | |
918 | } else { | |
919 | if (oldfile) | |
920 | fput(oldfile); | |
921 | } | |
922 | return ret; | |
923 | ||
4c78513e DV |
924 | } |
925 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
926 | |
927 | /** | |
12c4727e SS |
928 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
929 | * address space. Same restrictions as for vmap and friends apply. | |
930 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
931 | * |
932 | * This call may fail due to lack of virtual mapping address space. | |
933 | * These calls are optional in drivers. The intended use for them | |
934 | * is for mapping objects linear in kernel space for high use objects. | |
935 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
936 | * |
937 | * Returns NULL on error. | |
98f86c9e DA |
938 | */ |
939 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
940 | { | |
f00b4dad DV |
941 | void *ptr; |
942 | ||
98f86c9e DA |
943 | if (WARN_ON(!dmabuf)) |
944 | return NULL; | |
945 | ||
f00b4dad DV |
946 | if (!dmabuf->ops->vmap) |
947 | return NULL; | |
948 | ||
949 | mutex_lock(&dmabuf->lock); | |
950 | if (dmabuf->vmapping_counter) { | |
951 | dmabuf->vmapping_counter++; | |
952 | BUG_ON(!dmabuf->vmap_ptr); | |
953 | ptr = dmabuf->vmap_ptr; | |
954 | goto out_unlock; | |
955 | } | |
956 | ||
957 | BUG_ON(dmabuf->vmap_ptr); | |
958 | ||
959 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
960 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
961 | ptr = NULL; | |
962 | if (!ptr) | |
f00b4dad DV |
963 | goto out_unlock; |
964 | ||
965 | dmabuf->vmap_ptr = ptr; | |
966 | dmabuf->vmapping_counter = 1; | |
967 | ||
968 | out_unlock: | |
969 | mutex_unlock(&dmabuf->lock); | |
970 | return ptr; | |
98f86c9e DA |
971 | } |
972 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
973 | ||
974 | /** | |
975 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 976 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 977 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
978 | */ |
979 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
980 | { | |
981 | if (WARN_ON(!dmabuf)) | |
982 | return; | |
983 | ||
f00b4dad DV |
984 | BUG_ON(!dmabuf->vmap_ptr); |
985 | BUG_ON(dmabuf->vmapping_counter == 0); | |
986 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
987 | ||
988 | mutex_lock(&dmabuf->lock); | |
989 | if (--dmabuf->vmapping_counter == 0) { | |
990 | if (dmabuf->ops->vunmap) | |
991 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
992 | dmabuf->vmap_ptr = NULL; | |
993 | } | |
994 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
995 | } |
996 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
997 | |
998 | #ifdef CONFIG_DEBUG_FS | |
eb0b947e | 999 | static int dma_buf_debug_show(struct seq_file *s, void *unused) |
b89e3563 SS |
1000 | { |
1001 | int ret; | |
1002 | struct dma_buf *buf_obj; | |
1003 | struct dma_buf_attachment *attach_obj; | |
5eb2c72c RK |
1004 | struct reservation_object *robj; |
1005 | struct reservation_object_list *fobj; | |
1006 | struct dma_fence *fence; | |
1007 | unsigned seq; | |
1008 | int count = 0, attach_count, shared_count, i; | |
b89e3563 SS |
1009 | size_t size = 0; |
1010 | ||
1011 | ret = mutex_lock_interruptible(&db_list.lock); | |
1012 | ||
1013 | if (ret) | |
1014 | return ret; | |
1015 | ||
c0b00a52 | 1016 | seq_puts(s, "\nDma-buf Objects:\n"); |
da6c8f5e RK |
1017 | seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\n", |
1018 | "size", "flags", "mode", "count"); | |
b89e3563 SS |
1019 | |
1020 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
1021 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
1022 | ||
1023 | if (ret) { | |
c0b00a52 SS |
1024 | seq_puts(s, |
1025 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
1026 | continue; |
1027 | } | |
1028 | ||
c0b00a52 SS |
1029 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", |
1030 | buf_obj->size, | |
b89e3563 | 1031 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 1032 | file_count(buf_obj->file), |
c0b00a52 | 1033 | buf_obj->exp_name); |
b89e3563 | 1034 | |
5eb2c72c RK |
1035 | robj = buf_obj->resv; |
1036 | while (true) { | |
1037 | seq = read_seqcount_begin(&robj->seq); | |
1038 | rcu_read_lock(); | |
1039 | fobj = rcu_dereference(robj->fence); | |
1040 | shared_count = fobj ? fobj->shared_count : 0; | |
1041 | fence = rcu_dereference(robj->fence_excl); | |
1042 | if (!read_seqcount_retry(&robj->seq, seq)) | |
1043 | break; | |
1044 | rcu_read_unlock(); | |
1045 | } | |
1046 | ||
1047 | if (fence) | |
1048 | seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", | |
1049 | fence->ops->get_driver_name(fence), | |
1050 | fence->ops->get_timeline_name(fence), | |
1051 | dma_fence_is_signaled(fence) ? "" : "un"); | |
1052 | for (i = 0; i < shared_count; i++) { | |
1053 | fence = rcu_dereference(fobj->shared[i]); | |
1054 | if (!dma_fence_get_rcu(fence)) | |
1055 | continue; | |
1056 | seq_printf(s, "\tShared fence: %s %s %ssignalled\n", | |
1057 | fence->ops->get_driver_name(fence), | |
1058 | fence->ops->get_timeline_name(fence), | |
1059 | dma_fence_is_signaled(fence) ? "" : "un"); | |
1060 | } | |
1061 | rcu_read_unlock(); | |
1062 | ||
c0b00a52 | 1063 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
1064 | attach_count = 0; |
1065 | ||
1066 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
9eddb41d | 1067 | seq_printf(s, "\t%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
1068 | attach_count++; |
1069 | } | |
1070 | ||
c0b00a52 | 1071 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
1072 | attach_count); |
1073 | ||
1074 | count++; | |
1075 | size += buf_obj->size; | |
1076 | mutex_unlock(&buf_obj->lock); | |
1077 | } | |
1078 | ||
1079 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
1080 | ||
1081 | mutex_unlock(&db_list.lock); | |
1082 | return 0; | |
1083 | } | |
1084 | ||
2674305a | 1085 | DEFINE_SHOW_ATTRIBUTE(dma_buf_debug); |
b89e3563 SS |
1086 | |
1087 | static struct dentry *dma_buf_debugfs_dir; | |
1088 | ||
1089 | static int dma_buf_init_debugfs(void) | |
1090 | { | |
bd3e2208 | 1091 | struct dentry *d; |
b89e3563 | 1092 | int err = 0; |
5136629d | 1093 | |
bd3e2208 MK |
1094 | d = debugfs_create_dir("dma_buf", NULL); |
1095 | if (IS_ERR(d)) | |
1096 | return PTR_ERR(d); | |
5136629d | 1097 | |
bd3e2208 | 1098 | dma_buf_debugfs_dir = d; |
b89e3563 | 1099 | |
bd3e2208 MK |
1100 | d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, |
1101 | NULL, &dma_buf_debug_fops); | |
1102 | if (IS_ERR(d)) { | |
b89e3563 | 1103 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); |
b7479990 MK |
1104 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
1105 | dma_buf_debugfs_dir = NULL; | |
bd3e2208 | 1106 | err = PTR_ERR(d); |
b7479990 | 1107 | } |
b89e3563 SS |
1108 | |
1109 | return err; | |
1110 | } | |
1111 | ||
1112 | static void dma_buf_uninit_debugfs(void) | |
1113 | { | |
298b6a81 | 1114 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
b89e3563 | 1115 | } |
b89e3563 SS |
1116 | #else |
1117 | static inline int dma_buf_init_debugfs(void) | |
1118 | { | |
1119 | return 0; | |
1120 | } | |
1121 | static inline void dma_buf_uninit_debugfs(void) | |
1122 | { | |
1123 | } | |
1124 | #endif | |
1125 | ||
1126 | static int __init dma_buf_init(void) | |
1127 | { | |
1128 | mutex_init(&db_list.lock); | |
1129 | INIT_LIST_HEAD(&db_list.head); | |
1130 | dma_buf_init_debugfs(); | |
1131 | return 0; | |
1132 | } | |
1133 | subsys_initcall(dma_buf_init); | |
1134 | ||
1135 | static void __exit dma_buf_deinit(void) | |
1136 | { | |
1137 | dma_buf_uninit_debugfs(); | |
1138 | } | |
1139 | __exitcall(dma_buf_deinit); |