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> |
ed63bb1d | 37 | #include <linux/mount.h> |
d15bd7ee | 38 | |
c11e391d | 39 | #include <uapi/linux/dma-buf.h> |
ed63bb1d | 40 | #include <uapi/linux/magic.h> |
c11e391d | 41 | |
d15bd7ee SS |
42 | static inline int is_dma_buf_file(struct file *); |
43 | ||
b89e3563 SS |
44 | struct dma_buf_list { |
45 | struct list_head head; | |
46 | struct mutex lock; | |
47 | }; | |
48 | ||
49 | static struct dma_buf_list db_list; | |
50 | ||
bb2bb903 GH |
51 | static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen) |
52 | { | |
53 | struct dma_buf *dmabuf; | |
54 | char name[DMA_BUF_NAME_LEN]; | |
55 | size_t ret = 0; | |
56 | ||
57 | dmabuf = dentry->d_fsdata; | |
58 | mutex_lock(&dmabuf->lock); | |
59 | if (dmabuf->name) | |
60 | ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN); | |
61 | mutex_unlock(&dmabuf->lock); | |
62 | ||
63 | return dynamic_dname(dentry, buffer, buflen, "/%s:%s", | |
64 | dentry->d_name.name, ret > 0 ? name : ""); | |
65 | } | |
66 | ||
ed63bb1d | 67 | static const struct dentry_operations dma_buf_dentry_ops = { |
bb2bb903 | 68 | .d_dname = dmabuffs_dname, |
ed63bb1d GH |
69 | }; |
70 | ||
71 | static struct vfsmount *dma_buf_mnt; | |
72 | ||
73 | static struct dentry *dma_buf_fs_mount(struct file_system_type *fs_type, | |
74 | int flags, const char *name, void *data) | |
75 | { | |
76 | return mount_pseudo(fs_type, "dmabuf:", NULL, &dma_buf_dentry_ops, | |
77 | DMA_BUF_MAGIC); | |
78 | } | |
79 | ||
80 | static struct file_system_type dma_buf_fs_type = { | |
81 | .name = "dmabuf", | |
82 | .mount = dma_buf_fs_mount, | |
83 | .kill_sb = kill_anon_super, | |
84 | }; | |
85 | ||
d15bd7ee SS |
86 | static int dma_buf_release(struct inode *inode, struct file *file) |
87 | { | |
88 | struct dma_buf *dmabuf; | |
89 | ||
90 | if (!is_dma_buf_file(file)) | |
91 | return -EINVAL; | |
92 | ||
93 | dmabuf = file->private_data; | |
94 | ||
f00b4dad DV |
95 | BUG_ON(dmabuf->vmapping_counter); |
96 | ||
9b495a58 ML |
97 | /* |
98 | * Any fences that a dma-buf poll can wait on should be signaled | |
99 | * before releasing dma-buf. This is the responsibility of each | |
100 | * driver that uses the reservation objects. | |
101 | * | |
102 | * If you hit this BUG() it means someone dropped their ref to the | |
103 | * dma-buf while still having pending operation to the buffer. | |
104 | */ | |
105 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
106 | ||
d15bd7ee | 107 | dmabuf->ops->release(dmabuf); |
b89e3563 SS |
108 | |
109 | mutex_lock(&db_list.lock); | |
110 | list_del(&dmabuf->list_node); | |
111 | mutex_unlock(&db_list.lock); | |
112 | ||
3aac4502 ML |
113 | if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) |
114 | reservation_object_fini(dmabuf->resv); | |
115 | ||
9abdffe2 | 116 | module_put(dmabuf->owner); |
d15bd7ee SS |
117 | kfree(dmabuf); |
118 | return 0; | |
119 | } | |
120 | ||
4c78513e DV |
121 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
122 | { | |
123 | struct dma_buf *dmabuf; | |
124 | ||
125 | if (!is_dma_buf_file(file)) | |
126 | return -EINVAL; | |
127 | ||
128 | dmabuf = file->private_data; | |
129 | ||
e3a9d6c5 AD |
130 | /* check if buffer supports mmap */ |
131 | if (!dmabuf->ops->mmap) | |
132 | return -EINVAL; | |
133 | ||
4c78513e | 134 | /* check for overflowing the buffer's size */ |
b02da6f8 | 135 | if (vma->vm_pgoff + vma_pages(vma) > |
4c78513e DV |
136 | dmabuf->size >> PAGE_SHIFT) |
137 | return -EINVAL; | |
138 | ||
139 | return dmabuf->ops->mmap(dmabuf, vma); | |
140 | } | |
141 | ||
19e8697b CJHR |
142 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
143 | { | |
144 | struct dma_buf *dmabuf; | |
145 | loff_t base; | |
146 | ||
147 | if (!is_dma_buf_file(file)) | |
148 | return -EBADF; | |
149 | ||
150 | dmabuf = file->private_data; | |
151 | ||
152 | /* only support discovering the end of the buffer, | |
153 | but also allow SEEK_SET to maintain the idiomatic | |
154 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
155 | if (whence == SEEK_END) | |
156 | base = dmabuf->size; | |
157 | else if (whence == SEEK_SET) | |
158 | base = 0; | |
159 | else | |
160 | return -EINVAL; | |
161 | ||
162 | if (offset != 0) | |
163 | return -EINVAL; | |
164 | ||
165 | return base + offset; | |
166 | } | |
167 | ||
e7e21c72 DV |
168 | /** |
169 | * DOC: fence polling | |
170 | * | |
171 | * To support cross-device and cross-driver synchronization of buffer access | |
f641d3b5 | 172 | * implicit fences (represented internally in the kernel with &struct fence) can |
e7e21c72 DV |
173 | * be attached to a &dma_buf. The glue for that and a few related things are |
174 | * provided in the &reservation_object structure. | |
175 | * | |
176 | * Userspace can query the state of these implicitly tracked fences using poll() | |
177 | * and related system calls: | |
178 | * | |
a9a08845 | 179 | * - Checking for EPOLLIN, i.e. read access, can be use to query the state of the |
e7e21c72 DV |
180 | * most recent write or exclusive fence. |
181 | * | |
a9a08845 | 182 | * - Checking for EPOLLOUT, i.e. write access, can be used to query the state of |
e7e21c72 DV |
183 | * all attached fences, shared and exclusive ones. |
184 | * | |
185 | * Note that this only signals the completion of the respective fences, i.e. the | |
186 | * DMA transfers are complete. Cache flushing and any other necessary | |
187 | * preparations before CPU access can begin still need to happen. | |
188 | */ | |
189 | ||
f54d1867 | 190 | static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb) |
9b495a58 ML |
191 | { |
192 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
193 | unsigned long flags; | |
194 | ||
195 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
196 | wake_up_locked_poll(dcb->poll, dcb->active); | |
197 | dcb->active = 0; | |
198 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
199 | } | |
200 | ||
afc9a42b | 201 | static __poll_t dma_buf_poll(struct file *file, poll_table *poll) |
9b495a58 ML |
202 | { |
203 | struct dma_buf *dmabuf; | |
204 | struct reservation_object *resv; | |
04a5faa8 | 205 | struct reservation_object_list *fobj; |
f54d1867 | 206 | struct dma_fence *fence_excl; |
01699437 | 207 | __poll_t events; |
3c3b177a | 208 | unsigned shared_count, seq; |
9b495a58 ML |
209 | |
210 | dmabuf = file->private_data; | |
211 | if (!dmabuf || !dmabuf->resv) | |
a9a08845 | 212 | return EPOLLERR; |
9b495a58 ML |
213 | |
214 | resv = dmabuf->resv; | |
215 | ||
216 | poll_wait(file, &dmabuf->poll, poll); | |
217 | ||
a9a08845 | 218 | events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT); |
9b495a58 ML |
219 | if (!events) |
220 | return 0; | |
221 | ||
3c3b177a ML |
222 | retry: |
223 | seq = read_seqcount_begin(&resv->seq); | |
224 | rcu_read_lock(); | |
9b495a58 | 225 | |
3c3b177a ML |
226 | fobj = rcu_dereference(resv->fence); |
227 | if (fobj) | |
228 | shared_count = fobj->shared_count; | |
229 | else | |
230 | shared_count = 0; | |
231 | fence_excl = rcu_dereference(resv->fence_excl); | |
232 | if (read_seqcount_retry(&resv->seq, seq)) { | |
233 | rcu_read_unlock(); | |
234 | goto retry; | |
235 | } | |
04a5faa8 | 236 | |
a9a08845 | 237 | if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) { |
9b495a58 | 238 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
a9a08845 | 239 | __poll_t pevents = EPOLLIN; |
9b495a58 | 240 | |
04a5faa8 | 241 | if (shared_count == 0) |
a9a08845 | 242 | pevents |= EPOLLOUT; |
9b495a58 ML |
243 | |
244 | spin_lock_irq(&dmabuf->poll.lock); | |
245 | if (dcb->active) { | |
246 | dcb->active |= pevents; | |
247 | events &= ~pevents; | |
248 | } else | |
249 | dcb->active = pevents; | |
250 | spin_unlock_irq(&dmabuf->poll.lock); | |
251 | ||
252 | if (events & pevents) { | |
f54d1867 | 253 | if (!dma_fence_get_rcu(fence_excl)) { |
3c3b177a ML |
254 | /* force a recheck */ |
255 | events &= ~pevents; | |
256 | dma_buf_poll_cb(NULL, &dcb->cb); | |
f54d1867 CW |
257 | } else if (!dma_fence_add_callback(fence_excl, &dcb->cb, |
258 | dma_buf_poll_cb)) { | |
9b495a58 | 259 | events &= ~pevents; |
f54d1867 | 260 | dma_fence_put(fence_excl); |
04a5faa8 | 261 | } else { |
9b495a58 ML |
262 | /* |
263 | * No callback queued, wake up any additional | |
264 | * waiters. | |
265 | */ | |
f54d1867 | 266 | dma_fence_put(fence_excl); |
9b495a58 | 267 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 268 | } |
9b495a58 ML |
269 | } |
270 | } | |
271 | ||
a9a08845 | 272 | if ((events & EPOLLOUT) && shared_count > 0) { |
9b495a58 ML |
273 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
274 | int i; | |
275 | ||
276 | /* Only queue a new callback if no event has fired yet */ | |
277 | spin_lock_irq(&dmabuf->poll.lock); | |
278 | if (dcb->active) | |
a9a08845 | 279 | events &= ~EPOLLOUT; |
9b495a58 | 280 | else |
a9a08845 | 281 | dcb->active = EPOLLOUT; |
9b495a58 ML |
282 | spin_unlock_irq(&dmabuf->poll.lock); |
283 | ||
a9a08845 | 284 | if (!(events & EPOLLOUT)) |
9b495a58 ML |
285 | goto out; |
286 | ||
04a5faa8 | 287 | for (i = 0; i < shared_count; ++i) { |
f54d1867 | 288 | struct dma_fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 289 | |
f54d1867 | 290 | if (!dma_fence_get_rcu(fence)) { |
3c3b177a ML |
291 | /* |
292 | * fence refcount dropped to zero, this means | |
293 | * that fobj has been freed | |
294 | * | |
295 | * call dma_buf_poll_cb and force a recheck! | |
296 | */ | |
a9a08845 | 297 | events &= ~EPOLLOUT; |
3c3b177a ML |
298 | dma_buf_poll_cb(NULL, &dcb->cb); |
299 | break; | |
300 | } | |
f54d1867 CW |
301 | if (!dma_fence_add_callback(fence, &dcb->cb, |
302 | dma_buf_poll_cb)) { | |
303 | dma_fence_put(fence); | |
a9a08845 | 304 | events &= ~EPOLLOUT; |
9b495a58 ML |
305 | break; |
306 | } | |
f54d1867 | 307 | dma_fence_put(fence); |
04a5faa8 | 308 | } |
9b495a58 ML |
309 | |
310 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 311 | if (i == shared_count) |
9b495a58 ML |
312 | dma_buf_poll_cb(NULL, &dcb->cb); |
313 | } | |
314 | ||
315 | out: | |
3c3b177a | 316 | rcu_read_unlock(); |
9b495a58 ML |
317 | return events; |
318 | } | |
319 | ||
bb2bb903 GH |
320 | /** |
321 | * dma_buf_set_name - Set a name to a specific dma_buf to track the usage. | |
322 | * The name of the dma-buf buffer can only be set when the dma-buf is not | |
323 | * attached to any devices. It could theoritically support changing the | |
324 | * name of the dma-buf if the same piece of memory is used for multiple | |
325 | * purpose between different devices. | |
326 | * | |
327 | * @dmabuf [in] dmabuf buffer that will be renamed. | |
328 | * @buf: [in] A piece of userspace memory that contains the name of | |
329 | * the dma-buf. | |
330 | * | |
331 | * Returns 0 on success. If the dma-buf buffer is already attached to | |
332 | * devices, return -EBUSY. | |
333 | * | |
334 | */ | |
335 | static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) | |
336 | { | |
337 | char *name = strndup_user(buf, DMA_BUF_NAME_LEN); | |
338 | long ret = 0; | |
339 | ||
340 | if (IS_ERR(name)) | |
341 | return PTR_ERR(name); | |
342 | ||
343 | mutex_lock(&dmabuf->lock); | |
344 | if (!list_empty(&dmabuf->attachments)) { | |
345 | ret = -EBUSY; | |
346 | kfree(name); | |
347 | goto out_unlock; | |
348 | } | |
349 | kfree(dmabuf->name); | |
350 | dmabuf->name = name; | |
351 | ||
352 | out_unlock: | |
353 | mutex_unlock(&dmabuf->lock); | |
354 | return ret; | |
355 | } | |
356 | ||
c11e391d DV |
357 | static long dma_buf_ioctl(struct file *file, |
358 | unsigned int cmd, unsigned long arg) | |
359 | { | |
360 | struct dma_buf *dmabuf; | |
361 | struct dma_buf_sync sync; | |
362 | enum dma_data_direction direction; | |
18b862dc | 363 | int ret; |
c11e391d DV |
364 | |
365 | dmabuf = file->private_data; | |
366 | ||
367 | switch (cmd) { | |
368 | case DMA_BUF_IOCTL_SYNC: | |
369 | if (copy_from_user(&sync, (void __user *) arg, sizeof(sync))) | |
370 | return -EFAULT; | |
371 | ||
372 | if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK) | |
373 | return -EINVAL; | |
374 | ||
375 | switch (sync.flags & DMA_BUF_SYNC_RW) { | |
376 | case DMA_BUF_SYNC_READ: | |
377 | direction = DMA_FROM_DEVICE; | |
378 | break; | |
379 | case DMA_BUF_SYNC_WRITE: | |
380 | direction = DMA_TO_DEVICE; | |
381 | break; | |
382 | case DMA_BUF_SYNC_RW: | |
383 | direction = DMA_BIDIRECTIONAL; | |
384 | break; | |
385 | default: | |
386 | return -EINVAL; | |
387 | } | |
388 | ||
389 | if (sync.flags & DMA_BUF_SYNC_END) | |
18b862dc | 390 | ret = dma_buf_end_cpu_access(dmabuf, direction); |
c11e391d | 391 | else |
18b862dc | 392 | ret = dma_buf_begin_cpu_access(dmabuf, direction); |
c11e391d | 393 | |
18b862dc | 394 | return ret; |
bb2bb903 GH |
395 | |
396 | case DMA_BUF_SET_NAME: | |
397 | return dma_buf_set_name(dmabuf, (const char __user *)arg); | |
398 | ||
c11e391d DV |
399 | default: |
400 | return -ENOTTY; | |
401 | } | |
402 | } | |
403 | ||
d15bd7ee SS |
404 | static const struct file_operations dma_buf_fops = { |
405 | .release = dma_buf_release, | |
4c78513e | 406 | .mmap = dma_buf_mmap_internal, |
19e8697b | 407 | .llseek = dma_buf_llseek, |
9b495a58 | 408 | .poll = dma_buf_poll, |
c11e391d | 409 | .unlocked_ioctl = dma_buf_ioctl, |
888022c0 MS |
410 | #ifdef CONFIG_COMPAT |
411 | .compat_ioctl = dma_buf_ioctl, | |
412 | #endif | |
d15bd7ee SS |
413 | }; |
414 | ||
415 | /* | |
416 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
417 | */ | |
418 | static inline int is_dma_buf_file(struct file *file) | |
419 | { | |
420 | return file->f_op == &dma_buf_fops; | |
421 | } | |
422 | ||
ed63bb1d GH |
423 | static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags) |
424 | { | |
425 | struct file *file; | |
426 | struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb); | |
427 | ||
428 | if (IS_ERR(inode)) | |
429 | return ERR_CAST(inode); | |
430 | ||
431 | inode->i_size = dmabuf->size; | |
432 | inode_set_bytes(inode, dmabuf->size); | |
433 | ||
434 | file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf", | |
435 | flags, &dma_buf_fops); | |
436 | if (IS_ERR(file)) | |
437 | goto err_alloc_file; | |
438 | file->f_flags = flags & (O_ACCMODE | O_NONBLOCK); | |
439 | file->private_data = dmabuf; | |
bb2bb903 | 440 | file->f_path.dentry->d_fsdata = dmabuf; |
ed63bb1d GH |
441 | |
442 | return file; | |
443 | ||
444 | err_alloc_file: | |
445 | iput(inode); | |
446 | return file; | |
447 | } | |
448 | ||
2904a8c1 DV |
449 | /** |
450 | * DOC: dma buf device access | |
451 | * | |
452 | * For device DMA access to a shared DMA buffer the usual sequence of operations | |
453 | * is fairly simple: | |
454 | * | |
455 | * 1. The exporter defines his exporter instance using | |
456 | * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private | |
457 | * buffer object into a &dma_buf. It then exports that &dma_buf to userspace | |
458 | * as a file descriptor by calling dma_buf_fd(). | |
459 | * | |
460 | * 2. Userspace passes this file-descriptors to all drivers it wants this buffer | |
461 | * to share with: First the filedescriptor is converted to a &dma_buf using | |
c138782d | 462 | * dma_buf_get(). Then the buffer is attached to the device using |
2904a8c1 DV |
463 | * dma_buf_attach(). |
464 | * | |
465 | * Up to this stage the exporter is still free to migrate or reallocate the | |
466 | * backing storage. | |
467 | * | |
c138782d | 468 | * 3. Once the buffer is attached to all devices userspace can initiate DMA |
2904a8c1 DV |
469 | * access to the shared buffer. In the kernel this is done by calling |
470 | * dma_buf_map_attachment() and dma_buf_unmap_attachment(). | |
471 | * | |
472 | * 4. Once a driver is done with a shared buffer it needs to call | |
473 | * dma_buf_detach() (after cleaning up any mappings) and then release the | |
474 | * reference acquired with dma_buf_get by calling dma_buf_put(). | |
475 | * | |
476 | * For the detailed semantics exporters are expected to implement see | |
477 | * &dma_buf_ops. | |
478 | */ | |
479 | ||
d15bd7ee | 480 | /** |
d8fbe341 | 481 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
482 | * with this buffer, so it can be exported. |
483 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 484 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 485 | * |
d8fbe341 | 486 | * @exp_info: [in] holds all the export related information provided |
f641d3b5 | 487 | * by the exporter. see &struct dma_buf_export_info |
d8fbe341 | 488 | * for further details. |
d15bd7ee SS |
489 | * |
490 | * Returns, on success, a newly created dma_buf object, which wraps the | |
491 | * supplied private data and operations for dma_buf_ops. On either missing | |
492 | * ops, or error in allocating struct dma_buf, will return negative error. | |
493 | * | |
2904a8c1 DV |
494 | * For most cases the easiest way to create @exp_info is through the |
495 | * %DEFINE_DMA_BUF_EXPORT_INFO macro. | |
d15bd7ee | 496 | */ |
d8fbe341 | 497 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
498 | { |
499 | struct dma_buf *dmabuf; | |
d8fbe341 | 500 | struct reservation_object *resv = exp_info->resv; |
d15bd7ee | 501 | struct file *file; |
3aac4502 | 502 | size_t alloc_size = sizeof(struct dma_buf); |
a026df4c | 503 | int ret; |
5136629d | 504 | |
d8fbe341 | 505 | if (!exp_info->resv) |
3aac4502 ML |
506 | alloc_size += sizeof(struct reservation_object); |
507 | else | |
508 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
509 | alloc_size += 1; | |
d15bd7ee | 510 | |
d8fbe341 SS |
511 | if (WARN_ON(!exp_info->priv |
512 | || !exp_info->ops | |
513 | || !exp_info->ops->map_dma_buf | |
514 | || !exp_info->ops->unmap_dma_buf | |
e3a9d6c5 | 515 | || !exp_info->ops->release)) { |
d15bd7ee SS |
516 | return ERR_PTR(-EINVAL); |
517 | } | |
518 | ||
9abdffe2 SS |
519 | if (!try_module_get(exp_info->owner)) |
520 | return ERR_PTR(-ENOENT); | |
521 | ||
3aac4502 | 522 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 | 523 | if (!dmabuf) { |
a026df4c CW |
524 | ret = -ENOMEM; |
525 | goto err_module; | |
9abdffe2 | 526 | } |
d15bd7ee | 527 | |
d8fbe341 SS |
528 | dmabuf->priv = exp_info->priv; |
529 | dmabuf->ops = exp_info->ops; | |
530 | dmabuf->size = exp_info->size; | |
531 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 532 | dmabuf->owner = exp_info->owner; |
9b495a58 ML |
533 | init_waitqueue_head(&dmabuf->poll); |
534 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
535 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
536 | ||
3aac4502 ML |
537 | if (!resv) { |
538 | resv = (struct reservation_object *)&dmabuf[1]; | |
539 | reservation_object_init(resv); | |
540 | } | |
541 | dmabuf->resv = resv; | |
d15bd7ee | 542 | |
ed63bb1d | 543 | file = dma_buf_getfile(dmabuf, exp_info->flags); |
9022e24e | 544 | if (IS_ERR(file)) { |
a026df4c CW |
545 | ret = PTR_ERR(file); |
546 | goto err_dmabuf; | |
9022e24e | 547 | } |
19e8697b CJHR |
548 | |
549 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
550 | dmabuf->file = file; |
551 | ||
552 | mutex_init(&dmabuf->lock); | |
553 | INIT_LIST_HEAD(&dmabuf->attachments); | |
554 | ||
b89e3563 SS |
555 | mutex_lock(&db_list.lock); |
556 | list_add(&dmabuf->list_node, &db_list.head); | |
557 | mutex_unlock(&db_list.lock); | |
558 | ||
d15bd7ee | 559 | return dmabuf; |
a026df4c CW |
560 | |
561 | err_dmabuf: | |
562 | kfree(dmabuf); | |
563 | err_module: | |
564 | module_put(exp_info->owner); | |
565 | return ERR_PTR(ret); | |
d15bd7ee | 566 | } |
d8fbe341 | 567 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
568 | |
569 | /** | |
570 | * dma_buf_fd - returns a file descriptor for the given dma_buf | |
571 | * @dmabuf: [in] pointer to dma_buf for which fd is required. | |
55c1c4ca | 572 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
573 | * |
574 | * On success, returns an associated 'fd'. Else, returns error. | |
575 | */ | |
55c1c4ca | 576 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 577 | { |
f5e097f0 | 578 | int fd; |
d15bd7ee SS |
579 | |
580 | if (!dmabuf || !dmabuf->file) | |
581 | return -EINVAL; | |
582 | ||
f5e097f0 BP |
583 | fd = get_unused_fd_flags(flags); |
584 | if (fd < 0) | |
585 | return fd; | |
d15bd7ee SS |
586 | |
587 | fd_install(fd, dmabuf->file); | |
588 | ||
589 | return fd; | |
590 | } | |
591 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
592 | ||
593 | /** | |
594 | * dma_buf_get - returns the dma_buf structure related to an fd | |
595 | * @fd: [in] fd associated with the dma_buf to be returned | |
596 | * | |
597 | * On success, returns the dma_buf structure associated with an fd; uses | |
598 | * file's refcounting done by fget to increase refcount. returns ERR_PTR | |
599 | * otherwise. | |
600 | */ | |
601 | struct dma_buf *dma_buf_get(int fd) | |
602 | { | |
603 | struct file *file; | |
604 | ||
605 | file = fget(fd); | |
606 | ||
607 | if (!file) | |
608 | return ERR_PTR(-EBADF); | |
609 | ||
610 | if (!is_dma_buf_file(file)) { | |
611 | fput(file); | |
612 | return ERR_PTR(-EINVAL); | |
613 | } | |
614 | ||
615 | return file->private_data; | |
616 | } | |
617 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
618 | ||
619 | /** | |
620 | * dma_buf_put - decreases refcount of the buffer | |
621 | * @dmabuf: [in] buffer to reduce refcount of | |
622 | * | |
2904a8c1 DV |
623 | * Uses file's refcounting done implicitly by fput(). |
624 | * | |
625 | * If, as a result of this call, the refcount becomes 0, the 'release' file | |
e9b4d7b5 DV |
626 | * operation related to this fd is called. It calls &dma_buf_ops.release vfunc |
627 | * in turn, and frees the memory allocated for dmabuf when exported. | |
d15bd7ee SS |
628 | */ |
629 | void dma_buf_put(struct dma_buf *dmabuf) | |
630 | { | |
631 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
632 | return; | |
633 | ||
634 | fput(dmabuf->file); | |
635 | } | |
636 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
637 | ||
638 | /** | |
639 | * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, | |
640 | * calls attach() of dma_buf_ops to allow device-specific attach functionality | |
641 | * @dmabuf: [in] buffer to attach device to. | |
642 | * @dev: [in] device to be attached. | |
643 | * | |
2904a8c1 DV |
644 | * Returns struct dma_buf_attachment pointer for this attachment. Attachments |
645 | * must be cleaned up by calling dma_buf_detach(). | |
646 | * | |
647 | * Returns: | |
648 | * | |
649 | * A pointer to newly created &dma_buf_attachment on success, or a negative | |
650 | * error code wrapped into a pointer on failure. | |
651 | * | |
652 | * Note that this can fail if the backing storage of @dmabuf is in a place not | |
653 | * accessible to @dev, and cannot be moved to a more suitable place. This is | |
654 | * indicated with the error code -EBUSY. | |
d15bd7ee SS |
655 | */ |
656 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
657 | struct device *dev) | |
658 | { | |
659 | struct dma_buf_attachment *attach; | |
660 | int ret; | |
661 | ||
d1aa06a1 | 662 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
663 | return ERR_PTR(-EINVAL); |
664 | ||
db7942b6 | 665 | attach = kzalloc(sizeof(*attach), GFP_KERNEL); |
34d84ec4 | 666 | if (!attach) |
a9fbc3b7 | 667 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 668 | |
d15bd7ee SS |
669 | attach->dev = dev; |
670 | attach->dmabuf = dmabuf; | |
2ed9201b LP |
671 | |
672 | mutex_lock(&dmabuf->lock); | |
673 | ||
d15bd7ee | 674 | if (dmabuf->ops->attach) { |
a19741e5 | 675 | ret = dmabuf->ops->attach(dmabuf, attach); |
d15bd7ee SS |
676 | if (ret) |
677 | goto err_attach; | |
678 | } | |
679 | list_add(&attach->node, &dmabuf->attachments); | |
680 | ||
681 | mutex_unlock(&dmabuf->lock); | |
f13e143e | 682 | |
d15bd7ee SS |
683 | return attach; |
684 | ||
d15bd7ee SS |
685 | err_attach: |
686 | kfree(attach); | |
687 | mutex_unlock(&dmabuf->lock); | |
688 | return ERR_PTR(ret); | |
689 | } | |
690 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
691 | ||
692 | /** | |
693 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; | |
694 | * optionally calls detach() of dma_buf_ops for device-specific detach | |
695 | * @dmabuf: [in] buffer to detach from. | |
696 | * @attach: [in] attachment to be detached; is free'd after this call. | |
697 | * | |
2904a8c1 | 698 | * Clean up a device attachment obtained by calling dma_buf_attach(). |
d15bd7ee SS |
699 | */ |
700 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
701 | { | |
d1aa06a1 | 702 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
703 | return; |
704 | ||
f13e143e CK |
705 | if (attach->sgt) |
706 | dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); | |
707 | ||
d15bd7ee SS |
708 | mutex_lock(&dmabuf->lock); |
709 | list_del(&attach->node); | |
710 | if (dmabuf->ops->detach) | |
711 | dmabuf->ops->detach(dmabuf, attach); | |
712 | ||
713 | mutex_unlock(&dmabuf->lock); | |
714 | kfree(attach); | |
715 | } | |
716 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
717 | ||
718 | /** | |
719 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
720 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
721 | * dma_buf_ops. | |
722 | * @attach: [in] attachment whose scatterlist is to be returned | |
723 | * @direction: [in] direction of DMA transfer | |
724 | * | |
fee0c54e | 725 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
2904a8c1 DV |
726 | * on error. May return -EINTR if it is interrupted by a signal. |
727 | * | |
c138782d | 728 | * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that |
2904a8c1 DV |
729 | * the underlying backing storage is pinned for as long as a mapping exists, |
730 | * therefore users/importers should not hold onto a mapping for undue amounts of | |
731 | * time. | |
d15bd7ee SS |
732 | */ |
733 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
734 | enum dma_data_direction direction) | |
735 | { | |
531beb06 | 736 | struct sg_table *sg_table; |
d15bd7ee SS |
737 | |
738 | might_sleep(); | |
739 | ||
d1aa06a1 | 740 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
741 | return ERR_PTR(-EINVAL); |
742 | ||
f13e143e CK |
743 | if (attach->sgt) { |
744 | /* | |
745 | * Two mappings with different directions for the same | |
746 | * attachment are not allowed. | |
747 | */ | |
748 | if (attach->dir != direction && | |
749 | attach->dir != DMA_BIDIRECTIONAL) | |
750 | return ERR_PTR(-EBUSY); | |
751 | ||
752 | return attach->sgt; | |
753 | } | |
754 | ||
d1aa06a1 | 755 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); |
fee0c54e CC |
756 | if (!sg_table) |
757 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee | 758 | |
f13e143e CK |
759 | if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { |
760 | attach->sgt = sg_table; | |
761 | attach->dir = direction; | |
762 | } | |
763 | ||
d15bd7ee SS |
764 | return sg_table; |
765 | } | |
766 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
767 | ||
768 | /** | |
769 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
770 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
771 | * dma_buf_ops. | |
772 | * @attach: [in] attachment to unmap buffer from | |
773 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 774 | * @direction: [in] direction of DMA transfer |
d15bd7ee | 775 | * |
2904a8c1 | 776 | * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). |
d15bd7ee SS |
777 | */ |
778 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
779 | struct sg_table *sg_table, |
780 | enum dma_data_direction direction) | |
d15bd7ee | 781 | { |
b6fa0cd6 RC |
782 | might_sleep(); |
783 | ||
d1aa06a1 | 784 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
785 | return; |
786 | ||
f13e143e CK |
787 | if (attach->sgt == sg_table) |
788 | return; | |
789 | ||
790 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); | |
d15bd7ee SS |
791 | } |
792 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e | 793 | |
0959a168 DV |
794 | /** |
795 | * DOC: cpu access | |
796 | * | |
797 | * There are mutliple reasons for supporting CPU access to a dma buffer object: | |
798 | * | |
799 | * - Fallback operations in the kernel, for example when a device is connected | |
800 | * over USB and the kernel needs to shuffle the data around first before | |
801 | * sending it away. Cache coherency is handled by braketing any transactions | |
802 | * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access() | |
803 | * access. | |
804 | * | |
805 | * To support dma_buf objects residing in highmem cpu access is page-based | |
806 | * using an api similar to kmap. Accessing a dma_buf is done in aligned chunks | |
807 | * of PAGE_SIZE size. Before accessing a chunk it needs to be mapped, which | |
808 | * returns a pointer in kernel virtual address space. Afterwards the chunk | |
809 | * needs to be unmapped again. There is no limit on how often a given chunk | |
810 | * can be mapped and unmapped, i.e. the importer does not need to call | |
811 | * begin_cpu_access again before mapping the same chunk again. | |
812 | * | |
813 | * Interfaces:: | |
814 | * void \*dma_buf_kmap(struct dma_buf \*, unsigned long); | |
815 | * void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*); | |
816 | * | |
f664a526 CK |
817 | * Implementing the functions is optional for exporters and for importers all |
818 | * the restrictions of using kmap apply. | |
0959a168 DV |
819 | * |
820 | * dma_buf kmap calls outside of the range specified in begin_cpu_access are | |
821 | * undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on | |
822 | * the partial chunks at the beginning and end but may return stale or bogus | |
823 | * data outside of the range (in these partial chunks). | |
824 | * | |
0959a168 DV |
825 | * For some cases the overhead of kmap can be too high, a vmap interface |
826 | * is introduced. This interface should be used very carefully, as vmalloc | |
827 | * space is a limited resources on many architectures. | |
828 | * | |
829 | * Interfaces:: | |
830 | * void \*dma_buf_vmap(struct dma_buf \*dmabuf) | |
831 | * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr) | |
832 | * | |
833 | * The vmap call can fail if there is no vmap support in the exporter, or if | |
834 | * it runs out of vmalloc space. Fallback to kmap should be implemented. Note | |
835 | * that the dma-buf layer keeps a reference count for all vmap access and | |
836 | * calls down into the exporter's vmap function only when no vmapping exists, | |
837 | * and only unmaps it once. Protection against concurrent vmap/vunmap calls is | |
838 | * provided by taking the dma_buf->lock mutex. | |
839 | * | |
840 | * - For full compatibility on the importer side with existing userspace | |
841 | * interfaces, which might already support mmap'ing buffers. This is needed in | |
842 | * many processing pipelines (e.g. feeding a software rendered image into a | |
843 | * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION | |
844 | * framework already supported this and for DMA buffer file descriptors to | |
845 | * replace ION buffers mmap support was needed. | |
846 | * | |
847 | * There is no special interfaces, userspace simply calls mmap on the dma-buf | |
848 | * fd. But like for CPU access there's a need to braket the actual access, | |
849 | * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that | |
850 | * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must | |
851 | * be restarted. | |
852 | * | |
853 | * Some systems might need some sort of cache coherency management e.g. when | |
854 | * CPU and GPU domains are being accessed through dma-buf at the same time. | |
855 | * To circumvent this problem there are begin/end coherency markers, that | |
856 | * forward directly to existing dma-buf device drivers vfunc hooks. Userspace | |
857 | * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The | |
858 | * sequence would be used like following: | |
859 | * | |
860 | * - mmap dma-buf fd | |
861 | * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write | |
862 | * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you | |
863 | * want (with the new data being consumed by say the GPU or the scanout | |
864 | * device) | |
865 | * - munmap once you don't need the buffer any more | |
866 | * | |
867 | * For correctness and optimal performance, it is always required to use | |
868 | * SYNC_START and SYNC_END before and after, respectively, when accessing the | |
869 | * mapped address. Userspace cannot rely on coherent access, even when there | |
870 | * are systems where it just works without calling these ioctls. | |
871 | * | |
872 | * - And as a CPU fallback in userspace processing pipelines. | |
873 | * | |
874 | * Similar to the motivation for kernel cpu access it is again important that | |
875 | * the userspace code of a given importing subsystem can use the same | |
876 | * interfaces with a imported dma-buf buffer object as with a native buffer | |
877 | * object. This is especially important for drm where the userspace part of | |
878 | * contemporary OpenGL, X, and other drivers is huge, and reworking them to | |
879 | * use a different way to mmap a buffer rather invasive. | |
880 | * | |
881 | * The assumption in the current dma-buf interfaces is that redirecting the | |
882 | * initial mmap is all that's needed. A survey of some of the existing | |
883 | * subsystems shows that no driver seems to do any nefarious thing like | |
884 | * syncing up with outstanding asynchronous processing on the device or | |
885 | * allocating special resources at fault time. So hopefully this is good | |
886 | * enough, since adding interfaces to intercept pagefaults and allow pte | |
887 | * shootdowns would increase the complexity quite a bit. | |
888 | * | |
889 | * Interface:: | |
890 | * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*, | |
891 | * unsigned long); | |
892 | * | |
893 | * If the importing subsystem simply provides a special-purpose mmap call to | |
894 | * set up a mapping in userspace, calling do_mmap with dma_buf->file will | |
895 | * equally achieve that for a dma-buf object. | |
896 | */ | |
897 | ||
ae4e46b1 CW |
898 | static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
899 | enum dma_data_direction direction) | |
900 | { | |
901 | bool write = (direction == DMA_BIDIRECTIONAL || | |
902 | direction == DMA_TO_DEVICE); | |
903 | struct reservation_object *resv = dmabuf->resv; | |
904 | long ret; | |
905 | ||
906 | /* Wait on any implicit rendering fences */ | |
907 | ret = reservation_object_wait_timeout_rcu(resv, write, true, | |
908 | MAX_SCHEDULE_TIMEOUT); | |
909 | if (ret < 0) | |
910 | return ret; | |
911 | ||
912 | return 0; | |
913 | } | |
fc13020e DV |
914 | |
915 | /** | |
916 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
917 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
918 | * preparations. Coherency is only guaranteed in the specified range for the | |
919 | * specified access direction. | |
efb4df82 | 920 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
921 | * @direction: [in] length of range for cpu access. |
922 | * | |
0959a168 DV |
923 | * After the cpu access is complete the caller should call |
924 | * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is | |
925 | * it guaranteed to be coherent with other DMA access. | |
926 | * | |
fc13020e DV |
927 | * Can return negative error values, returns 0 on success. |
928 | */ | |
831e9da7 | 929 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
930 | enum dma_data_direction direction) |
931 | { | |
932 | int ret = 0; | |
933 | ||
934 | if (WARN_ON(!dmabuf)) | |
935 | return -EINVAL; | |
936 | ||
937 | if (dmabuf->ops->begin_cpu_access) | |
831e9da7 | 938 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e | 939 | |
ae4e46b1 CW |
940 | /* Ensure that all fences are waited upon - but we first allow |
941 | * the native handler the chance to do so more efficiently if it | |
942 | * chooses. A double invocation here will be reasonably cheap no-op. | |
943 | */ | |
944 | if (ret == 0) | |
945 | ret = __dma_buf_begin_cpu_access(dmabuf, direction); | |
946 | ||
fc13020e DV |
947 | return ret; |
948 | } | |
949 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
950 | ||
951 | /** | |
952 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
953 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
954 | * actions. Coherency is only guaranteed in the specified range for the | |
955 | * specified access direction. | |
efb4df82 | 956 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
957 | * @direction: [in] length of range for cpu access. |
958 | * | |
0959a168 DV |
959 | * This terminates CPU access started with dma_buf_begin_cpu_access(). |
960 | * | |
87e332d5 | 961 | * Can return negative error values, returns 0 on success. |
fc13020e | 962 | */ |
18b862dc CW |
963 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
964 | enum dma_data_direction direction) | |
fc13020e | 965 | { |
18b862dc CW |
966 | int ret = 0; |
967 | ||
fc13020e DV |
968 | WARN_ON(!dmabuf); |
969 | ||
970 | if (dmabuf->ops->end_cpu_access) | |
18b862dc CW |
971 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
972 | ||
973 | return ret; | |
fc13020e DV |
974 | } |
975 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
976 | ||
fc13020e DV |
977 | /** |
978 | * dma_buf_kmap - Map a page of the buffer object into kernel address space. The | |
979 | * same restrictions as for kmap and friends apply. | |
efb4df82 | 980 | * @dmabuf: [in] buffer to map page from. |
fc13020e DV |
981 | * @page_num: [in] page in PAGE_SIZE units to map. |
982 | * | |
983 | * This call must always succeed, any necessary preparations that might fail | |
984 | * need to be done in begin_cpu_access. | |
985 | */ | |
986 | void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) | |
987 | { | |
988 | WARN_ON(!dmabuf); | |
989 | ||
09ea0dfb GH |
990 | if (!dmabuf->ops->map) |
991 | return NULL; | |
f9b67f00 | 992 | return dmabuf->ops->map(dmabuf, page_num); |
fc13020e DV |
993 | } |
994 | EXPORT_SYMBOL_GPL(dma_buf_kmap); | |
995 | ||
996 | /** | |
997 | * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. | |
efb4df82 | 998 | * @dmabuf: [in] buffer to unmap page from. |
fc13020e DV |
999 | * @page_num: [in] page in PAGE_SIZE units to unmap. |
1000 | * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. | |
1001 | * | |
1002 | * This call must always succeed. | |
1003 | */ | |
1004 | void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, | |
1005 | void *vaddr) | |
1006 | { | |
1007 | WARN_ON(!dmabuf); | |
1008 | ||
f9b67f00 LG |
1009 | if (dmabuf->ops->unmap) |
1010 | dmabuf->ops->unmap(dmabuf, page_num, vaddr); | |
fc13020e DV |
1011 | } |
1012 | EXPORT_SYMBOL_GPL(dma_buf_kunmap); | |
4c78513e DV |
1013 | |
1014 | ||
1015 | /** | |
1016 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 1017 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
1018 | * @vma: [in] vma for the mmap |
1019 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 1020 | * dma-buf buffer. |
4c78513e DV |
1021 | * |
1022 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 1023 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
1024 | * checking on the size of the vma. Then it calls the exporters mmap function to |
1025 | * set up the mapping. | |
1026 | * | |
1027 | * Can return negative error values, returns 0 on success. | |
1028 | */ | |
1029 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
1030 | unsigned long pgoff) | |
1031 | { | |
495c10cc JS |
1032 | struct file *oldfile; |
1033 | int ret; | |
1034 | ||
4c78513e DV |
1035 | if (WARN_ON(!dmabuf || !vma)) |
1036 | return -EINVAL; | |
1037 | ||
e3a9d6c5 AD |
1038 | /* check if buffer supports mmap */ |
1039 | if (!dmabuf->ops->mmap) | |
1040 | return -EINVAL; | |
1041 | ||
4c78513e | 1042 | /* check for offset overflow */ |
b02da6f8 | 1043 | if (pgoff + vma_pages(vma) < pgoff) |
4c78513e DV |
1044 | return -EOVERFLOW; |
1045 | ||
1046 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 1047 | if (pgoff + vma_pages(vma) > |
4c78513e DV |
1048 | dmabuf->size >> PAGE_SHIFT) |
1049 | return -EINVAL; | |
1050 | ||
1051 | /* readjust the vma */ | |
495c10cc JS |
1052 | get_file(dmabuf->file); |
1053 | oldfile = vma->vm_file; | |
1054 | vma->vm_file = dmabuf->file; | |
4c78513e DV |
1055 | vma->vm_pgoff = pgoff; |
1056 | ||
495c10cc JS |
1057 | ret = dmabuf->ops->mmap(dmabuf, vma); |
1058 | if (ret) { | |
1059 | /* restore old parameters on failure */ | |
1060 | vma->vm_file = oldfile; | |
1061 | fput(dmabuf->file); | |
1062 | } else { | |
1063 | if (oldfile) | |
1064 | fput(oldfile); | |
1065 | } | |
1066 | return ret; | |
1067 | ||
4c78513e DV |
1068 | } |
1069 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
1070 | |
1071 | /** | |
12c4727e SS |
1072 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
1073 | * address space. Same restrictions as for vmap and friends apply. | |
1074 | * @dmabuf: [in] buffer to vmap | |
98f86c9e DA |
1075 | * |
1076 | * This call may fail due to lack of virtual mapping address space. | |
1077 | * These calls are optional in drivers. The intended use for them | |
1078 | * is for mapping objects linear in kernel space for high use objects. | |
1079 | * Please attempt to use kmap/kunmap before thinking about these interfaces. | |
fee0c54e CC |
1080 | * |
1081 | * Returns NULL on error. | |
98f86c9e DA |
1082 | */ |
1083 | void *dma_buf_vmap(struct dma_buf *dmabuf) | |
1084 | { | |
f00b4dad DV |
1085 | void *ptr; |
1086 | ||
98f86c9e DA |
1087 | if (WARN_ON(!dmabuf)) |
1088 | return NULL; | |
1089 | ||
f00b4dad DV |
1090 | if (!dmabuf->ops->vmap) |
1091 | return NULL; | |
1092 | ||
1093 | mutex_lock(&dmabuf->lock); | |
1094 | if (dmabuf->vmapping_counter) { | |
1095 | dmabuf->vmapping_counter++; | |
1096 | BUG_ON(!dmabuf->vmap_ptr); | |
1097 | ptr = dmabuf->vmap_ptr; | |
1098 | goto out_unlock; | |
1099 | } | |
1100 | ||
1101 | BUG_ON(dmabuf->vmap_ptr); | |
1102 | ||
1103 | ptr = dmabuf->ops->vmap(dmabuf); | |
fee0c54e CC |
1104 | if (WARN_ON_ONCE(IS_ERR(ptr))) |
1105 | ptr = NULL; | |
1106 | if (!ptr) | |
f00b4dad DV |
1107 | goto out_unlock; |
1108 | ||
1109 | dmabuf->vmap_ptr = ptr; | |
1110 | dmabuf->vmapping_counter = 1; | |
1111 | ||
1112 | out_unlock: | |
1113 | mutex_unlock(&dmabuf->lock); | |
1114 | return ptr; | |
98f86c9e DA |
1115 | } |
1116 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
1117 | ||
1118 | /** | |
1119 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 1120 | * @dmabuf: [in] buffer to vunmap |
6e7b4a59 | 1121 | * @vaddr: [in] vmap to vunmap |
98f86c9e DA |
1122 | */ |
1123 | void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) | |
1124 | { | |
1125 | if (WARN_ON(!dmabuf)) | |
1126 | return; | |
1127 | ||
f00b4dad DV |
1128 | BUG_ON(!dmabuf->vmap_ptr); |
1129 | BUG_ON(dmabuf->vmapping_counter == 0); | |
1130 | BUG_ON(dmabuf->vmap_ptr != vaddr); | |
1131 | ||
1132 | mutex_lock(&dmabuf->lock); | |
1133 | if (--dmabuf->vmapping_counter == 0) { | |
1134 | if (dmabuf->ops->vunmap) | |
1135 | dmabuf->ops->vunmap(dmabuf, vaddr); | |
1136 | dmabuf->vmap_ptr = NULL; | |
1137 | } | |
1138 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
1139 | } |
1140 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
1141 | |
1142 | #ifdef CONFIG_DEBUG_FS | |
eb0b947e | 1143 | static int dma_buf_debug_show(struct seq_file *s, void *unused) |
b89e3563 SS |
1144 | { |
1145 | int ret; | |
1146 | struct dma_buf *buf_obj; | |
1147 | struct dma_buf_attachment *attach_obj; | |
5eb2c72c RK |
1148 | struct reservation_object *robj; |
1149 | struct reservation_object_list *fobj; | |
1150 | struct dma_fence *fence; | |
1151 | unsigned seq; | |
1152 | int count = 0, attach_count, shared_count, i; | |
b89e3563 SS |
1153 | size_t size = 0; |
1154 | ||
1155 | ret = mutex_lock_interruptible(&db_list.lock); | |
1156 | ||
1157 | if (ret) | |
1158 | return ret; | |
1159 | ||
c0b00a52 | 1160 | seq_puts(s, "\nDma-buf Objects:\n"); |
ed63bb1d GH |
1161 | seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\n", |
1162 | "size", "flags", "mode", "count", "ino"); | |
b89e3563 SS |
1163 | |
1164 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
1165 | ret = mutex_lock_interruptible(&buf_obj->lock); | |
1166 | ||
1167 | if (ret) { | |
c0b00a52 SS |
1168 | seq_puts(s, |
1169 | "\tERROR locking buffer object: skipping\n"); | |
b89e3563 SS |
1170 | continue; |
1171 | } | |
1172 | ||
bb2bb903 | 1173 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n", |
c0b00a52 | 1174 | buf_obj->size, |
b89e3563 | 1175 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 1176 | file_count(buf_obj->file), |
ed63bb1d | 1177 | buf_obj->exp_name, |
bb2bb903 GH |
1178 | file_inode(buf_obj->file)->i_ino, |
1179 | buf_obj->name ?: ""); | |
b89e3563 | 1180 | |
5eb2c72c RK |
1181 | robj = buf_obj->resv; |
1182 | while (true) { | |
1183 | seq = read_seqcount_begin(&robj->seq); | |
1184 | rcu_read_lock(); | |
1185 | fobj = rcu_dereference(robj->fence); | |
1186 | shared_count = fobj ? fobj->shared_count : 0; | |
1187 | fence = rcu_dereference(robj->fence_excl); | |
1188 | if (!read_seqcount_retry(&robj->seq, seq)) | |
1189 | break; | |
1190 | rcu_read_unlock(); | |
1191 | } | |
1192 | ||
1193 | if (fence) | |
1194 | seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", | |
1195 | fence->ops->get_driver_name(fence), | |
1196 | fence->ops->get_timeline_name(fence), | |
1197 | dma_fence_is_signaled(fence) ? "" : "un"); | |
1198 | for (i = 0; i < shared_count; i++) { | |
1199 | fence = rcu_dereference(fobj->shared[i]); | |
1200 | if (!dma_fence_get_rcu(fence)) | |
1201 | continue; | |
1202 | seq_printf(s, "\tShared fence: %s %s %ssignalled\n", | |
1203 | fence->ops->get_driver_name(fence), | |
1204 | fence->ops->get_timeline_name(fence), | |
1205 | dma_fence_is_signaled(fence) ? "" : "un"); | |
5e383a97 | 1206 | dma_fence_put(fence); |
5eb2c72c RK |
1207 | } |
1208 | rcu_read_unlock(); | |
1209 | ||
c0b00a52 | 1210 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
1211 | attach_count = 0; |
1212 | ||
1213 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
9eddb41d | 1214 | seq_printf(s, "\t%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
1215 | attach_count++; |
1216 | } | |
1217 | ||
c0b00a52 | 1218 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
1219 | attach_count); |
1220 | ||
1221 | count++; | |
1222 | size += buf_obj->size; | |
1223 | mutex_unlock(&buf_obj->lock); | |
1224 | } | |
1225 | ||
1226 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
1227 | ||
1228 | mutex_unlock(&db_list.lock); | |
1229 | return 0; | |
1230 | } | |
1231 | ||
2674305a | 1232 | DEFINE_SHOW_ATTRIBUTE(dma_buf_debug); |
b89e3563 SS |
1233 | |
1234 | static struct dentry *dma_buf_debugfs_dir; | |
1235 | ||
1236 | static int dma_buf_init_debugfs(void) | |
1237 | { | |
bd3e2208 | 1238 | struct dentry *d; |
b89e3563 | 1239 | int err = 0; |
5136629d | 1240 | |
bd3e2208 MK |
1241 | d = debugfs_create_dir("dma_buf", NULL); |
1242 | if (IS_ERR(d)) | |
1243 | return PTR_ERR(d); | |
5136629d | 1244 | |
bd3e2208 | 1245 | dma_buf_debugfs_dir = d; |
b89e3563 | 1246 | |
bd3e2208 MK |
1247 | d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, |
1248 | NULL, &dma_buf_debug_fops); | |
1249 | if (IS_ERR(d)) { | |
b89e3563 | 1250 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); |
b7479990 MK |
1251 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
1252 | dma_buf_debugfs_dir = NULL; | |
bd3e2208 | 1253 | err = PTR_ERR(d); |
b7479990 | 1254 | } |
b89e3563 SS |
1255 | |
1256 | return err; | |
1257 | } | |
1258 | ||
1259 | static void dma_buf_uninit_debugfs(void) | |
1260 | { | |
298b6a81 | 1261 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
b89e3563 | 1262 | } |
b89e3563 SS |
1263 | #else |
1264 | static inline int dma_buf_init_debugfs(void) | |
1265 | { | |
1266 | return 0; | |
1267 | } | |
1268 | static inline void dma_buf_uninit_debugfs(void) | |
1269 | { | |
1270 | } | |
1271 | #endif | |
1272 | ||
1273 | static int __init dma_buf_init(void) | |
1274 | { | |
ed63bb1d GH |
1275 | dma_buf_mnt = kern_mount(&dma_buf_fs_type); |
1276 | if (IS_ERR(dma_buf_mnt)) | |
1277 | return PTR_ERR(dma_buf_mnt); | |
1278 | ||
b89e3563 SS |
1279 | mutex_init(&db_list.lock); |
1280 | INIT_LIST_HEAD(&db_list.head); | |
1281 | dma_buf_init_debugfs(); | |
1282 | return 0; | |
1283 | } | |
1284 | subsys_initcall(dma_buf_init); | |
1285 | ||
1286 | static void __exit dma_buf_deinit(void) | |
1287 | { | |
1288 | dma_buf_uninit_debugfs(); | |
ed63bb1d | 1289 | kern_unmount(dma_buf_mnt); |
b89e3563 SS |
1290 | } |
1291 | __exitcall(dma_buf_deinit); |