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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> |
52791eee | 24 | #include <linux/dma-resv.h> |
b02da6f8 | 25 | #include <linux/mm.h> |
ed63bb1d | 26 | #include <linux/mount.h> |
933a90bf | 27 | #include <linux/pseudo_fs.h> |
d15bd7ee | 28 | |
c11e391d | 29 | #include <uapi/linux/dma-buf.h> |
ed63bb1d | 30 | #include <uapi/linux/magic.h> |
c11e391d | 31 | |
d15bd7ee SS |
32 | static inline int is_dma_buf_file(struct file *); |
33 | ||
b89e3563 SS |
34 | struct dma_buf_list { |
35 | struct list_head head; | |
36 | struct mutex lock; | |
37 | }; | |
38 | ||
39 | static struct dma_buf_list db_list; | |
40 | ||
bb2bb903 GH |
41 | static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen) |
42 | { | |
43 | struct dma_buf *dmabuf; | |
44 | char name[DMA_BUF_NAME_LEN]; | |
45 | size_t ret = 0; | |
46 | ||
47 | dmabuf = dentry->d_fsdata; | |
6348dd29 | 48 | spin_lock(&dmabuf->name_lock); |
bb2bb903 GH |
49 | if (dmabuf->name) |
50 | ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN); | |
6348dd29 | 51 | spin_unlock(&dmabuf->name_lock); |
bb2bb903 GH |
52 | |
53 | return dynamic_dname(dentry, buffer, buflen, "/%s:%s", | |
54 | dentry->d_name.name, ret > 0 ? name : ""); | |
55 | } | |
56 | ||
4ab59c3c | 57 | static void dma_buf_release(struct dentry *dentry) |
d15bd7ee SS |
58 | { |
59 | struct dma_buf *dmabuf; | |
60 | ||
4ab59c3c | 61 | dmabuf = dentry->d_fsdata; |
19a508bd CTR |
62 | if (unlikely(!dmabuf)) |
63 | return; | |
d15bd7ee | 64 | |
f00b4dad DV |
65 | BUG_ON(dmabuf->vmapping_counter); |
66 | ||
9b495a58 ML |
67 | /* |
68 | * Any fences that a dma-buf poll can wait on should be signaled | |
69 | * before releasing dma-buf. This is the responsibility of each | |
70 | * driver that uses the reservation objects. | |
71 | * | |
72 | * If you hit this BUG() it means someone dropped their ref to the | |
73 | * dma-buf while still having pending operation to the buffer. | |
74 | */ | |
75 | BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); | |
76 | ||
d15bd7ee | 77 | dmabuf->ops->release(dmabuf); |
b89e3563 | 78 | |
52791eee CK |
79 | if (dmabuf->resv == (struct dma_resv *)&dmabuf[1]) |
80 | dma_resv_fini(dmabuf->resv); | |
3aac4502 | 81 | |
9abdffe2 | 82 | module_put(dmabuf->owner); |
d1f37226 | 83 | kfree(dmabuf->name); |
d15bd7ee | 84 | kfree(dmabuf); |
4ab59c3c SS |
85 | } |
86 | ||
05cd8469 CTR |
87 | static int dma_buf_file_release(struct inode *inode, struct file *file) |
88 | { | |
89 | struct dma_buf *dmabuf; | |
90 | ||
91 | if (!is_dma_buf_file(file)) | |
92 | return -EINVAL; | |
93 | ||
94 | dmabuf = file->private_data; | |
95 | ||
96 | mutex_lock(&db_list.lock); | |
97 | list_del(&dmabuf->list_node); | |
98 | mutex_unlock(&db_list.lock); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
4ab59c3c SS |
103 | static const struct dentry_operations dma_buf_dentry_ops = { |
104 | .d_dname = dmabuffs_dname, | |
105 | .d_release = dma_buf_release, | |
106 | }; | |
107 | ||
108 | static struct vfsmount *dma_buf_mnt; | |
109 | ||
110 | static int dma_buf_fs_init_context(struct fs_context *fc) | |
111 | { | |
112 | struct pseudo_fs_context *ctx; | |
113 | ||
114 | ctx = init_pseudo(fc, DMA_BUF_MAGIC); | |
115 | if (!ctx) | |
116 | return -ENOMEM; | |
117 | ctx->dops = &dma_buf_dentry_ops; | |
d15bd7ee SS |
118 | return 0; |
119 | } | |
120 | ||
4ab59c3c SS |
121 | static struct file_system_type dma_buf_fs_type = { |
122 | .name = "dmabuf", | |
123 | .init_fs_context = dma_buf_fs_init_context, | |
124 | .kill_sb = kill_anon_super, | |
125 | }; | |
126 | ||
4c78513e DV |
127 | static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) |
128 | { | |
129 | struct dma_buf *dmabuf; | |
130 | ||
131 | if (!is_dma_buf_file(file)) | |
132 | return -EINVAL; | |
133 | ||
134 | dmabuf = file->private_data; | |
135 | ||
e3a9d6c5 AD |
136 | /* check if buffer supports mmap */ |
137 | if (!dmabuf->ops->mmap) | |
138 | return -EINVAL; | |
139 | ||
4c78513e | 140 | /* check for overflowing the buffer's size */ |
b02da6f8 | 141 | if (vma->vm_pgoff + vma_pages(vma) > |
4c78513e DV |
142 | dmabuf->size >> PAGE_SHIFT) |
143 | return -EINVAL; | |
144 | ||
145 | return dmabuf->ops->mmap(dmabuf, vma); | |
146 | } | |
147 | ||
19e8697b CJHR |
148 | static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) |
149 | { | |
150 | struct dma_buf *dmabuf; | |
151 | loff_t base; | |
152 | ||
153 | if (!is_dma_buf_file(file)) | |
154 | return -EBADF; | |
155 | ||
156 | dmabuf = file->private_data; | |
157 | ||
158 | /* only support discovering the end of the buffer, | |
159 | but also allow SEEK_SET to maintain the idiomatic | |
160 | SEEK_END(0), SEEK_CUR(0) pattern */ | |
161 | if (whence == SEEK_END) | |
162 | base = dmabuf->size; | |
163 | else if (whence == SEEK_SET) | |
164 | base = 0; | |
165 | else | |
166 | return -EINVAL; | |
167 | ||
168 | if (offset != 0) | |
169 | return -EINVAL; | |
170 | ||
171 | return base + offset; | |
172 | } | |
173 | ||
e7e21c72 | 174 | /** |
102514ec | 175 | * DOC: implicit fence polling |
e7e21c72 DV |
176 | * |
177 | * To support cross-device and cross-driver synchronization of buffer access | |
102514ec DV |
178 | * implicit fences (represented internally in the kernel with &struct dma_fence) |
179 | * can be attached to a &dma_buf. The glue for that and a few related things are | |
52791eee | 180 | * provided in the &dma_resv structure. |
e7e21c72 DV |
181 | * |
182 | * Userspace can query the state of these implicitly tracked fences using poll() | |
183 | * and related system calls: | |
184 | * | |
a9a08845 | 185 | * - Checking for EPOLLIN, i.e. read access, can be use to query the state of the |
e7e21c72 DV |
186 | * most recent write or exclusive fence. |
187 | * | |
a9a08845 | 188 | * - Checking for EPOLLOUT, i.e. write access, can be used to query the state of |
e7e21c72 DV |
189 | * all attached fences, shared and exclusive ones. |
190 | * | |
191 | * Note that this only signals the completion of the respective fences, i.e. the | |
192 | * DMA transfers are complete. Cache flushing and any other necessary | |
193 | * preparations before CPU access can begin still need to happen. | |
194 | */ | |
195 | ||
f54d1867 | 196 | static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb) |
9b495a58 ML |
197 | { |
198 | struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; | |
199 | unsigned long flags; | |
200 | ||
201 | spin_lock_irqsave(&dcb->poll->lock, flags); | |
202 | wake_up_locked_poll(dcb->poll, dcb->active); | |
203 | dcb->active = 0; | |
204 | spin_unlock_irqrestore(&dcb->poll->lock, flags); | |
205 | } | |
206 | ||
afc9a42b | 207 | static __poll_t dma_buf_poll(struct file *file, poll_table *poll) |
9b495a58 ML |
208 | { |
209 | struct dma_buf *dmabuf; | |
52791eee CK |
210 | struct dma_resv *resv; |
211 | struct dma_resv_list *fobj; | |
f54d1867 | 212 | struct dma_fence *fence_excl; |
01699437 | 213 | __poll_t events; |
b016cd6e | 214 | unsigned shared_count, seq; |
9b495a58 ML |
215 | |
216 | dmabuf = file->private_data; | |
217 | if (!dmabuf || !dmabuf->resv) | |
a9a08845 | 218 | return EPOLLERR; |
9b495a58 ML |
219 | |
220 | resv = dmabuf->resv; | |
221 | ||
222 | poll_wait(file, &dmabuf->poll, poll); | |
223 | ||
a9a08845 | 224 | events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT); |
9b495a58 ML |
225 | if (!events) |
226 | return 0; | |
227 | ||
b016cd6e CW |
228 | retry: |
229 | seq = read_seqcount_begin(&resv->seq); | |
3c3b177a | 230 | rcu_read_lock(); |
b016cd6e CW |
231 | |
232 | fobj = rcu_dereference(resv->fence); | |
233 | if (fobj) | |
234 | shared_count = fobj->shared_count; | |
235 | else | |
236 | shared_count = 0; | |
6edbd6ab | 237 | fence_excl = dma_resv_excl_fence(resv); |
b016cd6e CW |
238 | if (read_seqcount_retry(&resv->seq, seq)) { |
239 | rcu_read_unlock(); | |
240 | goto retry; | |
241 | } | |
242 | ||
a9a08845 | 243 | if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) { |
9b495a58 | 244 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; |
a9a08845 | 245 | __poll_t pevents = EPOLLIN; |
9b495a58 | 246 | |
04a5faa8 | 247 | if (shared_count == 0) |
a9a08845 | 248 | pevents |= EPOLLOUT; |
9b495a58 ML |
249 | |
250 | spin_lock_irq(&dmabuf->poll.lock); | |
251 | if (dcb->active) { | |
252 | dcb->active |= pevents; | |
253 | events &= ~pevents; | |
254 | } else | |
255 | dcb->active = pevents; | |
256 | spin_unlock_irq(&dmabuf->poll.lock); | |
257 | ||
258 | if (events & pevents) { | |
f54d1867 | 259 | if (!dma_fence_get_rcu(fence_excl)) { |
3c3b177a ML |
260 | /* force a recheck */ |
261 | events &= ~pevents; | |
262 | dma_buf_poll_cb(NULL, &dcb->cb); | |
f54d1867 CW |
263 | } else if (!dma_fence_add_callback(fence_excl, &dcb->cb, |
264 | dma_buf_poll_cb)) { | |
9b495a58 | 265 | events &= ~pevents; |
f54d1867 | 266 | dma_fence_put(fence_excl); |
04a5faa8 | 267 | } else { |
9b495a58 ML |
268 | /* |
269 | * No callback queued, wake up any additional | |
270 | * waiters. | |
271 | */ | |
f54d1867 | 272 | dma_fence_put(fence_excl); |
9b495a58 | 273 | dma_buf_poll_cb(NULL, &dcb->cb); |
04a5faa8 | 274 | } |
9b495a58 ML |
275 | } |
276 | } | |
277 | ||
a9a08845 | 278 | if ((events & EPOLLOUT) && shared_count > 0) { |
9b495a58 ML |
279 | struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; |
280 | int i; | |
281 | ||
282 | /* Only queue a new callback if no event has fired yet */ | |
283 | spin_lock_irq(&dmabuf->poll.lock); | |
284 | if (dcb->active) | |
a9a08845 | 285 | events &= ~EPOLLOUT; |
9b495a58 | 286 | else |
a9a08845 | 287 | dcb->active = EPOLLOUT; |
9b495a58 ML |
288 | spin_unlock_irq(&dmabuf->poll.lock); |
289 | ||
a9a08845 | 290 | if (!(events & EPOLLOUT)) |
9b495a58 ML |
291 | goto out; |
292 | ||
04a5faa8 | 293 | for (i = 0; i < shared_count; ++i) { |
f54d1867 | 294 | struct dma_fence *fence = rcu_dereference(fobj->shared[i]); |
04a5faa8 | 295 | |
f54d1867 | 296 | if (!dma_fence_get_rcu(fence)) { |
3c3b177a ML |
297 | /* |
298 | * fence refcount dropped to zero, this means | |
299 | * that fobj has been freed | |
300 | * | |
301 | * call dma_buf_poll_cb and force a recheck! | |
302 | */ | |
a9a08845 | 303 | events &= ~EPOLLOUT; |
3c3b177a ML |
304 | dma_buf_poll_cb(NULL, &dcb->cb); |
305 | break; | |
306 | } | |
f54d1867 CW |
307 | if (!dma_fence_add_callback(fence, &dcb->cb, |
308 | dma_buf_poll_cb)) { | |
309 | dma_fence_put(fence); | |
a9a08845 | 310 | events &= ~EPOLLOUT; |
9b495a58 ML |
311 | break; |
312 | } | |
f54d1867 | 313 | dma_fence_put(fence); |
04a5faa8 | 314 | } |
9b495a58 ML |
315 | |
316 | /* No callback queued, wake up any additional waiters. */ | |
04a5faa8 | 317 | if (i == shared_count) |
9b495a58 ML |
318 | dma_buf_poll_cb(NULL, &dcb->cb); |
319 | } | |
320 | ||
321 | out: | |
3c3b177a | 322 | rcu_read_unlock(); |
9b495a58 ML |
323 | return events; |
324 | } | |
325 | ||
bb2bb903 GH |
326 | /** |
327 | * dma_buf_set_name - Set a name to a specific dma_buf to track the usage. | |
328 | * The name of the dma-buf buffer can only be set when the dma-buf is not | |
329 | * attached to any devices. It could theoritically support changing the | |
330 | * name of the dma-buf if the same piece of memory is used for multiple | |
331 | * purpose between different devices. | |
332 | * | |
6d3ba803 KK |
333 | * @dmabuf: [in] dmabuf buffer that will be renamed. |
334 | * @buf: [in] A piece of userspace memory that contains the name of | |
335 | * the dma-buf. | |
bb2bb903 GH |
336 | * |
337 | * Returns 0 on success. If the dma-buf buffer is already attached to | |
338 | * devices, return -EBUSY. | |
339 | * | |
340 | */ | |
341 | static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) | |
342 | { | |
343 | char *name = strndup_user(buf, DMA_BUF_NAME_LEN); | |
344 | long ret = 0; | |
345 | ||
346 | if (IS_ERR(name)) | |
347 | return PTR_ERR(name); | |
348 | ||
15fd552d | 349 | dma_resv_lock(dmabuf->resv, NULL); |
bb2bb903 GH |
350 | if (!list_empty(&dmabuf->attachments)) { |
351 | ret = -EBUSY; | |
352 | kfree(name); | |
353 | goto out_unlock; | |
354 | } | |
6348dd29 | 355 | spin_lock(&dmabuf->name_lock); |
bb2bb903 GH |
356 | kfree(dmabuf->name); |
357 | dmabuf->name = name; | |
6348dd29 | 358 | spin_unlock(&dmabuf->name_lock); |
bb2bb903 GH |
359 | |
360 | out_unlock: | |
15fd552d | 361 | dma_resv_unlock(dmabuf->resv); |
bb2bb903 GH |
362 | return ret; |
363 | } | |
364 | ||
c11e391d DV |
365 | static long dma_buf_ioctl(struct file *file, |
366 | unsigned int cmd, unsigned long arg) | |
367 | { | |
368 | struct dma_buf *dmabuf; | |
369 | struct dma_buf_sync sync; | |
370 | enum dma_data_direction direction; | |
18b862dc | 371 | int ret; |
c11e391d DV |
372 | |
373 | dmabuf = file->private_data; | |
374 | ||
375 | switch (cmd) { | |
376 | case DMA_BUF_IOCTL_SYNC: | |
377 | if (copy_from_user(&sync, (void __user *) arg, sizeof(sync))) | |
378 | return -EFAULT; | |
379 | ||
380 | if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK) | |
381 | return -EINVAL; | |
382 | ||
383 | switch (sync.flags & DMA_BUF_SYNC_RW) { | |
384 | case DMA_BUF_SYNC_READ: | |
385 | direction = DMA_FROM_DEVICE; | |
386 | break; | |
387 | case DMA_BUF_SYNC_WRITE: | |
388 | direction = DMA_TO_DEVICE; | |
389 | break; | |
390 | case DMA_BUF_SYNC_RW: | |
391 | direction = DMA_BIDIRECTIONAL; | |
392 | break; | |
393 | default: | |
394 | return -EINVAL; | |
395 | } | |
396 | ||
397 | if (sync.flags & DMA_BUF_SYNC_END) | |
18b862dc | 398 | ret = dma_buf_end_cpu_access(dmabuf, direction); |
c11e391d | 399 | else |
18b862dc | 400 | ret = dma_buf_begin_cpu_access(dmabuf, direction); |
c11e391d | 401 | |
18b862dc | 402 | return ret; |
bb2bb903 | 403 | |
a5bff92e DV |
404 | case DMA_BUF_SET_NAME_A: |
405 | case DMA_BUF_SET_NAME_B: | |
bb2bb903 GH |
406 | return dma_buf_set_name(dmabuf, (const char __user *)arg); |
407 | ||
c11e391d DV |
408 | default: |
409 | return -ENOTTY; | |
410 | } | |
411 | } | |
412 | ||
bcc07111 GH |
413 | static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file) |
414 | { | |
415 | struct dma_buf *dmabuf = file->private_data; | |
416 | ||
417 | seq_printf(m, "size:\t%zu\n", dmabuf->size); | |
418 | /* Don't count the temporary reference taken inside procfs seq_show */ | |
419 | seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1); | |
420 | seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name); | |
6348dd29 | 421 | spin_lock(&dmabuf->name_lock); |
bcc07111 GH |
422 | if (dmabuf->name) |
423 | seq_printf(m, "name:\t%s\n", dmabuf->name); | |
6348dd29 | 424 | spin_unlock(&dmabuf->name_lock); |
bcc07111 GH |
425 | } |
426 | ||
d15bd7ee | 427 | static const struct file_operations dma_buf_fops = { |
05cd8469 | 428 | .release = dma_buf_file_release, |
4c78513e | 429 | .mmap = dma_buf_mmap_internal, |
19e8697b | 430 | .llseek = dma_buf_llseek, |
9b495a58 | 431 | .poll = dma_buf_poll, |
c11e391d | 432 | .unlocked_ioctl = dma_buf_ioctl, |
1832f2d8 | 433 | .compat_ioctl = compat_ptr_ioctl, |
bcc07111 | 434 | .show_fdinfo = dma_buf_show_fdinfo, |
d15bd7ee SS |
435 | }; |
436 | ||
437 | /* | |
438 | * is_dma_buf_file - Check if struct file* is associated with dma_buf | |
439 | */ | |
440 | static inline int is_dma_buf_file(struct file *file) | |
441 | { | |
442 | return file->f_op == &dma_buf_fops; | |
443 | } | |
444 | ||
ed63bb1d GH |
445 | static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags) |
446 | { | |
447 | struct file *file; | |
448 | struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb); | |
449 | ||
450 | if (IS_ERR(inode)) | |
451 | return ERR_CAST(inode); | |
452 | ||
453 | inode->i_size = dmabuf->size; | |
454 | inode_set_bytes(inode, dmabuf->size); | |
455 | ||
456 | file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf", | |
457 | flags, &dma_buf_fops); | |
458 | if (IS_ERR(file)) | |
459 | goto err_alloc_file; | |
460 | file->f_flags = flags & (O_ACCMODE | O_NONBLOCK); | |
461 | file->private_data = dmabuf; | |
bb2bb903 | 462 | file->f_path.dentry->d_fsdata = dmabuf; |
ed63bb1d GH |
463 | |
464 | return file; | |
465 | ||
466 | err_alloc_file: | |
467 | iput(inode); | |
468 | return file; | |
469 | } | |
470 | ||
2904a8c1 DV |
471 | /** |
472 | * DOC: dma buf device access | |
473 | * | |
474 | * For device DMA access to a shared DMA buffer the usual sequence of operations | |
475 | * is fairly simple: | |
476 | * | |
477 | * 1. The exporter defines his exporter instance using | |
478 | * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private | |
479 | * buffer object into a &dma_buf. It then exports that &dma_buf to userspace | |
480 | * as a file descriptor by calling dma_buf_fd(). | |
481 | * | |
482 | * 2. Userspace passes this file-descriptors to all drivers it wants this buffer | |
483 | * to share with: First the filedescriptor is converted to a &dma_buf using | |
c138782d | 484 | * dma_buf_get(). Then the buffer is attached to the device using |
2904a8c1 DV |
485 | * dma_buf_attach(). |
486 | * | |
487 | * Up to this stage the exporter is still free to migrate or reallocate the | |
488 | * backing storage. | |
489 | * | |
c138782d | 490 | * 3. Once the buffer is attached to all devices userspace can initiate DMA |
2904a8c1 DV |
491 | * access to the shared buffer. In the kernel this is done by calling |
492 | * dma_buf_map_attachment() and dma_buf_unmap_attachment(). | |
493 | * | |
494 | * 4. Once a driver is done with a shared buffer it needs to call | |
495 | * dma_buf_detach() (after cleaning up any mappings) and then release the | |
85804b70 | 496 | * reference acquired with dma_buf_get() by calling dma_buf_put(). |
2904a8c1 DV |
497 | * |
498 | * For the detailed semantics exporters are expected to implement see | |
499 | * &dma_buf_ops. | |
500 | */ | |
501 | ||
d15bd7ee | 502 | /** |
d8fbe341 | 503 | * dma_buf_export - Creates a new dma_buf, and associates an anon file |
d15bd7ee SS |
504 | * with this buffer, so it can be exported. |
505 | * Also connect the allocator specific data and ops to the buffer. | |
78df9695 | 506 | * Additionally, provide a name string for exporter; useful in debugging. |
d15bd7ee | 507 | * |
d8fbe341 | 508 | * @exp_info: [in] holds all the export related information provided |
f641d3b5 | 509 | * by the exporter. see &struct dma_buf_export_info |
d8fbe341 | 510 | * for further details. |
d15bd7ee | 511 | * |
85804b70 DV |
512 | * Returns, on success, a newly created struct dma_buf object, which wraps the |
513 | * supplied private data and operations for struct dma_buf_ops. On either | |
514 | * missing ops, or error in allocating struct dma_buf, will return negative | |
515 | * error. | |
d15bd7ee | 516 | * |
2904a8c1 DV |
517 | * For most cases the easiest way to create @exp_info is through the |
518 | * %DEFINE_DMA_BUF_EXPORT_INFO macro. | |
d15bd7ee | 519 | */ |
d8fbe341 | 520 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) |
d15bd7ee SS |
521 | { |
522 | struct dma_buf *dmabuf; | |
52791eee | 523 | struct dma_resv *resv = exp_info->resv; |
d15bd7ee | 524 | struct file *file; |
3aac4502 | 525 | size_t alloc_size = sizeof(struct dma_buf); |
a026df4c | 526 | int ret; |
5136629d | 527 | |
d8fbe341 | 528 | if (!exp_info->resv) |
52791eee | 529 | alloc_size += sizeof(struct dma_resv); |
3aac4502 ML |
530 | else |
531 | /* prevent &dma_buf[1] == dma_buf->resv */ | |
532 | alloc_size += 1; | |
d15bd7ee | 533 | |
d8fbe341 SS |
534 | if (WARN_ON(!exp_info->priv |
535 | || !exp_info->ops | |
536 | || !exp_info->ops->map_dma_buf | |
537 | || !exp_info->ops->unmap_dma_buf | |
e3a9d6c5 | 538 | || !exp_info->ops->release)) { |
d15bd7ee SS |
539 | return ERR_PTR(-EINVAL); |
540 | } | |
541 | ||
15fd552d | 542 | if (WARN_ON(exp_info->ops->cache_sgt_mapping && |
bd2275ee | 543 | (exp_info->ops->pin || exp_info->ops->unpin))) |
15fd552d CK |
544 | return ERR_PTR(-EINVAL); |
545 | ||
bd2275ee | 546 | if (WARN_ON(!exp_info->ops->pin != !exp_info->ops->unpin)) |
15fd552d CK |
547 | return ERR_PTR(-EINVAL); |
548 | ||
9abdffe2 SS |
549 | if (!try_module_get(exp_info->owner)) |
550 | return ERR_PTR(-ENOENT); | |
551 | ||
3aac4502 | 552 | dmabuf = kzalloc(alloc_size, GFP_KERNEL); |
9abdffe2 | 553 | if (!dmabuf) { |
a026df4c CW |
554 | ret = -ENOMEM; |
555 | goto err_module; | |
9abdffe2 | 556 | } |
d15bd7ee | 557 | |
d8fbe341 SS |
558 | dmabuf->priv = exp_info->priv; |
559 | dmabuf->ops = exp_info->ops; | |
560 | dmabuf->size = exp_info->size; | |
561 | dmabuf->exp_name = exp_info->exp_name; | |
9abdffe2 | 562 | dmabuf->owner = exp_info->owner; |
6348dd29 | 563 | spin_lock_init(&dmabuf->name_lock); |
9b495a58 ML |
564 | init_waitqueue_head(&dmabuf->poll); |
565 | dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; | |
566 | dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; | |
567 | ||
3aac4502 | 568 | if (!resv) { |
52791eee CK |
569 | resv = (struct dma_resv *)&dmabuf[1]; |
570 | dma_resv_init(resv); | |
3aac4502 ML |
571 | } |
572 | dmabuf->resv = resv; | |
d15bd7ee | 573 | |
ed63bb1d | 574 | file = dma_buf_getfile(dmabuf, exp_info->flags); |
9022e24e | 575 | if (IS_ERR(file)) { |
a026df4c CW |
576 | ret = PTR_ERR(file); |
577 | goto err_dmabuf; | |
9022e24e | 578 | } |
19e8697b CJHR |
579 | |
580 | file->f_mode |= FMODE_LSEEK; | |
d15bd7ee SS |
581 | dmabuf->file = file; |
582 | ||
583 | mutex_init(&dmabuf->lock); | |
584 | INIT_LIST_HEAD(&dmabuf->attachments); | |
585 | ||
b89e3563 SS |
586 | mutex_lock(&db_list.lock); |
587 | list_add(&dmabuf->list_node, &db_list.head); | |
588 | mutex_unlock(&db_list.lock); | |
589 | ||
d15bd7ee | 590 | return dmabuf; |
a026df4c CW |
591 | |
592 | err_dmabuf: | |
593 | kfree(dmabuf); | |
594 | err_module: | |
595 | module_put(exp_info->owner); | |
596 | return ERR_PTR(ret); | |
d15bd7ee | 597 | } |
d8fbe341 | 598 | EXPORT_SYMBOL_GPL(dma_buf_export); |
d15bd7ee SS |
599 | |
600 | /** | |
85804b70 | 601 | * dma_buf_fd - returns a file descriptor for the given struct dma_buf |
d15bd7ee | 602 | * @dmabuf: [in] pointer to dma_buf for which fd is required. |
55c1c4ca | 603 | * @flags: [in] flags to give to fd |
d15bd7ee SS |
604 | * |
605 | * On success, returns an associated 'fd'. Else, returns error. | |
606 | */ | |
55c1c4ca | 607 | int dma_buf_fd(struct dma_buf *dmabuf, int flags) |
d15bd7ee | 608 | { |
f5e097f0 | 609 | int fd; |
d15bd7ee SS |
610 | |
611 | if (!dmabuf || !dmabuf->file) | |
612 | return -EINVAL; | |
613 | ||
f5e097f0 BP |
614 | fd = get_unused_fd_flags(flags); |
615 | if (fd < 0) | |
616 | return fd; | |
d15bd7ee SS |
617 | |
618 | fd_install(fd, dmabuf->file); | |
619 | ||
620 | return fd; | |
621 | } | |
622 | EXPORT_SYMBOL_GPL(dma_buf_fd); | |
623 | ||
624 | /** | |
85804b70 DV |
625 | * dma_buf_get - returns the struct dma_buf related to an fd |
626 | * @fd: [in] fd associated with the struct dma_buf to be returned | |
d15bd7ee | 627 | * |
85804b70 | 628 | * On success, returns the struct dma_buf associated with an fd; uses |
d15bd7ee SS |
629 | * file's refcounting done by fget to increase refcount. returns ERR_PTR |
630 | * otherwise. | |
631 | */ | |
632 | struct dma_buf *dma_buf_get(int fd) | |
633 | { | |
634 | struct file *file; | |
635 | ||
636 | file = fget(fd); | |
637 | ||
638 | if (!file) | |
639 | return ERR_PTR(-EBADF); | |
640 | ||
641 | if (!is_dma_buf_file(file)) { | |
642 | fput(file); | |
643 | return ERR_PTR(-EINVAL); | |
644 | } | |
645 | ||
646 | return file->private_data; | |
647 | } | |
648 | EXPORT_SYMBOL_GPL(dma_buf_get); | |
649 | ||
650 | /** | |
651 | * dma_buf_put - decreases refcount of the buffer | |
652 | * @dmabuf: [in] buffer to reduce refcount of | |
653 | * | |
2904a8c1 DV |
654 | * Uses file's refcounting done implicitly by fput(). |
655 | * | |
656 | * If, as a result of this call, the refcount becomes 0, the 'release' file | |
e9b4d7b5 DV |
657 | * operation related to this fd is called. It calls &dma_buf_ops.release vfunc |
658 | * in turn, and frees the memory allocated for dmabuf when exported. | |
d15bd7ee SS |
659 | */ |
660 | void dma_buf_put(struct dma_buf *dmabuf) | |
661 | { | |
662 | if (WARN_ON(!dmabuf || !dmabuf->file)) | |
663 | return; | |
664 | ||
665 | fput(dmabuf->file); | |
666 | } | |
667 | EXPORT_SYMBOL_GPL(dma_buf_put); | |
668 | ||
84335675 DV |
669 | static void mangle_sg_table(struct sg_table *sg_table) |
670 | { | |
671 | #ifdef CONFIG_DMABUF_DEBUG | |
672 | int i; | |
673 | struct scatterlist *sg; | |
674 | ||
675 | /* To catch abuse of the underlying struct page by importers mix | |
676 | * up the bits, but take care to preserve the low SG_ bits to | |
677 | * not corrupt the sgt. The mixing is undone in __unmap_dma_buf | |
678 | * before passing the sgt back to the exporter. */ | |
679 | for_each_sgtable_sg(sg_table, sg, i) | |
680 | sg->page_link ^= ~0xffUL; | |
681 | #endif | |
682 | ||
683 | } | |
684 | static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach, | |
685 | enum dma_data_direction direction) | |
686 | { | |
687 | struct sg_table *sg_table; | |
688 | ||
689 | sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); | |
690 | ||
691 | if (!IS_ERR_OR_NULL(sg_table)) | |
692 | mangle_sg_table(sg_table); | |
693 | ||
694 | return sg_table; | |
695 | } | |
696 | ||
d15bd7ee | 697 | /** |
85804b70 | 698 | * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list |
15fd552d CK |
699 | * @dmabuf: [in] buffer to attach device to. |
700 | * @dev: [in] device to be attached. | |
6f49c251 RD |
701 | * @importer_ops: [in] importer operations for the attachment |
702 | * @importer_priv: [in] importer private pointer for the attachment | |
d15bd7ee | 703 | * |
2904a8c1 DV |
704 | * Returns struct dma_buf_attachment pointer for this attachment. Attachments |
705 | * must be cleaned up by calling dma_buf_detach(). | |
706 | * | |
85804b70 DV |
707 | * Optionally this calls &dma_buf_ops.attach to allow device-specific attach |
708 | * functionality. | |
709 | * | |
2904a8c1 DV |
710 | * Returns: |
711 | * | |
712 | * A pointer to newly created &dma_buf_attachment on success, or a negative | |
713 | * error code wrapped into a pointer on failure. | |
714 | * | |
715 | * Note that this can fail if the backing storage of @dmabuf is in a place not | |
716 | * accessible to @dev, and cannot be moved to a more suitable place. This is | |
717 | * indicated with the error code -EBUSY. | |
d15bd7ee | 718 | */ |
15fd552d CK |
719 | struct dma_buf_attachment * |
720 | dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, | |
bb42df46 CK |
721 | const struct dma_buf_attach_ops *importer_ops, |
722 | void *importer_priv) | |
d15bd7ee SS |
723 | { |
724 | struct dma_buf_attachment *attach; | |
725 | int ret; | |
726 | ||
d1aa06a1 | 727 | if (WARN_ON(!dmabuf || !dev)) |
d15bd7ee SS |
728 | return ERR_PTR(-EINVAL); |
729 | ||
4981cdb0 CK |
730 | if (WARN_ON(importer_ops && !importer_ops->move_notify)) |
731 | return ERR_PTR(-EINVAL); | |
732 | ||
db7942b6 | 733 | attach = kzalloc(sizeof(*attach), GFP_KERNEL); |
34d84ec4 | 734 | if (!attach) |
a9fbc3b7 | 735 | return ERR_PTR(-ENOMEM); |
d15bd7ee | 736 | |
d15bd7ee SS |
737 | attach->dev = dev; |
738 | attach->dmabuf = dmabuf; | |
09606b54 CK |
739 | if (importer_ops) |
740 | attach->peer2peer = importer_ops->allow_peer2peer; | |
bb42df46 CK |
741 | attach->importer_ops = importer_ops; |
742 | attach->importer_priv = importer_priv; | |
2ed9201b | 743 | |
d15bd7ee | 744 | if (dmabuf->ops->attach) { |
a19741e5 | 745 | ret = dmabuf->ops->attach(dmabuf, attach); |
d15bd7ee SS |
746 | if (ret) |
747 | goto err_attach; | |
748 | } | |
15fd552d | 749 | dma_resv_lock(dmabuf->resv, NULL); |
d15bd7ee | 750 | list_add(&attach->node, &dmabuf->attachments); |
15fd552d | 751 | dma_resv_unlock(dmabuf->resv); |
d15bd7ee | 752 | |
15fd552d CK |
753 | /* When either the importer or the exporter can't handle dynamic |
754 | * mappings we cache the mapping here to avoid issues with the | |
755 | * reservation object lock. | |
756 | */ | |
757 | if (dma_buf_attachment_is_dynamic(attach) != | |
758 | dma_buf_is_dynamic(dmabuf)) { | |
759 | struct sg_table *sgt; | |
760 | ||
bb42df46 | 761 | if (dma_buf_is_dynamic(attach->dmabuf)) { |
15fd552d | 762 | dma_resv_lock(attach->dmabuf->resv, NULL); |
7e008b02 | 763 | ret = dmabuf->ops->pin(attach); |
bb42df46 CK |
764 | if (ret) |
765 | goto err_unlock; | |
766 | } | |
15fd552d | 767 | |
84335675 | 768 | sgt = __map_dma_buf(attach, DMA_BIDIRECTIONAL); |
15fd552d CK |
769 | if (!sgt) |
770 | sgt = ERR_PTR(-ENOMEM); | |
771 | if (IS_ERR(sgt)) { | |
772 | ret = PTR_ERR(sgt); | |
bb42df46 | 773 | goto err_unpin; |
15fd552d CK |
774 | } |
775 | if (dma_buf_is_dynamic(attach->dmabuf)) | |
776 | dma_resv_unlock(attach->dmabuf->resv); | |
777 | attach->sgt = sgt; | |
778 | attach->dir = DMA_BIDIRECTIONAL; | |
779 | } | |
780 | ||
d15bd7ee SS |
781 | return attach; |
782 | ||
d15bd7ee SS |
783 | err_attach: |
784 | kfree(attach); | |
d15bd7ee | 785 | return ERR_PTR(ret); |
15fd552d | 786 | |
bb42df46 CK |
787 | err_unpin: |
788 | if (dma_buf_is_dynamic(attach->dmabuf)) | |
7e008b02 | 789 | dmabuf->ops->unpin(attach); |
bb42df46 | 790 | |
15fd552d CK |
791 | err_unlock: |
792 | if (dma_buf_is_dynamic(attach->dmabuf)) | |
793 | dma_resv_unlock(attach->dmabuf->resv); | |
794 | ||
795 | dma_buf_detach(dmabuf, attach); | |
796 | return ERR_PTR(ret); | |
797 | } | |
798 | EXPORT_SYMBOL_GPL(dma_buf_dynamic_attach); | |
799 | ||
800 | /** | |
801 | * dma_buf_attach - Wrapper for dma_buf_dynamic_attach | |
802 | * @dmabuf: [in] buffer to attach device to. | |
803 | * @dev: [in] device to be attached. | |
804 | * | |
805 | * Wrapper to call dma_buf_dynamic_attach() for drivers which still use a static | |
806 | * mapping. | |
807 | */ | |
808 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, | |
809 | struct device *dev) | |
810 | { | |
bb42df46 | 811 | return dma_buf_dynamic_attach(dmabuf, dev, NULL, NULL); |
d15bd7ee SS |
812 | } |
813 | EXPORT_SYMBOL_GPL(dma_buf_attach); | |
814 | ||
84335675 DV |
815 | static void __unmap_dma_buf(struct dma_buf_attachment *attach, |
816 | struct sg_table *sg_table, | |
817 | enum dma_data_direction direction) | |
818 | { | |
819 | /* uses XOR, hence this unmangles */ | |
820 | mangle_sg_table(sg_table); | |
821 | ||
822 | attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); | |
823 | } | |
824 | ||
d15bd7ee | 825 | /** |
85804b70 | 826 | * dma_buf_detach - Remove the given attachment from dmabuf's attachments list |
d15bd7ee SS |
827 | * @dmabuf: [in] buffer to detach from. |
828 | * @attach: [in] attachment to be detached; is free'd after this call. | |
829 | * | |
2904a8c1 | 830 | * Clean up a device attachment obtained by calling dma_buf_attach(). |
85804b70 DV |
831 | * |
832 | * Optionally this calls &dma_buf_ops.detach for device-specific detach. | |
d15bd7ee SS |
833 | */ |
834 | void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) | |
835 | { | |
d1aa06a1 | 836 | if (WARN_ON(!dmabuf || !attach)) |
d15bd7ee SS |
837 | return; |
838 | ||
15fd552d CK |
839 | if (attach->sgt) { |
840 | if (dma_buf_is_dynamic(attach->dmabuf)) | |
841 | dma_resv_lock(attach->dmabuf->resv, NULL); | |
842 | ||
84335675 | 843 | __unmap_dma_buf(attach, attach->sgt, attach->dir); |
f13e143e | 844 | |
bb42df46 | 845 | if (dma_buf_is_dynamic(attach->dmabuf)) { |
7e008b02 | 846 | dmabuf->ops->unpin(attach); |
15fd552d | 847 | dma_resv_unlock(attach->dmabuf->resv); |
bb42df46 | 848 | } |
15fd552d CK |
849 | } |
850 | ||
15fd552d | 851 | dma_resv_lock(dmabuf->resv, NULL); |
d15bd7ee | 852 | list_del(&attach->node); |
15fd552d | 853 | dma_resv_unlock(dmabuf->resv); |
d15bd7ee SS |
854 | if (dmabuf->ops->detach) |
855 | dmabuf->ops->detach(dmabuf, attach); | |
856 | ||
d15bd7ee SS |
857 | kfree(attach); |
858 | } | |
859 | EXPORT_SYMBOL_GPL(dma_buf_detach); | |
860 | ||
bb42df46 CK |
861 | /** |
862 | * dma_buf_pin - Lock down the DMA-buf | |
bb42df46 CK |
863 | * @attach: [in] attachment which should be pinned |
864 | * | |
c545781e DV |
865 | * Only dynamic importers (who set up @attach with dma_buf_dynamic_attach()) may |
866 | * call this, and only for limited use cases like scanout and not for temporary | |
867 | * pin operations. It is not permitted to allow userspace to pin arbitrary | |
868 | * amounts of buffers through this interface. | |
869 | * | |
870 | * Buffers must be unpinned by calling dma_buf_unpin(). | |
871 | * | |
bb42df46 CK |
872 | * Returns: |
873 | * 0 on success, negative error code on failure. | |
874 | */ | |
875 | int dma_buf_pin(struct dma_buf_attachment *attach) | |
876 | { | |
877 | struct dma_buf *dmabuf = attach->dmabuf; | |
878 | int ret = 0; | |
879 | ||
c545781e DV |
880 | WARN_ON(!dma_buf_attachment_is_dynamic(attach)); |
881 | ||
bb42df46 CK |
882 | dma_resv_assert_held(dmabuf->resv); |
883 | ||
884 | if (dmabuf->ops->pin) | |
885 | ret = dmabuf->ops->pin(attach); | |
886 | ||
887 | return ret; | |
888 | } | |
889 | EXPORT_SYMBOL_GPL(dma_buf_pin); | |
890 | ||
891 | /** | |
c545781e | 892 | * dma_buf_unpin - Unpin a DMA-buf |
bb42df46 | 893 | * @attach: [in] attachment which should be unpinned |
c545781e DV |
894 | * |
895 | * This unpins a buffer pinned by dma_buf_pin() and allows the exporter to move | |
896 | * any mapping of @attach again and inform the importer through | |
897 | * &dma_buf_attach_ops.move_notify. | |
bb42df46 CK |
898 | */ |
899 | void dma_buf_unpin(struct dma_buf_attachment *attach) | |
900 | { | |
901 | struct dma_buf *dmabuf = attach->dmabuf; | |
902 | ||
c545781e DV |
903 | WARN_ON(!dma_buf_attachment_is_dynamic(attach)); |
904 | ||
bb42df46 CK |
905 | dma_resv_assert_held(dmabuf->resv); |
906 | ||
907 | if (dmabuf->ops->unpin) | |
908 | dmabuf->ops->unpin(attach); | |
909 | } | |
910 | EXPORT_SYMBOL_GPL(dma_buf_unpin); | |
911 | ||
d15bd7ee SS |
912 | /** |
913 | * dma_buf_map_attachment - Returns the scatterlist table of the attachment; | |
914 | * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the | |
915 | * dma_buf_ops. | |
916 | * @attach: [in] attachment whose scatterlist is to be returned | |
917 | * @direction: [in] direction of DMA transfer | |
918 | * | |
fee0c54e | 919 | * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR |
2904a8c1 DV |
920 | * on error. May return -EINTR if it is interrupted by a signal. |
921 | * | |
ac80cd17 JX |
922 | * On success, the DMA addresses and lengths in the returned scatterlist are |
923 | * PAGE_SIZE aligned. | |
924 | * | |
c138782d | 925 | * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that |
2904a8c1 DV |
926 | * the underlying backing storage is pinned for as long as a mapping exists, |
927 | * therefore users/importers should not hold onto a mapping for undue amounts of | |
928 | * time. | |
d15bd7ee SS |
929 | */ |
930 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, | |
931 | enum dma_data_direction direction) | |
932 | { | |
531beb06 | 933 | struct sg_table *sg_table; |
bb42df46 | 934 | int r; |
d15bd7ee SS |
935 | |
936 | might_sleep(); | |
937 | ||
d1aa06a1 | 938 | if (WARN_ON(!attach || !attach->dmabuf)) |
d15bd7ee SS |
939 | return ERR_PTR(-EINVAL); |
940 | ||
15fd552d CK |
941 | if (dma_buf_attachment_is_dynamic(attach)) |
942 | dma_resv_assert_held(attach->dmabuf->resv); | |
943 | ||
f13e143e CK |
944 | if (attach->sgt) { |
945 | /* | |
946 | * Two mappings with different directions for the same | |
947 | * attachment are not allowed. | |
948 | */ | |
949 | if (attach->dir != direction && | |
950 | attach->dir != DMA_BIDIRECTIONAL) | |
951 | return ERR_PTR(-EBUSY); | |
952 | ||
953 | return attach->sgt; | |
954 | } | |
955 | ||
bb42df46 | 956 | if (dma_buf_is_dynamic(attach->dmabuf)) { |
15fd552d | 957 | dma_resv_assert_held(attach->dmabuf->resv); |
4981cdb0 | 958 | if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) { |
7e008b02 | 959 | r = attach->dmabuf->ops->pin(attach); |
bb42df46 CK |
960 | if (r) |
961 | return ERR_PTR(r); | |
962 | } | |
963 | } | |
15fd552d | 964 | |
84335675 | 965 | sg_table = __map_dma_buf(attach, direction); |
fee0c54e CC |
966 | if (!sg_table) |
967 | sg_table = ERR_PTR(-ENOMEM); | |
d15bd7ee | 968 | |
bb42df46 | 969 | if (IS_ERR(sg_table) && dma_buf_is_dynamic(attach->dmabuf) && |
4981cdb0 | 970 | !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) |
7e008b02 | 971 | attach->dmabuf->ops->unpin(attach); |
bb42df46 | 972 | |
f13e143e CK |
973 | if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { |
974 | attach->sgt = sg_table; | |
975 | attach->dir = direction; | |
976 | } | |
977 | ||
ac80cd17 | 978 | #ifdef CONFIG_DMA_API_DEBUG |
00efd65a | 979 | if (!IS_ERR(sg_table)) { |
ac80cd17 JX |
980 | struct scatterlist *sg; |
981 | u64 addr; | |
982 | int len; | |
983 | int i; | |
984 | ||
985 | for_each_sgtable_dma_sg(sg_table, sg, i) { | |
986 | addr = sg_dma_address(sg); | |
987 | len = sg_dma_len(sg); | |
988 | if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(len)) { | |
989 | pr_debug("%s: addr %llx or len %x is not page aligned!\n", | |
990 | __func__, addr, len); | |
991 | } | |
992 | } | |
993 | } | |
994 | #endif /* CONFIG_DMA_API_DEBUG */ | |
995 | ||
d15bd7ee SS |
996 | return sg_table; |
997 | } | |
998 | EXPORT_SYMBOL_GPL(dma_buf_map_attachment); | |
999 | ||
1000 | /** | |
1001 | * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might | |
1002 | * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of | |
1003 | * dma_buf_ops. | |
1004 | * @attach: [in] attachment to unmap buffer from | |
1005 | * @sg_table: [in] scatterlist info of the buffer to unmap | |
33ea2dcb | 1006 | * @direction: [in] direction of DMA transfer |
d15bd7ee | 1007 | * |
2904a8c1 | 1008 | * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). |
d15bd7ee SS |
1009 | */ |
1010 | void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, | |
33ea2dcb SS |
1011 | struct sg_table *sg_table, |
1012 | enum dma_data_direction direction) | |
d15bd7ee | 1013 | { |
b6fa0cd6 RC |
1014 | might_sleep(); |
1015 | ||
d1aa06a1 | 1016 | if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) |
d15bd7ee SS |
1017 | return; |
1018 | ||
15fd552d CK |
1019 | if (dma_buf_attachment_is_dynamic(attach)) |
1020 | dma_resv_assert_held(attach->dmabuf->resv); | |
1021 | ||
f13e143e CK |
1022 | if (attach->sgt == sg_table) |
1023 | return; | |
1024 | ||
15fd552d CK |
1025 | if (dma_buf_is_dynamic(attach->dmabuf)) |
1026 | dma_resv_assert_held(attach->dmabuf->resv); | |
1027 | ||
84335675 | 1028 | __unmap_dma_buf(attach, sg_table, direction); |
bb42df46 CK |
1029 | |
1030 | if (dma_buf_is_dynamic(attach->dmabuf) && | |
4981cdb0 | 1031 | !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) |
bb42df46 | 1032 | dma_buf_unpin(attach); |
d15bd7ee SS |
1033 | } |
1034 | EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); | |
fc13020e | 1035 | |
bb42df46 CK |
1036 | /** |
1037 | * dma_buf_move_notify - notify attachments that DMA-buf is moving | |
1038 | * | |
1039 | * @dmabuf: [in] buffer which is moving | |
1040 | * | |
1041 | * Informs all attachmenst that they need to destroy and recreated all their | |
1042 | * mappings. | |
1043 | */ | |
1044 | void dma_buf_move_notify(struct dma_buf *dmabuf) | |
1045 | { | |
1046 | struct dma_buf_attachment *attach; | |
1047 | ||
1048 | dma_resv_assert_held(dmabuf->resv); | |
1049 | ||
1050 | list_for_each_entry(attach, &dmabuf->attachments, node) | |
4981cdb0 | 1051 | if (attach->importer_ops) |
bb42df46 CK |
1052 | attach->importer_ops->move_notify(attach); |
1053 | } | |
1054 | EXPORT_SYMBOL_GPL(dma_buf_move_notify); | |
1055 | ||
0959a168 DV |
1056 | /** |
1057 | * DOC: cpu access | |
1058 | * | |
1059 | * There are mutliple reasons for supporting CPU access to a dma buffer object: | |
1060 | * | |
1061 | * - Fallback operations in the kernel, for example when a device is connected | |
1062 | * over USB and the kernel needs to shuffle the data around first before | |
1063 | * sending it away. Cache coherency is handled by braketing any transactions | |
1064 | * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access() | |
1065 | * access. | |
1066 | * | |
7f0de8d8 DV |
1067 | * Since for most kernel internal dma-buf accesses need the entire buffer, a |
1068 | * vmap interface is introduced. Note that on very old 32-bit architectures | |
1069 | * vmalloc space might be limited and result in vmap calls failing. | |
0959a168 DV |
1070 | * |
1071 | * Interfaces:: | |
de9114ec | 1072 | * |
0959a168 DV |
1073 | * void \*dma_buf_vmap(struct dma_buf \*dmabuf) |
1074 | * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr) | |
1075 | * | |
1076 | * The vmap call can fail if there is no vmap support in the exporter, or if | |
de9114ec DV |
1077 | * it runs out of vmalloc space. Note that the dma-buf layer keeps a reference |
1078 | * count for all vmap access and calls down into the exporter's vmap function | |
1079 | * only when no vmapping exists, and only unmaps it once. Protection against | |
1080 | * concurrent vmap/vunmap calls is provided by taking the &dma_buf.lock mutex. | |
0959a168 DV |
1081 | * |
1082 | * - For full compatibility on the importer side with existing userspace | |
1083 | * interfaces, which might already support mmap'ing buffers. This is needed in | |
1084 | * many processing pipelines (e.g. feeding a software rendered image into a | |
1085 | * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION | |
1086 | * framework already supported this and for DMA buffer file descriptors to | |
1087 | * replace ION buffers mmap support was needed. | |
1088 | * | |
1089 | * There is no special interfaces, userspace simply calls mmap on the dma-buf | |
1090 | * fd. But like for CPU access there's a need to braket the actual access, | |
1091 | * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that | |
1092 | * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must | |
1093 | * be restarted. | |
1094 | * | |
1095 | * Some systems might need some sort of cache coherency management e.g. when | |
1096 | * CPU and GPU domains are being accessed through dma-buf at the same time. | |
1097 | * To circumvent this problem there are begin/end coherency markers, that | |
1098 | * forward directly to existing dma-buf device drivers vfunc hooks. Userspace | |
1099 | * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The | |
1100 | * sequence would be used like following: | |
1101 | * | |
1102 | * - mmap dma-buf fd | |
1103 | * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write | |
1104 | * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you | |
1105 | * want (with the new data being consumed by say the GPU or the scanout | |
1106 | * device) | |
1107 | * - munmap once you don't need the buffer any more | |
1108 | * | |
1109 | * For correctness and optimal performance, it is always required to use | |
1110 | * SYNC_START and SYNC_END before and after, respectively, when accessing the | |
1111 | * mapped address. Userspace cannot rely on coherent access, even when there | |
1112 | * are systems where it just works without calling these ioctls. | |
1113 | * | |
1114 | * - And as a CPU fallback in userspace processing pipelines. | |
1115 | * | |
1116 | * Similar to the motivation for kernel cpu access it is again important that | |
1117 | * the userspace code of a given importing subsystem can use the same | |
1118 | * interfaces with a imported dma-buf buffer object as with a native buffer | |
1119 | * object. This is especially important for drm where the userspace part of | |
1120 | * contemporary OpenGL, X, and other drivers is huge, and reworking them to | |
1121 | * use a different way to mmap a buffer rather invasive. | |
1122 | * | |
1123 | * The assumption in the current dma-buf interfaces is that redirecting the | |
1124 | * initial mmap is all that's needed. A survey of some of the existing | |
1125 | * subsystems shows that no driver seems to do any nefarious thing like | |
1126 | * syncing up with outstanding asynchronous processing on the device or | |
1127 | * allocating special resources at fault time. So hopefully this is good | |
1128 | * enough, since adding interfaces to intercept pagefaults and allow pte | |
1129 | * shootdowns would increase the complexity quite a bit. | |
1130 | * | |
1131 | * Interface:: | |
85804b70 | 1132 | * |
0959a168 DV |
1133 | * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*, |
1134 | * unsigned long); | |
1135 | * | |
1136 | * If the importing subsystem simply provides a special-purpose mmap call to | |
85804b70 | 1137 | * set up a mapping in userspace, calling do_mmap with &dma_buf.file will |
0959a168 DV |
1138 | * equally achieve that for a dma-buf object. |
1139 | */ | |
1140 | ||
ae4e46b1 CW |
1141 | static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
1142 | enum dma_data_direction direction) | |
1143 | { | |
1144 | bool write = (direction == DMA_BIDIRECTIONAL || | |
1145 | direction == DMA_TO_DEVICE); | |
52791eee | 1146 | struct dma_resv *resv = dmabuf->resv; |
ae4e46b1 CW |
1147 | long ret; |
1148 | ||
1149 | /* Wait on any implicit rendering fences */ | |
d3fae3b3 | 1150 | ret = dma_resv_wait_timeout(resv, write, true, MAX_SCHEDULE_TIMEOUT); |
ae4e46b1 CW |
1151 | if (ret < 0) |
1152 | return ret; | |
1153 | ||
1154 | return 0; | |
1155 | } | |
fc13020e DV |
1156 | |
1157 | /** | |
1158 | * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the | |
1159 | * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific | |
1160 | * preparations. Coherency is only guaranteed in the specified range for the | |
1161 | * specified access direction. | |
efb4df82 | 1162 | * @dmabuf: [in] buffer to prepare cpu access for. |
fc13020e DV |
1163 | * @direction: [in] length of range for cpu access. |
1164 | * | |
0959a168 DV |
1165 | * After the cpu access is complete the caller should call |
1166 | * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is | |
1167 | * it guaranteed to be coherent with other DMA access. | |
1168 | * | |
de9114ec DV |
1169 | * This function will also wait for any DMA transactions tracked through |
1170 | * implicit synchronization in &dma_buf.resv. For DMA transactions with explicit | |
1171 | * synchronization this function will only ensure cache coherency, callers must | |
1172 | * ensure synchronization with such DMA transactions on their own. | |
1173 | * | |
fc13020e DV |
1174 | * Can return negative error values, returns 0 on success. |
1175 | */ | |
831e9da7 | 1176 | int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, |
fc13020e DV |
1177 | enum dma_data_direction direction) |
1178 | { | |
1179 | int ret = 0; | |
1180 | ||
1181 | if (WARN_ON(!dmabuf)) | |
1182 | return -EINVAL; | |
1183 | ||
8ccf0a29 DV |
1184 | might_lock(&dmabuf->resv->lock.base); |
1185 | ||
fc13020e | 1186 | if (dmabuf->ops->begin_cpu_access) |
831e9da7 | 1187 | ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); |
fc13020e | 1188 | |
ae4e46b1 CW |
1189 | /* Ensure that all fences are waited upon - but we first allow |
1190 | * the native handler the chance to do so more efficiently if it | |
1191 | * chooses. A double invocation here will be reasonably cheap no-op. | |
1192 | */ | |
1193 | if (ret == 0) | |
1194 | ret = __dma_buf_begin_cpu_access(dmabuf, direction); | |
1195 | ||
fc13020e DV |
1196 | return ret; |
1197 | } | |
1198 | EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); | |
1199 | ||
1200 | /** | |
1201 | * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the | |
1202 | * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific | |
1203 | * actions. Coherency is only guaranteed in the specified range for the | |
1204 | * specified access direction. | |
efb4df82 | 1205 | * @dmabuf: [in] buffer to complete cpu access for. |
fc13020e DV |
1206 | * @direction: [in] length of range for cpu access. |
1207 | * | |
0959a168 DV |
1208 | * This terminates CPU access started with dma_buf_begin_cpu_access(). |
1209 | * | |
87e332d5 | 1210 | * Can return negative error values, returns 0 on success. |
fc13020e | 1211 | */ |
18b862dc CW |
1212 | int dma_buf_end_cpu_access(struct dma_buf *dmabuf, |
1213 | enum dma_data_direction direction) | |
fc13020e | 1214 | { |
18b862dc CW |
1215 | int ret = 0; |
1216 | ||
fc13020e DV |
1217 | WARN_ON(!dmabuf); |
1218 | ||
8ccf0a29 DV |
1219 | might_lock(&dmabuf->resv->lock.base); |
1220 | ||
fc13020e | 1221 | if (dmabuf->ops->end_cpu_access) |
18b862dc CW |
1222 | ret = dmabuf->ops->end_cpu_access(dmabuf, direction); |
1223 | ||
1224 | return ret; | |
fc13020e DV |
1225 | } |
1226 | EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); | |
1227 | ||
4c78513e DV |
1228 | |
1229 | /** | |
1230 | * dma_buf_mmap - Setup up a userspace mmap with the given vma | |
12c4727e | 1231 | * @dmabuf: [in] buffer that should back the vma |
4c78513e DV |
1232 | * @vma: [in] vma for the mmap |
1233 | * @pgoff: [in] offset in pages where this mmap should start within the | |
5136629d | 1234 | * dma-buf buffer. |
4c78513e DV |
1235 | * |
1236 | * This function adjusts the passed in vma so that it points at the file of the | |
ecf1dbac | 1237 | * dma_buf operation. It also adjusts the starting pgoff and does bounds |
4c78513e DV |
1238 | * checking on the size of the vma. Then it calls the exporters mmap function to |
1239 | * set up the mapping. | |
1240 | * | |
1241 | * Can return negative error values, returns 0 on success. | |
1242 | */ | |
1243 | int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, | |
1244 | unsigned long pgoff) | |
1245 | { | |
1246 | if (WARN_ON(!dmabuf || !vma)) | |
1247 | return -EINVAL; | |
1248 | ||
e3a9d6c5 AD |
1249 | /* check if buffer supports mmap */ |
1250 | if (!dmabuf->ops->mmap) | |
1251 | return -EINVAL; | |
1252 | ||
4c78513e | 1253 | /* check for offset overflow */ |
b02da6f8 | 1254 | if (pgoff + vma_pages(vma) < pgoff) |
4c78513e DV |
1255 | return -EOVERFLOW; |
1256 | ||
1257 | /* check for overflowing the buffer's size */ | |
b02da6f8 | 1258 | if (pgoff + vma_pages(vma) > |
4c78513e DV |
1259 | dmabuf->size >> PAGE_SHIFT) |
1260 | return -EINVAL; | |
1261 | ||
1262 | /* readjust the vma */ | |
295992fb | 1263 | vma_set_file(vma, dmabuf->file); |
4c78513e DV |
1264 | vma->vm_pgoff = pgoff; |
1265 | ||
1527f926 | 1266 | return dmabuf->ops->mmap(dmabuf, vma); |
4c78513e DV |
1267 | } |
1268 | EXPORT_SYMBOL_GPL(dma_buf_mmap); | |
98f86c9e DA |
1269 | |
1270 | /** | |
12c4727e SS |
1271 | * dma_buf_vmap - Create virtual mapping for the buffer object into kernel |
1272 | * address space. Same restrictions as for vmap and friends apply. | |
1273 | * @dmabuf: [in] buffer to vmap | |
6619ccf1 | 1274 | * @map: [out] returns the vmap pointer |
98f86c9e DA |
1275 | * |
1276 | * This call may fail due to lack of virtual mapping address space. | |
1277 | * These calls are optional in drivers. The intended use for them | |
1278 | * is for mapping objects linear in kernel space for high use objects. | |
de9114ec DV |
1279 | * |
1280 | * To ensure coherency users must call dma_buf_begin_cpu_access() and | |
1281 | * dma_buf_end_cpu_access() around any cpu access performed through this | |
1282 | * mapping. | |
fee0c54e | 1283 | * |
6619ccf1 | 1284 | * Returns 0 on success, or a negative errno code otherwise. |
98f86c9e | 1285 | */ |
6619ccf1 | 1286 | int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map) |
98f86c9e | 1287 | { |
6619ccf1 TZ |
1288 | struct dma_buf_map ptr; |
1289 | int ret = 0; | |
1290 | ||
1291 | dma_buf_map_clear(map); | |
f00b4dad | 1292 | |
98f86c9e | 1293 | if (WARN_ON(!dmabuf)) |
6619ccf1 | 1294 | return -EINVAL; |
98f86c9e | 1295 | |
f00b4dad | 1296 | if (!dmabuf->ops->vmap) |
6619ccf1 | 1297 | return -EINVAL; |
f00b4dad DV |
1298 | |
1299 | mutex_lock(&dmabuf->lock); | |
1300 | if (dmabuf->vmapping_counter) { | |
1301 | dmabuf->vmapping_counter++; | |
01fd30da | 1302 | BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr)); |
6619ccf1 | 1303 | *map = dmabuf->vmap_ptr; |
f00b4dad DV |
1304 | goto out_unlock; |
1305 | } | |
1306 | ||
01fd30da | 1307 | BUG_ON(dma_buf_map_is_set(&dmabuf->vmap_ptr)); |
f00b4dad | 1308 | |
6619ccf1 TZ |
1309 | ret = dmabuf->ops->vmap(dmabuf, &ptr); |
1310 | if (WARN_ON_ONCE(ret)) | |
f00b4dad DV |
1311 | goto out_unlock; |
1312 | ||
6619ccf1 | 1313 | dmabuf->vmap_ptr = ptr; |
f00b4dad DV |
1314 | dmabuf->vmapping_counter = 1; |
1315 | ||
6619ccf1 TZ |
1316 | *map = dmabuf->vmap_ptr; |
1317 | ||
f00b4dad DV |
1318 | out_unlock: |
1319 | mutex_unlock(&dmabuf->lock); | |
6619ccf1 | 1320 | return ret; |
98f86c9e DA |
1321 | } |
1322 | EXPORT_SYMBOL_GPL(dma_buf_vmap); | |
1323 | ||
1324 | /** | |
1325 | * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. | |
12c4727e | 1326 | * @dmabuf: [in] buffer to vunmap |
20e76f1a | 1327 | * @map: [in] vmap pointer to vunmap |
98f86c9e | 1328 | */ |
20e76f1a | 1329 | void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) |
98f86c9e DA |
1330 | { |
1331 | if (WARN_ON(!dmabuf)) | |
1332 | return; | |
1333 | ||
01fd30da | 1334 | BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr)); |
f00b4dad | 1335 | BUG_ON(dmabuf->vmapping_counter == 0); |
20e76f1a | 1336 | BUG_ON(!dma_buf_map_is_equal(&dmabuf->vmap_ptr, map)); |
f00b4dad DV |
1337 | |
1338 | mutex_lock(&dmabuf->lock); | |
1339 | if (--dmabuf->vmapping_counter == 0) { | |
1340 | if (dmabuf->ops->vunmap) | |
20e76f1a | 1341 | dmabuf->ops->vunmap(dmabuf, map); |
01fd30da | 1342 | dma_buf_map_clear(&dmabuf->vmap_ptr); |
f00b4dad DV |
1343 | } |
1344 | mutex_unlock(&dmabuf->lock); | |
98f86c9e DA |
1345 | } |
1346 | EXPORT_SYMBOL_GPL(dma_buf_vunmap); | |
b89e3563 SS |
1347 | |
1348 | #ifdef CONFIG_DEBUG_FS | |
eb0b947e | 1349 | static int dma_buf_debug_show(struct seq_file *s, void *unused) |
b89e3563 | 1350 | { |
b89e3563 SS |
1351 | struct dma_buf *buf_obj; |
1352 | struct dma_buf_attachment *attach_obj; | |
52791eee CK |
1353 | struct dma_resv *robj; |
1354 | struct dma_resv_list *fobj; | |
5eb2c72c | 1355 | struct dma_fence *fence; |
5eb2c72c | 1356 | int count = 0, attach_count, shared_count, i; |
b89e3563 | 1357 | size_t size = 0; |
680753dd | 1358 | int ret; |
b89e3563 SS |
1359 | |
1360 | ret = mutex_lock_interruptible(&db_list.lock); | |
1361 | ||
1362 | if (ret) | |
1363 | return ret; | |
1364 | ||
c0b00a52 | 1365 | seq_puts(s, "\nDma-buf Objects:\n"); |
ed63bb1d GH |
1366 | seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\n", |
1367 | "size", "flags", "mode", "count", "ino"); | |
b89e3563 SS |
1368 | |
1369 | list_for_each_entry(buf_obj, &db_list.head, list_node) { | |
15fd552d | 1370 | |
15fd552d CK |
1371 | ret = dma_resv_lock_interruptible(buf_obj->resv, NULL); |
1372 | if (ret) | |
f45f57cc | 1373 | goto error_unlock; |
b89e3563 | 1374 | |
bb2bb903 | 1375 | seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n", |
c0b00a52 | 1376 | buf_obj->size, |
b89e3563 | 1377 | buf_obj->file->f_flags, buf_obj->file->f_mode, |
a1f6dbac | 1378 | file_count(buf_obj->file), |
ed63bb1d | 1379 | buf_obj->exp_name, |
bb2bb903 GH |
1380 | file_inode(buf_obj->file)->i_ino, |
1381 | buf_obj->name ?: ""); | |
b89e3563 | 1382 | |
5eb2c72c | 1383 | robj = buf_obj->resv; |
6edbd6ab | 1384 | fence = dma_resv_excl_fence(robj); |
5eb2c72c RK |
1385 | if (fence) |
1386 | seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", | |
1387 | fence->ops->get_driver_name(fence), | |
1388 | fence->ops->get_timeline_name(fence), | |
1389 | dma_fence_is_signaled(fence) ? "" : "un"); | |
680753dd CK |
1390 | |
1391 | fobj = rcu_dereference_protected(robj->fence, | |
1392 | dma_resv_held(robj)); | |
1393 | shared_count = fobj ? fobj->shared_count : 0; | |
5eb2c72c | 1394 | for (i = 0; i < shared_count; i++) { |
680753dd CK |
1395 | fence = rcu_dereference_protected(fobj->shared[i], |
1396 | dma_resv_held(robj)); | |
5eb2c72c RK |
1397 | seq_printf(s, "\tShared fence: %s %s %ssignalled\n", |
1398 | fence->ops->get_driver_name(fence), | |
1399 | fence->ops->get_timeline_name(fence), | |
1400 | dma_fence_is_signaled(fence) ? "" : "un"); | |
1401 | } | |
5eb2c72c | 1402 | |
c0b00a52 | 1403 | seq_puts(s, "\tAttached Devices:\n"); |
b89e3563 SS |
1404 | attach_count = 0; |
1405 | ||
1406 | list_for_each_entry(attach_obj, &buf_obj->attachments, node) { | |
9eddb41d | 1407 | seq_printf(s, "\t%s\n", dev_name(attach_obj->dev)); |
b89e3563 SS |
1408 | attach_count++; |
1409 | } | |
15fd552d | 1410 | dma_resv_unlock(buf_obj->resv); |
b89e3563 | 1411 | |
c0b00a52 | 1412 | seq_printf(s, "Total %d devices attached\n\n", |
b89e3563 SS |
1413 | attach_count); |
1414 | ||
1415 | count++; | |
1416 | size += buf_obj->size; | |
b89e3563 SS |
1417 | } |
1418 | ||
1419 | seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); | |
1420 | ||
1421 | mutex_unlock(&db_list.lock); | |
1422 | return 0; | |
15fd552d | 1423 | |
f45f57cc | 1424 | error_unlock: |
15fd552d CK |
1425 | mutex_unlock(&db_list.lock); |
1426 | return ret; | |
b89e3563 SS |
1427 | } |
1428 | ||
2674305a | 1429 | DEFINE_SHOW_ATTRIBUTE(dma_buf_debug); |
b89e3563 SS |
1430 | |
1431 | static struct dentry *dma_buf_debugfs_dir; | |
1432 | ||
1433 | static int dma_buf_init_debugfs(void) | |
1434 | { | |
bd3e2208 | 1435 | struct dentry *d; |
b89e3563 | 1436 | int err = 0; |
5136629d | 1437 | |
bd3e2208 MK |
1438 | d = debugfs_create_dir("dma_buf", NULL); |
1439 | if (IS_ERR(d)) | |
1440 | return PTR_ERR(d); | |
5136629d | 1441 | |
bd3e2208 | 1442 | dma_buf_debugfs_dir = d; |
b89e3563 | 1443 | |
bd3e2208 MK |
1444 | d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, |
1445 | NULL, &dma_buf_debug_fops); | |
1446 | if (IS_ERR(d)) { | |
b89e3563 | 1447 | pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); |
b7479990 MK |
1448 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
1449 | dma_buf_debugfs_dir = NULL; | |
bd3e2208 | 1450 | err = PTR_ERR(d); |
b7479990 | 1451 | } |
b89e3563 SS |
1452 | |
1453 | return err; | |
1454 | } | |
1455 | ||
1456 | static void dma_buf_uninit_debugfs(void) | |
1457 | { | |
298b6a81 | 1458 | debugfs_remove_recursive(dma_buf_debugfs_dir); |
b89e3563 | 1459 | } |
b89e3563 SS |
1460 | #else |
1461 | static inline int dma_buf_init_debugfs(void) | |
1462 | { | |
1463 | return 0; | |
1464 | } | |
1465 | static inline void dma_buf_uninit_debugfs(void) | |
1466 | { | |
1467 | } | |
1468 | #endif | |
1469 | ||
1470 | static int __init dma_buf_init(void) | |
1471 | { | |
ed63bb1d GH |
1472 | dma_buf_mnt = kern_mount(&dma_buf_fs_type); |
1473 | if (IS_ERR(dma_buf_mnt)) | |
1474 | return PTR_ERR(dma_buf_mnt); | |
1475 | ||
b89e3563 SS |
1476 | mutex_init(&db_list.lock); |
1477 | INIT_LIST_HEAD(&db_list.head); | |
1478 | dma_buf_init_debugfs(); | |
1479 | return 0; | |
1480 | } | |
1481 | subsys_initcall(dma_buf_init); | |
1482 | ||
1483 | static void __exit dma_buf_deinit(void) | |
1484 | { | |
1485 | dma_buf_uninit_debugfs(); | |
ed63bb1d | 1486 | kern_unmount(dma_buf_mnt); |
b89e3563 SS |
1487 | } |
1488 | __exitcall(dma_buf_deinit); |