blob: 6b54e02da10c9c447b5dc573a2bd79f94329ebcb [file] [log] [blame]
Sumit Semwald15bd7e2011-12-26 14:53:15 +05301/*
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>
Maarten Lankhorst3aac4502014-07-01 12:57:26 +020028#include <linux/fence.h>
Sumit Semwald15bd7e2011-12-26 14:53:15 +053029#include <linux/anon_inodes.h>
30#include <linux/export.h>
Sumit Semwalb89e3562013-04-04 11:44:37 +053031#include <linux/debugfs.h>
Sumit Semwal9abdffe2015-05-05 14:56:15 +053032#include <linux/module.h>
Sumit Semwalb89e3562013-04-04 11:44:37 +053033#include <linux/seq_file.h>
Maarten Lankhorst9b495a52014-07-01 12:57:43 +020034#include <linux/poll.h>
Maarten Lankhorst3aac4502014-07-01 12:57:26 +020035#include <linux/reservation.h>
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +053036#include <linux/mm.h>
Sumit Semwald15bd7e2011-12-26 14:53:15 +053037
Daniel Vetterc11e3912016-02-11 20:04:51 -020038#include <uapi/linux/dma-buf.h>
39
Sumit Semwald15bd7e2011-12-26 14:53:15 +053040static inline int is_dma_buf_file(struct file *);
41
Sumit Semwalb89e3562013-04-04 11:44:37 +053042struct dma_buf_list {
43 struct list_head head;
44 struct mutex lock;
45};
46
47static struct dma_buf_list db_list;
48
Sumit Semwald15bd7e2011-12-26 14:53:15 +053049static int dma_buf_release(struct inode *inode, struct file *file)
50{
51 struct dma_buf *dmabuf;
52
53 if (!is_dma_buf_file(file))
54 return -EINVAL;
55
56 dmabuf = file->private_data;
57
Daniel Vetterf00b4da2012-12-20 14:14:23 +010058 BUG_ON(dmabuf->vmapping_counter);
59
Maarten Lankhorst9b495a52014-07-01 12:57:43 +020060 /*
61 * Any fences that a dma-buf poll can wait on should be signaled
62 * before releasing dma-buf. This is the responsibility of each
63 * driver that uses the reservation objects.
64 *
65 * If you hit this BUG() it means someone dropped their ref to the
66 * dma-buf while still having pending operation to the buffer.
67 */
68 BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active);
69
Sumit Semwald15bd7e2011-12-26 14:53:15 +053070 dmabuf->ops->release(dmabuf);
Sumit Semwalb89e3562013-04-04 11:44:37 +053071
72 mutex_lock(&db_list.lock);
73 list_del(&dmabuf->list_node);
74 mutex_unlock(&db_list.lock);
75
Maarten Lankhorst3aac4502014-07-01 12:57:26 +020076 if (dmabuf->resv == (struct reservation_object *)&dmabuf[1])
77 reservation_object_fini(dmabuf->resv);
78
Sumit Semwal9abdffe2015-05-05 14:56:15 +053079 module_put(dmabuf->owner);
Sumit Semwald15bd7e2011-12-26 14:53:15 +053080 kfree(dmabuf);
81 return 0;
82}
83
Daniel Vetter4c785132012-04-24 14:38:52 +053084static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
85{
86 struct dma_buf *dmabuf;
87
88 if (!is_dma_buf_file(file))
89 return -EINVAL;
90
91 dmabuf = file->private_data;
92
93 /* check for overflowing the buffer's size */
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +053094 if (vma->vm_pgoff + vma_pages(vma) >
Daniel Vetter4c785132012-04-24 14:38:52 +053095 dmabuf->size >> PAGE_SHIFT)
96 return -EINVAL;
97
98 return dmabuf->ops->mmap(dmabuf, vma);
99}
100
Christopher James Halse Rogers19e86972013-09-10 11:36:45 +0530101static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
102{
103 struct dma_buf *dmabuf;
104 loff_t base;
105
106 if (!is_dma_buf_file(file))
107 return -EBADF;
108
109 dmabuf = file->private_data;
110
111 /* only support discovering the end of the buffer,
112 but also allow SEEK_SET to maintain the idiomatic
113 SEEK_END(0), SEEK_CUR(0) pattern */
114 if (whence == SEEK_END)
115 base = dmabuf->size;
116 else if (whence == SEEK_SET)
117 base = 0;
118 else
119 return -EINVAL;
120
121 if (offset != 0)
122 return -EINVAL;
123
124 return base + offset;
125}
126
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200127static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb)
128{
129 struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
130 unsigned long flags;
131
132 spin_lock_irqsave(&dcb->poll->lock, flags);
133 wake_up_locked_poll(dcb->poll, dcb->active);
134 dcb->active = 0;
135 spin_unlock_irqrestore(&dcb->poll->lock, flags);
136}
137
138static unsigned int dma_buf_poll(struct file *file, poll_table *poll)
139{
140 struct dma_buf *dmabuf;
141 struct reservation_object *resv;
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200142 struct reservation_object_list *fobj;
143 struct fence *fence_excl;
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200144 unsigned long events;
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200145 unsigned shared_count, seq;
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200146
147 dmabuf = file->private_data;
148 if (!dmabuf || !dmabuf->resv)
149 return POLLERR;
150
151 resv = dmabuf->resv;
152
153 poll_wait(file, &dmabuf->poll, poll);
154
155 events = poll_requested_events(poll) & (POLLIN | POLLOUT);
156 if (!events)
157 return 0;
158
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200159retry:
160 seq = read_seqcount_begin(&resv->seq);
161 rcu_read_lock();
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200162
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200163 fobj = rcu_dereference(resv->fence);
164 if (fobj)
165 shared_count = fobj->shared_count;
166 else
167 shared_count = 0;
168 fence_excl = rcu_dereference(resv->fence_excl);
169 if (read_seqcount_retry(&resv->seq, seq)) {
170 rcu_read_unlock();
171 goto retry;
172 }
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200173
174 if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) {
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200175 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl;
176 unsigned long pevents = POLLIN;
177
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200178 if (shared_count == 0)
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200179 pevents |= POLLOUT;
180
181 spin_lock_irq(&dmabuf->poll.lock);
182 if (dcb->active) {
183 dcb->active |= pevents;
184 events &= ~pevents;
185 } else
186 dcb->active = pevents;
187 spin_unlock_irq(&dmabuf->poll.lock);
188
189 if (events & pevents) {
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200190 if (!fence_get_rcu(fence_excl)) {
191 /* force a recheck */
192 events &= ~pevents;
193 dma_buf_poll_cb(NULL, &dcb->cb);
194 } else if (!fence_add_callback(fence_excl, &dcb->cb,
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200195 dma_buf_poll_cb)) {
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200196 events &= ~pevents;
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200197 fence_put(fence_excl);
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200198 } else {
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200199 /*
200 * No callback queued, wake up any additional
201 * waiters.
202 */
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200203 fence_put(fence_excl);
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200204 dma_buf_poll_cb(NULL, &dcb->cb);
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200205 }
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200206 }
207 }
208
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200209 if ((events & POLLOUT) && shared_count > 0) {
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200210 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared;
211 int i;
212
213 /* Only queue a new callback if no event has fired yet */
214 spin_lock_irq(&dmabuf->poll.lock);
215 if (dcb->active)
216 events &= ~POLLOUT;
217 else
218 dcb->active = POLLOUT;
219 spin_unlock_irq(&dmabuf->poll.lock);
220
221 if (!(events & POLLOUT))
222 goto out;
223
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200224 for (i = 0; i < shared_count; ++i) {
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200225 struct fence *fence = rcu_dereference(fobj->shared[i]);
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200226
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200227 if (!fence_get_rcu(fence)) {
228 /*
229 * fence refcount dropped to zero, this means
230 * that fobj has been freed
231 *
232 * call dma_buf_poll_cb and force a recheck!
233 */
234 events &= ~POLLOUT;
235 dma_buf_poll_cb(NULL, &dcb->cb);
236 break;
237 }
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200238 if (!fence_add_callback(fence, &dcb->cb,
239 dma_buf_poll_cb)) {
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200240 fence_put(fence);
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200241 events &= ~POLLOUT;
242 break;
243 }
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200244 fence_put(fence);
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200245 }
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200246
247 /* No callback queued, wake up any additional waiters. */
Maarten Lankhorst04a5faa2014-07-01 12:57:54 +0200248 if (i == shared_count)
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200249 dma_buf_poll_cb(NULL, &dcb->cb);
250 }
251
252out:
Maarten Lankhorst3c3b1772014-07-01 12:58:00 +0200253 rcu_read_unlock();
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200254 return events;
255}
256
Daniel Vetterc11e3912016-02-11 20:04:51 -0200257static long dma_buf_ioctl(struct file *file,
258 unsigned int cmd, unsigned long arg)
259{
260 struct dma_buf *dmabuf;
261 struct dma_buf_sync sync;
262 enum dma_data_direction direction;
Chris Wilson18b862d2016-03-18 20:02:39 +0000263 int ret;
Daniel Vetterc11e3912016-02-11 20:04:51 -0200264
265 dmabuf = file->private_data;
266
267 switch (cmd) {
268 case DMA_BUF_IOCTL_SYNC:
269 if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
270 return -EFAULT;
271
272 if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
273 return -EINVAL;
274
275 switch (sync.flags & DMA_BUF_SYNC_RW) {
276 case DMA_BUF_SYNC_READ:
277 direction = DMA_FROM_DEVICE;
278 break;
279 case DMA_BUF_SYNC_WRITE:
280 direction = DMA_TO_DEVICE;
281 break;
282 case DMA_BUF_SYNC_RW:
283 direction = DMA_BIDIRECTIONAL;
284 break;
285 default:
286 return -EINVAL;
287 }
288
289 if (sync.flags & DMA_BUF_SYNC_END)
Chris Wilson18b862d2016-03-18 20:02:39 +0000290 ret = dma_buf_end_cpu_access(dmabuf, direction);
Daniel Vetterc11e3912016-02-11 20:04:51 -0200291 else
Chris Wilson18b862d2016-03-18 20:02:39 +0000292 ret = dma_buf_begin_cpu_access(dmabuf, direction);
Daniel Vetterc11e3912016-02-11 20:04:51 -0200293
Chris Wilson18b862d2016-03-18 20:02:39 +0000294 return ret;
Daniel Vetterc11e3912016-02-11 20:04:51 -0200295 default:
296 return -ENOTTY;
297 }
298}
299
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530300static const struct file_operations dma_buf_fops = {
301 .release = dma_buf_release,
Daniel Vetter4c785132012-04-24 14:38:52 +0530302 .mmap = dma_buf_mmap_internal,
Christopher James Halse Rogers19e86972013-09-10 11:36:45 +0530303 .llseek = dma_buf_llseek,
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200304 .poll = dma_buf_poll,
Daniel Vetterc11e3912016-02-11 20:04:51 -0200305 .unlocked_ioctl = dma_buf_ioctl,
Marek Szyprowski0ade21a2017-02-21 14:21:01 +0100306#ifdef CONFIG_COMPAT
307 .compat_ioctl = dma_buf_ioctl,
308#endif
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530309};
310
311/*
312 * is_dma_buf_file - Check if struct file* is associated with dma_buf
313 */
314static inline int is_dma_buf_file(struct file *file)
315{
316 return file->f_op == &dma_buf_fops;
317}
318
319/**
Sumit Semwald8fbe342015-01-23 12:53:43 +0530320 * dma_buf_export - Creates a new dma_buf, and associates an anon file
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530321 * with this buffer, so it can be exported.
322 * Also connect the allocator specific data and ops to the buffer.
Sumit Semwal78df9692013-03-22 18:22:16 +0530323 * Additionally, provide a name string for exporter; useful in debugging.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530324 *
Sumit Semwald8fbe342015-01-23 12:53:43 +0530325 * @exp_info: [in] holds all the export related information provided
326 * by the exporter. see struct dma_buf_export_info
327 * for further details.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530328 *
329 * Returns, on success, a newly created dma_buf object, which wraps the
330 * supplied private data and operations for dma_buf_ops. On either missing
331 * ops, or error in allocating struct dma_buf, will return negative error.
332 *
333 */
Sumit Semwald8fbe342015-01-23 12:53:43 +0530334struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530335{
336 struct dma_buf *dmabuf;
Sumit Semwald8fbe342015-01-23 12:53:43 +0530337 struct reservation_object *resv = exp_info->resv;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530338 struct file *file;
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200339 size_t alloc_size = sizeof(struct dma_buf);
Chris Wilsona026df42016-07-18 12:16:22 +0100340 int ret;
Jagan Teki51366292015-05-21 01:09:31 +0530341
Sumit Semwald8fbe342015-01-23 12:53:43 +0530342 if (!exp_info->resv)
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200343 alloc_size += sizeof(struct reservation_object);
344 else
345 /* prevent &dma_buf[1] == dma_buf->resv */
346 alloc_size += 1;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530347
Sumit Semwald8fbe342015-01-23 12:53:43 +0530348 if (WARN_ON(!exp_info->priv
349 || !exp_info->ops
350 || !exp_info->ops->map_dma_buf
351 || !exp_info->ops->unmap_dma_buf
352 || !exp_info->ops->release
353 || !exp_info->ops->kmap_atomic
354 || !exp_info->ops->kmap
355 || !exp_info->ops->mmap)) {
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530356 return ERR_PTR(-EINVAL);
357 }
358
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530359 if (!try_module_get(exp_info->owner))
360 return ERR_PTR(-ENOENT);
361
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200362 dmabuf = kzalloc(alloc_size, GFP_KERNEL);
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530363 if (!dmabuf) {
Chris Wilsona026df42016-07-18 12:16:22 +0100364 ret = -ENOMEM;
365 goto err_module;
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530366 }
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530367
Sumit Semwald8fbe342015-01-23 12:53:43 +0530368 dmabuf->priv = exp_info->priv;
369 dmabuf->ops = exp_info->ops;
370 dmabuf->size = exp_info->size;
371 dmabuf->exp_name = exp_info->exp_name;
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530372 dmabuf->owner = exp_info->owner;
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200373 init_waitqueue_head(&dmabuf->poll);
374 dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
375 dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
376
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200377 if (!resv) {
378 resv = (struct reservation_object *)&dmabuf[1];
379 reservation_object_init(resv);
380 }
381 dmabuf->resv = resv;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530382
Sumit Semwald8fbe342015-01-23 12:53:43 +0530383 file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
384 exp_info->flags);
Tuomas Tynkkynen9022e242013-08-27 16:30:38 +0300385 if (IS_ERR(file)) {
Chris Wilsona026df42016-07-18 12:16:22 +0100386 ret = PTR_ERR(file);
387 goto err_dmabuf;
Tuomas Tynkkynen9022e242013-08-27 16:30:38 +0300388 }
Christopher James Halse Rogers19e86972013-09-10 11:36:45 +0530389
390 file->f_mode |= FMODE_LSEEK;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530391 dmabuf->file = file;
392
393 mutex_init(&dmabuf->lock);
394 INIT_LIST_HEAD(&dmabuf->attachments);
395
Sumit Semwalb89e3562013-04-04 11:44:37 +0530396 mutex_lock(&db_list.lock);
397 list_add(&dmabuf->list_node, &db_list.head);
398 mutex_unlock(&db_list.lock);
399
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530400 return dmabuf;
Chris Wilsona026df42016-07-18 12:16:22 +0100401
402err_dmabuf:
403 kfree(dmabuf);
404err_module:
405 module_put(exp_info->owner);
406 return ERR_PTR(ret);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530407}
Sumit Semwald8fbe342015-01-23 12:53:43 +0530408EXPORT_SYMBOL_GPL(dma_buf_export);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530409
410/**
411 * dma_buf_fd - returns a file descriptor for the given dma_buf
412 * @dmabuf: [in] pointer to dma_buf for which fd is required.
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000413 * @flags: [in] flags to give to fd
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530414 *
415 * On success, returns an associated 'fd'. Else, returns error.
416 */
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000417int dma_buf_fd(struct dma_buf *dmabuf, int flags)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530418{
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100419 int fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530420
421 if (!dmabuf || !dmabuf->file)
422 return -EINVAL;
423
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100424 fd = get_unused_fd_flags(flags);
425 if (fd < 0)
426 return fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530427
428 fd_install(fd, dmabuf->file);
429
430 return fd;
431}
432EXPORT_SYMBOL_GPL(dma_buf_fd);
433
434/**
435 * dma_buf_get - returns the dma_buf structure related to an fd
436 * @fd: [in] fd associated with the dma_buf to be returned
437 *
438 * On success, returns the dma_buf structure associated with an fd; uses
439 * file's refcounting done by fget to increase refcount. returns ERR_PTR
440 * otherwise.
441 */
442struct dma_buf *dma_buf_get(int fd)
443{
444 struct file *file;
445
446 file = fget(fd);
447
448 if (!file)
449 return ERR_PTR(-EBADF);
450
451 if (!is_dma_buf_file(file)) {
452 fput(file);
453 return ERR_PTR(-EINVAL);
454 }
455
456 return file->private_data;
457}
458EXPORT_SYMBOL_GPL(dma_buf_get);
459
460/**
461 * dma_buf_put - decreases refcount of the buffer
462 * @dmabuf: [in] buffer to reduce refcount of
463 *
464 * Uses file's refcounting done implicitly by fput()
465 */
466void dma_buf_put(struct dma_buf *dmabuf)
467{
468 if (WARN_ON(!dmabuf || !dmabuf->file))
469 return;
470
471 fput(dmabuf->file);
472}
473EXPORT_SYMBOL_GPL(dma_buf_put);
474
475/**
476 * dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
477 * calls attach() of dma_buf_ops to allow device-specific attach functionality
478 * @dmabuf: [in] buffer to attach device to.
479 * @dev: [in] device to be attached.
480 *
Colin Crossfee0c542013-12-20 16:43:50 -0800481 * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on
482 * error.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530483 */
484struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
485 struct device *dev)
486{
487 struct dma_buf_attachment *attach;
488 int ret;
489
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100490 if (WARN_ON(!dmabuf || !dev))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530491 return ERR_PTR(-EINVAL);
492
493 attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL);
494 if (attach == NULL)
Laurent Pincharta9fbc3b2012-01-26 12:27:24 +0100495 return ERR_PTR(-ENOMEM);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530496
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530497 attach->dev = dev;
498 attach->dmabuf = dmabuf;
Laurent Pinchart2ed92012012-01-26 12:27:25 +0100499
500 mutex_lock(&dmabuf->lock);
501
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530502 if (dmabuf->ops->attach) {
503 ret = dmabuf->ops->attach(dmabuf, dev, attach);
504 if (ret)
505 goto err_attach;
506 }
507 list_add(&attach->node, &dmabuf->attachments);
508
509 mutex_unlock(&dmabuf->lock);
510 return attach;
511
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530512err_attach:
513 kfree(attach);
514 mutex_unlock(&dmabuf->lock);
515 return ERR_PTR(ret);
516}
517EXPORT_SYMBOL_GPL(dma_buf_attach);
518
519/**
520 * dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
521 * optionally calls detach() of dma_buf_ops for device-specific detach
522 * @dmabuf: [in] buffer to detach from.
523 * @attach: [in] attachment to be detached; is free'd after this call.
524 *
525 */
526void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
527{
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100528 if (WARN_ON(!dmabuf || !attach))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530529 return;
530
531 mutex_lock(&dmabuf->lock);
532 list_del(&attach->node);
533 if (dmabuf->ops->detach)
534 dmabuf->ops->detach(dmabuf, attach);
535
536 mutex_unlock(&dmabuf->lock);
537 kfree(attach);
538}
539EXPORT_SYMBOL_GPL(dma_buf_detach);
540
541/**
542 * dma_buf_map_attachment - Returns the scatterlist table of the attachment;
543 * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
544 * dma_buf_ops.
545 * @attach: [in] attachment whose scatterlist is to be returned
546 * @direction: [in] direction of DMA transfer
547 *
Colin Crossfee0c542013-12-20 16:43:50 -0800548 * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
549 * on error.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530550 */
551struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
552 enum dma_data_direction direction)
553{
554 struct sg_table *sg_table = ERR_PTR(-EINVAL);
555
556 might_sleep();
557
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100558 if (WARN_ON(!attach || !attach->dmabuf))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530559 return ERR_PTR(-EINVAL);
560
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100561 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
Colin Crossfee0c542013-12-20 16:43:50 -0800562 if (!sg_table)
563 sg_table = ERR_PTR(-ENOMEM);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530564
565 return sg_table;
566}
567EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
568
569/**
570 * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
571 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
572 * dma_buf_ops.
573 * @attach: [in] attachment to unmap buffer from
574 * @sg_table: [in] scatterlist info of the buffer to unmap
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530575 * @direction: [in] direction of DMA transfer
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530576 *
577 */
578void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530579 struct sg_table *sg_table,
580 enum dma_data_direction direction)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530581{
Rob Clarkb6fa0cd2012-09-28 09:29:43 +0200582 might_sleep();
583
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100584 if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530585 return;
586
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530587 attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
588 direction);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530589}
590EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
Daniel Vetterfc130202012-03-20 00:02:37 +0100591
Chris Wilsonae4e46b2016-08-15 16:42:18 +0100592static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
593 enum dma_data_direction direction)
594{
595 bool write = (direction == DMA_BIDIRECTIONAL ||
596 direction == DMA_TO_DEVICE);
597 struct reservation_object *resv = dmabuf->resv;
598 long ret;
599
600 /* Wait on any implicit rendering fences */
601 ret = reservation_object_wait_timeout_rcu(resv, write, true,
602 MAX_SCHEDULE_TIMEOUT);
603 if (ret < 0)
604 return ret;
605
606 return 0;
607}
Daniel Vetterfc130202012-03-20 00:02:37 +0100608
609/**
610 * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
611 * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
612 * preparations. Coherency is only guaranteed in the specified range for the
613 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700614 * @dmabuf: [in] buffer to prepare cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100615 * @direction: [in] length of range for cpu access.
616 *
617 * Can return negative error values, returns 0 on success.
618 */
Tiago Vignatti831e9da2015-12-22 19:36:45 -0200619int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
Daniel Vetterfc130202012-03-20 00:02:37 +0100620 enum dma_data_direction direction)
621{
622 int ret = 0;
623
624 if (WARN_ON(!dmabuf))
625 return -EINVAL;
626
627 if (dmabuf->ops->begin_cpu_access)
Tiago Vignatti831e9da2015-12-22 19:36:45 -0200628 ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
Daniel Vetterfc130202012-03-20 00:02:37 +0100629
Chris Wilsonae4e46b2016-08-15 16:42:18 +0100630 /* Ensure that all fences are waited upon - but we first allow
631 * the native handler the chance to do so more efficiently if it
632 * chooses. A double invocation here will be reasonably cheap no-op.
633 */
634 if (ret == 0)
635 ret = __dma_buf_begin_cpu_access(dmabuf, direction);
636
Daniel Vetterfc130202012-03-20 00:02:37 +0100637 return ret;
638}
639EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
640
641/**
642 * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
643 * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
644 * actions. Coherency is only guaranteed in the specified range for the
645 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700646 * @dmabuf: [in] buffer to complete cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100647 * @direction: [in] length of range for cpu access.
648 *
Daniel Vetter87e332d2016-03-21 08:24:22 +0100649 * Can return negative error values, returns 0 on success.
Daniel Vetterfc130202012-03-20 00:02:37 +0100650 */
Chris Wilson18b862d2016-03-18 20:02:39 +0000651int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
652 enum dma_data_direction direction)
Daniel Vetterfc130202012-03-20 00:02:37 +0100653{
Chris Wilson18b862d2016-03-18 20:02:39 +0000654 int ret = 0;
655
Daniel Vetterfc130202012-03-20 00:02:37 +0100656 WARN_ON(!dmabuf);
657
658 if (dmabuf->ops->end_cpu_access)
Chris Wilson18b862d2016-03-18 20:02:39 +0000659 ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
660
661 return ret;
Daniel Vetterfc130202012-03-20 00:02:37 +0100662}
663EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
664
665/**
666 * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
667 * space. The same restrictions as for kmap_atomic and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700668 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100669 * @page_num: [in] page in PAGE_SIZE units to map.
670 *
671 * This call must always succeed, any necessary preparations that might fail
672 * need to be done in begin_cpu_access.
673 */
674void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num)
675{
676 WARN_ON(!dmabuf);
677
678 return dmabuf->ops->kmap_atomic(dmabuf, page_num);
679}
680EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic);
681
682/**
683 * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700684 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100685 * @page_num: [in] page in PAGE_SIZE units to unmap.
686 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic.
687 *
688 * This call must always succeed.
689 */
690void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num,
691 void *vaddr)
692{
693 WARN_ON(!dmabuf);
694
695 if (dmabuf->ops->kunmap_atomic)
696 dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr);
697}
698EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic);
699
700/**
701 * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
702 * same restrictions as for kmap and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700703 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100704 * @page_num: [in] page in PAGE_SIZE units to map.
705 *
706 * This call must always succeed, any necessary preparations that might fail
707 * need to be done in begin_cpu_access.
708 */
709void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
710{
711 WARN_ON(!dmabuf);
712
713 return dmabuf->ops->kmap(dmabuf, page_num);
714}
715EXPORT_SYMBOL_GPL(dma_buf_kmap);
716
717/**
718 * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700719 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100720 * @page_num: [in] page in PAGE_SIZE units to unmap.
721 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
722 *
723 * This call must always succeed.
724 */
725void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
726 void *vaddr)
727{
728 WARN_ON(!dmabuf);
729
730 if (dmabuf->ops->kunmap)
731 dmabuf->ops->kunmap(dmabuf, page_num, vaddr);
732}
733EXPORT_SYMBOL_GPL(dma_buf_kunmap);
Daniel Vetter4c785132012-04-24 14:38:52 +0530734
735
736/**
737 * dma_buf_mmap - Setup up a userspace mmap with the given vma
Sumit Semwal12c47272012-05-23 15:27:40 +0530738 * @dmabuf: [in] buffer that should back the vma
Daniel Vetter4c785132012-04-24 14:38:52 +0530739 * @vma: [in] vma for the mmap
740 * @pgoff: [in] offset in pages where this mmap should start within the
Jagan Teki51366292015-05-21 01:09:31 +0530741 * dma-buf buffer.
Daniel Vetter4c785132012-04-24 14:38:52 +0530742 *
743 * This function adjusts the passed in vma so that it points at the file of the
Javier Martinez Canillasecf1dba2014-04-10 01:30:05 +0200744 * dma_buf operation. It also adjusts the starting pgoff and does bounds
Daniel Vetter4c785132012-04-24 14:38:52 +0530745 * checking on the size of the vma. Then it calls the exporters mmap function to
746 * set up the mapping.
747 *
748 * Can return negative error values, returns 0 on success.
749 */
750int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
751 unsigned long pgoff)
752{
John Sheu495c10c2013-02-11 17:50:24 -0800753 struct file *oldfile;
754 int ret;
755
Daniel Vetter4c785132012-04-24 14:38:52 +0530756 if (WARN_ON(!dmabuf || !vma))
757 return -EINVAL;
758
759 /* check for offset overflow */
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +0530760 if (pgoff + vma_pages(vma) < pgoff)
Daniel Vetter4c785132012-04-24 14:38:52 +0530761 return -EOVERFLOW;
762
763 /* check for overflowing the buffer's size */
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +0530764 if (pgoff + vma_pages(vma) >
Daniel Vetter4c785132012-04-24 14:38:52 +0530765 dmabuf->size >> PAGE_SHIFT)
766 return -EINVAL;
767
768 /* readjust the vma */
John Sheu495c10c2013-02-11 17:50:24 -0800769 get_file(dmabuf->file);
770 oldfile = vma->vm_file;
771 vma->vm_file = dmabuf->file;
Daniel Vetter4c785132012-04-24 14:38:52 +0530772 vma->vm_pgoff = pgoff;
773
John Sheu495c10c2013-02-11 17:50:24 -0800774 ret = dmabuf->ops->mmap(dmabuf, vma);
775 if (ret) {
776 /* restore old parameters on failure */
777 vma->vm_file = oldfile;
778 fput(dmabuf->file);
779 } else {
780 if (oldfile)
781 fput(oldfile);
782 }
783 return ret;
784
Daniel Vetter4c785132012-04-24 14:38:52 +0530785}
786EXPORT_SYMBOL_GPL(dma_buf_mmap);
Dave Airlie98f86c92012-05-20 12:33:56 +0530787
788/**
Sumit Semwal12c47272012-05-23 15:27:40 +0530789 * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
790 * address space. Same restrictions as for vmap and friends apply.
791 * @dmabuf: [in] buffer to vmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530792 *
793 * This call may fail due to lack of virtual mapping address space.
794 * These calls are optional in drivers. The intended use for them
795 * is for mapping objects linear in kernel space for high use objects.
796 * Please attempt to use kmap/kunmap before thinking about these interfaces.
Colin Crossfee0c542013-12-20 16:43:50 -0800797 *
798 * Returns NULL on error.
Dave Airlie98f86c92012-05-20 12:33:56 +0530799 */
800void *dma_buf_vmap(struct dma_buf *dmabuf)
801{
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100802 void *ptr;
803
Dave Airlie98f86c92012-05-20 12:33:56 +0530804 if (WARN_ON(!dmabuf))
805 return NULL;
806
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100807 if (!dmabuf->ops->vmap)
808 return NULL;
809
810 mutex_lock(&dmabuf->lock);
811 if (dmabuf->vmapping_counter) {
812 dmabuf->vmapping_counter++;
813 BUG_ON(!dmabuf->vmap_ptr);
814 ptr = dmabuf->vmap_ptr;
815 goto out_unlock;
816 }
817
818 BUG_ON(dmabuf->vmap_ptr);
819
820 ptr = dmabuf->ops->vmap(dmabuf);
Colin Crossfee0c542013-12-20 16:43:50 -0800821 if (WARN_ON_ONCE(IS_ERR(ptr)))
822 ptr = NULL;
823 if (!ptr)
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100824 goto out_unlock;
825
826 dmabuf->vmap_ptr = ptr;
827 dmabuf->vmapping_counter = 1;
828
829out_unlock:
830 mutex_unlock(&dmabuf->lock);
831 return ptr;
Dave Airlie98f86c92012-05-20 12:33:56 +0530832}
833EXPORT_SYMBOL_GPL(dma_buf_vmap);
834
835/**
836 * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
Sumit Semwal12c47272012-05-23 15:27:40 +0530837 * @dmabuf: [in] buffer to vunmap
Randy Dunlap6e7b4a52012-06-09 15:02:59 -0700838 * @vaddr: [in] vmap to vunmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530839 */
840void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
841{
842 if (WARN_ON(!dmabuf))
843 return;
844
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100845 BUG_ON(!dmabuf->vmap_ptr);
846 BUG_ON(dmabuf->vmapping_counter == 0);
847 BUG_ON(dmabuf->vmap_ptr != vaddr);
848
849 mutex_lock(&dmabuf->lock);
850 if (--dmabuf->vmapping_counter == 0) {
851 if (dmabuf->ops->vunmap)
852 dmabuf->ops->vunmap(dmabuf, vaddr);
853 dmabuf->vmap_ptr = NULL;
854 }
855 mutex_unlock(&dmabuf->lock);
Dave Airlie98f86c92012-05-20 12:33:56 +0530856}
857EXPORT_SYMBOL_GPL(dma_buf_vunmap);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530858
859#ifdef CONFIG_DEBUG_FS
Mathias Krauseeb0b9472016-06-19 14:31:29 +0200860static int dma_buf_debug_show(struct seq_file *s, void *unused)
Sumit Semwalb89e3562013-04-04 11:44:37 +0530861{
862 int ret;
863 struct dma_buf *buf_obj;
864 struct dma_buf_attachment *attach_obj;
865 int count = 0, attach_count;
866 size_t size = 0;
867
868 ret = mutex_lock_interruptible(&db_list.lock);
869
870 if (ret)
871 return ret;
872
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530873 seq_puts(s, "\nDma-buf Objects:\n");
874 seq_puts(s, "size\tflags\tmode\tcount\texp_name\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530875
876 list_for_each_entry(buf_obj, &db_list.head, list_node) {
877 ret = mutex_lock_interruptible(&buf_obj->lock);
878
879 if (ret) {
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530880 seq_puts(s,
881 "\tERROR locking buffer object: skipping\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530882 continue;
883 }
884
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530885 seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n",
886 buf_obj->size,
Sumit Semwalb89e3562013-04-04 11:44:37 +0530887 buf_obj->file->f_flags, buf_obj->file->f_mode,
Al Viroa1f6dba2014-08-20 11:05:50 -0400888 file_count(buf_obj->file),
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530889 buf_obj->exp_name);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530890
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530891 seq_puts(s, "\tAttached Devices:\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530892 attach_count = 0;
893
894 list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530895 seq_puts(s, "\t");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530896
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530897 seq_printf(s, "%s\n", dev_name(attach_obj->dev));
Sumit Semwalb89e3562013-04-04 11:44:37 +0530898 attach_count++;
899 }
900
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530901 seq_printf(s, "Total %d devices attached\n\n",
Sumit Semwalb89e3562013-04-04 11:44:37 +0530902 attach_count);
903
904 count++;
905 size += buf_obj->size;
906 mutex_unlock(&buf_obj->lock);
907 }
908
909 seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
910
911 mutex_unlock(&db_list.lock);
912 return 0;
913}
914
Sumit Semwalb89e3562013-04-04 11:44:37 +0530915static int dma_buf_debug_open(struct inode *inode, struct file *file)
916{
Mathias Krauseeb0b9472016-06-19 14:31:29 +0200917 return single_open(file, dma_buf_debug_show, NULL);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530918}
919
920static const struct file_operations dma_buf_debug_fops = {
921 .open = dma_buf_debug_open,
922 .read = seq_read,
923 .llseek = seq_lseek,
924 .release = single_release,
925};
926
927static struct dentry *dma_buf_debugfs_dir;
928
929static int dma_buf_init_debugfs(void)
930{
Mathias Krausebd3e2202016-06-19 14:31:31 +0200931 struct dentry *d;
Sumit Semwalb89e3562013-04-04 11:44:37 +0530932 int err = 0;
Jagan Teki51366292015-05-21 01:09:31 +0530933
Mathias Krausebd3e2202016-06-19 14:31:31 +0200934 d = debugfs_create_dir("dma_buf", NULL);
935 if (IS_ERR(d))
936 return PTR_ERR(d);
Jagan Teki51366292015-05-21 01:09:31 +0530937
Mathias Krausebd3e2202016-06-19 14:31:31 +0200938 dma_buf_debugfs_dir = d;
Sumit Semwalb89e3562013-04-04 11:44:37 +0530939
Mathias Krausebd3e2202016-06-19 14:31:31 +0200940 d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir,
941 NULL, &dma_buf_debug_fops);
942 if (IS_ERR(d)) {
Sumit Semwalb89e3562013-04-04 11:44:37 +0530943 pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
Mathias Krauseb7479992016-06-19 14:31:30 +0200944 debugfs_remove_recursive(dma_buf_debugfs_dir);
945 dma_buf_debugfs_dir = NULL;
Mathias Krausebd3e2202016-06-19 14:31:31 +0200946 err = PTR_ERR(d);
Mathias Krauseb7479992016-06-19 14:31:30 +0200947 }
Sumit Semwalb89e3562013-04-04 11:44:37 +0530948
949 return err;
950}
951
952static void dma_buf_uninit_debugfs(void)
953{
954 if (dma_buf_debugfs_dir)
955 debugfs_remove_recursive(dma_buf_debugfs_dir);
956}
Sumit Semwalb89e3562013-04-04 11:44:37 +0530957#else
958static inline int dma_buf_init_debugfs(void)
959{
960 return 0;
961}
962static inline void dma_buf_uninit_debugfs(void)
963{
964}
965#endif
966
967static int __init dma_buf_init(void)
968{
969 mutex_init(&db_list.lock);
970 INIT_LIST_HEAD(&db_list.head);
971 dma_buf_init_debugfs();
972 return 0;
973}
974subsys_initcall(dma_buf_init);
975
976static void __exit dma_buf_deinit(void)
977{
978 dma_buf_uninit_debugfs();
979}
980__exitcall(dma_buf_deinit);