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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,
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530306};
307
308/*
309 * is_dma_buf_file - Check if struct file* is associated with dma_buf
310 */
311static inline int is_dma_buf_file(struct file *file)
312{
313 return file->f_op == &dma_buf_fops;
314}
315
316/**
Sumit Semwald8fbe342015-01-23 12:53:43 +0530317 * dma_buf_export - Creates a new dma_buf, and associates an anon file
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530318 * with this buffer, so it can be exported.
319 * Also connect the allocator specific data and ops to the buffer.
Sumit Semwal78df9692013-03-22 18:22:16 +0530320 * Additionally, provide a name string for exporter; useful in debugging.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530321 *
Sumit Semwald8fbe342015-01-23 12:53:43 +0530322 * @exp_info: [in] holds all the export related information provided
323 * by the exporter. see struct dma_buf_export_info
324 * for further details.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530325 *
326 * Returns, on success, a newly created dma_buf object, which wraps the
327 * supplied private data and operations for dma_buf_ops. On either missing
328 * ops, or error in allocating struct dma_buf, will return negative error.
329 *
330 */
Sumit Semwald8fbe342015-01-23 12:53:43 +0530331struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530332{
333 struct dma_buf *dmabuf;
Sumit Semwald8fbe342015-01-23 12:53:43 +0530334 struct reservation_object *resv = exp_info->resv;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530335 struct file *file;
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200336 size_t alloc_size = sizeof(struct dma_buf);
Jagan Teki51366292015-05-21 01:09:31 +0530337
Sumit Semwald8fbe342015-01-23 12:53:43 +0530338 if (!exp_info->resv)
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200339 alloc_size += sizeof(struct reservation_object);
340 else
341 /* prevent &dma_buf[1] == dma_buf->resv */
342 alloc_size += 1;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530343
Sumit Semwald8fbe342015-01-23 12:53:43 +0530344 if (WARN_ON(!exp_info->priv
345 || !exp_info->ops
346 || !exp_info->ops->map_dma_buf
347 || !exp_info->ops->unmap_dma_buf
348 || !exp_info->ops->release
349 || !exp_info->ops->kmap_atomic
350 || !exp_info->ops->kmap
351 || !exp_info->ops->mmap)) {
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530352 return ERR_PTR(-EINVAL);
353 }
354
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530355 if (!try_module_get(exp_info->owner))
356 return ERR_PTR(-ENOENT);
357
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200358 dmabuf = kzalloc(alloc_size, GFP_KERNEL);
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530359 if (!dmabuf) {
360 module_put(exp_info->owner);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530361 return ERR_PTR(-ENOMEM);
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530362 }
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530363
Sumit Semwald8fbe342015-01-23 12:53:43 +0530364 dmabuf->priv = exp_info->priv;
365 dmabuf->ops = exp_info->ops;
366 dmabuf->size = exp_info->size;
367 dmabuf->exp_name = exp_info->exp_name;
Sumit Semwal9abdffe2015-05-05 14:56:15 +0530368 dmabuf->owner = exp_info->owner;
Maarten Lankhorst9b495a52014-07-01 12:57:43 +0200369 init_waitqueue_head(&dmabuf->poll);
370 dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
371 dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
372
Maarten Lankhorst3aac4502014-07-01 12:57:26 +0200373 if (!resv) {
374 resv = (struct reservation_object *)&dmabuf[1];
375 reservation_object_init(resv);
376 }
377 dmabuf->resv = resv;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530378
Sumit Semwald8fbe342015-01-23 12:53:43 +0530379 file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
380 exp_info->flags);
Tuomas Tynkkynen9022e242013-08-27 16:30:38 +0300381 if (IS_ERR(file)) {
382 kfree(dmabuf);
383 return ERR_CAST(file);
384 }
Christopher James Halse Rogers19e86972013-09-10 11:36:45 +0530385
386 file->f_mode |= FMODE_LSEEK;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530387 dmabuf->file = file;
388
389 mutex_init(&dmabuf->lock);
390 INIT_LIST_HEAD(&dmabuf->attachments);
391
Sumit Semwalb89e3562013-04-04 11:44:37 +0530392 mutex_lock(&db_list.lock);
393 list_add(&dmabuf->list_node, &db_list.head);
394 mutex_unlock(&db_list.lock);
395
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530396 return dmabuf;
397}
Sumit Semwald8fbe342015-01-23 12:53:43 +0530398EXPORT_SYMBOL_GPL(dma_buf_export);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530399
400/**
401 * dma_buf_fd - returns a file descriptor for the given dma_buf
402 * @dmabuf: [in] pointer to dma_buf for which fd is required.
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000403 * @flags: [in] flags to give to fd
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530404 *
405 * On success, returns an associated 'fd'. Else, returns error.
406 */
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000407int dma_buf_fd(struct dma_buf *dmabuf, int flags)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530408{
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100409 int fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530410
411 if (!dmabuf || !dmabuf->file)
412 return -EINVAL;
413
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100414 fd = get_unused_fd_flags(flags);
415 if (fd < 0)
416 return fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530417
418 fd_install(fd, dmabuf->file);
419
420 return fd;
421}
422EXPORT_SYMBOL_GPL(dma_buf_fd);
423
424/**
425 * dma_buf_get - returns the dma_buf structure related to an fd
426 * @fd: [in] fd associated with the dma_buf to be returned
427 *
428 * On success, returns the dma_buf structure associated with an fd; uses
429 * file's refcounting done by fget to increase refcount. returns ERR_PTR
430 * otherwise.
431 */
432struct dma_buf *dma_buf_get(int fd)
433{
434 struct file *file;
435
436 file = fget(fd);
437
438 if (!file)
439 return ERR_PTR(-EBADF);
440
441 if (!is_dma_buf_file(file)) {
442 fput(file);
443 return ERR_PTR(-EINVAL);
444 }
445
446 return file->private_data;
447}
448EXPORT_SYMBOL_GPL(dma_buf_get);
449
450/**
451 * dma_buf_put - decreases refcount of the buffer
452 * @dmabuf: [in] buffer to reduce refcount of
453 *
454 * Uses file's refcounting done implicitly by fput()
455 */
456void dma_buf_put(struct dma_buf *dmabuf)
457{
458 if (WARN_ON(!dmabuf || !dmabuf->file))
459 return;
460
461 fput(dmabuf->file);
462}
463EXPORT_SYMBOL_GPL(dma_buf_put);
464
465/**
466 * dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
467 * calls attach() of dma_buf_ops to allow device-specific attach functionality
468 * @dmabuf: [in] buffer to attach device to.
469 * @dev: [in] device to be attached.
470 *
Colin Crossfee0c542013-12-20 16:43:50 -0800471 * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on
472 * error.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530473 */
474struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
475 struct device *dev)
476{
477 struct dma_buf_attachment *attach;
478 int ret;
479
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100480 if (WARN_ON(!dmabuf || !dev))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530481 return ERR_PTR(-EINVAL);
482
483 attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL);
484 if (attach == NULL)
Laurent Pincharta9fbc3b2012-01-26 12:27:24 +0100485 return ERR_PTR(-ENOMEM);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530486
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530487 attach->dev = dev;
488 attach->dmabuf = dmabuf;
Laurent Pinchart2ed92012012-01-26 12:27:25 +0100489
490 mutex_lock(&dmabuf->lock);
491
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530492 if (dmabuf->ops->attach) {
493 ret = dmabuf->ops->attach(dmabuf, dev, attach);
494 if (ret)
495 goto err_attach;
496 }
497 list_add(&attach->node, &dmabuf->attachments);
498
499 mutex_unlock(&dmabuf->lock);
500 return attach;
501
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530502err_attach:
503 kfree(attach);
504 mutex_unlock(&dmabuf->lock);
505 return ERR_PTR(ret);
506}
507EXPORT_SYMBOL_GPL(dma_buf_attach);
508
509/**
510 * dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
511 * optionally calls detach() of dma_buf_ops for device-specific detach
512 * @dmabuf: [in] buffer to detach from.
513 * @attach: [in] attachment to be detached; is free'd after this call.
514 *
515 */
516void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
517{
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100518 if (WARN_ON(!dmabuf || !attach))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530519 return;
520
521 mutex_lock(&dmabuf->lock);
522 list_del(&attach->node);
523 if (dmabuf->ops->detach)
524 dmabuf->ops->detach(dmabuf, attach);
525
526 mutex_unlock(&dmabuf->lock);
527 kfree(attach);
528}
529EXPORT_SYMBOL_GPL(dma_buf_detach);
530
531/**
532 * dma_buf_map_attachment - Returns the scatterlist table of the attachment;
533 * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
534 * dma_buf_ops.
535 * @attach: [in] attachment whose scatterlist is to be returned
536 * @direction: [in] direction of DMA transfer
537 *
Colin Crossfee0c542013-12-20 16:43:50 -0800538 * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
539 * on error.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530540 */
541struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
542 enum dma_data_direction direction)
543{
544 struct sg_table *sg_table = ERR_PTR(-EINVAL);
545
546 might_sleep();
547
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100548 if (WARN_ON(!attach || !attach->dmabuf))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530549 return ERR_PTR(-EINVAL);
550
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100551 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
Colin Crossfee0c542013-12-20 16:43:50 -0800552 if (!sg_table)
553 sg_table = ERR_PTR(-ENOMEM);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530554
555 return sg_table;
556}
557EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
558
559/**
560 * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
561 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
562 * dma_buf_ops.
563 * @attach: [in] attachment to unmap buffer from
564 * @sg_table: [in] scatterlist info of the buffer to unmap
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530565 * @direction: [in] direction of DMA transfer
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530566 *
567 */
568void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530569 struct sg_table *sg_table,
570 enum dma_data_direction direction)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530571{
Rob Clarkb6fa0cd2012-09-28 09:29:43 +0200572 might_sleep();
573
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100574 if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530575 return;
576
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530577 attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
578 direction);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530579}
580EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
Daniel Vetterfc130202012-03-20 00:02:37 +0100581
582
583/**
584 * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
585 * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
586 * preparations. Coherency is only guaranteed in the specified range for the
587 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700588 * @dmabuf: [in] buffer to prepare cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100589 * @direction: [in] length of range for cpu access.
590 *
591 * Can return negative error values, returns 0 on success.
592 */
Tiago Vignatti831e9da2015-12-22 19:36:45 -0200593int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
Daniel Vetterfc130202012-03-20 00:02:37 +0100594 enum dma_data_direction direction)
595{
596 int ret = 0;
597
598 if (WARN_ON(!dmabuf))
599 return -EINVAL;
600
601 if (dmabuf->ops->begin_cpu_access)
Tiago Vignatti831e9da2015-12-22 19:36:45 -0200602 ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
Daniel Vetterfc130202012-03-20 00:02:37 +0100603
604 return ret;
605}
606EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
607
608/**
609 * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
610 * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
611 * actions. Coherency is only guaranteed in the specified range for the
612 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700613 * @dmabuf: [in] buffer to complete cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100614 * @direction: [in] length of range for cpu access.
615 *
Daniel Vetter87e332d2016-03-21 08:24:22 +0100616 * Can return negative error values, returns 0 on success.
Daniel Vetterfc130202012-03-20 00:02:37 +0100617 */
Chris Wilson18b862d2016-03-18 20:02:39 +0000618int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
619 enum dma_data_direction direction)
Daniel Vetterfc130202012-03-20 00:02:37 +0100620{
Chris Wilson18b862d2016-03-18 20:02:39 +0000621 int ret = 0;
622
Daniel Vetterfc130202012-03-20 00:02:37 +0100623 WARN_ON(!dmabuf);
624
625 if (dmabuf->ops->end_cpu_access)
Chris Wilson18b862d2016-03-18 20:02:39 +0000626 ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
627
628 return ret;
Daniel Vetterfc130202012-03-20 00:02:37 +0100629}
630EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
631
632/**
633 * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
634 * space. The same restrictions as for kmap_atomic and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700635 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100636 * @page_num: [in] page in PAGE_SIZE units to map.
637 *
638 * This call must always succeed, any necessary preparations that might fail
639 * need to be done in begin_cpu_access.
640 */
641void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num)
642{
643 WARN_ON(!dmabuf);
644
645 return dmabuf->ops->kmap_atomic(dmabuf, page_num);
646}
647EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic);
648
649/**
650 * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700651 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100652 * @page_num: [in] page in PAGE_SIZE units to unmap.
653 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic.
654 *
655 * This call must always succeed.
656 */
657void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num,
658 void *vaddr)
659{
660 WARN_ON(!dmabuf);
661
662 if (dmabuf->ops->kunmap_atomic)
663 dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr);
664}
665EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic);
666
667/**
668 * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
669 * same restrictions as for kmap and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700670 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100671 * @page_num: [in] page in PAGE_SIZE units to map.
672 *
673 * This call must always succeed, any necessary preparations that might fail
674 * need to be done in begin_cpu_access.
675 */
676void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
677{
678 WARN_ON(!dmabuf);
679
680 return dmabuf->ops->kmap(dmabuf, page_num);
681}
682EXPORT_SYMBOL_GPL(dma_buf_kmap);
683
684/**
685 * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700686 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100687 * @page_num: [in] page in PAGE_SIZE units to unmap.
688 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
689 *
690 * This call must always succeed.
691 */
692void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
693 void *vaddr)
694{
695 WARN_ON(!dmabuf);
696
697 if (dmabuf->ops->kunmap)
698 dmabuf->ops->kunmap(dmabuf, page_num, vaddr);
699}
700EXPORT_SYMBOL_GPL(dma_buf_kunmap);
Daniel Vetter4c785132012-04-24 14:38:52 +0530701
702
703/**
704 * dma_buf_mmap - Setup up a userspace mmap with the given vma
Sumit Semwal12c47272012-05-23 15:27:40 +0530705 * @dmabuf: [in] buffer that should back the vma
Daniel Vetter4c785132012-04-24 14:38:52 +0530706 * @vma: [in] vma for the mmap
707 * @pgoff: [in] offset in pages where this mmap should start within the
Jagan Teki51366292015-05-21 01:09:31 +0530708 * dma-buf buffer.
Daniel Vetter4c785132012-04-24 14:38:52 +0530709 *
710 * This function adjusts the passed in vma so that it points at the file of the
Javier Martinez Canillasecf1dba2014-04-10 01:30:05 +0200711 * dma_buf operation. It also adjusts the starting pgoff and does bounds
Daniel Vetter4c785132012-04-24 14:38:52 +0530712 * checking on the size of the vma. Then it calls the exporters mmap function to
713 * set up the mapping.
714 *
715 * Can return negative error values, returns 0 on success.
716 */
717int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
718 unsigned long pgoff)
719{
John Sheu495c10c2013-02-11 17:50:24 -0800720 struct file *oldfile;
721 int ret;
722
Daniel Vetter4c785132012-04-24 14:38:52 +0530723 if (WARN_ON(!dmabuf || !vma))
724 return -EINVAL;
725
726 /* check for offset overflow */
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +0530727 if (pgoff + vma_pages(vma) < pgoff)
Daniel Vetter4c785132012-04-24 14:38:52 +0530728 return -EOVERFLOW;
729
730 /* check for overflowing the buffer's size */
Muhammad Falak R Wanib02da6f2016-05-23 17:08:42 +0530731 if (pgoff + vma_pages(vma) >
Daniel Vetter4c785132012-04-24 14:38:52 +0530732 dmabuf->size >> PAGE_SHIFT)
733 return -EINVAL;
734
735 /* readjust the vma */
John Sheu495c10c2013-02-11 17:50:24 -0800736 get_file(dmabuf->file);
737 oldfile = vma->vm_file;
738 vma->vm_file = dmabuf->file;
Daniel Vetter4c785132012-04-24 14:38:52 +0530739 vma->vm_pgoff = pgoff;
740
John Sheu495c10c2013-02-11 17:50:24 -0800741 ret = dmabuf->ops->mmap(dmabuf, vma);
742 if (ret) {
743 /* restore old parameters on failure */
744 vma->vm_file = oldfile;
745 fput(dmabuf->file);
746 } else {
747 if (oldfile)
748 fput(oldfile);
749 }
750 return ret;
751
Daniel Vetter4c785132012-04-24 14:38:52 +0530752}
753EXPORT_SYMBOL_GPL(dma_buf_mmap);
Dave Airlie98f86c92012-05-20 12:33:56 +0530754
755/**
Sumit Semwal12c47272012-05-23 15:27:40 +0530756 * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
757 * address space. Same restrictions as for vmap and friends apply.
758 * @dmabuf: [in] buffer to vmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530759 *
760 * This call may fail due to lack of virtual mapping address space.
761 * These calls are optional in drivers. The intended use for them
762 * is for mapping objects linear in kernel space for high use objects.
763 * Please attempt to use kmap/kunmap before thinking about these interfaces.
Colin Crossfee0c542013-12-20 16:43:50 -0800764 *
765 * Returns NULL on error.
Dave Airlie98f86c92012-05-20 12:33:56 +0530766 */
767void *dma_buf_vmap(struct dma_buf *dmabuf)
768{
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100769 void *ptr;
770
Dave Airlie98f86c92012-05-20 12:33:56 +0530771 if (WARN_ON(!dmabuf))
772 return NULL;
773
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100774 if (!dmabuf->ops->vmap)
775 return NULL;
776
777 mutex_lock(&dmabuf->lock);
778 if (dmabuf->vmapping_counter) {
779 dmabuf->vmapping_counter++;
780 BUG_ON(!dmabuf->vmap_ptr);
781 ptr = dmabuf->vmap_ptr;
782 goto out_unlock;
783 }
784
785 BUG_ON(dmabuf->vmap_ptr);
786
787 ptr = dmabuf->ops->vmap(dmabuf);
Colin Crossfee0c542013-12-20 16:43:50 -0800788 if (WARN_ON_ONCE(IS_ERR(ptr)))
789 ptr = NULL;
790 if (!ptr)
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100791 goto out_unlock;
792
793 dmabuf->vmap_ptr = ptr;
794 dmabuf->vmapping_counter = 1;
795
796out_unlock:
797 mutex_unlock(&dmabuf->lock);
798 return ptr;
Dave Airlie98f86c92012-05-20 12:33:56 +0530799}
800EXPORT_SYMBOL_GPL(dma_buf_vmap);
801
802/**
803 * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
Sumit Semwal12c47272012-05-23 15:27:40 +0530804 * @dmabuf: [in] buffer to vunmap
Randy Dunlap6e7b4a52012-06-09 15:02:59 -0700805 * @vaddr: [in] vmap to vunmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530806 */
807void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
808{
809 if (WARN_ON(!dmabuf))
810 return;
811
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100812 BUG_ON(!dmabuf->vmap_ptr);
813 BUG_ON(dmabuf->vmapping_counter == 0);
814 BUG_ON(dmabuf->vmap_ptr != vaddr);
815
816 mutex_lock(&dmabuf->lock);
817 if (--dmabuf->vmapping_counter == 0) {
818 if (dmabuf->ops->vunmap)
819 dmabuf->ops->vunmap(dmabuf, vaddr);
820 dmabuf->vmap_ptr = NULL;
821 }
822 mutex_unlock(&dmabuf->lock);
Dave Airlie98f86c92012-05-20 12:33:56 +0530823}
824EXPORT_SYMBOL_GPL(dma_buf_vunmap);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530825
826#ifdef CONFIG_DEBUG_FS
Mathias Krauseeb0b9472016-06-19 14:31:29 +0200827static int dma_buf_debug_show(struct seq_file *s, void *unused)
Sumit Semwalb89e3562013-04-04 11:44:37 +0530828{
829 int ret;
830 struct dma_buf *buf_obj;
831 struct dma_buf_attachment *attach_obj;
832 int count = 0, attach_count;
833 size_t size = 0;
834
835 ret = mutex_lock_interruptible(&db_list.lock);
836
837 if (ret)
838 return ret;
839
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530840 seq_puts(s, "\nDma-buf Objects:\n");
841 seq_puts(s, "size\tflags\tmode\tcount\texp_name\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530842
843 list_for_each_entry(buf_obj, &db_list.head, list_node) {
844 ret = mutex_lock_interruptible(&buf_obj->lock);
845
846 if (ret) {
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530847 seq_puts(s,
848 "\tERROR locking buffer object: skipping\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530849 continue;
850 }
851
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530852 seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n",
853 buf_obj->size,
Sumit Semwalb89e3562013-04-04 11:44:37 +0530854 buf_obj->file->f_flags, buf_obj->file->f_mode,
Al Viroa1f6dba2014-08-20 11:05:50 -0400855 file_count(buf_obj->file),
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530856 buf_obj->exp_name);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530857
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530858 seq_puts(s, "\tAttached Devices:\n");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530859 attach_count = 0;
860
861 list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530862 seq_puts(s, "\t");
Sumit Semwalb89e3562013-04-04 11:44:37 +0530863
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530864 seq_printf(s, "%s\n", dev_name(attach_obj->dev));
Sumit Semwalb89e3562013-04-04 11:44:37 +0530865 attach_count++;
866 }
867
Sumit Semwalc0b00a52014-02-03 15:09:12 +0530868 seq_printf(s, "Total %d devices attached\n\n",
Sumit Semwalb89e3562013-04-04 11:44:37 +0530869 attach_count);
870
871 count++;
872 size += buf_obj->size;
873 mutex_unlock(&buf_obj->lock);
874 }
875
876 seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
877
878 mutex_unlock(&db_list.lock);
879 return 0;
880}
881
Sumit Semwalb89e3562013-04-04 11:44:37 +0530882static int dma_buf_debug_open(struct inode *inode, struct file *file)
883{
Mathias Krauseeb0b9472016-06-19 14:31:29 +0200884 return single_open(file, dma_buf_debug_show, NULL);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530885}
886
887static const struct file_operations dma_buf_debug_fops = {
888 .open = dma_buf_debug_open,
889 .read = seq_read,
890 .llseek = seq_lseek,
891 .release = single_release,
892};
893
894static struct dentry *dma_buf_debugfs_dir;
895
896static int dma_buf_init_debugfs(void)
897{
898 int err = 0;
Jagan Teki51366292015-05-21 01:09:31 +0530899
Sumit Semwalb89e3562013-04-04 11:44:37 +0530900 dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL);
Jagan Teki51366292015-05-21 01:09:31 +0530901
Sumit Semwalb89e3562013-04-04 11:44:37 +0530902 if (IS_ERR(dma_buf_debugfs_dir)) {
903 err = PTR_ERR(dma_buf_debugfs_dir);
904 dma_buf_debugfs_dir = NULL;
905 return err;
906 }
907
Mathias Krauseeb0b9472016-06-19 14:31:29 +0200908 err = dma_buf_debugfs_create_file("bufinfo", NULL);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530909
Mathias Krauseb7479992016-06-19 14:31:30 +0200910 if (err) {
Sumit Semwalb89e3562013-04-04 11:44:37 +0530911 pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
Mathias Krauseb7479992016-06-19 14:31:30 +0200912 debugfs_remove_recursive(dma_buf_debugfs_dir);
913 dma_buf_debugfs_dir = NULL;
914 }
Sumit Semwalb89e3562013-04-04 11:44:37 +0530915
916 return err;
917}
918
919static void dma_buf_uninit_debugfs(void)
920{
921 if (dma_buf_debugfs_dir)
922 debugfs_remove_recursive(dma_buf_debugfs_dir);
923}
924
925int dma_buf_debugfs_create_file(const char *name,
926 int (*write)(struct seq_file *))
927{
928 struct dentry *d;
929
930 d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir,
931 write, &dma_buf_debug_fops);
932
Sachin Kamat28ce4202013-07-15 15:51:22 +0530933 return PTR_ERR_OR_ZERO(d);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530934}
935#else
936static inline int dma_buf_init_debugfs(void)
937{
938 return 0;
939}
940static inline void dma_buf_uninit_debugfs(void)
941{
942}
943#endif
944
945static int __init dma_buf_init(void)
946{
947 mutex_init(&db_list.lock);
948 INIT_LIST_HEAD(&db_list.head);
949 dma_buf_init_debugfs();
950 return 0;
951}
952subsys_initcall(dma_buf_init);
953
954static void __exit dma_buf_deinit(void)
955{
956 dma_buf_uninit_debugfs();
957}
958__exitcall(dma_buf_deinit);