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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>
28#include <linux/anon_inodes.h>
29#include <linux/export.h>
Sumit Semwalb89e3562013-04-04 11:44:37 +053030#include <linux/debugfs.h>
31#include <linux/seq_file.h>
Sumit Semwald15bd7e2011-12-26 14:53:15 +053032
33static inline int is_dma_buf_file(struct file *);
34
Sumit Semwalb89e3562013-04-04 11:44:37 +053035struct dma_buf_list {
36 struct list_head head;
37 struct mutex lock;
38};
39
40static struct dma_buf_list db_list;
41
Sumit Semwald15bd7e2011-12-26 14:53:15 +053042static int dma_buf_release(struct inode *inode, struct file *file)
43{
44 struct dma_buf *dmabuf;
45
46 if (!is_dma_buf_file(file))
47 return -EINVAL;
48
49 dmabuf = file->private_data;
50
Daniel Vetterf00b4da2012-12-20 14:14:23 +010051 BUG_ON(dmabuf->vmapping_counter);
52
Sumit Semwald15bd7e2011-12-26 14:53:15 +053053 dmabuf->ops->release(dmabuf);
Sumit Semwalb89e3562013-04-04 11:44:37 +053054
55 mutex_lock(&db_list.lock);
56 list_del(&dmabuf->list_node);
57 mutex_unlock(&db_list.lock);
58
Sumit Semwald15bd7e2011-12-26 14:53:15 +053059 kfree(dmabuf);
60 return 0;
61}
62
Daniel Vetter4c785132012-04-24 14:38:52 +053063static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
64{
65 struct dma_buf *dmabuf;
66
67 if (!is_dma_buf_file(file))
68 return -EINVAL;
69
70 dmabuf = file->private_data;
71
72 /* check for overflowing the buffer's size */
73 if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
74 dmabuf->size >> PAGE_SHIFT)
75 return -EINVAL;
76
77 return dmabuf->ops->mmap(dmabuf, vma);
78}
79
Sumit Semwald15bd7e2011-12-26 14:53:15 +053080static const struct file_operations dma_buf_fops = {
81 .release = dma_buf_release,
Daniel Vetter4c785132012-04-24 14:38:52 +053082 .mmap = dma_buf_mmap_internal,
Sumit Semwald15bd7e2011-12-26 14:53:15 +053083};
84
85/*
86 * is_dma_buf_file - Check if struct file* is associated with dma_buf
87 */
88static inline int is_dma_buf_file(struct file *file)
89{
90 return file->f_op == &dma_buf_fops;
91}
92
93/**
Sumit Semwal78df9692013-03-22 18:22:16 +053094 * dma_buf_export_named - Creates a new dma_buf, and associates an anon file
Sumit Semwald15bd7e2011-12-26 14:53:15 +053095 * with this buffer, so it can be exported.
96 * Also connect the allocator specific data and ops to the buffer.
Sumit Semwal78df9692013-03-22 18:22:16 +053097 * Additionally, provide a name string for exporter; useful in debugging.
Sumit Semwald15bd7e2011-12-26 14:53:15 +053098 *
99 * @priv: [in] Attach private data of allocator to this buffer
100 * @ops: [in] Attach allocator-defined dma buf ops to the new buffer.
101 * @size: [in] Size of the buffer
102 * @flags: [in] mode flags for the file.
Sumit Semwal78df9692013-03-22 18:22:16 +0530103 * @exp_name: [in] name of the exporting module - useful for debugging.
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530104 *
105 * Returns, on success, a newly created dma_buf object, which wraps the
106 * supplied private data and operations for dma_buf_ops. On either missing
107 * ops, or error in allocating struct dma_buf, will return negative error.
108 *
109 */
Sumit Semwal78df9692013-03-22 18:22:16 +0530110struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
111 size_t size, int flags, const char *exp_name)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530112{
113 struct dma_buf *dmabuf;
114 struct file *file;
115
116 if (WARN_ON(!priv || !ops
117 || !ops->map_dma_buf
118 || !ops->unmap_dma_buf
Daniel Vetterfc130202012-03-20 00:02:37 +0100119 || !ops->release
120 || !ops->kmap_atomic
Daniel Vetter4c785132012-04-24 14:38:52 +0530121 || !ops->kmap
122 || !ops->mmap)) {
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530123 return ERR_PTR(-EINVAL);
124 }
125
126 dmabuf = kzalloc(sizeof(struct dma_buf), GFP_KERNEL);
127 if (dmabuf == NULL)
128 return ERR_PTR(-ENOMEM);
129
130 dmabuf->priv = priv;
131 dmabuf->ops = ops;
132 dmabuf->size = size;
Sumit Semwal78df9692013-03-22 18:22:16 +0530133 dmabuf->exp_name = exp_name;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530134
135 file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags);
136
137 dmabuf->file = file;
138
139 mutex_init(&dmabuf->lock);
140 INIT_LIST_HEAD(&dmabuf->attachments);
141
Sumit Semwalb89e3562013-04-04 11:44:37 +0530142 mutex_lock(&db_list.lock);
143 list_add(&dmabuf->list_node, &db_list.head);
144 mutex_unlock(&db_list.lock);
145
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530146 return dmabuf;
147}
Sumit Semwal78df9692013-03-22 18:22:16 +0530148EXPORT_SYMBOL_GPL(dma_buf_export_named);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530149
150
151/**
152 * dma_buf_fd - returns a file descriptor for the given dma_buf
153 * @dmabuf: [in] pointer to dma_buf for which fd is required.
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000154 * @flags: [in] flags to give to fd
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530155 *
156 * On success, returns an associated 'fd'. Else, returns error.
157 */
Dave Airlie55c1c4c2012-03-16 10:34:02 +0000158int dma_buf_fd(struct dma_buf *dmabuf, int flags)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530159{
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100160 int fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530161
162 if (!dmabuf || !dmabuf->file)
163 return -EINVAL;
164
Borislav Petkovf5e097f2012-12-11 16:05:26 +0100165 fd = get_unused_fd_flags(flags);
166 if (fd < 0)
167 return fd;
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530168
169 fd_install(fd, dmabuf->file);
170
171 return fd;
172}
173EXPORT_SYMBOL_GPL(dma_buf_fd);
174
175/**
176 * dma_buf_get - returns the dma_buf structure related to an fd
177 * @fd: [in] fd associated with the dma_buf to be returned
178 *
179 * On success, returns the dma_buf structure associated with an fd; uses
180 * file's refcounting done by fget to increase refcount. returns ERR_PTR
181 * otherwise.
182 */
183struct dma_buf *dma_buf_get(int fd)
184{
185 struct file *file;
186
187 file = fget(fd);
188
189 if (!file)
190 return ERR_PTR(-EBADF);
191
192 if (!is_dma_buf_file(file)) {
193 fput(file);
194 return ERR_PTR(-EINVAL);
195 }
196
197 return file->private_data;
198}
199EXPORT_SYMBOL_GPL(dma_buf_get);
200
201/**
202 * dma_buf_put - decreases refcount of the buffer
203 * @dmabuf: [in] buffer to reduce refcount of
204 *
205 * Uses file's refcounting done implicitly by fput()
206 */
207void dma_buf_put(struct dma_buf *dmabuf)
208{
209 if (WARN_ON(!dmabuf || !dmabuf->file))
210 return;
211
212 fput(dmabuf->file);
213}
214EXPORT_SYMBOL_GPL(dma_buf_put);
215
216/**
217 * dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
218 * calls attach() of dma_buf_ops to allow device-specific attach functionality
219 * @dmabuf: [in] buffer to attach device to.
220 * @dev: [in] device to be attached.
221 *
222 * Returns struct dma_buf_attachment * for this attachment; may return negative
223 * error codes.
224 *
225 */
226struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
227 struct device *dev)
228{
229 struct dma_buf_attachment *attach;
230 int ret;
231
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100232 if (WARN_ON(!dmabuf || !dev))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530233 return ERR_PTR(-EINVAL);
234
235 attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL);
236 if (attach == NULL)
Laurent Pincharta9fbc3b2012-01-26 12:27:24 +0100237 return ERR_PTR(-ENOMEM);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530238
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530239 attach->dev = dev;
240 attach->dmabuf = dmabuf;
Laurent Pinchart2ed92012012-01-26 12:27:25 +0100241
242 mutex_lock(&dmabuf->lock);
243
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530244 if (dmabuf->ops->attach) {
245 ret = dmabuf->ops->attach(dmabuf, dev, attach);
246 if (ret)
247 goto err_attach;
248 }
249 list_add(&attach->node, &dmabuf->attachments);
250
251 mutex_unlock(&dmabuf->lock);
252 return attach;
253
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530254err_attach:
255 kfree(attach);
256 mutex_unlock(&dmabuf->lock);
257 return ERR_PTR(ret);
258}
259EXPORT_SYMBOL_GPL(dma_buf_attach);
260
261/**
262 * dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
263 * optionally calls detach() of dma_buf_ops for device-specific detach
264 * @dmabuf: [in] buffer to detach from.
265 * @attach: [in] attachment to be detached; is free'd after this call.
266 *
267 */
268void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
269{
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100270 if (WARN_ON(!dmabuf || !attach))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530271 return;
272
273 mutex_lock(&dmabuf->lock);
274 list_del(&attach->node);
275 if (dmabuf->ops->detach)
276 dmabuf->ops->detach(dmabuf, attach);
277
278 mutex_unlock(&dmabuf->lock);
279 kfree(attach);
280}
281EXPORT_SYMBOL_GPL(dma_buf_detach);
282
283/**
284 * dma_buf_map_attachment - Returns the scatterlist table of the attachment;
285 * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
286 * dma_buf_ops.
287 * @attach: [in] attachment whose scatterlist is to be returned
288 * @direction: [in] direction of DMA transfer
289 *
290 * Returns sg_table containing the scatterlist to be returned; may return NULL
291 * or ERR_PTR.
292 *
293 */
294struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
295 enum dma_data_direction direction)
296{
297 struct sg_table *sg_table = ERR_PTR(-EINVAL);
298
299 might_sleep();
300
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100301 if (WARN_ON(!attach || !attach->dmabuf))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530302 return ERR_PTR(-EINVAL);
303
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100304 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530305
306 return sg_table;
307}
308EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
309
310/**
311 * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
312 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
313 * dma_buf_ops.
314 * @attach: [in] attachment to unmap buffer from
315 * @sg_table: [in] scatterlist info of the buffer to unmap
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530316 * @direction: [in] direction of DMA transfer
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530317 *
318 */
319void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530320 struct sg_table *sg_table,
321 enum dma_data_direction direction)
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530322{
Rob Clarkb6fa0cd2012-09-28 09:29:43 +0200323 might_sleep();
324
Laurent Pinchartd1aa06a2012-01-26 12:27:23 +0100325 if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530326 return;
327
Sumit Semwal33ea2dc2012-01-27 15:09:27 +0530328 attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
329 direction);
Sumit Semwald15bd7e2011-12-26 14:53:15 +0530330}
331EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
Daniel Vetterfc130202012-03-20 00:02:37 +0100332
333
334/**
335 * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
336 * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
337 * preparations. Coherency is only guaranteed in the specified range for the
338 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700339 * @dmabuf: [in] buffer to prepare cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100340 * @start: [in] start of range for cpu access.
341 * @len: [in] length of range for cpu access.
342 * @direction: [in] length of range for cpu access.
343 *
344 * Can return negative error values, returns 0 on success.
345 */
346int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
347 enum dma_data_direction direction)
348{
349 int ret = 0;
350
351 if (WARN_ON(!dmabuf))
352 return -EINVAL;
353
354 if (dmabuf->ops->begin_cpu_access)
355 ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction);
356
357 return ret;
358}
359EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
360
361/**
362 * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
363 * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
364 * actions. Coherency is only guaranteed in the specified range for the
365 * specified access direction.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700366 * @dmabuf: [in] buffer to complete cpu access for.
Daniel Vetterfc130202012-03-20 00:02:37 +0100367 * @start: [in] start of range for cpu access.
368 * @len: [in] length of range for cpu access.
369 * @direction: [in] length of range for cpu access.
370 *
371 * This call must always succeed.
372 */
373void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
374 enum dma_data_direction direction)
375{
376 WARN_ON(!dmabuf);
377
378 if (dmabuf->ops->end_cpu_access)
379 dmabuf->ops->end_cpu_access(dmabuf, start, len, direction);
380}
381EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
382
383/**
384 * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
385 * space. The same restrictions as for kmap_atomic and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700386 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100387 * @page_num: [in] page in PAGE_SIZE units to map.
388 *
389 * This call must always succeed, any necessary preparations that might fail
390 * need to be done in begin_cpu_access.
391 */
392void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num)
393{
394 WARN_ON(!dmabuf);
395
396 return dmabuf->ops->kmap_atomic(dmabuf, page_num);
397}
398EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic);
399
400/**
401 * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700402 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100403 * @page_num: [in] page in PAGE_SIZE units to unmap.
404 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic.
405 *
406 * This call must always succeed.
407 */
408void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num,
409 void *vaddr)
410{
411 WARN_ON(!dmabuf);
412
413 if (dmabuf->ops->kunmap_atomic)
414 dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr);
415}
416EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic);
417
418/**
419 * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
420 * same restrictions as for kmap and friends apply.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700421 * @dmabuf: [in] buffer to map page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100422 * @page_num: [in] page in PAGE_SIZE units to map.
423 *
424 * This call must always succeed, any necessary preparations that might fail
425 * need to be done in begin_cpu_access.
426 */
427void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
428{
429 WARN_ON(!dmabuf);
430
431 return dmabuf->ops->kmap(dmabuf, page_num);
432}
433EXPORT_SYMBOL_GPL(dma_buf_kmap);
434
435/**
436 * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
Randy Dunlapefb4df822012-04-17 17:03:30 -0700437 * @dmabuf: [in] buffer to unmap page from.
Daniel Vetterfc130202012-03-20 00:02:37 +0100438 * @page_num: [in] page in PAGE_SIZE units to unmap.
439 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
440 *
441 * This call must always succeed.
442 */
443void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
444 void *vaddr)
445{
446 WARN_ON(!dmabuf);
447
448 if (dmabuf->ops->kunmap)
449 dmabuf->ops->kunmap(dmabuf, page_num, vaddr);
450}
451EXPORT_SYMBOL_GPL(dma_buf_kunmap);
Daniel Vetter4c785132012-04-24 14:38:52 +0530452
453
454/**
455 * dma_buf_mmap - Setup up a userspace mmap with the given vma
Sumit Semwal12c47272012-05-23 15:27:40 +0530456 * @dmabuf: [in] buffer that should back the vma
Daniel Vetter4c785132012-04-24 14:38:52 +0530457 * @vma: [in] vma for the mmap
458 * @pgoff: [in] offset in pages where this mmap should start within the
459 * dma-buf buffer.
460 *
461 * This function adjusts the passed in vma so that it points at the file of the
462 * dma_buf operation. It alsog adjusts the starting pgoff and does bounds
463 * checking on the size of the vma. Then it calls the exporters mmap function to
464 * set up the mapping.
465 *
466 * Can return negative error values, returns 0 on success.
467 */
468int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
469 unsigned long pgoff)
470{
John Sheu495c10c2013-02-11 17:50:24 -0800471 struct file *oldfile;
472 int ret;
473
Daniel Vetter4c785132012-04-24 14:38:52 +0530474 if (WARN_ON(!dmabuf || !vma))
475 return -EINVAL;
476
477 /* check for offset overflow */
478 if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff)
479 return -EOVERFLOW;
480
481 /* check for overflowing the buffer's size */
482 if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
483 dmabuf->size >> PAGE_SHIFT)
484 return -EINVAL;
485
486 /* readjust the vma */
John Sheu495c10c2013-02-11 17:50:24 -0800487 get_file(dmabuf->file);
488 oldfile = vma->vm_file;
489 vma->vm_file = dmabuf->file;
Daniel Vetter4c785132012-04-24 14:38:52 +0530490 vma->vm_pgoff = pgoff;
491
John Sheu495c10c2013-02-11 17:50:24 -0800492 ret = dmabuf->ops->mmap(dmabuf, vma);
493 if (ret) {
494 /* restore old parameters on failure */
495 vma->vm_file = oldfile;
496 fput(dmabuf->file);
497 } else {
498 if (oldfile)
499 fput(oldfile);
500 }
501 return ret;
502
Daniel Vetter4c785132012-04-24 14:38:52 +0530503}
504EXPORT_SYMBOL_GPL(dma_buf_mmap);
Dave Airlie98f86c92012-05-20 12:33:56 +0530505
506/**
Sumit Semwal12c47272012-05-23 15:27:40 +0530507 * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
508 * address space. Same restrictions as for vmap and friends apply.
509 * @dmabuf: [in] buffer to vmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530510 *
511 * This call may fail due to lack of virtual mapping address space.
512 * These calls are optional in drivers. The intended use for them
513 * is for mapping objects linear in kernel space for high use objects.
514 * Please attempt to use kmap/kunmap before thinking about these interfaces.
515 */
516void *dma_buf_vmap(struct dma_buf *dmabuf)
517{
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100518 void *ptr;
519
Dave Airlie98f86c92012-05-20 12:33:56 +0530520 if (WARN_ON(!dmabuf))
521 return NULL;
522
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100523 if (!dmabuf->ops->vmap)
524 return NULL;
525
526 mutex_lock(&dmabuf->lock);
527 if (dmabuf->vmapping_counter) {
528 dmabuf->vmapping_counter++;
529 BUG_ON(!dmabuf->vmap_ptr);
530 ptr = dmabuf->vmap_ptr;
531 goto out_unlock;
532 }
533
534 BUG_ON(dmabuf->vmap_ptr);
535
536 ptr = dmabuf->ops->vmap(dmabuf);
537 if (IS_ERR_OR_NULL(ptr))
538 goto out_unlock;
539
540 dmabuf->vmap_ptr = ptr;
541 dmabuf->vmapping_counter = 1;
542
543out_unlock:
544 mutex_unlock(&dmabuf->lock);
545 return ptr;
Dave Airlie98f86c92012-05-20 12:33:56 +0530546}
547EXPORT_SYMBOL_GPL(dma_buf_vmap);
548
549/**
550 * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
Sumit Semwal12c47272012-05-23 15:27:40 +0530551 * @dmabuf: [in] buffer to vunmap
Randy Dunlap6e7b4a52012-06-09 15:02:59 -0700552 * @vaddr: [in] vmap to vunmap
Dave Airlie98f86c92012-05-20 12:33:56 +0530553 */
554void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
555{
556 if (WARN_ON(!dmabuf))
557 return;
558
Daniel Vetterf00b4da2012-12-20 14:14:23 +0100559 BUG_ON(!dmabuf->vmap_ptr);
560 BUG_ON(dmabuf->vmapping_counter == 0);
561 BUG_ON(dmabuf->vmap_ptr != vaddr);
562
563 mutex_lock(&dmabuf->lock);
564 if (--dmabuf->vmapping_counter == 0) {
565 if (dmabuf->ops->vunmap)
566 dmabuf->ops->vunmap(dmabuf, vaddr);
567 dmabuf->vmap_ptr = NULL;
568 }
569 mutex_unlock(&dmabuf->lock);
Dave Airlie98f86c92012-05-20 12:33:56 +0530570}
571EXPORT_SYMBOL_GPL(dma_buf_vunmap);
Sumit Semwalb89e3562013-04-04 11:44:37 +0530572
573#ifdef CONFIG_DEBUG_FS
574static int dma_buf_describe(struct seq_file *s)
575{
576 int ret;
577 struct dma_buf *buf_obj;
578 struct dma_buf_attachment *attach_obj;
579 int count = 0, attach_count;
580 size_t size = 0;
581
582 ret = mutex_lock_interruptible(&db_list.lock);
583
584 if (ret)
585 return ret;
586
587 seq_printf(s, "\nDma-buf Objects:\n");
588 seq_printf(s, "\texp_name\tsize\tflags\tmode\tcount\n");
589
590 list_for_each_entry(buf_obj, &db_list.head, list_node) {
591 ret = mutex_lock_interruptible(&buf_obj->lock);
592
593 if (ret) {
594 seq_printf(s,
595 "\tERROR locking buffer object: skipping\n");
596 continue;
597 }
598
599 seq_printf(s, "\t");
600
601 seq_printf(s, "\t%s\t%08zu\t%08x\t%08x\t%08ld\n",
602 buf_obj->exp_name, buf_obj->size,
603 buf_obj->file->f_flags, buf_obj->file->f_mode,
604 (long)(buf_obj->file->f_count.counter));
605
606 seq_printf(s, "\t\tAttached Devices:\n");
607 attach_count = 0;
608
609 list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
610 seq_printf(s, "\t\t");
611
612 seq_printf(s, "%s\n", attach_obj->dev->init_name);
613 attach_count++;
614 }
615
616 seq_printf(s, "\n\t\tTotal %d devices attached\n",
617 attach_count);
618
619 count++;
620 size += buf_obj->size;
621 mutex_unlock(&buf_obj->lock);
622 }
623
624 seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
625
626 mutex_unlock(&db_list.lock);
627 return 0;
628}
629
630static int dma_buf_show(struct seq_file *s, void *unused)
631{
632 void (*func)(struct seq_file *) = s->private;
633 func(s);
634 return 0;
635}
636
637static int dma_buf_debug_open(struct inode *inode, struct file *file)
638{
639 return single_open(file, dma_buf_show, inode->i_private);
640}
641
642static const struct file_operations dma_buf_debug_fops = {
643 .open = dma_buf_debug_open,
644 .read = seq_read,
645 .llseek = seq_lseek,
646 .release = single_release,
647};
648
649static struct dentry *dma_buf_debugfs_dir;
650
651static int dma_buf_init_debugfs(void)
652{
653 int err = 0;
654 dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL);
655 if (IS_ERR(dma_buf_debugfs_dir)) {
656 err = PTR_ERR(dma_buf_debugfs_dir);
657 dma_buf_debugfs_dir = NULL;
658 return err;
659 }
660
661 err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe);
662
663 if (err)
664 pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
665
666 return err;
667}
668
669static void dma_buf_uninit_debugfs(void)
670{
671 if (dma_buf_debugfs_dir)
672 debugfs_remove_recursive(dma_buf_debugfs_dir);
673}
674
675int dma_buf_debugfs_create_file(const char *name,
676 int (*write)(struct seq_file *))
677{
678 struct dentry *d;
679
680 d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir,
681 write, &dma_buf_debug_fops);
682
683 if (IS_ERR(d))
684 return PTR_ERR(d);
685
686 return 0;
687}
688#else
689static inline int dma_buf_init_debugfs(void)
690{
691 return 0;
692}
693static inline void dma_buf_uninit_debugfs(void)
694{
695}
696#endif
697
698static int __init dma_buf_init(void)
699{
700 mutex_init(&db_list.lock);
701 INIT_LIST_HEAD(&db_list.head);
702 dma_buf_init_debugfs();
703 return 0;
704}
705subsys_initcall(dma_buf_init);
706
707static void __exit dma_buf_deinit(void)
708{
709 dma_buf_uninit_debugfs();
710}
711__exitcall(dma_buf_deinit);