2 * Framework for buffer objects that can be shared across devices/subsystems.
4 * Copyright(C) 2011 Linaro Limited. All rights reserved.
5 * Author: Sumit Semwal <sumit.semwal@ti.com>
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.
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.
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
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/>.
26 #include <linux/slab.h>
27 #include <linux/dma-buf.h>
28 #include <linux/fence.h>
29 #include <linux/anon_inodes.h>
30 #include <linux/export.h>
31 #include <linux/debugfs.h>
32 #include <linux/module.h>
33 #include <linux/seq_file.h>
34 #include <linux/poll.h>
35 #include <linux/reservation.h>
38 #include <uapi/linux/dma-buf.h>
40 static inline int is_dma_buf_file(struct file
*);
43 struct list_head head
;
47 static struct dma_buf_list db_list
;
49 static int dma_buf_release(struct inode
*inode
, struct file
*file
)
51 struct dma_buf
*dmabuf
;
53 if (!is_dma_buf_file(file
))
56 dmabuf
= file
->private_data
;
58 BUG_ON(dmabuf
->vmapping_counter
);
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.
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.
68 BUG_ON(dmabuf
->cb_shared
.active
|| dmabuf
->cb_excl
.active
);
70 dmabuf
->ops
->release(dmabuf
);
72 mutex_lock(&db_list
.lock
);
73 list_del(&dmabuf
->list_node
);
74 mutex_unlock(&db_list
.lock
);
76 if (dmabuf
->resv
== (struct reservation_object
*)&dmabuf
[1])
77 reservation_object_fini(dmabuf
->resv
);
79 module_put(dmabuf
->owner
);
84 static int dma_buf_mmap_internal(struct file
*file
, struct vm_area_struct
*vma
)
86 struct dma_buf
*dmabuf
;
88 if (!is_dma_buf_file(file
))
91 dmabuf
= file
->private_data
;
93 /* check for overflowing the buffer's size */
94 if (vma
->vm_pgoff
+ vma_pages(vma
) >
95 dmabuf
->size
>> PAGE_SHIFT
)
98 return dmabuf
->ops
->mmap(dmabuf
, vma
);
101 static loff_t
dma_buf_llseek(struct file
*file
, loff_t offset
, int whence
)
103 struct dma_buf
*dmabuf
;
106 if (!is_dma_buf_file(file
))
109 dmabuf
= file
->private_data
;
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
)
116 else if (whence
== SEEK_SET
)
124 return base
+ offset
;
127 static void dma_buf_poll_cb(struct fence
*fence
, struct fence_cb
*cb
)
129 struct dma_buf_poll_cb_t
*dcb
= (struct dma_buf_poll_cb_t
*)cb
;
132 spin_lock_irqsave(&dcb
->poll
->lock
, flags
);
133 wake_up_locked_poll(dcb
->poll
, dcb
->active
);
135 spin_unlock_irqrestore(&dcb
->poll
->lock
, flags
);
138 static unsigned int dma_buf_poll(struct file
*file
, poll_table
*poll
)
140 struct dma_buf
*dmabuf
;
141 struct reservation_object
*resv
;
142 struct reservation_object_list
*fobj
;
143 struct fence
*fence_excl
;
144 unsigned long events
;
145 unsigned shared_count
, seq
;
147 dmabuf
= file
->private_data
;
148 if (!dmabuf
|| !dmabuf
->resv
)
153 poll_wait(file
, &dmabuf
->poll
, poll
);
155 events
= poll_requested_events(poll
) & (POLLIN
| POLLOUT
);
160 seq
= read_seqcount_begin(&resv
->seq
);
163 fobj
= rcu_dereference(resv
->fence
);
165 shared_count
= fobj
->shared_count
;
168 fence_excl
= rcu_dereference(resv
->fence_excl
);
169 if (read_seqcount_retry(&resv
->seq
, seq
)) {
174 if (fence_excl
&& (!(events
& POLLOUT
) || shared_count
== 0)) {
175 struct dma_buf_poll_cb_t
*dcb
= &dmabuf
->cb_excl
;
176 unsigned long pevents
= POLLIN
;
178 if (shared_count
== 0)
181 spin_lock_irq(&dmabuf
->poll
.lock
);
183 dcb
->active
|= pevents
;
186 dcb
->active
= pevents
;
187 spin_unlock_irq(&dmabuf
->poll
.lock
);
189 if (events
& pevents
) {
190 if (!fence_get_rcu(fence_excl
)) {
191 /* force a recheck */
193 dma_buf_poll_cb(NULL
, &dcb
->cb
);
194 } else if (!fence_add_callback(fence_excl
, &dcb
->cb
,
197 fence_put(fence_excl
);
200 * No callback queued, wake up any additional
203 fence_put(fence_excl
);
204 dma_buf_poll_cb(NULL
, &dcb
->cb
);
209 if ((events
& POLLOUT
) && shared_count
> 0) {
210 struct dma_buf_poll_cb_t
*dcb
= &dmabuf
->cb_shared
;
213 /* Only queue a new callback if no event has fired yet */
214 spin_lock_irq(&dmabuf
->poll
.lock
);
218 dcb
->active
= POLLOUT
;
219 spin_unlock_irq(&dmabuf
->poll
.lock
);
221 if (!(events
& POLLOUT
))
224 for (i
= 0; i
< shared_count
; ++i
) {
225 struct fence
*fence
= rcu_dereference(fobj
->shared
[i
]);
227 if (!fence_get_rcu(fence
)) {
229 * fence refcount dropped to zero, this means
230 * that fobj has been freed
232 * call dma_buf_poll_cb and force a recheck!
235 dma_buf_poll_cb(NULL
, &dcb
->cb
);
238 if (!fence_add_callback(fence
, &dcb
->cb
,
247 /* No callback queued, wake up any additional waiters. */
248 if (i
== shared_count
)
249 dma_buf_poll_cb(NULL
, &dcb
->cb
);
257 static long dma_buf_ioctl(struct file
*file
,
258 unsigned int cmd
, unsigned long arg
)
260 struct dma_buf
*dmabuf
;
261 struct dma_buf_sync sync
;
262 enum dma_data_direction direction
;
265 dmabuf
= file
->private_data
;
268 case DMA_BUF_IOCTL_SYNC
:
269 if (copy_from_user(&sync
, (void __user
*) arg
, sizeof(sync
)))
272 if (sync
.flags
& ~DMA_BUF_SYNC_VALID_FLAGS_MASK
)
275 switch (sync
.flags
& DMA_BUF_SYNC_RW
) {
276 case DMA_BUF_SYNC_READ
:
277 direction
= DMA_FROM_DEVICE
;
279 case DMA_BUF_SYNC_WRITE
:
280 direction
= DMA_TO_DEVICE
;
282 case DMA_BUF_SYNC_RW
:
283 direction
= DMA_BIDIRECTIONAL
;
289 if (sync
.flags
& DMA_BUF_SYNC_END
)
290 ret
= dma_buf_end_cpu_access(dmabuf
, direction
);
292 ret
= dma_buf_begin_cpu_access(dmabuf
, direction
);
300 static const struct file_operations dma_buf_fops
= {
301 .release
= dma_buf_release
,
302 .mmap
= dma_buf_mmap_internal
,
303 .llseek
= dma_buf_llseek
,
304 .poll
= dma_buf_poll
,
305 .unlocked_ioctl
= dma_buf_ioctl
,
309 * is_dma_buf_file - Check if struct file* is associated with dma_buf
311 static inline int is_dma_buf_file(struct file
*file
)
313 return file
->f_op
== &dma_buf_fops
;
317 * dma_buf_export - Creates a new dma_buf, and associates an anon file
318 * with this buffer, so it can be exported.
319 * Also connect the allocator specific data and ops to the buffer.
320 * Additionally, provide a name string for exporter; useful in debugging.
322 * @exp_info: [in] holds all the export related information provided
323 * by the exporter. see struct dma_buf_export_info
324 * for further details.
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.
331 struct dma_buf
*dma_buf_export(const struct dma_buf_export_info
*exp_info
)
333 struct dma_buf
*dmabuf
;
334 struct reservation_object
*resv
= exp_info
->resv
;
336 size_t alloc_size
= sizeof(struct dma_buf
);
339 alloc_size
+= sizeof(struct reservation_object
);
341 /* prevent &dma_buf[1] == dma_buf->resv */
344 if (WARN_ON(!exp_info
->priv
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
)) {
352 return ERR_PTR(-EINVAL
);
355 if (!try_module_get(exp_info
->owner
))
356 return ERR_PTR(-ENOENT
);
358 dmabuf
= kzalloc(alloc_size
, GFP_KERNEL
);
360 module_put(exp_info
->owner
);
361 return ERR_PTR(-ENOMEM
);
364 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
;
368 dmabuf
->owner
= exp_info
->owner
;
369 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;
374 resv
= (struct reservation_object
*)&dmabuf
[1];
375 reservation_object_init(resv
);
379 file
= anon_inode_getfile("dmabuf", &dma_buf_fops
, dmabuf
,
383 return ERR_CAST(file
);
386 file
->f_mode
|= FMODE_LSEEK
;
389 mutex_init(&dmabuf
->lock
);
390 INIT_LIST_HEAD(&dmabuf
->attachments
);
392 mutex_lock(&db_list
.lock
);
393 list_add(&dmabuf
->list_node
, &db_list
.head
);
394 mutex_unlock(&db_list
.lock
);
398 EXPORT_SYMBOL_GPL(dma_buf_export
);
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.
403 * @flags: [in] flags to give to fd
405 * On success, returns an associated 'fd'. Else, returns error.
407 int dma_buf_fd(struct dma_buf
*dmabuf
, int flags
)
411 if (!dmabuf
|| !dmabuf
->file
)
414 fd
= get_unused_fd_flags(flags
);
418 fd_install(fd
, dmabuf
->file
);
422 EXPORT_SYMBOL_GPL(dma_buf_fd
);
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
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
432 struct dma_buf
*dma_buf_get(int fd
)
439 return ERR_PTR(-EBADF
);
441 if (!is_dma_buf_file(file
)) {
443 return ERR_PTR(-EINVAL
);
446 return file
->private_data
;
448 EXPORT_SYMBOL_GPL(dma_buf_get
);
451 * dma_buf_put - decreases refcount of the buffer
452 * @dmabuf: [in] buffer to reduce refcount of
454 * Uses file's refcounting done implicitly by fput()
456 void dma_buf_put(struct dma_buf
*dmabuf
)
458 if (WARN_ON(!dmabuf
|| !dmabuf
->file
))
463 EXPORT_SYMBOL_GPL(dma_buf_put
);
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.
471 * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on
474 struct dma_buf_attachment
*dma_buf_attach(struct dma_buf
*dmabuf
,
477 struct dma_buf_attachment
*attach
;
480 if (WARN_ON(!dmabuf
|| !dev
))
481 return ERR_PTR(-EINVAL
);
483 attach
= kzalloc(sizeof(struct dma_buf_attachment
), GFP_KERNEL
);
485 return ERR_PTR(-ENOMEM
);
488 attach
->dmabuf
= dmabuf
;
490 mutex_lock(&dmabuf
->lock
);
492 if (dmabuf
->ops
->attach
) {
493 ret
= dmabuf
->ops
->attach(dmabuf
, dev
, attach
);
497 list_add(&attach
->node
, &dmabuf
->attachments
);
499 mutex_unlock(&dmabuf
->lock
);
504 mutex_unlock(&dmabuf
->lock
);
507 EXPORT_SYMBOL_GPL(dma_buf_attach
);
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.
516 void dma_buf_detach(struct dma_buf
*dmabuf
, struct dma_buf_attachment
*attach
)
518 if (WARN_ON(!dmabuf
|| !attach
))
521 mutex_lock(&dmabuf
->lock
);
522 list_del(&attach
->node
);
523 if (dmabuf
->ops
->detach
)
524 dmabuf
->ops
->detach(dmabuf
, attach
);
526 mutex_unlock(&dmabuf
->lock
);
529 EXPORT_SYMBOL_GPL(dma_buf_detach
);
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
535 * @attach: [in] attachment whose scatterlist is to be returned
536 * @direction: [in] direction of DMA transfer
538 * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
541 struct sg_table
*dma_buf_map_attachment(struct dma_buf_attachment
*attach
,
542 enum dma_data_direction direction
)
544 struct sg_table
*sg_table
= ERR_PTR(-EINVAL
);
548 if (WARN_ON(!attach
|| !attach
->dmabuf
))
549 return ERR_PTR(-EINVAL
);
551 sg_table
= attach
->dmabuf
->ops
->map_dma_buf(attach
, direction
);
553 sg_table
= ERR_PTR(-ENOMEM
);
557 EXPORT_SYMBOL_GPL(dma_buf_map_attachment
);
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
563 * @attach: [in] attachment to unmap buffer from
564 * @sg_table: [in] scatterlist info of the buffer to unmap
565 * @direction: [in] direction of DMA transfer
568 void dma_buf_unmap_attachment(struct dma_buf_attachment
*attach
,
569 struct sg_table
*sg_table
,
570 enum dma_data_direction direction
)
574 if (WARN_ON(!attach
|| !attach
->dmabuf
|| !sg_table
))
577 attach
->dmabuf
->ops
->unmap_dma_buf(attach
, sg_table
,
580 EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment
);
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.
588 * @dmabuf: [in] buffer to prepare cpu access for.
589 * @direction: [in] length of range for cpu access.
591 * Can return negative error values, returns 0 on success.
593 int dma_buf_begin_cpu_access(struct dma_buf
*dmabuf
,
594 enum dma_data_direction direction
)
598 if (WARN_ON(!dmabuf
))
601 if (dmabuf
->ops
->begin_cpu_access
)
602 ret
= dmabuf
->ops
->begin_cpu_access(dmabuf
, direction
);
606 EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access
);
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.
613 * @dmabuf: [in] buffer to complete cpu access for.
614 * @direction: [in] length of range for cpu access.
616 * Can return negative error values, returns 0 on success.
618 int dma_buf_end_cpu_access(struct dma_buf
*dmabuf
,
619 enum dma_data_direction direction
)
625 if (dmabuf
->ops
->end_cpu_access
)
626 ret
= dmabuf
->ops
->end_cpu_access(dmabuf
, direction
);
630 EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access
);
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.
635 * @dmabuf: [in] buffer to map page from.
636 * @page_num: [in] page in PAGE_SIZE units to map.
638 * This call must always succeed, any necessary preparations that might fail
639 * need to be done in begin_cpu_access.
641 void *dma_buf_kmap_atomic(struct dma_buf
*dmabuf
, unsigned long page_num
)
645 return dmabuf
->ops
->kmap_atomic(dmabuf
, page_num
);
647 EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic
);
650 * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
651 * @dmabuf: [in] buffer to unmap page from.
652 * @page_num: [in] page in PAGE_SIZE units to unmap.
653 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic.
655 * This call must always succeed.
657 void dma_buf_kunmap_atomic(struct dma_buf
*dmabuf
, unsigned long page_num
,
662 if (dmabuf
->ops
->kunmap_atomic
)
663 dmabuf
->ops
->kunmap_atomic(dmabuf
, page_num
, vaddr
);
665 EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic
);
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.
670 * @dmabuf: [in] buffer to map page from.
671 * @page_num: [in] page in PAGE_SIZE units to map.
673 * This call must always succeed, any necessary preparations that might fail
674 * need to be done in begin_cpu_access.
676 void *dma_buf_kmap(struct dma_buf
*dmabuf
, unsigned long page_num
)
680 return dmabuf
->ops
->kmap(dmabuf
, page_num
);
682 EXPORT_SYMBOL_GPL(dma_buf_kmap
);
685 * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
686 * @dmabuf: [in] buffer to unmap page from.
687 * @page_num: [in] page in PAGE_SIZE units to unmap.
688 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
690 * This call must always succeed.
692 void dma_buf_kunmap(struct dma_buf
*dmabuf
, unsigned long page_num
,
697 if (dmabuf
->ops
->kunmap
)
698 dmabuf
->ops
->kunmap(dmabuf
, page_num
, vaddr
);
700 EXPORT_SYMBOL_GPL(dma_buf_kunmap
);
704 * dma_buf_mmap - Setup up a userspace mmap with the given vma
705 * @dmabuf: [in] buffer that should back the vma
706 * @vma: [in] vma for the mmap
707 * @pgoff: [in] offset in pages where this mmap should start within the
710 * This function adjusts the passed in vma so that it points at the file of the
711 * dma_buf operation. It also adjusts the starting pgoff and does bounds
712 * checking on the size of the vma. Then it calls the exporters mmap function to
713 * set up the mapping.
715 * Can return negative error values, returns 0 on success.
717 int dma_buf_mmap(struct dma_buf
*dmabuf
, struct vm_area_struct
*vma
,
720 struct file
*oldfile
;
723 if (WARN_ON(!dmabuf
|| !vma
))
726 /* check for offset overflow */
727 if (pgoff
+ vma_pages(vma
) < pgoff
)
730 /* check for overflowing the buffer's size */
731 if (pgoff
+ vma_pages(vma
) >
732 dmabuf
->size
>> PAGE_SHIFT
)
735 /* readjust the vma */
736 get_file(dmabuf
->file
);
737 oldfile
= vma
->vm_file
;
738 vma
->vm_file
= dmabuf
->file
;
739 vma
->vm_pgoff
= pgoff
;
741 ret
= dmabuf
->ops
->mmap(dmabuf
, vma
);
743 /* restore old parameters on failure */
744 vma
->vm_file
= oldfile
;
753 EXPORT_SYMBOL_GPL(dma_buf_mmap
);
756 * 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
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.
765 * Returns NULL on error.
767 void *dma_buf_vmap(struct dma_buf
*dmabuf
)
771 if (WARN_ON(!dmabuf
))
774 if (!dmabuf
->ops
->vmap
)
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
;
785 BUG_ON(dmabuf
->vmap_ptr
);
787 ptr
= dmabuf
->ops
->vmap(dmabuf
);
788 if (WARN_ON_ONCE(IS_ERR(ptr
)))
793 dmabuf
->vmap_ptr
= ptr
;
794 dmabuf
->vmapping_counter
= 1;
797 mutex_unlock(&dmabuf
->lock
);
800 EXPORT_SYMBOL_GPL(dma_buf_vmap
);
803 * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
804 * @dmabuf: [in] buffer to vunmap
805 * @vaddr: [in] vmap to vunmap
807 void dma_buf_vunmap(struct dma_buf
*dmabuf
, void *vaddr
)
809 if (WARN_ON(!dmabuf
))
812 BUG_ON(!dmabuf
->vmap_ptr
);
813 BUG_ON(dmabuf
->vmapping_counter
== 0);
814 BUG_ON(dmabuf
->vmap_ptr
!= vaddr
);
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
;
822 mutex_unlock(&dmabuf
->lock
);
824 EXPORT_SYMBOL_GPL(dma_buf_vunmap
);
826 #ifdef CONFIG_DEBUG_FS
827 static int dma_buf_describe(struct seq_file
*s
)
830 struct dma_buf
*buf_obj
;
831 struct dma_buf_attachment
*attach_obj
;
832 int count
= 0, attach_count
;
835 ret
= mutex_lock_interruptible(&db_list
.lock
);
840 seq_puts(s
, "\nDma-buf Objects:\n");
841 seq_puts(s
, "size\tflags\tmode\tcount\texp_name\n");
843 list_for_each_entry(buf_obj
, &db_list
.head
, list_node
) {
844 ret
= mutex_lock_interruptible(&buf_obj
->lock
);
848 "\tERROR locking buffer object: skipping\n");
852 seq_printf(s
, "%08zu\t%08x\t%08x\t%08ld\t%s\n",
854 buf_obj
->file
->f_flags
, buf_obj
->file
->f_mode
,
855 file_count(buf_obj
->file
),
858 seq_puts(s
, "\tAttached Devices:\n");
861 list_for_each_entry(attach_obj
, &buf_obj
->attachments
, node
) {
864 seq_printf(s
, "%s\n", dev_name(attach_obj
->dev
));
868 seq_printf(s
, "Total %d devices attached\n\n",
872 size
+= buf_obj
->size
;
873 mutex_unlock(&buf_obj
->lock
);
876 seq_printf(s
, "\nTotal %d objects, %zu bytes\n", count
, size
);
878 mutex_unlock(&db_list
.lock
);
882 static int dma_buf_show(struct seq_file
*s
, void *unused
)
884 void (*func
)(struct seq_file
*) = s
->private;
890 static int dma_buf_debug_open(struct inode
*inode
, struct file
*file
)
892 return single_open(file
, dma_buf_show
, inode
->i_private
);
895 static const struct file_operations dma_buf_debug_fops
= {
896 .open
= dma_buf_debug_open
,
899 .release
= single_release
,
902 static struct dentry
*dma_buf_debugfs_dir
;
904 static int dma_buf_init_debugfs(void)
908 dma_buf_debugfs_dir
= debugfs_create_dir("dma_buf", NULL
);
910 if (IS_ERR(dma_buf_debugfs_dir
)) {
911 err
= PTR_ERR(dma_buf_debugfs_dir
);
912 dma_buf_debugfs_dir
= NULL
;
916 err
= dma_buf_debugfs_create_file("bufinfo", dma_buf_describe
);
919 pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
924 static void dma_buf_uninit_debugfs(void)
926 if (dma_buf_debugfs_dir
)
927 debugfs_remove_recursive(dma_buf_debugfs_dir
);
930 int dma_buf_debugfs_create_file(const char *name
,
931 int (*write
)(struct seq_file
*))
935 d
= debugfs_create_file(name
, S_IRUGO
, dma_buf_debugfs_dir
,
936 write
, &dma_buf_debug_fops
);
938 return PTR_ERR_OR_ZERO(d
);
941 static inline int dma_buf_init_debugfs(void)
945 static inline void dma_buf_uninit_debugfs(void)
950 static int __init
dma_buf_init(void)
952 mutex_init(&db_list
.lock
);
953 INIT_LIST_HEAD(&db_list
.head
);
954 dma_buf_init_debugfs();
957 subsys_initcall(dma_buf_init
);
959 static void __exit
dma_buf_deinit(void)
961 dma_buf_uninit_debugfs();
963 __exitcall(dma_buf_deinit
);