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1/*
2 * Copyright © 2012 Red Hat
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Dave Airlie <airlied@redhat.com>
25 * Rob Clark <rob.clark@linaro.org>
26 *
27 */
28
29#include <linux/export.h>
30#include <linux/dma-buf.h>
31#include <linux/rbtree.h>
32#include <drm/drmP.h>
33#include <drm/drm_gem.h>
34
35#include "drm_internal.h"
36
37/*
38 * DMA-BUF/GEM Object references and lifetime overview:
39 *
40 * On the export the dma_buf holds a reference to the exporting GEM
41 * object. It takes this reference in handle_to_fd_ioctl, when it
42 * first calls .prime_export and stores the exporting GEM object in
43 * the dma_buf priv. This reference is released when the dma_buf
44 * object goes away in the driver .release function.
45 *
46 * On the import the importing GEM object holds a reference to the
47 * dma_buf (which in turn holds a ref to the exporting GEM object).
48 * It takes that reference in the fd_to_handle ioctl.
49 * It calls dma_buf_get, creates an attachment to it and stores the
50 * attachment in the GEM object. When this attachment is destroyed
51 * when the imported object is destroyed, we remove the attachment
52 * and drop the reference to the dma_buf.
53 *
54 * Thus the chain of references always flows in one direction
55 * (avoiding loops): importing_gem -> dmabuf -> exporting_gem
56 *
57 * Self-importing: if userspace is using PRIME as a replacement for flink
58 * then it will get a fd->handle request for a GEM object that it created.
59 * Drivers should detect this situation and return back the gem object
60 * from the dma-buf private. Prime will do this automatically for drivers that
61 * use the drm_gem_prime_{import,export} helpers.
62 */
63
64struct drm_prime_member {
65 struct dma_buf *dma_buf;
66 uint32_t handle;
67
68 struct rb_node dmabuf_rb;
69 struct rb_node handle_rb;
70};
71
72struct drm_prime_attachment {
73 struct sg_table *sgt;
74 enum dma_data_direction dir;
75};
76
77static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv,
78 struct dma_buf *dma_buf, uint32_t handle)
79{
80 struct drm_prime_member *member;
81 struct rb_node **p, *rb;
82
83 member = kmalloc(sizeof(*member), GFP_KERNEL);
84 if (!member)
85 return -ENOMEM;
86
87 get_dma_buf(dma_buf);
88 member->dma_buf = dma_buf;
89 member->handle = handle;
90
91 rb = NULL;
92 p = &prime_fpriv->dmabufs.rb_node;
93 while (*p) {
94 struct drm_prime_member *pos;
95
96 rb = *p;
97 pos = rb_entry(rb, struct drm_prime_member, dmabuf_rb);
98 if (dma_buf > pos->dma_buf)
99 p = &rb->rb_right;
100 else
101 p = &rb->rb_left;
102 }
103 rb_link_node(&member->dmabuf_rb, rb, p);
104 rb_insert_color(&member->dmabuf_rb, &prime_fpriv->dmabufs);
105
106 rb = NULL;
107 p = &prime_fpriv->handles.rb_node;
108 while (*p) {
109 struct drm_prime_member *pos;
110
111 rb = *p;
112 pos = rb_entry(rb, struct drm_prime_member, handle_rb);
113 if (handle > pos->handle)
114 p = &rb->rb_right;
115 else
116 p = &rb->rb_left;
117 }
118 rb_link_node(&member->handle_rb, rb, p);
119 rb_insert_color(&member->handle_rb, &prime_fpriv->handles);
120
121 return 0;
122}
123
124static struct dma_buf *drm_prime_lookup_buf_by_handle(struct drm_prime_file_private *prime_fpriv,
125 uint32_t handle)
126{
127 struct rb_node *rb;
128
129 rb = prime_fpriv->handles.rb_node;
130 while (rb) {
131 struct drm_prime_member *member;
132
133 member = rb_entry(rb, struct drm_prime_member, handle_rb);
134 if (member->handle == handle)
135 return member->dma_buf;
136 else if (member->handle < handle)
137 rb = rb->rb_right;
138 else
139 rb = rb->rb_left;
140 }
141
142 return NULL;
143}
144
145static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv,
146 struct dma_buf *dma_buf,
147 uint32_t *handle)
148{
149 struct rb_node *rb;
150
151 rb = prime_fpriv->dmabufs.rb_node;
152 while (rb) {
153 struct drm_prime_member *member;
154
155 member = rb_entry(rb, struct drm_prime_member, dmabuf_rb);
156 if (member->dma_buf == dma_buf) {
157 *handle = member->handle;
158 return 0;
159 } else if (member->dma_buf < dma_buf) {
160 rb = rb->rb_right;
161 } else {
162 rb = rb->rb_left;
163 }
164 }
165
166 return -ENOENT;
167}
168
169static int drm_gem_map_attach(struct dma_buf *dma_buf,
170 struct device *target_dev,
171 struct dma_buf_attachment *attach)
172{
173 struct drm_prime_attachment *prime_attach;
174 struct drm_gem_object *obj = dma_buf->priv;
175 struct drm_device *dev = obj->dev;
176
177 prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL);
178 if (!prime_attach)
179 return -ENOMEM;
180
181 prime_attach->dir = DMA_NONE;
182 attach->priv = prime_attach;
183
184 if (!dev->driver->gem_prime_pin)
185 return 0;
186
187 return dev->driver->gem_prime_pin(obj);
188}
189
190static void drm_gem_map_detach(struct dma_buf *dma_buf,
191 struct dma_buf_attachment *attach)
192{
193 struct drm_prime_attachment *prime_attach = attach->priv;
194 struct drm_gem_object *obj = dma_buf->priv;
195 struct drm_device *dev = obj->dev;
196 struct sg_table *sgt;
197
198 if (dev->driver->gem_prime_unpin)
199 dev->driver->gem_prime_unpin(obj);
200
201 if (!prime_attach)
202 return;
203
204 sgt = prime_attach->sgt;
205 if (sgt) {
206 if (prime_attach->dir != DMA_NONE)
207 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
208 prime_attach->dir);
209 sg_free_table(sgt);
210 }
211
212 kfree(sgt);
213 kfree(prime_attach);
214 attach->priv = NULL;
215}
216
217void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv,
218 struct dma_buf *dma_buf)
219{
220 struct rb_node *rb;
221
222 rb = prime_fpriv->dmabufs.rb_node;
223 while (rb) {
224 struct drm_prime_member *member;
225
226 member = rb_entry(rb, struct drm_prime_member, dmabuf_rb);
227 if (member->dma_buf == dma_buf) {
228 rb_erase(&member->handle_rb, &prime_fpriv->handles);
229 rb_erase(&member->dmabuf_rb, &prime_fpriv->dmabufs);
230
231 dma_buf_put(dma_buf);
232 kfree(member);
233 return;
234 } else if (member->dma_buf < dma_buf) {
235 rb = rb->rb_right;
236 } else {
237 rb = rb->rb_left;
238 }
239 }
240}
241
242static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
243 enum dma_data_direction dir)
244{
245 struct drm_prime_attachment *prime_attach = attach->priv;
246 struct drm_gem_object *obj = attach->dmabuf->priv;
247 struct sg_table *sgt;
248
249 if (WARN_ON(dir == DMA_NONE || !prime_attach))
250 return ERR_PTR(-EINVAL);
251
252 /* return the cached mapping when possible */
253 if (prime_attach->dir == dir)
254 return prime_attach->sgt;
255
256 /*
257 * two mappings with different directions for the same attachment are
258 * not allowed
259 */
260 if (WARN_ON(prime_attach->dir != DMA_NONE))
261 return ERR_PTR(-EBUSY);
262
263 sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
264
265 if (!IS_ERR(sgt)) {
266 if (!dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir)) {
267 sg_free_table(sgt);
268 kfree(sgt);
269 sgt = ERR_PTR(-ENOMEM);
270 } else {
271 prime_attach->sgt = sgt;
272 prime_attach->dir = dir;
273 }
274 }
275
276 return sgt;
277}
278
279static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
280 struct sg_table *sgt,
281 enum dma_data_direction dir)
282{
283 /* nothing to be done here */
284}
285
286/**
287 * drm_gem_dmabuf_export - dma_buf export implementation for GEM
288 * @dev: parent device for the exported dmabuf
289 * @exp_info: the export information used by dma_buf_export()
290 *
291 * This wraps dma_buf_export() for use by generic GEM drivers that are using
292 * drm_gem_dmabuf_release(). In addition to calling dma_buf_export(), we take
293 * a reference to the &drm_device and the exported &drm_gem_object (stored in
294 * exp_info->priv) which is released by drm_gem_dmabuf_release().
295 *
296 * Returns the new dmabuf.
297 */
298struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
299 struct dma_buf_export_info *exp_info)
300{
301 struct dma_buf *dma_buf;
302
303 dma_buf = dma_buf_export(exp_info);
304 if (IS_ERR(dma_buf))
305 return dma_buf;
306
307 drm_dev_ref(dev);
308 drm_gem_object_reference(exp_info->priv);
309
310 return dma_buf;
311}
312EXPORT_SYMBOL(drm_gem_dmabuf_export);
313
314/**
315 * drm_gem_dmabuf_release - dma_buf release implementation for GEM
316 * @dma_buf: buffer to be released
317 *
318 * Generic release function for dma_bufs exported as PRIME buffers. GEM drivers
319 * must use this in their dma_buf ops structure as the release callback.
320 * drm_gem_dmabuf_release() should be used in conjunction with
321 * drm_gem_dmabuf_export().
322 */
323void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
324{
325 struct drm_gem_object *obj = dma_buf->priv;
326 struct drm_device *dev = obj->dev;
327
328 /* drop the reference on the export fd holds */
329 drm_gem_object_unreference_unlocked(obj);
330
331 drm_dev_unref(dev);
332}
333EXPORT_SYMBOL(drm_gem_dmabuf_release);
334
335static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
336{
337 struct drm_gem_object *obj = dma_buf->priv;
338 struct drm_device *dev = obj->dev;
339
340 return dev->driver->gem_prime_vmap(obj);
341}
342
343static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
344{
345 struct drm_gem_object *obj = dma_buf->priv;
346 struct drm_device *dev = obj->dev;
347
348 dev->driver->gem_prime_vunmap(obj, vaddr);
349}
350
351static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
352 unsigned long page_num)
353{
354 return NULL;
355}
356
357static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
358 unsigned long page_num, void *addr)
359{
360
361}
362static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
363 unsigned long page_num)
364{
365 return NULL;
366}
367
368static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
369 unsigned long page_num, void *addr)
370{
371
372}
373
374static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
375 struct vm_area_struct *vma)
376{
377 struct drm_gem_object *obj = dma_buf->priv;
378 struct drm_device *dev = obj->dev;
379
380 if (!dev->driver->gem_prime_mmap)
381 return -ENOSYS;
382
383 return dev->driver->gem_prime_mmap(obj, vma);
384}
385
386static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
387 .attach = drm_gem_map_attach,
388 .detach = drm_gem_map_detach,
389 .map_dma_buf = drm_gem_map_dma_buf,
390 .unmap_dma_buf = drm_gem_unmap_dma_buf,
391 .release = drm_gem_dmabuf_release,
392 .kmap = drm_gem_dmabuf_kmap,
393 .kmap_atomic = drm_gem_dmabuf_kmap_atomic,
394 .kunmap = drm_gem_dmabuf_kunmap,
395 .kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
396 .mmap = drm_gem_dmabuf_mmap,
397 .vmap = drm_gem_dmabuf_vmap,
398 .vunmap = drm_gem_dmabuf_vunmap,
399};
400
401/**
402 * DOC: PRIME Helpers
403 *
404 * Drivers can implement @gem_prime_export and @gem_prime_import in terms of
405 * simpler APIs by using the helper functions @drm_gem_prime_export and
406 * @drm_gem_prime_import. These functions implement dma-buf support in terms of
407 * six lower-level driver callbacks:
408 *
409 * Export callbacks:
410 *
411 * * @gem_prime_pin (optional): prepare a GEM object for exporting
412 * * @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
413 * * @gem_prime_vmap: vmap a buffer exported by your driver
414 * * @gem_prime_vunmap: vunmap a buffer exported by your driver
415 * * @gem_prime_mmap (optional): mmap a buffer exported by your driver
416 *
417 * Import callback:
418 *
419 * * @gem_prime_import_sg_table (import): produce a GEM object from another
420 * driver's scatter/gather table
421 */
422
423/**
424 * drm_gem_prime_export - helper library implementation of the export callback
425 * @dev: drm_device to export from
426 * @obj: GEM object to export
427 * @flags: flags like DRM_CLOEXEC and DRM_RDWR
428 *
429 * This is the implementation of the gem_prime_export functions for GEM drivers
430 * using the PRIME helpers.
431 */
432struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
433 struct drm_gem_object *obj,
434 int flags)
435{
436 struct dma_buf_export_info exp_info = {
437 .exp_name = KBUILD_MODNAME, /* white lie for debug */
438 .owner = dev->driver->fops->owner,
439 .ops = &drm_gem_prime_dmabuf_ops,
440 .size = obj->size,
441 .flags = flags,
442 .priv = obj,
443 };
444
445 if (dev->driver->gem_prime_res_obj)
446 exp_info.resv = dev->driver->gem_prime_res_obj(obj);
447
448 return drm_gem_dmabuf_export(dev, &exp_info);
449}
450EXPORT_SYMBOL(drm_gem_prime_export);
451
452static struct dma_buf *export_and_register_object(struct drm_device *dev,
453 struct drm_gem_object *obj,
454 uint32_t flags)
455{
456 struct dma_buf *dmabuf;
457
458 /* prevent races with concurrent gem_close. */
459 if (obj->handle_count == 0) {
460 dmabuf = ERR_PTR(-ENOENT);
461 return dmabuf;
462 }
463
464 dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
465 if (IS_ERR(dmabuf)) {
466 /* normally the created dma-buf takes ownership of the ref,
467 * but if that fails then drop the ref
468 */
469 return dmabuf;
470 }
471
472 /*
473 * Note that callers do not need to clean up the export cache
474 * since the check for obj->handle_count guarantees that someone
475 * will clean it up.
476 */
477 obj->dma_buf = dmabuf;
478 get_dma_buf(obj->dma_buf);
479
480 return dmabuf;
481}
482
483/**
484 * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
485 * @dev: dev to export the buffer from
486 * @file_priv: drm file-private structure
487 * @handle: buffer handle to export
488 * @flags: flags like DRM_CLOEXEC
489 * @prime_fd: pointer to storage for the fd id of the create dma-buf
490 *
491 * This is the PRIME export function which must be used mandatorily by GEM
492 * drivers to ensure correct lifetime management of the underlying GEM object.
493 * The actual exporting from GEM object to a dma-buf is done through the
494 * gem_prime_export driver callback.
495 */
496int drm_gem_prime_handle_to_fd(struct drm_device *dev,
497 struct drm_file *file_priv, uint32_t handle,
498 uint32_t flags,
499 int *prime_fd)
500{
501 struct drm_gem_object *obj;
502 int ret = 0;
503 struct dma_buf *dmabuf;
504
505 mutex_lock(&file_priv->prime.lock);
506 obj = drm_gem_object_lookup(file_priv, handle);
507 if (!obj) {
508 ret = -ENOENT;
509 goto out_unlock;
510 }
511
512 dmabuf = drm_prime_lookup_buf_by_handle(&file_priv->prime, handle);
513 if (dmabuf) {
514 get_dma_buf(dmabuf);
515 goto out_have_handle;
516 }
517
518 mutex_lock(&dev->object_name_lock);
519 /* re-export the original imported object */
520 if (obj->import_attach) {
521 dmabuf = obj->import_attach->dmabuf;
522 get_dma_buf(dmabuf);
523 goto out_have_obj;
524 }
525
526 if (obj->dma_buf) {
527 get_dma_buf(obj->dma_buf);
528 dmabuf = obj->dma_buf;
529 goto out_have_obj;
530 }
531
532 dmabuf = export_and_register_object(dev, obj, flags);
533 if (IS_ERR(dmabuf)) {
534 /* normally the created dma-buf takes ownership of the ref,
535 * but if that fails then drop the ref
536 */
537 ret = PTR_ERR(dmabuf);
538 mutex_unlock(&dev->object_name_lock);
539 goto out;
540 }
541
542out_have_obj:
543 /*
544 * If we've exported this buffer then cheat and add it to the import list
545 * so we get the correct handle back. We must do this under the
546 * protection of dev->object_name_lock to ensure that a racing gem close
547 * ioctl doesn't miss to remove this buffer handle from the cache.
548 */
549 ret = drm_prime_add_buf_handle(&file_priv->prime,
550 dmabuf, handle);
551 mutex_unlock(&dev->object_name_lock);
552 if (ret)
553 goto fail_put_dmabuf;
554
555out_have_handle:
556 ret = dma_buf_fd(dmabuf, flags);
557 /*
558 * We must _not_ remove the buffer from the handle cache since the newly
559 * created dma buf is already linked in the global obj->dma_buf pointer,
560 * and that is invariant as long as a userspace gem handle exists.
561 * Closing the handle will clean out the cache anyway, so we don't leak.
562 */
563 if (ret < 0) {
564 goto fail_put_dmabuf;
565 } else {
566 *prime_fd = ret;
567 ret = 0;
568 }
569
570 goto out;
571
572fail_put_dmabuf:
573 dma_buf_put(dmabuf);
574out:
575 drm_gem_object_unreference_unlocked(obj);
576out_unlock:
577 mutex_unlock(&file_priv->prime.lock);
578
579 return ret;
580}
581EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
582
583/**
584 * drm_gem_prime_import - helper library implementation of the import callback
585 * @dev: drm_device to import into
586 * @dma_buf: dma-buf object to import
587 *
588 * This is the implementation of the gem_prime_import functions for GEM drivers
589 * using the PRIME helpers.
590 */
591struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
592 struct dma_buf *dma_buf)
593{
594 struct dma_buf_attachment *attach;
595 struct sg_table *sgt;
596 struct drm_gem_object *obj;
597 int ret;
598
599 if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
600 obj = dma_buf->priv;
601 if (obj->dev == dev) {
602 /*
603 * Importing dmabuf exported from out own gem increases
604 * refcount on gem itself instead of f_count of dmabuf.
605 */
606 drm_gem_object_reference(obj);
607 return obj;
608 }
609 }
610
611 if (!dev->driver->gem_prime_import_sg_table)
612 return ERR_PTR(-EINVAL);
613
614 attach = dma_buf_attach(dma_buf, dev->dev);
615 if (IS_ERR(attach))
616 return ERR_CAST(attach);
617
618 get_dma_buf(dma_buf);
619
620 sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
621 if (IS_ERR(sgt)) {
622 ret = PTR_ERR(sgt);
623 goto fail_detach;
624 }
625
626 obj = dev->driver->gem_prime_import_sg_table(dev, attach, sgt);
627 if (IS_ERR(obj)) {
628 ret = PTR_ERR(obj);
629 goto fail_unmap;
630 }
631
632 obj->import_attach = attach;
633
634 return obj;
635
636fail_unmap:
637 dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
638fail_detach:
639 dma_buf_detach(dma_buf, attach);
640 dma_buf_put(dma_buf);
641
642 return ERR_PTR(ret);
643}
644EXPORT_SYMBOL(drm_gem_prime_import);
645
646/**
647 * drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers
648 * @dev: dev to export the buffer from
649 * @file_priv: drm file-private structure
650 * @prime_fd: fd id of the dma-buf which should be imported
651 * @handle: pointer to storage for the handle of the imported buffer object
652 *
653 * This is the PRIME import function which must be used mandatorily by GEM
654 * drivers to ensure correct lifetime management of the underlying GEM object.
655 * The actual importing of GEM object from the dma-buf is done through the
656 * gem_import_export driver callback.
657 */
658int drm_gem_prime_fd_to_handle(struct drm_device *dev,
659 struct drm_file *file_priv, int prime_fd,
660 uint32_t *handle)
661{
662 struct dma_buf *dma_buf;
663 struct drm_gem_object *obj;
664 int ret;
665
666 dma_buf = dma_buf_get(prime_fd);
667 if (IS_ERR(dma_buf))
668 return PTR_ERR(dma_buf);
669
670 mutex_lock(&file_priv->prime.lock);
671
672 ret = drm_prime_lookup_buf_handle(&file_priv->prime,
673 dma_buf, handle);
674 if (ret == 0)
675 goto out_put;
676
677 /* never seen this one, need to import */
678 mutex_lock(&dev->object_name_lock);
679 obj = dev->driver->gem_prime_import(dev, dma_buf);
680 if (IS_ERR(obj)) {
681 ret = PTR_ERR(obj);
682 goto out_unlock;
683 }
684
685 if (obj->dma_buf) {
686 WARN_ON(obj->dma_buf != dma_buf);
687 } else {
688 obj->dma_buf = dma_buf;
689 get_dma_buf(dma_buf);
690 }
691
692 /* _handle_create_tail unconditionally unlocks dev->object_name_lock. */
693 ret = drm_gem_handle_create_tail(file_priv, obj, handle);
694 drm_gem_object_unreference_unlocked(obj);
695 if (ret)
696 goto out_put;
697
698 ret = drm_prime_add_buf_handle(&file_priv->prime,
699 dma_buf, *handle);
700 mutex_unlock(&file_priv->prime.lock);
701 if (ret)
702 goto fail;
703
704 dma_buf_put(dma_buf);
705
706 return 0;
707
708fail:
709 /* hmm, if driver attached, we are relying on the free-object path
710 * to detach.. which seems ok..
711 */
712 drm_gem_handle_delete(file_priv, *handle);
713 dma_buf_put(dma_buf);
714 return ret;
715
716out_unlock:
717 mutex_unlock(&dev->object_name_lock);
718out_put:
719 mutex_unlock(&file_priv->prime.lock);
720 dma_buf_put(dma_buf);
721 return ret;
722}
723EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
724
725int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
726 struct drm_file *file_priv)
727{
728 struct drm_prime_handle *args = data;
729
730 if (!drm_core_check_feature(dev, DRIVER_PRIME))
731 return -EINVAL;
732
733 if (!dev->driver->prime_handle_to_fd)
734 return -ENOSYS;
735
736 /* check flags are valid */
737 if (args->flags & ~(DRM_CLOEXEC | DRM_RDWR))
738 return -EINVAL;
739
740 return dev->driver->prime_handle_to_fd(dev, file_priv,
741 args->handle, args->flags, &args->fd);
742}
743
744int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
745 struct drm_file *file_priv)
746{
747 struct drm_prime_handle *args = data;
748
749 if (!drm_core_check_feature(dev, DRIVER_PRIME))
750 return -EINVAL;
751
752 if (!dev->driver->prime_fd_to_handle)
753 return -ENOSYS;
754
755 return dev->driver->prime_fd_to_handle(dev, file_priv,
756 args->fd, &args->handle);
757}
758
759/**
760 * drm_prime_pages_to_sg - converts a page array into an sg list
761 * @pages: pointer to the array of page pointers to convert
762 * @nr_pages: length of the page vector
763 *
764 * This helper creates an sg table object from a set of pages
765 * the driver is responsible for mapping the pages into the
766 * importers address space for use with dma_buf itself.
767 */
768struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_pages)
769{
770 struct sg_table *sg = NULL;
771 int ret;
772
773 sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
774 if (!sg) {
775 ret = -ENOMEM;
776 goto out;
777 }
778
779 ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
780 nr_pages << PAGE_SHIFT, GFP_KERNEL);
781 if (ret)
782 goto out;
783
784 return sg;
785out:
786 kfree(sg);
787 return ERR_PTR(ret);
788}
789EXPORT_SYMBOL(drm_prime_pages_to_sg);
790
791/**
792 * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
793 * @sgt: scatter-gather table to convert
794 * @pages: array of page pointers to store the page array in
795 * @addrs: optional array to store the dma bus address of each page
796 * @max_pages: size of both the passed-in arrays
797 *
798 * Exports an sg table into an array of pages and addresses. This is currently
799 * required by the TTM driver in order to do correct fault handling.
800 */
801int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
802 dma_addr_t *addrs, int max_pages)
803{
804 unsigned count;
805 struct scatterlist *sg;
806 struct page *page;
807 u32 len;
808 int pg_index;
809 dma_addr_t addr;
810
811 pg_index = 0;
812 for_each_sg(sgt->sgl, sg, sgt->nents, count) {
813 len = sg->length;
814 page = sg_page(sg);
815 addr = sg_dma_address(sg);
816
817 while (len > 0) {
818 if (WARN_ON(pg_index >= max_pages))
819 return -1;
820 pages[pg_index] = page;
821 if (addrs)
822 addrs[pg_index] = addr;
823
824 page++;
825 addr += PAGE_SIZE;
826 len -= PAGE_SIZE;
827 pg_index++;
828 }
829 }
830 return 0;
831}
832EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
833
834/**
835 * drm_prime_gem_destroy - helper to clean up a PRIME-imported GEM object
836 * @obj: GEM object which was created from a dma-buf
837 * @sg: the sg-table which was pinned at import time
838 *
839 * This is the cleanup functions which GEM drivers need to call when they use
840 * @drm_gem_prime_import to import dma-bufs.
841 */
842void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
843{
844 struct dma_buf_attachment *attach;
845 struct dma_buf *dma_buf;
846 attach = obj->import_attach;
847 if (sg)
848 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
849 dma_buf = attach->dmabuf;
850 dma_buf_detach(attach->dmabuf, attach);
851 /* remove the reference */
852 dma_buf_put(dma_buf);
853}
854EXPORT_SYMBOL(drm_prime_gem_destroy);
855
856void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
857{
858 mutex_init(&prime_fpriv->lock);
859 prime_fpriv->dmabufs = RB_ROOT;
860 prime_fpriv->handles = RB_ROOT;
861}
862
863void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
864{
865 /* by now drm_gem_release should've made sure the list is empty */
866 WARN_ON(!RB_EMPTY_ROOT(&prime_fpriv->dmabufs));
867}