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 <drm/drmP.h>
32 #include <drm/drm_gem.h>
33
34 #include "drm_internal.h"
35
36 /*
37 * DMA-BUF/GEM Object references and lifetime overview:
38 *
39 * On the export the dma_buf holds a reference to the exporting GEM
40 * object. It takes this reference in handle_to_fd_ioctl, when it
41 * first calls .prime_export and stores the exporting GEM object in
42 * the dma_buf priv. This reference is released when the dma_buf
43 * object goes away in the driver .release function.
44 *
45 * On the import the importing GEM object holds a reference to the
46 * dma_buf (which in turn holds a ref to the exporting GEM object).
47 * It takes that reference in the fd_to_handle ioctl.
48 * It calls dma_buf_get, creates an attachment to it and stores the
49 * attachment in the GEM object. When this attachment is destroyed
50 * when the imported object is destroyed, we remove the attachment
51 * and drop the reference to the dma_buf.
52 *
53 * Thus the chain of references always flows in one direction
54 * (avoiding loops): importing_gem -> dmabuf -> exporting_gem
55 *
56 * Self-importing: if userspace is using PRIME as a replacement for flink
57 * then it will get a fd->handle request for a GEM object that it created.
58 * Drivers should detect this situation and return back the gem object
59 * from the dma-buf private. Prime will do this automatically for drivers that
60 * use the drm_gem_prime_{import,export} helpers.
61 */
62
63 struct drm_prime_member {
64 struct list_head entry;
65 struct dma_buf *dma_buf;
66 uint32_t handle;
67 };
68
69 struct drm_prime_attachment {
70 struct sg_table *sgt;
71 enum dma_data_direction dir;
72 };
73
drm_prime_add_buf_handle(struct drm_prime_file_private * prime_fpriv,struct dma_buf * dma_buf,uint32_t handle)74 static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv,
75 struct dma_buf *dma_buf, uint32_t handle)
76 {
77 struct drm_prime_member *member;
78
79 member = kmalloc(sizeof(*member), GFP_KERNEL);
80 if (!member)
81 return -ENOMEM;
82
83 get_dma_buf(dma_buf);
84 member->dma_buf = dma_buf;
85 member->handle = handle;
86 list_add(&member->entry, &prime_fpriv->head);
87 return 0;
88 }
89
drm_prime_lookup_buf_by_handle(struct drm_prime_file_private * prime_fpriv,uint32_t handle)90 static struct dma_buf *drm_prime_lookup_buf_by_handle(struct drm_prime_file_private *prime_fpriv,
91 uint32_t handle)
92 {
93 struct drm_prime_member *member;
94
95 list_for_each_entry(member, &prime_fpriv->head, entry) {
96 if (member->handle == handle)
97 return member->dma_buf;
98 }
99
100 return NULL;
101 }
102
drm_prime_lookup_buf_handle(struct drm_prime_file_private * prime_fpriv,struct dma_buf * dma_buf,uint32_t * handle)103 static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv,
104 struct dma_buf *dma_buf,
105 uint32_t *handle)
106 {
107 struct drm_prime_member *member;
108
109 list_for_each_entry(member, &prime_fpriv->head, entry) {
110 if (member->dma_buf == dma_buf) {
111 *handle = member->handle;
112 return 0;
113 }
114 }
115 return -ENOENT;
116 }
117
drm_gem_map_attach(struct dma_buf * dma_buf,struct device * target_dev,struct dma_buf_attachment * attach)118 static int drm_gem_map_attach(struct dma_buf *dma_buf,
119 struct device *target_dev,
120 struct dma_buf_attachment *attach)
121 {
122 struct drm_prime_attachment *prime_attach;
123 struct drm_gem_object *obj = dma_buf->priv;
124 struct drm_device *dev = obj->dev;
125
126 prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL);
127 if (!prime_attach)
128 return -ENOMEM;
129
130 prime_attach->dir = DMA_NONE;
131 attach->priv = prime_attach;
132
133 if (!dev->driver->gem_prime_pin)
134 return 0;
135
136 return dev->driver->gem_prime_pin(obj);
137 }
138
drm_gem_map_detach(struct dma_buf * dma_buf,struct dma_buf_attachment * attach)139 static void drm_gem_map_detach(struct dma_buf *dma_buf,
140 struct dma_buf_attachment *attach)
141 {
142 struct drm_prime_attachment *prime_attach = attach->priv;
143 struct drm_gem_object *obj = dma_buf->priv;
144 struct drm_device *dev = obj->dev;
145 struct sg_table *sgt;
146
147 if (dev->driver->gem_prime_unpin)
148 dev->driver->gem_prime_unpin(obj);
149
150 if (!prime_attach)
151 return;
152
153 sgt = prime_attach->sgt;
154 if (sgt) {
155 if (prime_attach->dir != DMA_NONE)
156 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
157 prime_attach->dir);
158 sg_free_table(sgt);
159 }
160
161 kfree(sgt);
162 kfree(prime_attach);
163 attach->priv = NULL;
164 }
165
drm_prime_remove_buf_handle_locked(struct drm_prime_file_private * prime_fpriv,struct dma_buf * dma_buf)166 void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv,
167 struct dma_buf *dma_buf)
168 {
169 struct drm_prime_member *member, *safe;
170
171 list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) {
172 if (member->dma_buf == dma_buf) {
173 dma_buf_put(dma_buf);
174 list_del(&member->entry);
175 kfree(member);
176 }
177 }
178 }
179
drm_gem_map_dma_buf(struct dma_buf_attachment * attach,enum dma_data_direction dir)180 static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
181 enum dma_data_direction dir)
182 {
183 struct drm_prime_attachment *prime_attach = attach->priv;
184 struct drm_gem_object *obj = attach->dmabuf->priv;
185 struct sg_table *sgt;
186
187 if (WARN_ON(dir == DMA_NONE || !prime_attach))
188 return ERR_PTR(-EINVAL);
189
190 /* return the cached mapping when possible */
191 if (prime_attach->dir == dir)
192 return prime_attach->sgt;
193
194 /*
195 * two mappings with different directions for the same attachment are
196 * not allowed
197 */
198 if (WARN_ON(prime_attach->dir != DMA_NONE))
199 return ERR_PTR(-EBUSY);
200
201 sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
202
203 if (!IS_ERR(sgt)) {
204 if (!dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir)) {
205 sg_free_table(sgt);
206 kfree(sgt);
207 sgt = ERR_PTR(-ENOMEM);
208 } else {
209 prime_attach->sgt = sgt;
210 prime_attach->dir = dir;
211 }
212 }
213
214 return sgt;
215 }
216
drm_gem_unmap_dma_buf(struct dma_buf_attachment * attach,struct sg_table * sgt,enum dma_data_direction dir)217 static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
218 struct sg_table *sgt,
219 enum dma_data_direction dir)
220 {
221 /* nothing to be done here */
222 }
223
224 /**
225 * drm_gem_dmabuf_release - dma_buf release implementation for GEM
226 * @dma_buf: buffer to be released
227 *
228 * Generic release function for dma_bufs exported as PRIME buffers. GEM drivers
229 * must use this in their dma_buf ops structure as the release callback.
230 */
drm_gem_dmabuf_release(struct dma_buf * dma_buf)231 void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
232 {
233 struct drm_gem_object *obj = dma_buf->priv;
234
235 /* drop the reference on the export fd holds */
236 drm_gem_object_unreference_unlocked(obj);
237 }
238 EXPORT_SYMBOL(drm_gem_dmabuf_release);
239
drm_gem_dmabuf_vmap(struct dma_buf * dma_buf)240 static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
241 {
242 struct drm_gem_object *obj = dma_buf->priv;
243 struct drm_device *dev = obj->dev;
244
245 return dev->driver->gem_prime_vmap(obj);
246 }
247
drm_gem_dmabuf_vunmap(struct dma_buf * dma_buf,void * vaddr)248 static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
249 {
250 struct drm_gem_object *obj = dma_buf->priv;
251 struct drm_device *dev = obj->dev;
252
253 dev->driver->gem_prime_vunmap(obj, vaddr);
254 }
255
drm_gem_dmabuf_kmap_atomic(struct dma_buf * dma_buf,unsigned long page_num)256 static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
257 unsigned long page_num)
258 {
259 return NULL;
260 }
261
drm_gem_dmabuf_kunmap_atomic(struct dma_buf * dma_buf,unsigned long page_num,void * addr)262 static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
263 unsigned long page_num, void *addr)
264 {
265
266 }
drm_gem_dmabuf_kmap(struct dma_buf * dma_buf,unsigned long page_num)267 static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
268 unsigned long page_num)
269 {
270 return NULL;
271 }
272
drm_gem_dmabuf_kunmap(struct dma_buf * dma_buf,unsigned long page_num,void * addr)273 static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
274 unsigned long page_num, void *addr)
275 {
276
277 }
278
drm_gem_dmabuf_mmap(struct dma_buf * dma_buf,struct vm_area_struct * vma)279 static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
280 struct vm_area_struct *vma)
281 {
282 struct drm_gem_object *obj = dma_buf->priv;
283 struct drm_device *dev = obj->dev;
284
285 if (!dev->driver->gem_prime_mmap)
286 return -ENOSYS;
287
288 return dev->driver->gem_prime_mmap(obj, vma);
289 }
290
291 static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
292 .attach = drm_gem_map_attach,
293 .detach = drm_gem_map_detach,
294 .map_dma_buf = drm_gem_map_dma_buf,
295 .unmap_dma_buf = drm_gem_unmap_dma_buf,
296 .release = drm_gem_dmabuf_release,
297 .kmap = drm_gem_dmabuf_kmap,
298 .kmap_atomic = drm_gem_dmabuf_kmap_atomic,
299 .kunmap = drm_gem_dmabuf_kunmap,
300 .kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
301 .mmap = drm_gem_dmabuf_mmap,
302 .vmap = drm_gem_dmabuf_vmap,
303 .vunmap = drm_gem_dmabuf_vunmap,
304 };
305
306 /**
307 * DOC: PRIME Helpers
308 *
309 * Drivers can implement @gem_prime_export and @gem_prime_import in terms of
310 * simpler APIs by using the helper functions @drm_gem_prime_export and
311 * @drm_gem_prime_import. These functions implement dma-buf support in terms of
312 * five lower-level driver callbacks:
313 *
314 * Export callbacks:
315 *
316 * - @gem_prime_pin (optional): prepare a GEM object for exporting
317 *
318 * - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
319 *
320 * - @gem_prime_vmap: vmap a buffer exported by your driver
321 *
322 * - @gem_prime_vunmap: vunmap a buffer exported by your driver
323 *
324 * Import callback:
325 *
326 * - @gem_prime_import_sg_table (import): produce a GEM object from another
327 * driver's scatter/gather table
328 */
329
330 /**
331 * drm_gem_prime_export - helper library implemention of the export callback
332 * @dev: drm_device to export from
333 * @obj: GEM object to export
334 * @flags: flags like DRM_CLOEXEC
335 *
336 * This is the implementation of the gem_prime_export functions for GEM drivers
337 * using the PRIME helpers.
338 */
drm_gem_prime_export(struct drm_device * dev,struct drm_gem_object * obj,int flags)339 struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
340 struct drm_gem_object *obj, int flags)
341 {
342 struct reservation_object *robj = NULL;
343
344 if (dev->driver->gem_prime_res_obj)
345 robj = dev->driver->gem_prime_res_obj(obj);
346
347 return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
348 flags, robj);
349 }
350 EXPORT_SYMBOL(drm_gem_prime_export);
351
export_and_register_object(struct drm_device * dev,struct drm_gem_object * obj,uint32_t flags)352 static struct dma_buf *export_and_register_object(struct drm_device *dev,
353 struct drm_gem_object *obj,
354 uint32_t flags)
355 {
356 struct dma_buf *dmabuf;
357
358 /* prevent races with concurrent gem_close. */
359 if (obj->handle_count == 0) {
360 dmabuf = ERR_PTR(-ENOENT);
361 return dmabuf;
362 }
363
364 dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
365 if (IS_ERR(dmabuf)) {
366 /* normally the created dma-buf takes ownership of the ref,
367 * but if that fails then drop the ref
368 */
369 return dmabuf;
370 }
371
372 /*
373 * Note that callers do not need to clean up the export cache
374 * since the check for obj->handle_count guarantees that someone
375 * will clean it up.
376 */
377 obj->dma_buf = dmabuf;
378 get_dma_buf(obj->dma_buf);
379 /* Grab a new ref since the callers is now used by the dma-buf */
380 drm_gem_object_reference(obj);
381
382 return dmabuf;
383 }
384
385 /**
386 * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
387 * @dev: dev to export the buffer from
388 * @file_priv: drm file-private structure
389 * @handle: buffer handle to export
390 * @flags: flags like DRM_CLOEXEC
391 * @prime_fd: pointer to storage for the fd id of the create dma-buf
392 *
393 * This is the PRIME export function which must be used mandatorily by GEM
394 * drivers to ensure correct lifetime management of the underlying GEM object.
395 * The actual exporting from GEM object to a dma-buf is done through the
396 * gem_prime_export driver callback.
397 */
drm_gem_prime_handle_to_fd(struct drm_device * dev,struct drm_file * file_priv,uint32_t handle,uint32_t flags,int * prime_fd)398 int drm_gem_prime_handle_to_fd(struct drm_device *dev,
399 struct drm_file *file_priv, uint32_t handle,
400 uint32_t flags,
401 int *prime_fd)
402 {
403 struct drm_gem_object *obj;
404 int ret = 0;
405 struct dma_buf *dmabuf;
406
407 mutex_lock(&file_priv->prime.lock);
408 obj = drm_gem_object_lookup(dev, file_priv, handle);
409 if (!obj) {
410 ret = -ENOENT;
411 goto out_unlock;
412 }
413
414 dmabuf = drm_prime_lookup_buf_by_handle(&file_priv->prime, handle);
415 if (dmabuf) {
416 get_dma_buf(dmabuf);
417 goto out_have_handle;
418 }
419
420 mutex_lock(&dev->object_name_lock);
421 /* re-export the original imported object */
422 if (obj->import_attach) {
423 dmabuf = obj->import_attach->dmabuf;
424 get_dma_buf(dmabuf);
425 goto out_have_obj;
426 }
427
428 if (obj->dma_buf) {
429 get_dma_buf(obj->dma_buf);
430 dmabuf = obj->dma_buf;
431 goto out_have_obj;
432 }
433
434 dmabuf = export_and_register_object(dev, obj, flags);
435 if (IS_ERR(dmabuf)) {
436 /* normally the created dma-buf takes ownership of the ref,
437 * but if that fails then drop the ref
438 */
439 ret = PTR_ERR(dmabuf);
440 mutex_unlock(&dev->object_name_lock);
441 goto out;
442 }
443
444 out_have_obj:
445 /*
446 * If we've exported this buffer then cheat and add it to the import list
447 * so we get the correct handle back. We must do this under the
448 * protection of dev->object_name_lock to ensure that a racing gem close
449 * ioctl doesn't miss to remove this buffer handle from the cache.
450 */
451 ret = drm_prime_add_buf_handle(&file_priv->prime,
452 dmabuf, handle);
453 mutex_unlock(&dev->object_name_lock);
454 if (ret)
455 goto fail_put_dmabuf;
456
457 out_have_handle:
458 ret = dma_buf_fd(dmabuf, flags);
459 /*
460 * We must _not_ remove the buffer from the handle cache since the newly
461 * created dma buf is already linked in the global obj->dma_buf pointer,
462 * and that is invariant as long as a userspace gem handle exists.
463 * Closing the handle will clean out the cache anyway, so we don't leak.
464 */
465 if (ret < 0) {
466 goto fail_put_dmabuf;
467 } else {
468 *prime_fd = ret;
469 ret = 0;
470 }
471
472 goto out;
473
474 fail_put_dmabuf:
475 dma_buf_put(dmabuf);
476 out:
477 drm_gem_object_unreference_unlocked(obj);
478 out_unlock:
479 mutex_unlock(&file_priv->prime.lock);
480
481 return ret;
482 }
483 EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
484
485 /**
486 * drm_gem_prime_import - helper library implemention of the import callback
487 * @dev: drm_device to import into
488 * @dma_buf: dma-buf object to import
489 *
490 * This is the implementation of the gem_prime_import functions for GEM drivers
491 * using the PRIME helpers.
492 */
drm_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)493 struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
494 struct dma_buf *dma_buf)
495 {
496 struct dma_buf_attachment *attach;
497 struct sg_table *sgt;
498 struct drm_gem_object *obj;
499 int ret;
500
501 if (!dev->driver->gem_prime_import_sg_table)
502 return ERR_PTR(-EINVAL);
503
504 if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
505 obj = dma_buf->priv;
506 if (obj->dev == dev) {
507 /*
508 * Importing dmabuf exported from out own gem increases
509 * refcount on gem itself instead of f_count of dmabuf.
510 */
511 drm_gem_object_reference(obj);
512 return obj;
513 }
514 }
515
516 attach = dma_buf_attach(dma_buf, dev->dev);
517 if (IS_ERR(attach))
518 return ERR_CAST(attach);
519
520 get_dma_buf(dma_buf);
521
522 sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
523 if (IS_ERR(sgt)) {
524 ret = PTR_ERR(sgt);
525 goto fail_detach;
526 }
527
528 obj = dev->driver->gem_prime_import_sg_table(dev, attach, sgt);
529 if (IS_ERR(obj)) {
530 ret = PTR_ERR(obj);
531 goto fail_unmap;
532 }
533
534 obj->import_attach = attach;
535
536 return obj;
537
538 fail_unmap:
539 dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
540 fail_detach:
541 dma_buf_detach(dma_buf, attach);
542 dma_buf_put(dma_buf);
543
544 return ERR_PTR(ret);
545 }
546 EXPORT_SYMBOL(drm_gem_prime_import);
547
548 /**
549 * drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers
550 * @dev: dev to export the buffer from
551 * @file_priv: drm file-private structure
552 * @prime_fd: fd id of the dma-buf which should be imported
553 * @handle: pointer to storage for the handle of the imported buffer object
554 *
555 * This is the PRIME import function which must be used mandatorily by GEM
556 * drivers to ensure correct lifetime management of the underlying GEM object.
557 * The actual importing of GEM object from the dma-buf is done through the
558 * gem_import_export driver callback.
559 */
drm_gem_prime_fd_to_handle(struct drm_device * dev,struct drm_file * file_priv,int prime_fd,uint32_t * handle)560 int drm_gem_prime_fd_to_handle(struct drm_device *dev,
561 struct drm_file *file_priv, int prime_fd,
562 uint32_t *handle)
563 {
564 struct dma_buf *dma_buf;
565 struct drm_gem_object *obj;
566 int ret;
567
568 dma_buf = dma_buf_get(prime_fd);
569 if (IS_ERR(dma_buf))
570 return PTR_ERR(dma_buf);
571
572 mutex_lock(&file_priv->prime.lock);
573
574 ret = drm_prime_lookup_buf_handle(&file_priv->prime,
575 dma_buf, handle);
576 if (ret == 0)
577 goto out_put;
578
579 /* never seen this one, need to import */
580 mutex_lock(&dev->object_name_lock);
581 obj = dev->driver->gem_prime_import(dev, dma_buf);
582 if (IS_ERR(obj)) {
583 ret = PTR_ERR(obj);
584 goto out_unlock;
585 }
586
587 if (obj->dma_buf) {
588 WARN_ON(obj->dma_buf != dma_buf);
589 } else {
590 obj->dma_buf = dma_buf;
591 get_dma_buf(dma_buf);
592 }
593
594 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
595 ret = drm_gem_handle_create_tail(file_priv, obj, handle);
596 drm_gem_object_unreference_unlocked(obj);
597 if (ret)
598 goto out_put;
599
600 ret = drm_prime_add_buf_handle(&file_priv->prime,
601 dma_buf, *handle);
602 if (ret)
603 goto fail;
604
605 mutex_unlock(&file_priv->prime.lock);
606
607 dma_buf_put(dma_buf);
608
609 return 0;
610
611 fail:
612 /* hmm, if driver attached, we are relying on the free-object path
613 * to detach.. which seems ok..
614 */
615 drm_gem_handle_delete(file_priv, *handle);
616 out_unlock:
617 mutex_unlock(&dev->object_name_lock);
618 out_put:
619 dma_buf_put(dma_buf);
620 mutex_unlock(&file_priv->prime.lock);
621 return ret;
622 }
623 EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
624
drm_prime_handle_to_fd_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)625 int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
626 struct drm_file *file_priv)
627 {
628 struct drm_prime_handle *args = data;
629 uint32_t flags;
630
631 if (!drm_core_check_feature(dev, DRIVER_PRIME))
632 return -EINVAL;
633
634 if (!dev->driver->prime_handle_to_fd)
635 return -ENOSYS;
636
637 /* check flags are valid */
638 if (args->flags & ~DRM_CLOEXEC)
639 return -EINVAL;
640
641 /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
642 flags = args->flags & DRM_CLOEXEC;
643
644 return dev->driver->prime_handle_to_fd(dev, file_priv,
645 args->handle, flags, &args->fd);
646 }
647
drm_prime_fd_to_handle_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)648 int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
649 struct drm_file *file_priv)
650 {
651 struct drm_prime_handle *args = data;
652
653 if (!drm_core_check_feature(dev, DRIVER_PRIME))
654 return -EINVAL;
655
656 if (!dev->driver->prime_fd_to_handle)
657 return -ENOSYS;
658
659 return dev->driver->prime_fd_to_handle(dev, file_priv,
660 args->fd, &args->handle);
661 }
662
663 /**
664 * drm_prime_pages_to_sg - converts a page array into an sg list
665 * @pages: pointer to the array of page pointers to convert
666 * @nr_pages: length of the page vector
667 *
668 * This helper creates an sg table object from a set of pages
669 * the driver is responsible for mapping the pages into the
670 * importers address space for use with dma_buf itself.
671 */
drm_prime_pages_to_sg(struct page ** pages,int nr_pages)672 struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages)
673 {
674 struct sg_table *sg = NULL;
675 int ret;
676
677 sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
678 if (!sg) {
679 ret = -ENOMEM;
680 goto out;
681 }
682
683 ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
684 nr_pages << PAGE_SHIFT, GFP_KERNEL);
685 if (ret)
686 goto out;
687
688 return sg;
689 out:
690 kfree(sg);
691 return ERR_PTR(ret);
692 }
693 EXPORT_SYMBOL(drm_prime_pages_to_sg);
694
695 /**
696 * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
697 * @sgt: scatter-gather table to convert
698 * @pages: array of page pointers to store the page array in
699 * @addrs: optional array to store the dma bus address of each page
700 * @max_pages: size of both the passed-in arrays
701 *
702 * Exports an sg table into an array of pages and addresses. This is currently
703 * required by the TTM driver in order to do correct fault handling.
704 */
drm_prime_sg_to_page_addr_arrays(struct sg_table * sgt,struct page ** pages,dma_addr_t * addrs,int max_pages)705 int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
706 dma_addr_t *addrs, int max_pages)
707 {
708 unsigned count;
709 struct scatterlist *sg;
710 struct page *page;
711 u32 len;
712 int pg_index;
713 dma_addr_t addr;
714
715 pg_index = 0;
716 for_each_sg(sgt->sgl, sg, sgt->nents, count) {
717 len = sg->length;
718 page = sg_page(sg);
719 addr = sg_dma_address(sg);
720
721 while (len > 0) {
722 if (WARN_ON(pg_index >= max_pages))
723 return -1;
724 pages[pg_index] = page;
725 if (addrs)
726 addrs[pg_index] = addr;
727
728 page++;
729 addr += PAGE_SIZE;
730 len -= PAGE_SIZE;
731 pg_index++;
732 }
733 }
734 return 0;
735 }
736 EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
737
738 /**
739 * drm_prime_gem_destroy - helper to clean up a PRIME-imported GEM object
740 * @obj: GEM object which was created from a dma-buf
741 * @sg: the sg-table which was pinned at import time
742 *
743 * This is the cleanup functions which GEM drivers need to call when they use
744 * @drm_gem_prime_import to import dma-bufs.
745 */
drm_prime_gem_destroy(struct drm_gem_object * obj,struct sg_table * sg)746 void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
747 {
748 struct dma_buf_attachment *attach;
749 struct dma_buf *dma_buf;
750 attach = obj->import_attach;
751 if (sg)
752 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
753 dma_buf = attach->dmabuf;
754 dma_buf_detach(attach->dmabuf, attach);
755 /* remove the reference */
756 dma_buf_put(dma_buf);
757 }
758 EXPORT_SYMBOL(drm_prime_gem_destroy);
759
drm_prime_init_file_private(struct drm_prime_file_private * prime_fpriv)760 void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
761 {
762 INIT_LIST_HEAD(&prime_fpriv->head);
763 mutex_init(&prime_fpriv->lock);
764 }
765
drm_prime_destroy_file_private(struct drm_prime_file_private * prime_fpriv)766 void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
767 {
768 /* by now drm_gem_release should've made sure the list is empty */
769 WARN_ON(!list_empty(&prime_fpriv->head));
770 }
771