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 * six 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 * - @gem_prime_mmap (optional): mmap a buffer exported by your driver
325 *
326 * Import callback:
327 *
328 * - @gem_prime_import_sg_table (import): produce a GEM object from another
329 * driver's scatter/gather table
330 */
331
332 /**
333 * drm_gem_prime_export - helper library implementation of the export callback
334 * @dev: drm_device to export from
335 * @obj: GEM object to export
336 * @flags: flags like DRM_CLOEXEC
337 *
338 * This is the implementation of the gem_prime_export functions for GEM drivers
339 * using the PRIME helpers.
340 */
drm_gem_prime_export(struct drm_device * dev,struct drm_gem_object * obj,int flags)341 struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
342 struct drm_gem_object *obj,
343 int flags)
344 {
345 struct dma_buf_export_info exp_info = {
346 .exp_name = KBUILD_MODNAME, /* white lie for debug */
347 .owner = dev->driver->fops->owner,
348 .ops = &drm_gem_prime_dmabuf_ops,
349 .size = obj->size,
350 .flags = flags,
351 .priv = obj,
352 };
353
354 if (dev->driver->gem_prime_res_obj)
355 exp_info.resv = dev->driver->gem_prime_res_obj(obj);
356
357 return dma_buf_export(&exp_info);
358 }
359 EXPORT_SYMBOL(drm_gem_prime_export);
360
export_and_register_object(struct drm_device * dev,struct drm_gem_object * obj,uint32_t flags)361 static struct dma_buf *export_and_register_object(struct drm_device *dev,
362 struct drm_gem_object *obj,
363 uint32_t flags)
364 {
365 struct dma_buf *dmabuf;
366
367 /* prevent races with concurrent gem_close. */
368 if (obj->handle_count == 0) {
369 dmabuf = ERR_PTR(-ENOENT);
370 return dmabuf;
371 }
372
373 dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
374 if (IS_ERR(dmabuf)) {
375 /* normally the created dma-buf takes ownership of the ref,
376 * but if that fails then drop the ref
377 */
378 return dmabuf;
379 }
380
381 /*
382 * Note that callers do not need to clean up the export cache
383 * since the check for obj->handle_count guarantees that someone
384 * will clean it up.
385 */
386 obj->dma_buf = dmabuf;
387 get_dma_buf(obj->dma_buf);
388 /* Grab a new ref since the callers is now used by the dma-buf */
389 drm_gem_object_reference(obj);
390
391 return dmabuf;
392 }
393
394 /**
395 * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
396 * @dev: dev to export the buffer from
397 * @file_priv: drm file-private structure
398 * @handle: buffer handle to export
399 * @flags: flags like DRM_CLOEXEC
400 * @prime_fd: pointer to storage for the fd id of the create dma-buf
401 *
402 * This is the PRIME export function which must be used mandatorily by GEM
403 * drivers to ensure correct lifetime management of the underlying GEM object.
404 * The actual exporting from GEM object to a dma-buf is done through the
405 * gem_prime_export driver callback.
406 */
drm_gem_prime_handle_to_fd(struct drm_device * dev,struct drm_file * file_priv,uint32_t handle,uint32_t flags,int * prime_fd)407 int drm_gem_prime_handle_to_fd(struct drm_device *dev,
408 struct drm_file *file_priv, uint32_t handle,
409 uint32_t flags,
410 int *prime_fd)
411 {
412 struct drm_gem_object *obj;
413 int ret = 0;
414 struct dma_buf *dmabuf;
415
416 mutex_lock(&file_priv->prime.lock);
417 obj = drm_gem_object_lookup(dev, file_priv, handle);
418 if (!obj) {
419 ret = -ENOENT;
420 goto out_unlock;
421 }
422
423 dmabuf = drm_prime_lookup_buf_by_handle(&file_priv->prime, handle);
424 if (dmabuf) {
425 get_dma_buf(dmabuf);
426 goto out_have_handle;
427 }
428
429 mutex_lock(&dev->object_name_lock);
430 /* re-export the original imported object */
431 if (obj->import_attach) {
432 dmabuf = obj->import_attach->dmabuf;
433 get_dma_buf(dmabuf);
434 goto out_have_obj;
435 }
436
437 if (obj->dma_buf) {
438 get_dma_buf(obj->dma_buf);
439 dmabuf = obj->dma_buf;
440 goto out_have_obj;
441 }
442
443 dmabuf = export_and_register_object(dev, obj, flags);
444 if (IS_ERR(dmabuf)) {
445 /* normally the created dma-buf takes ownership of the ref,
446 * but if that fails then drop the ref
447 */
448 ret = PTR_ERR(dmabuf);
449 mutex_unlock(&dev->object_name_lock);
450 goto out;
451 }
452
453 out_have_obj:
454 /*
455 * If we've exported this buffer then cheat and add it to the import list
456 * so we get the correct handle back. We must do this under the
457 * protection of dev->object_name_lock to ensure that a racing gem close
458 * ioctl doesn't miss to remove this buffer handle from the cache.
459 */
460 ret = drm_prime_add_buf_handle(&file_priv->prime,
461 dmabuf, handle);
462 mutex_unlock(&dev->object_name_lock);
463 if (ret)
464 goto fail_put_dmabuf;
465
466 out_have_handle:
467 ret = dma_buf_fd(dmabuf, flags);
468 /*
469 * We must _not_ remove the buffer from the handle cache since the newly
470 * created dma buf is already linked in the global obj->dma_buf pointer,
471 * and that is invariant as long as a userspace gem handle exists.
472 * Closing the handle will clean out the cache anyway, so we don't leak.
473 */
474 if (ret < 0) {
475 goto fail_put_dmabuf;
476 } else {
477 *prime_fd = ret;
478 ret = 0;
479 }
480
481 goto out;
482
483 fail_put_dmabuf:
484 dma_buf_put(dmabuf);
485 out:
486 drm_gem_object_unreference_unlocked(obj);
487 out_unlock:
488 mutex_unlock(&file_priv->prime.lock);
489
490 return ret;
491 }
492 EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
493
494 /**
495 * drm_gem_prime_import - helper library implementation of the import callback
496 * @dev: drm_device to import into
497 * @dma_buf: dma-buf object to import
498 *
499 * This is the implementation of the gem_prime_import functions for GEM drivers
500 * using the PRIME helpers.
501 */
drm_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)502 struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
503 struct dma_buf *dma_buf)
504 {
505 struct dma_buf_attachment *attach;
506 struct sg_table *sgt;
507 struct drm_gem_object *obj;
508 int ret;
509
510 if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
511 obj = dma_buf->priv;
512 if (obj->dev == dev) {
513 /*
514 * Importing dmabuf exported from out own gem increases
515 * refcount on gem itself instead of f_count of dmabuf.
516 */
517 drm_gem_object_reference(obj);
518 return obj;
519 }
520 }
521
522 if (!dev->driver->gem_prime_import_sg_table)
523 return ERR_PTR(-EINVAL);
524
525 attach = dma_buf_attach(dma_buf, dev->dev);
526 if (IS_ERR(attach))
527 return ERR_CAST(attach);
528
529 get_dma_buf(dma_buf);
530
531 sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
532 if (IS_ERR(sgt)) {
533 ret = PTR_ERR(sgt);
534 goto fail_detach;
535 }
536
537 obj = dev->driver->gem_prime_import_sg_table(dev, attach, sgt);
538 if (IS_ERR(obj)) {
539 ret = PTR_ERR(obj);
540 goto fail_unmap;
541 }
542
543 obj->import_attach = attach;
544
545 return obj;
546
547 fail_unmap:
548 dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
549 fail_detach:
550 dma_buf_detach(dma_buf, attach);
551 dma_buf_put(dma_buf);
552
553 return ERR_PTR(ret);
554 }
555 EXPORT_SYMBOL(drm_gem_prime_import);
556
557 /**
558 * drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers
559 * @dev: dev to export the buffer from
560 * @file_priv: drm file-private structure
561 * @prime_fd: fd id of the dma-buf which should be imported
562 * @handle: pointer to storage for the handle of the imported buffer object
563 *
564 * This is the PRIME import function which must be used mandatorily by GEM
565 * drivers to ensure correct lifetime management of the underlying GEM object.
566 * The actual importing of GEM object from the dma-buf is done through the
567 * gem_import_export driver callback.
568 */
drm_gem_prime_fd_to_handle(struct drm_device * dev,struct drm_file * file_priv,int prime_fd,uint32_t * handle)569 int drm_gem_prime_fd_to_handle(struct drm_device *dev,
570 struct drm_file *file_priv, int prime_fd,
571 uint32_t *handle)
572 {
573 struct dma_buf *dma_buf;
574 struct drm_gem_object *obj;
575 int ret;
576
577 dma_buf = dma_buf_get(prime_fd);
578 if (IS_ERR(dma_buf))
579 return PTR_ERR(dma_buf);
580
581 mutex_lock(&file_priv->prime.lock);
582
583 ret = drm_prime_lookup_buf_handle(&file_priv->prime,
584 dma_buf, handle);
585 if (ret == 0)
586 goto out_put;
587
588 /* never seen this one, need to import */
589 mutex_lock(&dev->object_name_lock);
590 obj = dev->driver->gem_prime_import(dev, dma_buf);
591 if (IS_ERR(obj)) {
592 ret = PTR_ERR(obj);
593 goto out_unlock;
594 }
595
596 if (obj->dma_buf) {
597 WARN_ON(obj->dma_buf != dma_buf);
598 } else {
599 obj->dma_buf = dma_buf;
600 get_dma_buf(dma_buf);
601 }
602
603 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
604 ret = drm_gem_handle_create_tail(file_priv, obj, handle);
605 drm_gem_object_unreference_unlocked(obj);
606 if (ret)
607 goto out_put;
608
609 ret = drm_prime_add_buf_handle(&file_priv->prime,
610 dma_buf, *handle);
611 if (ret)
612 goto fail;
613
614 mutex_unlock(&file_priv->prime.lock);
615
616 dma_buf_put(dma_buf);
617
618 return 0;
619
620 fail:
621 /* hmm, if driver attached, we are relying on the free-object path
622 * to detach.. which seems ok..
623 */
624 drm_gem_handle_delete(file_priv, *handle);
625 out_unlock:
626 mutex_unlock(&dev->object_name_lock);
627 out_put:
628 dma_buf_put(dma_buf);
629 mutex_unlock(&file_priv->prime.lock);
630 return ret;
631 }
632 EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
633
drm_prime_handle_to_fd_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)634 int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
635 struct drm_file *file_priv)
636 {
637 struct drm_prime_handle *args = data;
638 uint32_t flags;
639
640 if (!drm_core_check_feature(dev, DRIVER_PRIME))
641 return -EINVAL;
642
643 if (!dev->driver->prime_handle_to_fd)
644 return -ENOSYS;
645
646 /* check flags are valid */
647 if (args->flags & ~DRM_CLOEXEC)
648 return -EINVAL;
649
650 /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
651 flags = args->flags & DRM_CLOEXEC;
652
653 return dev->driver->prime_handle_to_fd(dev, file_priv,
654 args->handle, flags, &args->fd);
655 }
656
drm_prime_fd_to_handle_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)657 int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
658 struct drm_file *file_priv)
659 {
660 struct drm_prime_handle *args = data;
661
662 if (!drm_core_check_feature(dev, DRIVER_PRIME))
663 return -EINVAL;
664
665 if (!dev->driver->prime_fd_to_handle)
666 return -ENOSYS;
667
668 return dev->driver->prime_fd_to_handle(dev, file_priv,
669 args->fd, &args->handle);
670 }
671
672 /**
673 * drm_prime_pages_to_sg - converts a page array into an sg list
674 * @pages: pointer to the array of page pointers to convert
675 * @nr_pages: length of the page vector
676 *
677 * This helper creates an sg table object from a set of pages
678 * the driver is responsible for mapping the pages into the
679 * importers address space for use with dma_buf itself.
680 */
drm_prime_pages_to_sg(struct page ** pages,unsigned int nr_pages)681 struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_pages)
682 {
683 struct sg_table *sg = NULL;
684 int ret;
685
686 sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
687 if (!sg) {
688 ret = -ENOMEM;
689 goto out;
690 }
691
692 ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
693 nr_pages << PAGE_SHIFT, GFP_KERNEL);
694 if (ret)
695 goto out;
696
697 return sg;
698 out:
699 kfree(sg);
700 return ERR_PTR(ret);
701 }
702 EXPORT_SYMBOL(drm_prime_pages_to_sg);
703
704 /**
705 * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
706 * @sgt: scatter-gather table to convert
707 * @pages: array of page pointers to store the page array in
708 * @addrs: optional array to store the dma bus address of each page
709 * @max_pages: size of both the passed-in arrays
710 *
711 * Exports an sg table into an array of pages and addresses. This is currently
712 * required by the TTM driver in order to do correct fault handling.
713 */
drm_prime_sg_to_page_addr_arrays(struct sg_table * sgt,struct page ** pages,dma_addr_t * addrs,int max_pages)714 int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
715 dma_addr_t *addrs, int max_pages)
716 {
717 unsigned count;
718 struct scatterlist *sg;
719 struct page *page;
720 u32 len;
721 int pg_index;
722 dma_addr_t addr;
723
724 pg_index = 0;
725 for_each_sg(sgt->sgl, sg, sgt->nents, count) {
726 len = sg->length;
727 page = sg_page(sg);
728 addr = sg_dma_address(sg);
729
730 while (len > 0) {
731 if (WARN_ON(pg_index >= max_pages))
732 return -1;
733 pages[pg_index] = page;
734 if (addrs)
735 addrs[pg_index] = addr;
736
737 page++;
738 addr += PAGE_SIZE;
739 len -= PAGE_SIZE;
740 pg_index++;
741 }
742 }
743 return 0;
744 }
745 EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
746
747 /**
748 * drm_prime_gem_destroy - helper to clean up a PRIME-imported GEM object
749 * @obj: GEM object which was created from a dma-buf
750 * @sg: the sg-table which was pinned at import time
751 *
752 * This is the cleanup functions which GEM drivers need to call when they use
753 * @drm_gem_prime_import to import dma-bufs.
754 */
drm_prime_gem_destroy(struct drm_gem_object * obj,struct sg_table * sg)755 void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
756 {
757 struct dma_buf_attachment *attach;
758 struct dma_buf *dma_buf;
759 attach = obj->import_attach;
760 if (sg)
761 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
762 dma_buf = attach->dmabuf;
763 dma_buf_detach(attach->dmabuf, attach);
764 /* remove the reference */
765 dma_buf_put(dma_buf);
766 }
767 EXPORT_SYMBOL(drm_prime_gem_destroy);
768
drm_prime_init_file_private(struct drm_prime_file_private * prime_fpriv)769 void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
770 {
771 INIT_LIST_HEAD(&prime_fpriv->head);
772 mutex_init(&prime_fpriv->lock);
773 }
774
drm_prime_destroy_file_private(struct drm_prime_file_private * prime_fpriv)775 void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
776 {
777 /* by now drm_gem_release should've made sure the list is empty */
778 WARN_ON(!list_empty(&prime_fpriv->head));
779 }
780