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3248877e DA |
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> | |
760285e7 | 31 | #include <drm/drmP.h> |
3248877e DA |
32 | |
33 | /* | |
34 | * DMA-BUF/GEM Object references and lifetime overview: | |
35 | * | |
36 | * On the export the dma_buf holds a reference to the exporting GEM | |
37 | * object. It takes this reference in handle_to_fd_ioctl, when it | |
38 | * first calls .prime_export and stores the exporting GEM object in | |
39 | * the dma_buf priv. This reference is released when the dma_buf | |
40 | * object goes away in the driver .release function. | |
41 | * | |
42 | * On the import the importing GEM object holds a reference to the | |
43 | * dma_buf (which in turn holds a ref to the exporting GEM object). | |
44 | * It takes that reference in the fd_to_handle ioctl. | |
45 | * It calls dma_buf_get, creates an attachment to it and stores the | |
46 | * attachment in the GEM object. When this attachment is destroyed | |
47 | * when the imported object is destroyed, we remove the attachment | |
48 | * and drop the reference to the dma_buf. | |
49 | * | |
50 | * Thus the chain of references always flows in one direction | |
51 | * (avoiding loops): importing_gem -> dmabuf -> exporting_gem | |
52 | * | |
53 | * Self-importing: if userspace is using PRIME as a replacement for flink | |
54 | * then it will get a fd->handle request for a GEM object that it created. | |
55 | * Drivers should detect this situation and return back the gem object | |
89177644 AP |
56 | * from the dma-buf private. Prime will do this automatically for drivers that |
57 | * use the drm_gem_prime_{import,export} helpers. | |
3248877e DA |
58 | */ |
59 | ||
60 | struct drm_prime_member { | |
61 | struct list_head entry; | |
62 | struct dma_buf *dma_buf; | |
63 | uint32_t handle; | |
64 | }; | |
65 | ||
89177644 AP |
66 | static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach, |
67 | enum dma_data_direction dir) | |
68 | { | |
69 | struct drm_gem_object *obj = attach->dmabuf->priv; | |
70 | struct sg_table *sgt; | |
71 | ||
72 | mutex_lock(&obj->dev->struct_mutex); | |
73 | ||
74 | sgt = obj->dev->driver->gem_prime_get_sg_table(obj); | |
75 | ||
76 | if (!IS_ERR_OR_NULL(sgt)) | |
77 | dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir); | |
78 | ||
79 | mutex_unlock(&obj->dev->struct_mutex); | |
80 | return sgt; | |
81 | } | |
82 | ||
83 | static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach, | |
84 | struct sg_table *sgt, enum dma_data_direction dir) | |
85 | { | |
86 | dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir); | |
87 | sg_free_table(sgt); | |
88 | kfree(sgt); | |
89 | } | |
90 | ||
91 | static void drm_gem_dmabuf_release(struct dma_buf *dma_buf) | |
92 | { | |
93 | struct drm_gem_object *obj = dma_buf->priv; | |
94 | ||
95 | if (obj->export_dma_buf == dma_buf) { | |
96 | /* drop the reference on the export fd holds */ | |
97 | obj->export_dma_buf = NULL; | |
98 | drm_gem_object_unreference_unlocked(obj); | |
99 | } | |
100 | } | |
101 | ||
102 | static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf) | |
103 | { | |
104 | struct drm_gem_object *obj = dma_buf->priv; | |
105 | struct drm_device *dev = obj->dev; | |
106 | ||
107 | return dev->driver->gem_prime_vmap(obj); | |
108 | } | |
109 | ||
110 | static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) | |
111 | { | |
112 | struct drm_gem_object *obj = dma_buf->priv; | |
113 | struct drm_device *dev = obj->dev; | |
114 | ||
115 | dev->driver->gem_prime_vunmap(obj, vaddr); | |
116 | } | |
117 | ||
118 | static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, | |
119 | unsigned long page_num) | |
120 | { | |
121 | return NULL; | |
122 | } | |
123 | ||
124 | static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, | |
125 | unsigned long page_num, void *addr) | |
126 | { | |
127 | ||
128 | } | |
129 | static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, | |
130 | unsigned long page_num) | |
131 | { | |
132 | return NULL; | |
133 | } | |
134 | ||
135 | static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, | |
136 | unsigned long page_num, void *addr) | |
137 | { | |
138 | ||
139 | } | |
140 | ||
141 | static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, | |
142 | struct vm_area_struct *vma) | |
143 | { | |
144 | return -EINVAL; | |
145 | } | |
146 | ||
147 | static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { | |
148 | .map_dma_buf = drm_gem_map_dma_buf, | |
149 | .unmap_dma_buf = drm_gem_unmap_dma_buf, | |
150 | .release = drm_gem_dmabuf_release, | |
151 | .kmap = drm_gem_dmabuf_kmap, | |
152 | .kmap_atomic = drm_gem_dmabuf_kmap_atomic, | |
153 | .kunmap = drm_gem_dmabuf_kunmap, | |
154 | .kunmap_atomic = drm_gem_dmabuf_kunmap_atomic, | |
155 | .mmap = drm_gem_dmabuf_mmap, | |
156 | .vmap = drm_gem_dmabuf_vmap, | |
157 | .vunmap = drm_gem_dmabuf_vunmap, | |
158 | }; | |
159 | ||
160 | /** | |
161 | * DOC: PRIME Helpers | |
162 | * | |
163 | * Drivers can implement @gem_prime_export and @gem_prime_import in terms of | |
164 | * simpler APIs by using the helper functions @drm_gem_prime_export and | |
165 | * @drm_gem_prime_import. These functions implement dma-buf support in terms of | |
166 | * five lower-level driver callbacks: | |
167 | * | |
168 | * Export callbacks: | |
169 | * | |
170 | * - @gem_prime_pin (optional): prepare a GEM object for exporting | |
171 | * | |
172 | * - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages | |
173 | * | |
174 | * - @gem_prime_vmap: vmap a buffer exported by your driver | |
175 | * | |
176 | * - @gem_prime_vunmap: vunmap a buffer exported by your driver | |
177 | * | |
178 | * Import callback: | |
179 | * | |
180 | * - @gem_prime_import_sg_table (import): produce a GEM object from another | |
181 | * driver's scatter/gather table | |
182 | */ | |
183 | ||
184 | struct dma_buf *drm_gem_prime_export(struct drm_device *dev, | |
185 | struct drm_gem_object *obj, int flags) | |
186 | { | |
187 | if (dev->driver->gem_prime_pin) { | |
188 | int ret = dev->driver->gem_prime_pin(obj); | |
189 | if (ret) | |
190 | return ERR_PTR(ret); | |
191 | } | |
192 | return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, | |
193 | 0600); | |
194 | } | |
195 | EXPORT_SYMBOL(drm_gem_prime_export); | |
196 | ||
3248877e DA |
197 | int drm_gem_prime_handle_to_fd(struct drm_device *dev, |
198 | struct drm_file *file_priv, uint32_t handle, uint32_t flags, | |
199 | int *prime_fd) | |
200 | { | |
201 | struct drm_gem_object *obj; | |
202 | void *buf; | |
0ff926c7 | 203 | int ret; |
3248877e DA |
204 | |
205 | obj = drm_gem_object_lookup(dev, file_priv, handle); | |
206 | if (!obj) | |
207 | return -ENOENT; | |
208 | ||
209 | mutex_lock(&file_priv->prime.lock); | |
210 | /* re-export the original imported object */ | |
211 | if (obj->import_attach) { | |
212 | get_dma_buf(obj->import_attach->dmabuf); | |
213 | *prime_fd = dma_buf_fd(obj->import_attach->dmabuf, flags); | |
214 | drm_gem_object_unreference_unlocked(obj); | |
215 | mutex_unlock(&file_priv->prime.lock); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | if (obj->export_dma_buf) { | |
220 | get_dma_buf(obj->export_dma_buf); | |
221 | *prime_fd = dma_buf_fd(obj->export_dma_buf, flags); | |
222 | drm_gem_object_unreference_unlocked(obj); | |
223 | } else { | |
224 | buf = dev->driver->gem_prime_export(dev, obj, flags); | |
225 | if (IS_ERR(buf)) { | |
226 | /* normally the created dma-buf takes ownership of the ref, | |
227 | * but if that fails then drop the ref | |
228 | */ | |
229 | drm_gem_object_unreference_unlocked(obj); | |
230 | mutex_unlock(&file_priv->prime.lock); | |
231 | return PTR_ERR(buf); | |
232 | } | |
233 | obj->export_dma_buf = buf; | |
234 | *prime_fd = dma_buf_fd(buf, flags); | |
235 | } | |
0ff926c7 DA |
236 | /* if we've exported this buffer the cheat and add it to the import list |
237 | * so we get the correct handle back | |
238 | */ | |
239 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, | |
240 | obj->export_dma_buf, handle); | |
241 | if (ret) { | |
242 | drm_gem_object_unreference_unlocked(obj); | |
243 | mutex_unlock(&file_priv->prime.lock); | |
244 | return ret; | |
245 | } | |
246 | ||
3248877e DA |
247 | mutex_unlock(&file_priv->prime.lock); |
248 | return 0; | |
249 | } | |
250 | EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); | |
251 | ||
89177644 AP |
252 | struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev, |
253 | struct dma_buf *dma_buf) | |
254 | { | |
255 | struct dma_buf_attachment *attach; | |
256 | struct sg_table *sgt; | |
257 | struct drm_gem_object *obj; | |
258 | int ret; | |
259 | ||
260 | if (!dev->driver->gem_prime_import_sg_table) | |
261 | return ERR_PTR(-EINVAL); | |
262 | ||
263 | if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) { | |
264 | obj = dma_buf->priv; | |
265 | if (obj->dev == dev) { | |
266 | /* | |
267 | * Importing dmabuf exported from out own gem increases | |
268 | * refcount on gem itself instead of f_count of dmabuf. | |
269 | */ | |
270 | drm_gem_object_reference(obj); | |
271 | dma_buf_put(dma_buf); | |
272 | return obj; | |
273 | } | |
274 | } | |
275 | ||
276 | attach = dma_buf_attach(dma_buf, dev->dev); | |
277 | if (IS_ERR(attach)) | |
278 | return ERR_PTR(PTR_ERR(attach)); | |
279 | ||
280 | sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); | |
281 | if (IS_ERR_OR_NULL(sgt)) { | |
282 | ret = PTR_ERR(sgt); | |
283 | goto fail_detach; | |
284 | } | |
285 | ||
286 | obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt); | |
287 | if (IS_ERR(obj)) { | |
288 | ret = PTR_ERR(obj); | |
289 | goto fail_unmap; | |
290 | } | |
291 | ||
292 | obj->import_attach = attach; | |
293 | ||
294 | return obj; | |
295 | ||
296 | fail_unmap: | |
297 | dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); | |
298 | fail_detach: | |
299 | dma_buf_detach(dma_buf, attach); | |
300 | return ERR_PTR(ret); | |
301 | } | |
302 | EXPORT_SYMBOL(drm_gem_prime_import); | |
303 | ||
3248877e DA |
304 | int drm_gem_prime_fd_to_handle(struct drm_device *dev, |
305 | struct drm_file *file_priv, int prime_fd, uint32_t *handle) | |
306 | { | |
307 | struct dma_buf *dma_buf; | |
308 | struct drm_gem_object *obj; | |
309 | int ret; | |
310 | ||
311 | dma_buf = dma_buf_get(prime_fd); | |
312 | if (IS_ERR(dma_buf)) | |
313 | return PTR_ERR(dma_buf); | |
314 | ||
315 | mutex_lock(&file_priv->prime.lock); | |
316 | ||
317 | ret = drm_prime_lookup_imported_buf_handle(&file_priv->prime, | |
318 | dma_buf, handle); | |
319 | if (!ret) { | |
320 | ret = 0; | |
321 | goto out_put; | |
322 | } | |
323 | ||
324 | /* never seen this one, need to import */ | |
325 | obj = dev->driver->gem_prime_import(dev, dma_buf); | |
326 | if (IS_ERR(obj)) { | |
327 | ret = PTR_ERR(obj); | |
328 | goto out_put; | |
329 | } | |
330 | ||
331 | ret = drm_gem_handle_create(file_priv, obj, handle); | |
332 | drm_gem_object_unreference_unlocked(obj); | |
333 | if (ret) | |
334 | goto out_put; | |
335 | ||
336 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, | |
337 | dma_buf, *handle); | |
338 | if (ret) | |
339 | goto fail; | |
340 | ||
341 | mutex_unlock(&file_priv->prime.lock); | |
342 | return 0; | |
343 | ||
344 | fail: | |
345 | /* hmm, if driver attached, we are relying on the free-object path | |
346 | * to detach.. which seems ok.. | |
347 | */ | |
348 | drm_gem_object_handle_unreference_unlocked(obj); | |
349 | out_put: | |
350 | dma_buf_put(dma_buf); | |
351 | mutex_unlock(&file_priv->prime.lock); | |
352 | return ret; | |
353 | } | |
354 | EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); | |
355 | ||
356 | int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, | |
357 | struct drm_file *file_priv) | |
358 | { | |
359 | struct drm_prime_handle *args = data; | |
360 | uint32_t flags; | |
361 | ||
362 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) | |
363 | return -EINVAL; | |
364 | ||
365 | if (!dev->driver->prime_handle_to_fd) | |
366 | return -ENOSYS; | |
367 | ||
368 | /* check flags are valid */ | |
369 | if (args->flags & ~DRM_CLOEXEC) | |
370 | return -EINVAL; | |
371 | ||
372 | /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ | |
373 | flags = args->flags & DRM_CLOEXEC; | |
374 | ||
375 | return dev->driver->prime_handle_to_fd(dev, file_priv, | |
376 | args->handle, flags, &args->fd); | |
377 | } | |
378 | ||
379 | int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, | |
380 | struct drm_file *file_priv) | |
381 | { | |
382 | struct drm_prime_handle *args = data; | |
383 | ||
384 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) | |
385 | return -EINVAL; | |
386 | ||
387 | if (!dev->driver->prime_fd_to_handle) | |
388 | return -ENOSYS; | |
389 | ||
390 | return dev->driver->prime_fd_to_handle(dev, file_priv, | |
391 | args->fd, &args->handle); | |
392 | } | |
393 | ||
394 | /* | |
395 | * drm_prime_pages_to_sg | |
396 | * | |
397 | * this helper creates an sg table object from a set of pages | |
398 | * the driver is responsible for mapping the pages into the | |
399 | * importers address space | |
400 | */ | |
401 | struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) | |
402 | { | |
403 | struct sg_table *sg = NULL; | |
404 | struct scatterlist *iter; | |
405 | int i; | |
406 | int ret; | |
407 | ||
408 | sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); | |
409 | if (!sg) | |
410 | goto out; | |
411 | ||
412 | ret = sg_alloc_table(sg, nr_pages, GFP_KERNEL); | |
413 | if (ret) | |
414 | goto out; | |
415 | ||
416 | for_each_sg(sg->sgl, iter, nr_pages, i) | |
417 | sg_set_page(iter, pages[i], PAGE_SIZE, 0); | |
418 | ||
419 | return sg; | |
420 | out: | |
421 | kfree(sg); | |
422 | return NULL; | |
423 | } | |
424 | EXPORT_SYMBOL(drm_prime_pages_to_sg); | |
425 | ||
51ab7ba2 DA |
426 | /* export an sg table into an array of pages and addresses |
427 | this is currently required by the TTM driver in order to do correct fault | |
428 | handling */ | |
429 | int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, | |
430 | dma_addr_t *addrs, int max_pages) | |
431 | { | |
432 | unsigned count; | |
433 | struct scatterlist *sg; | |
434 | struct page *page; | |
435 | u32 len, offset; | |
436 | int pg_index; | |
437 | dma_addr_t addr; | |
438 | ||
439 | pg_index = 0; | |
440 | for_each_sg(sgt->sgl, sg, sgt->nents, count) { | |
441 | len = sg->length; | |
442 | offset = sg->offset; | |
443 | page = sg_page(sg); | |
444 | addr = sg_dma_address(sg); | |
445 | ||
446 | while (len > 0) { | |
447 | if (WARN_ON(pg_index >= max_pages)) | |
448 | return -1; | |
449 | pages[pg_index] = page; | |
450 | if (addrs) | |
451 | addrs[pg_index] = addr; | |
452 | ||
453 | page++; | |
454 | addr += PAGE_SIZE; | |
455 | len -= PAGE_SIZE; | |
456 | pg_index++; | |
457 | } | |
458 | } | |
459 | return 0; | |
460 | } | |
461 | EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); | |
3248877e DA |
462 | /* helper function to cleanup a GEM/prime object */ |
463 | void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) | |
464 | { | |
465 | struct dma_buf_attachment *attach; | |
466 | struct dma_buf *dma_buf; | |
467 | attach = obj->import_attach; | |
468 | if (sg) | |
469 | dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); | |
470 | dma_buf = attach->dmabuf; | |
471 | dma_buf_detach(attach->dmabuf, attach); | |
472 | /* remove the reference */ | |
473 | dma_buf_put(dma_buf); | |
474 | } | |
475 | EXPORT_SYMBOL(drm_prime_gem_destroy); | |
476 | ||
477 | void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) | |
478 | { | |
479 | INIT_LIST_HEAD(&prime_fpriv->head); | |
480 | mutex_init(&prime_fpriv->lock); | |
481 | } | |
482 | EXPORT_SYMBOL(drm_prime_init_file_private); | |
483 | ||
484 | void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) | |
485 | { | |
486 | struct drm_prime_member *member, *safe; | |
487 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { | |
488 | list_del(&member->entry); | |
489 | kfree(member); | |
490 | } | |
491 | } | |
492 | EXPORT_SYMBOL(drm_prime_destroy_file_private); | |
493 | ||
494 | int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle) | |
495 | { | |
496 | struct drm_prime_member *member; | |
497 | ||
498 | member = kmalloc(sizeof(*member), GFP_KERNEL); | |
499 | if (!member) | |
500 | return -ENOMEM; | |
501 | ||
502 | member->dma_buf = dma_buf; | |
503 | member->handle = handle; | |
504 | list_add(&member->entry, &prime_fpriv->head); | |
505 | return 0; | |
506 | } | |
507 | EXPORT_SYMBOL(drm_prime_add_imported_buf_handle); | |
508 | ||
509 | int drm_prime_lookup_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle) | |
510 | { | |
511 | struct drm_prime_member *member; | |
512 | ||
513 | list_for_each_entry(member, &prime_fpriv->head, entry) { | |
514 | if (member->dma_buf == dma_buf) { | |
515 | *handle = member->handle; | |
516 | return 0; | |
517 | } | |
518 | } | |
519 | return -ENOENT; | |
520 | } | |
521 | EXPORT_SYMBOL(drm_prime_lookup_imported_buf_handle); | |
522 | ||
523 | void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) | |
524 | { | |
525 | struct drm_prime_member *member, *safe; | |
526 | ||
527 | mutex_lock(&prime_fpriv->lock); | |
528 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { | |
529 | if (member->dma_buf == dma_buf) { | |
530 | list_del(&member->entry); | |
531 | kfree(member); | |
532 | } | |
533 | } | |
534 | mutex_unlock(&prime_fpriv->lock); | |
535 | } | |
536 | EXPORT_SYMBOL(drm_prime_remove_imported_buf_handle); |