Commit | Line | Data |
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b9d47450 SH |
1 | /* |
2 | * drm gem CMA (contiguous memory allocator) helper functions | |
3 | * | |
4 | * Copyright (C) 2012 Sascha Hauer, Pengutronix | |
5 | * | |
6 | * Based on Samsung Exynos code | |
7 | * | |
8 | * Copyright (c) 2011 Samsung Electronics Co., Ltd. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version 2 | |
13 | * of the License, or (at your option) any later version. | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/mm.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/export.h> | |
71d7282a | 24 | #include <linux/dma-buf.h> |
b9d47450 SH |
25 | #include <linux/dma-mapping.h> |
26 | ||
27 | #include <drm/drmP.h> | |
28 | #include <drm/drm.h> | |
29 | #include <drm/drm_gem_cma_helper.h> | |
30 | ||
31 | static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj) | |
32 | { | |
33 | return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT; | |
34 | } | |
35 | ||
b9d47450 | 36 | /* |
a5ed8940 LP |
37 | * __drm_gem_cma_create - Create a GEM CMA object without allocating memory |
38 | * @drm: The drm device | |
39 | * @size: The GEM object size | |
b9d47450 | 40 | * |
a5ed8940 LP |
41 | * This function creates and initializes a GEM CMA object of the given size, but |
42 | * doesn't allocate any memory to back the object. | |
43 | * | |
44 | * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure. | |
b9d47450 | 45 | */ |
a5ed8940 LP |
46 | static struct drm_gem_cma_object * |
47 | __drm_gem_cma_create(struct drm_device *drm, unsigned int size) | |
b9d47450 SH |
48 | { |
49 | struct drm_gem_cma_object *cma_obj; | |
50 | struct drm_gem_object *gem_obj; | |
51 | int ret; | |
52 | ||
b9d47450 SH |
53 | cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); |
54 | if (!cma_obj) | |
55 | return ERR_PTR(-ENOMEM); | |
56 | ||
b9d47450 SH |
57 | gem_obj = &cma_obj->base; |
58 | ||
59 | ret = drm_gem_object_init(drm, gem_obj, size); | |
60 | if (ret) | |
a5ed8940 | 61 | goto error; |
b9d47450 SH |
62 | |
63 | ret = drm_gem_create_mmap_offset(gem_obj); | |
a5ed8940 LP |
64 | if (ret) { |
65 | drm_gem_object_release(gem_obj); | |
66 | goto error; | |
67 | } | |
b9d47450 SH |
68 | |
69 | return cma_obj; | |
70 | ||
a5ed8940 LP |
71 | error: |
72 | kfree(cma_obj); | |
73 | return ERR_PTR(ret); | |
74 | } | |
b9d47450 | 75 | |
a5ed8940 LP |
76 | /* |
77 | * drm_gem_cma_create - allocate an object with the given size | |
78 | * | |
79 | * returns a struct drm_gem_cma_object* on success or ERR_PTR values | |
80 | * on failure. | |
81 | */ | |
82 | struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, | |
83 | unsigned int size) | |
84 | { | |
85 | struct drm_gem_cma_object *cma_obj; | |
71d7282a LP |
86 | struct sg_table *sgt = NULL; |
87 | int ret; | |
b9d47450 | 88 | |
a5ed8940 | 89 | size = round_up(size, PAGE_SIZE); |
b9d47450 | 90 | |
a5ed8940 LP |
91 | cma_obj = __drm_gem_cma_create(drm, size); |
92 | if (IS_ERR(cma_obj)) | |
93 | return cma_obj; | |
94 | ||
95 | cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size, | |
96 | &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN); | |
97 | if (!cma_obj->vaddr) { | |
98 | dev_err(drm->dev, "failed to allocate buffer with size %d\n", | |
99 | size); | |
71d7282a LP |
100 | ret = -ENOMEM; |
101 | goto error; | |
102 | } | |
103 | ||
104 | sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL); | |
105 | if (sgt == NULL) { | |
106 | ret = -ENOMEM; | |
107 | goto error; | |
a5ed8940 LP |
108 | } |
109 | ||
71d7282a LP |
110 | ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr, |
111 | cma_obj->paddr, size); | |
112 | if (ret < 0) | |
113 | goto error; | |
114 | ||
115 | cma_obj->sgt = sgt; | |
116 | ||
a5ed8940 | 117 | return cma_obj; |
71d7282a LP |
118 | |
119 | error: | |
120 | kfree(sgt); | |
121 | drm_gem_cma_free_object(&cma_obj->base); | |
122 | return ERR_PTR(ret); | |
b9d47450 SH |
123 | } |
124 | EXPORT_SYMBOL_GPL(drm_gem_cma_create); | |
125 | ||
126 | /* | |
127 | * drm_gem_cma_create_with_handle - allocate an object with the given | |
128 | * size and create a gem handle on it | |
129 | * | |
130 | * returns a struct drm_gem_cma_object* on success or ERR_PTR values | |
131 | * on failure. | |
132 | */ | |
133 | static struct drm_gem_cma_object *drm_gem_cma_create_with_handle( | |
134 | struct drm_file *file_priv, | |
135 | struct drm_device *drm, unsigned int size, | |
136 | unsigned int *handle) | |
137 | { | |
138 | struct drm_gem_cma_object *cma_obj; | |
139 | struct drm_gem_object *gem_obj; | |
140 | int ret; | |
141 | ||
142 | cma_obj = drm_gem_cma_create(drm, size); | |
143 | if (IS_ERR(cma_obj)) | |
144 | return cma_obj; | |
145 | ||
146 | gem_obj = &cma_obj->base; | |
147 | ||
148 | /* | |
149 | * allocate a id of idr table where the obj is registered | |
150 | * and handle has the id what user can see. | |
151 | */ | |
152 | ret = drm_gem_handle_create(file_priv, gem_obj, handle); | |
153 | if (ret) | |
154 | goto err_handle_create; | |
155 | ||
156 | /* drop reference from allocate - handle holds it now. */ | |
157 | drm_gem_object_unreference_unlocked(gem_obj); | |
158 | ||
159 | return cma_obj; | |
160 | ||
161 | err_handle_create: | |
162 | drm_gem_cma_free_object(gem_obj); | |
163 | ||
164 | return ERR_PTR(ret); | |
165 | } | |
166 | ||
167 | /* | |
168 | * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback | |
169 | * function | |
170 | */ | |
171 | void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) | |
172 | { | |
173 | struct drm_gem_cma_object *cma_obj; | |
174 | ||
175 | if (gem_obj->map_list.map) | |
176 | drm_gem_free_mmap_offset(gem_obj); | |
177 | ||
b9d47450 SH |
178 | cma_obj = to_drm_gem_cma_obj(gem_obj); |
179 | ||
71d7282a | 180 | if (cma_obj->vaddr) { |
a5ed8940 LP |
181 | dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size, |
182 | cma_obj->vaddr, cma_obj->paddr); | |
71d7282a LP |
183 | if (cma_obj->sgt) { |
184 | sg_free_table(cma_obj->sgt); | |
185 | kfree(cma_obj->sgt); | |
186 | } | |
187 | } else if (gem_obj->import_attach) { | |
188 | drm_prime_gem_destroy(gem_obj, cma_obj->sgt); | |
189 | } | |
a5ed8940 LP |
190 | |
191 | drm_gem_object_release(gem_obj); | |
b9d47450 SH |
192 | |
193 | kfree(cma_obj); | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); | |
196 | ||
197 | /* | |
198 | * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback | |
199 | * function | |
200 | * | |
201 | * This aligns the pitch and size arguments to the minimum required. wrap | |
202 | * this into your own function if you need bigger alignment. | |
203 | */ | |
204 | int drm_gem_cma_dumb_create(struct drm_file *file_priv, | |
205 | struct drm_device *dev, struct drm_mode_create_dumb *args) | |
206 | { | |
207 | struct drm_gem_cma_object *cma_obj; | |
208 | int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); | |
209 | ||
210 | if (args->pitch < min_pitch) | |
211 | args->pitch = min_pitch; | |
212 | ||
213 | if (args->size < args->pitch * args->height) | |
214 | args->size = args->pitch * args->height; | |
215 | ||
216 | cma_obj = drm_gem_cma_create_with_handle(file_priv, dev, | |
217 | args->size, &args->handle); | |
f6fb754d | 218 | return PTR_RET(cma_obj); |
b9d47450 SH |
219 | } |
220 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); | |
221 | ||
222 | /* | |
223 | * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback | |
224 | * function | |
225 | */ | |
226 | int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, | |
227 | struct drm_device *drm, uint32_t handle, uint64_t *offset) | |
228 | { | |
229 | struct drm_gem_object *gem_obj; | |
230 | ||
231 | mutex_lock(&drm->struct_mutex); | |
232 | ||
233 | gem_obj = drm_gem_object_lookup(drm, file_priv, handle); | |
234 | if (!gem_obj) { | |
235 | dev_err(drm->dev, "failed to lookup gem object\n"); | |
236 | mutex_unlock(&drm->struct_mutex); | |
237 | return -EINVAL; | |
238 | } | |
239 | ||
240 | *offset = get_gem_mmap_offset(gem_obj); | |
241 | ||
242 | drm_gem_object_unreference(gem_obj); | |
243 | ||
244 | mutex_unlock(&drm->struct_mutex); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset); | |
249 | ||
250 | const struct vm_operations_struct drm_gem_cma_vm_ops = { | |
251 | .open = drm_gem_vm_open, | |
252 | .close = drm_gem_vm_close, | |
253 | }; | |
254 | EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops); | |
255 | ||
ebaf9e03 LP |
256 | static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj, |
257 | struct vm_area_struct *vma) | |
258 | { | |
259 | int ret; | |
260 | ||
261 | ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT, | |
262 | vma->vm_end - vma->vm_start, vma->vm_page_prot); | |
263 | if (ret) | |
264 | drm_gem_vm_close(vma); | |
265 | ||
266 | return ret; | |
267 | } | |
268 | ||
b9d47450 SH |
269 | /* |
270 | * drm_gem_cma_mmap - (struct file_operation)->mmap callback function | |
271 | */ | |
272 | int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) | |
273 | { | |
b9d47450 | 274 | struct drm_gem_cma_object *cma_obj; |
ebaf9e03 | 275 | struct drm_gem_object *gem_obj; |
b9d47450 SH |
276 | int ret; |
277 | ||
278 | ret = drm_gem_mmap(filp, vma); | |
279 | if (ret) | |
280 | return ret; | |
281 | ||
282 | gem_obj = vma->vm_private_data; | |
283 | cma_obj = to_drm_gem_cma_obj(gem_obj); | |
284 | ||
ebaf9e03 | 285 | return drm_gem_cma_mmap_obj(cma_obj, vma); |
b9d47450 SH |
286 | } |
287 | EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); | |
288 | ||
289 | /* | |
290 | * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function | |
291 | */ | |
292 | int drm_gem_cma_dumb_destroy(struct drm_file *file_priv, | |
293 | struct drm_device *drm, unsigned int handle) | |
294 | { | |
295 | return drm_gem_handle_delete(file_priv, handle); | |
296 | } | |
297 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy); | |
6f646095 RC |
298 | |
299 | #ifdef CONFIG_DEBUG_FS | |
300 | void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m) | |
301 | { | |
302 | struct drm_gem_object *obj = &cma_obj->base; | |
303 | struct drm_device *dev = obj->dev; | |
304 | uint64_t off = 0; | |
305 | ||
306 | WARN_ON(!mutex_is_locked(&dev->struct_mutex)); | |
307 | ||
308 | if (obj->map_list.map) | |
309 | off = (uint64_t)obj->map_list.hash.key; | |
310 | ||
311 | seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d", | |
312 | obj->name, obj->refcount.refcount.counter, | |
313 | off, cma_obj->paddr, cma_obj->vaddr, obj->size); | |
314 | ||
315 | seq_printf(m, "\n"); | |
316 | } | |
317 | EXPORT_SYMBOL_GPL(drm_gem_cma_describe); | |
318 | #endif | |
71d7282a LP |
319 | |
320 | /* ----------------------------------------------------------------------------- | |
321 | * DMA-BUF | |
322 | */ | |
323 | ||
324 | struct drm_gem_cma_dmabuf_attachment { | |
325 | struct sg_table sgt; | |
326 | enum dma_data_direction dir; | |
327 | }; | |
328 | ||
329 | static int drm_gem_cma_dmabuf_attach(struct dma_buf *dmabuf, struct device *dev, | |
330 | struct dma_buf_attachment *attach) | |
331 | { | |
332 | struct drm_gem_cma_dmabuf_attachment *cma_attach; | |
333 | ||
334 | cma_attach = kzalloc(sizeof(*cma_attach), GFP_KERNEL); | |
335 | if (!cma_attach) | |
336 | return -ENOMEM; | |
337 | ||
338 | cma_attach->dir = DMA_NONE; | |
339 | attach->priv = cma_attach; | |
340 | ||
341 | return 0; | |
342 | } | |
343 | ||
344 | static void drm_gem_cma_dmabuf_detach(struct dma_buf *dmabuf, | |
345 | struct dma_buf_attachment *attach) | |
346 | { | |
347 | struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv; | |
348 | struct sg_table *sgt; | |
349 | ||
350 | if (cma_attach == NULL) | |
351 | return; | |
352 | ||
353 | sgt = &cma_attach->sgt; | |
354 | ||
355 | if (cma_attach->dir != DMA_NONE) | |
356 | dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, | |
357 | cma_attach->dir); | |
358 | ||
359 | sg_free_table(sgt); | |
360 | kfree(cma_attach); | |
361 | attach->priv = NULL; | |
362 | } | |
363 | ||
364 | static struct sg_table * | |
365 | drm_gem_cma_dmabuf_map(struct dma_buf_attachment *attach, | |
366 | enum dma_data_direction dir) | |
367 | { | |
368 | struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv; | |
369 | struct drm_gem_cma_object *cma_obj = attach->dmabuf->priv; | |
370 | struct drm_device *drm = cma_obj->base.dev; | |
371 | struct scatterlist *rd, *wr; | |
372 | struct sg_table *sgt; | |
373 | unsigned int i; | |
374 | int nents, ret; | |
375 | ||
376 | DRM_DEBUG_PRIME("\n"); | |
377 | ||
378 | if (WARN_ON(dir == DMA_NONE)) | |
379 | return ERR_PTR(-EINVAL); | |
380 | ||
381 | /* Return the cached mapping when possible. */ | |
382 | if (cma_attach->dir == dir) | |
383 | return &cma_attach->sgt; | |
384 | ||
385 | /* Two mappings with different directions for the same attachment are | |
386 | * not allowed. | |
387 | */ | |
388 | if (WARN_ON(cma_attach->dir != DMA_NONE)) | |
389 | return ERR_PTR(-EBUSY); | |
390 | ||
391 | sgt = &cma_attach->sgt; | |
392 | ||
393 | ret = sg_alloc_table(sgt, cma_obj->sgt->orig_nents, GFP_KERNEL); | |
394 | if (ret) { | |
395 | DRM_ERROR("failed to alloc sgt.\n"); | |
396 | return ERR_PTR(-ENOMEM); | |
397 | } | |
398 | ||
399 | mutex_lock(&drm->struct_mutex); | |
400 | ||
401 | rd = cma_obj->sgt->sgl; | |
402 | wr = sgt->sgl; | |
403 | for (i = 0; i < sgt->orig_nents; ++i) { | |
404 | sg_set_page(wr, sg_page(rd), rd->length, rd->offset); | |
405 | rd = sg_next(rd); | |
406 | wr = sg_next(wr); | |
407 | } | |
408 | ||
409 | nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir); | |
410 | if (!nents) { | |
411 | DRM_ERROR("failed to map sgl with iommu.\n"); | |
412 | sg_free_table(sgt); | |
413 | sgt = ERR_PTR(-EIO); | |
414 | goto done; | |
415 | } | |
416 | ||
417 | cma_attach->dir = dir; | |
418 | attach->priv = cma_attach; | |
419 | ||
420 | DRM_DEBUG_PRIME("buffer size = %zu\n", cma_obj->base.size); | |
421 | ||
422 | done: | |
423 | mutex_unlock(&drm->struct_mutex); | |
424 | return sgt; | |
425 | } | |
426 | ||
427 | static void drm_gem_cma_dmabuf_unmap(struct dma_buf_attachment *attach, | |
428 | struct sg_table *sgt, | |
429 | enum dma_data_direction dir) | |
430 | { | |
431 | /* Nothing to do. */ | |
432 | } | |
433 | ||
434 | static void drm_gem_cma_dmabuf_release(struct dma_buf *dmabuf) | |
435 | { | |
436 | struct drm_gem_cma_object *cma_obj = dmabuf->priv; | |
437 | ||
438 | DRM_DEBUG_PRIME("%s\n", __FILE__); | |
439 | ||
440 | /* | |
441 | * drm_gem_cma_dmabuf_release() call means that file object's | |
442 | * f_count is 0 and it calls drm_gem_object_handle_unreference() | |
443 | * to drop the references that these values had been increased | |
444 | * at drm_prime_handle_to_fd() | |
445 | */ | |
446 | if (cma_obj->base.export_dma_buf == dmabuf) { | |
447 | cma_obj->base.export_dma_buf = NULL; | |
448 | ||
449 | /* | |
450 | * drop this gem object refcount to release allocated buffer | |
451 | * and resources. | |
452 | */ | |
453 | drm_gem_object_unreference_unlocked(&cma_obj->base); | |
454 | } | |
455 | } | |
456 | ||
457 | static void *drm_gem_cma_dmabuf_kmap_atomic(struct dma_buf *dmabuf, | |
458 | unsigned long page_num) | |
459 | { | |
460 | /* TODO */ | |
461 | ||
462 | return NULL; | |
463 | } | |
464 | ||
465 | static void drm_gem_cma_dmabuf_kunmap_atomic(struct dma_buf *dmabuf, | |
466 | unsigned long page_num, void *addr) | |
467 | { | |
468 | /* TODO */ | |
469 | } | |
470 | ||
471 | static void *drm_gem_cma_dmabuf_kmap(struct dma_buf *dmabuf, | |
472 | unsigned long page_num) | |
473 | { | |
474 | /* TODO */ | |
475 | ||
476 | return NULL; | |
477 | } | |
478 | ||
479 | static void drm_gem_cma_dmabuf_kunmap(struct dma_buf *dmabuf, | |
480 | unsigned long page_num, void *addr) | |
481 | { | |
482 | /* TODO */ | |
483 | } | |
484 | ||
485 | static int drm_gem_cma_dmabuf_mmap(struct dma_buf *dmabuf, | |
486 | struct vm_area_struct *vma) | |
487 | { | |
488 | struct drm_gem_cma_object *cma_obj = dmabuf->priv; | |
489 | struct drm_gem_object *gem_obj = &cma_obj->base; | |
4368dd84 | 490 | struct drm_device *dev = gem_obj->dev; |
71d7282a LP |
491 | int ret; |
492 | ||
4368dd84 | 493 | mutex_lock(&dev->struct_mutex); |
71d7282a | 494 | ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma); |
4368dd84 | 495 | mutex_unlock(&dev->struct_mutex); |
71d7282a LP |
496 | if (ret < 0) |
497 | return ret; | |
498 | ||
499 | return drm_gem_cma_mmap_obj(cma_obj, vma); | |
500 | } | |
501 | ||
502 | static void *drm_gem_cma_dmabuf_vmap(struct dma_buf *dmabuf) | |
503 | { | |
504 | struct drm_gem_cma_object *cma_obj = dmabuf->priv; | |
505 | ||
506 | return cma_obj->vaddr; | |
507 | } | |
508 | ||
509 | static struct dma_buf_ops drm_gem_cma_dmabuf_ops = { | |
510 | .attach = drm_gem_cma_dmabuf_attach, | |
511 | .detach = drm_gem_cma_dmabuf_detach, | |
512 | .map_dma_buf = drm_gem_cma_dmabuf_map, | |
513 | .unmap_dma_buf = drm_gem_cma_dmabuf_unmap, | |
514 | .kmap = drm_gem_cma_dmabuf_kmap, | |
515 | .kmap_atomic = drm_gem_cma_dmabuf_kmap_atomic, | |
516 | .kunmap = drm_gem_cma_dmabuf_kunmap, | |
517 | .kunmap_atomic = drm_gem_cma_dmabuf_kunmap_atomic, | |
518 | .mmap = drm_gem_cma_dmabuf_mmap, | |
519 | .vmap = drm_gem_cma_dmabuf_vmap, | |
520 | .release = drm_gem_cma_dmabuf_release, | |
521 | }; | |
522 | ||
523 | struct dma_buf *drm_gem_cma_dmabuf_export(struct drm_device *drm, | |
524 | struct drm_gem_object *obj, int flags) | |
525 | { | |
526 | struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); | |
527 | ||
528 | return dma_buf_export(cma_obj, &drm_gem_cma_dmabuf_ops, | |
529 | cma_obj->base.size, flags); | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_export); | |
532 | ||
533 | struct drm_gem_object *drm_gem_cma_dmabuf_import(struct drm_device *drm, | |
534 | struct dma_buf *dma_buf) | |
535 | { | |
536 | struct drm_gem_cma_object *cma_obj; | |
537 | struct dma_buf_attachment *attach; | |
538 | struct sg_table *sgt; | |
539 | int ret; | |
540 | ||
541 | DRM_DEBUG_PRIME("%s\n", __FILE__); | |
542 | ||
543 | /* is this one of own objects? */ | |
544 | if (dma_buf->ops == &drm_gem_cma_dmabuf_ops) { | |
545 | struct drm_gem_object *obj; | |
546 | ||
547 | cma_obj = dma_buf->priv; | |
548 | obj = &cma_obj->base; | |
549 | ||
550 | /* is it from our device? */ | |
551 | if (obj->dev == drm) { | |
552 | /* | |
553 | * Importing dmabuf exported from out own gem increases | |
554 | * refcount on gem itself instead of f_count of dmabuf. | |
555 | */ | |
556 | drm_gem_object_reference(obj); | |
557 | dma_buf_put(dma_buf); | |
558 | return obj; | |
559 | } | |
560 | } | |
561 | ||
562 | /* Create a CMA GEM buffer. */ | |
563 | cma_obj = __drm_gem_cma_create(drm, dma_buf->size); | |
564 | if (IS_ERR(cma_obj)) | |
565 | return ERR_PTR(PTR_ERR(cma_obj)); | |
566 | ||
567 | /* Attach to the buffer and map it. Make sure the mapping is contiguous | |
568 | * on the device memory bus, as that's all we support. | |
569 | */ | |
570 | attach = dma_buf_attach(dma_buf, drm->dev); | |
571 | if (IS_ERR(attach)) { | |
572 | ret = -EINVAL; | |
573 | goto error_gem_free; | |
574 | } | |
575 | ||
576 | sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); | |
577 | if (IS_ERR_OR_NULL(sgt)) { | |
578 | ret = sgt ? PTR_ERR(sgt) : -ENOMEM; | |
579 | goto error_buf_detach; | |
580 | } | |
581 | ||
582 | if (sgt->nents != 1) { | |
583 | ret = -EINVAL; | |
584 | goto error_buf_unmap; | |
585 | } | |
586 | ||
587 | cma_obj->base.import_attach = attach; | |
588 | cma_obj->paddr = sg_dma_address(sgt->sgl); | |
589 | cma_obj->sgt = sgt; | |
590 | ||
591 | DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr, | |
592 | dma_buf->size); | |
593 | ||
594 | return &cma_obj->base; | |
595 | ||
596 | error_buf_unmap: | |
597 | dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); | |
598 | error_buf_detach: | |
599 | dma_buf_detach(dma_buf, attach); | |
600 | error_gem_free: | |
601 | drm_gem_cma_free_object(&cma_obj->base); | |
602 | return ERR_PTR(ret); | |
603 | } | |
604 | EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_import); |