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2194a63a NT |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright 2018 Noralf Trønnes | |
4 | */ | |
5 | ||
6 | #include <linux/dma-buf.h> | |
7 | #include <linux/export.h> | |
8 | #include <linux/mutex.h> | |
9 | #include <linux/shmem_fs.h> | |
10 | #include <linux/slab.h> | |
11 | #include <linux/vmalloc.h> | |
12 | ||
13 | #include <drm/drm_device.h> | |
14 | #include <drm/drm_drv.h> | |
15 | #include <drm/drm_gem_shmem_helper.h> | |
16 | #include <drm/drm_prime.h> | |
17 | #include <drm/drm_print.h> | |
18 | ||
19 | /** | |
20 | * DOC: overview | |
21 | * | |
22 | * This library provides helpers for GEM objects backed by shmem buffers | |
23 | * allocated using anonymous pageable memory. | |
24 | */ | |
25 | ||
26 | static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { | |
27 | .free = drm_gem_shmem_free_object, | |
28 | .print_info = drm_gem_shmem_print_info, | |
29 | .pin = drm_gem_shmem_pin, | |
30 | .unpin = drm_gem_shmem_unpin, | |
31 | .get_sg_table = drm_gem_shmem_get_sg_table, | |
32 | .vmap = drm_gem_shmem_vmap, | |
33 | .vunmap = drm_gem_shmem_vunmap, | |
34 | .vm_ops = &drm_gem_shmem_vm_ops, | |
35 | }; | |
36 | ||
37 | /** | |
38 | * drm_gem_shmem_create - Allocate an object with the given size | |
39 | * @dev: DRM device | |
40 | * @size: Size of the object to allocate | |
41 | * | |
42 | * This function creates a shmem GEM object. | |
43 | * | |
44 | * Returns: | |
45 | * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative | |
46 | * error code on failure. | |
47 | */ | |
48 | struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size) | |
49 | { | |
50 | struct drm_gem_shmem_object *shmem; | |
51 | struct drm_gem_object *obj; | |
52 | int ret; | |
53 | ||
54 | size = PAGE_ALIGN(size); | |
55 | ||
56 | if (dev->driver->gem_create_object) | |
57 | obj = dev->driver->gem_create_object(dev, size); | |
58 | else | |
59 | obj = kzalloc(sizeof(*shmem), GFP_KERNEL); | |
60 | if (!obj) | |
61 | return ERR_PTR(-ENOMEM); | |
62 | ||
63 | if (!obj->funcs) | |
64 | obj->funcs = &drm_gem_shmem_funcs; | |
65 | ||
66 | ret = drm_gem_object_init(dev, obj, size); | |
67 | if (ret) | |
68 | goto err_free; | |
69 | ||
70 | ret = drm_gem_create_mmap_offset(obj); | |
71 | if (ret) | |
72 | goto err_release; | |
73 | ||
74 | shmem = to_drm_gem_shmem_obj(obj); | |
75 | mutex_init(&shmem->pages_lock); | |
76 | mutex_init(&shmem->vmap_lock); | |
77 | ||
78 | /* | |
79 | * Our buffers are kept pinned, so allocating them | |
80 | * from the MOVABLE zone is a really bad idea, and | |
81 | * conflicts with CMA. See comments above new_inode() | |
82 | * why this is required _and_ expected if you're | |
83 | * going to pin these pages. | |
84 | */ | |
85 | mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER | | |
86 | __GFP_RETRY_MAYFAIL | __GFP_NOWARN); | |
87 | ||
88 | return shmem; | |
89 | ||
90 | err_release: | |
91 | drm_gem_object_release(obj); | |
92 | err_free: | |
93 | kfree(obj); | |
94 | ||
95 | return ERR_PTR(ret); | |
96 | } | |
97 | EXPORT_SYMBOL_GPL(drm_gem_shmem_create); | |
98 | ||
99 | /** | |
100 | * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object | |
101 | * @obj: GEM object to free | |
102 | * | |
103 | * This function cleans up the GEM object state and frees the memory used to | |
104 | * store the object itself. | |
105 | */ | |
106 | void drm_gem_shmem_free_object(struct drm_gem_object *obj) | |
107 | { | |
108 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
109 | ||
110 | WARN_ON(shmem->vmap_use_count); | |
111 | ||
112 | if (obj->import_attach) { | |
113 | shmem->pages_use_count--; | |
114 | drm_prime_gem_destroy(obj, shmem->sgt); | |
115 | kvfree(shmem->pages); | |
116 | } else { | |
117 | if (shmem->sgt) { | |
118 | dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl, | |
119 | shmem->sgt->nents, DMA_BIDIRECTIONAL); | |
120 | ||
121 | drm_gem_shmem_put_pages(shmem); | |
122 | sg_free_table(shmem->sgt); | |
123 | kfree(shmem->sgt); | |
124 | } | |
125 | } | |
126 | ||
127 | WARN_ON(shmem->pages_use_count); | |
128 | ||
129 | drm_gem_object_release(obj); | |
130 | mutex_destroy(&shmem->pages_lock); | |
131 | mutex_destroy(&shmem->vmap_lock); | |
132 | kfree(shmem); | |
133 | } | |
134 | EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object); | |
135 | ||
136 | static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) | |
137 | { | |
138 | struct drm_gem_object *obj = &shmem->base; | |
139 | struct page **pages; | |
140 | ||
141 | if (shmem->pages_use_count++ > 0) | |
142 | return 0; | |
143 | ||
144 | pages = drm_gem_get_pages(obj); | |
145 | if (IS_ERR(pages)) { | |
146 | DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages)); | |
147 | shmem->pages_use_count = 0; | |
148 | return PTR_ERR(pages); | |
149 | } | |
150 | ||
151 | shmem->pages = pages; | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | /* | |
157 | * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object | |
158 | * @shmem: shmem GEM object | |
159 | * | |
160 | * This function makes sure that backing pages exists for the shmem GEM object | |
161 | * and increases the use count. | |
162 | * | |
163 | * Returns: | |
164 | * 0 on success or a negative error code on failure. | |
165 | */ | |
166 | int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) | |
167 | { | |
168 | int ret; | |
169 | ||
170 | ret = mutex_lock_interruptible(&shmem->pages_lock); | |
171 | if (ret) | |
172 | return ret; | |
173 | ret = drm_gem_shmem_get_pages_locked(shmem); | |
174 | mutex_unlock(&shmem->pages_lock); | |
175 | ||
176 | return ret; | |
177 | } | |
178 | EXPORT_SYMBOL(drm_gem_shmem_get_pages); | |
179 | ||
180 | static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) | |
181 | { | |
182 | struct drm_gem_object *obj = &shmem->base; | |
183 | ||
184 | if (WARN_ON_ONCE(!shmem->pages_use_count)) | |
185 | return; | |
186 | ||
187 | if (--shmem->pages_use_count > 0) | |
188 | return; | |
189 | ||
190 | drm_gem_put_pages(obj, shmem->pages, | |
191 | shmem->pages_mark_dirty_on_put, | |
192 | shmem->pages_mark_accessed_on_put); | |
193 | shmem->pages = NULL; | |
194 | } | |
195 | ||
196 | /* | |
197 | * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object | |
198 | * @shmem: shmem GEM object | |
199 | * | |
200 | * This function decreases the use count and puts the backing pages when use drops to zero. | |
201 | */ | |
202 | void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) | |
203 | { | |
204 | mutex_lock(&shmem->pages_lock); | |
205 | drm_gem_shmem_put_pages_locked(shmem); | |
206 | mutex_unlock(&shmem->pages_lock); | |
207 | } | |
208 | EXPORT_SYMBOL(drm_gem_shmem_put_pages); | |
209 | ||
210 | /** | |
211 | * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object | |
212 | * @obj: GEM object | |
213 | * | |
214 | * This function makes sure the backing pages are pinned in memory while the | |
215 | * buffer is exported. | |
216 | * | |
217 | * Returns: | |
218 | * 0 on success or a negative error code on failure. | |
219 | */ | |
220 | int drm_gem_shmem_pin(struct drm_gem_object *obj) | |
221 | { | |
222 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
223 | ||
224 | return drm_gem_shmem_get_pages(shmem); | |
225 | } | |
226 | EXPORT_SYMBOL(drm_gem_shmem_pin); | |
227 | ||
228 | /** | |
229 | * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object | |
230 | * @obj: GEM object | |
231 | * | |
232 | * This function removes the requirement that the backing pages are pinned in | |
233 | * memory. | |
234 | */ | |
235 | void drm_gem_shmem_unpin(struct drm_gem_object *obj) | |
236 | { | |
237 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
238 | ||
239 | drm_gem_shmem_put_pages(shmem); | |
240 | } | |
241 | EXPORT_SYMBOL(drm_gem_shmem_unpin); | |
242 | ||
243 | static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) | |
244 | { | |
245 | struct drm_gem_object *obj = &shmem->base; | |
246 | int ret; | |
247 | ||
248 | if (shmem->vmap_use_count++ > 0) | |
249 | return shmem->vaddr; | |
250 | ||
251 | ret = drm_gem_shmem_get_pages(shmem); | |
252 | if (ret) | |
253 | goto err_zero_use; | |
254 | ||
255 | if (obj->import_attach) | |
256 | shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); | |
257 | else | |
258 | shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL); | |
259 | ||
260 | if (!shmem->vaddr) { | |
261 | DRM_DEBUG_KMS("Failed to vmap pages\n"); | |
262 | ret = -ENOMEM; | |
263 | goto err_put_pages; | |
264 | } | |
265 | ||
266 | return shmem->vaddr; | |
267 | ||
268 | err_put_pages: | |
269 | drm_gem_shmem_put_pages(shmem); | |
270 | err_zero_use: | |
271 | shmem->vmap_use_count = 0; | |
272 | ||
273 | return ERR_PTR(ret); | |
274 | } | |
275 | ||
276 | /* | |
277 | * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object | |
278 | * @shmem: shmem GEM object | |
279 | * | |
280 | * This function makes sure that a virtual address exists for the buffer backing | |
281 | * the shmem GEM object. | |
282 | * | |
283 | * Returns: | |
284 | * 0 on success or a negative error code on failure. | |
285 | */ | |
286 | void *drm_gem_shmem_vmap(struct drm_gem_object *obj) | |
287 | { | |
288 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
289 | void *vaddr; | |
290 | int ret; | |
291 | ||
292 | ret = mutex_lock_interruptible(&shmem->vmap_lock); | |
293 | if (ret) | |
294 | return ERR_PTR(ret); | |
295 | vaddr = drm_gem_shmem_vmap_locked(shmem); | |
296 | mutex_unlock(&shmem->vmap_lock); | |
297 | ||
298 | return vaddr; | |
299 | } | |
300 | EXPORT_SYMBOL(drm_gem_shmem_vmap); | |
301 | ||
302 | static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem) | |
303 | { | |
304 | struct drm_gem_object *obj = &shmem->base; | |
305 | ||
306 | if (WARN_ON_ONCE(!shmem->vmap_use_count)) | |
307 | return; | |
308 | ||
309 | if (--shmem->vmap_use_count > 0) | |
310 | return; | |
311 | ||
312 | if (obj->import_attach) | |
313 | dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr); | |
314 | else | |
315 | vunmap(shmem->vaddr); | |
316 | ||
317 | shmem->vaddr = NULL; | |
318 | drm_gem_shmem_put_pages(shmem); | |
319 | } | |
320 | ||
321 | /* | |
322 | * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object | |
323 | * @shmem: shmem GEM object | |
324 | * | |
325 | * This function removes the virtual address when use count drops to zero. | |
326 | */ | |
327 | void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr) | |
328 | { | |
329 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
330 | ||
331 | mutex_lock(&shmem->vmap_lock); | |
332 | drm_gem_shmem_vunmap_locked(shmem); | |
333 | mutex_unlock(&shmem->vmap_lock); | |
334 | } | |
335 | EXPORT_SYMBOL(drm_gem_shmem_vunmap); | |
336 | ||
337 | struct drm_gem_shmem_object * | |
338 | drm_gem_shmem_create_with_handle(struct drm_file *file_priv, | |
339 | struct drm_device *dev, size_t size, | |
340 | uint32_t *handle) | |
341 | { | |
342 | struct drm_gem_shmem_object *shmem; | |
343 | int ret; | |
344 | ||
345 | shmem = drm_gem_shmem_create(dev, size); | |
346 | if (IS_ERR(shmem)) | |
347 | return shmem; | |
348 | ||
349 | /* | |
350 | * Allocate an id of idr table where the obj is registered | |
351 | * and handle has the id what user can see. | |
352 | */ | |
353 | ret = drm_gem_handle_create(file_priv, &shmem->base, handle); | |
354 | /* drop reference from allocate - handle holds it now. */ | |
355 | drm_gem_object_put_unlocked(&shmem->base); | |
356 | if (ret) | |
357 | return ERR_PTR(ret); | |
358 | ||
359 | return shmem; | |
360 | } | |
361 | EXPORT_SYMBOL(drm_gem_shmem_create_with_handle); | |
362 | ||
363 | /** | |
364 | * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object | |
365 | * @file: DRM file structure to create the dumb buffer for | |
366 | * @dev: DRM device | |
367 | * @args: IOCTL data | |
368 | * | |
369 | * This function computes the pitch of the dumb buffer and rounds it up to an | |
370 | * integer number of bytes per pixel. Drivers for hardware that doesn't have | |
371 | * any additional restrictions on the pitch can directly use this function as | |
372 | * their &drm_driver.dumb_create callback. | |
373 | * | |
374 | * For hardware with additional restrictions, drivers can adjust the fields | |
375 | * set up by userspace before calling into this function. | |
376 | * | |
377 | * Returns: | |
378 | * 0 on success or a negative error code on failure. | |
379 | */ | |
380 | int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, | |
381 | struct drm_mode_create_dumb *args) | |
382 | { | |
383 | u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); | |
384 | struct drm_gem_shmem_object *shmem; | |
385 | ||
386 | if (!args->pitch || !args->size) { | |
387 | args->pitch = min_pitch; | |
388 | args->size = args->pitch * args->height; | |
389 | } else { | |
390 | /* ensure sane minimum values */ | |
391 | if (args->pitch < min_pitch) | |
392 | args->pitch = min_pitch; | |
393 | if (args->size < args->pitch * args->height) | |
394 | args->size = args->pitch * args->height; | |
395 | } | |
396 | ||
397 | shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle); | |
398 | ||
399 | return PTR_ERR_OR_ZERO(shmem); | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); | |
402 | ||
403 | static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) | |
404 | { | |
405 | struct vm_area_struct *vma = vmf->vma; | |
406 | struct drm_gem_object *obj = vma->vm_private_data; | |
407 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
408 | loff_t num_pages = obj->size >> PAGE_SHIFT; | |
409 | struct page *page; | |
410 | ||
411 | if (vmf->pgoff > num_pages || WARN_ON_ONCE(!shmem->pages)) | |
412 | return VM_FAULT_SIGBUS; | |
413 | ||
414 | page = shmem->pages[vmf->pgoff]; | |
415 | ||
416 | return vmf_insert_page(vma, vmf->address, page); | |
417 | } | |
418 | ||
419 | static void drm_gem_shmem_vm_open(struct vm_area_struct *vma) | |
420 | { | |
421 | struct drm_gem_object *obj = vma->vm_private_data; | |
422 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
423 | int ret; | |
424 | ||
425 | ret = drm_gem_shmem_get_pages(shmem); | |
426 | WARN_ON_ONCE(ret != 0); | |
427 | ||
428 | drm_gem_vm_open(vma); | |
429 | } | |
430 | ||
431 | static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) | |
432 | { | |
433 | struct drm_gem_object *obj = vma->vm_private_data; | |
434 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
435 | ||
436 | drm_gem_shmem_put_pages(shmem); | |
437 | drm_gem_vm_close(vma); | |
438 | } | |
439 | ||
440 | const struct vm_operations_struct drm_gem_shmem_vm_ops = { | |
441 | .fault = drm_gem_shmem_fault, | |
442 | .open = drm_gem_shmem_vm_open, | |
443 | .close = drm_gem_shmem_vm_close, | |
444 | }; | |
445 | EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops); | |
446 | ||
447 | /** | |
448 | * drm_gem_shmem_mmap - Memory-map a shmem GEM object | |
449 | * @filp: File object | |
450 | * @vma: VMA for the area to be mapped | |
451 | * | |
452 | * This function implements an augmented version of the GEM DRM file mmap | |
453 | * operation for shmem objects. Drivers which employ the shmem helpers should | |
454 | * use this function as their &file_operations.mmap handler in the DRM device file's | |
455 | * file_operations structure. | |
456 | * | |
457 | * Instead of directly referencing this function, drivers should use the | |
458 | * DEFINE_DRM_GEM_SHMEM_FOPS() macro. | |
459 | * | |
460 | * Returns: | |
461 | * 0 on success or a negative error code on failure. | |
462 | */ | |
463 | int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma) | |
464 | { | |
465 | struct drm_gem_shmem_object *shmem; | |
466 | int ret; | |
467 | ||
468 | ret = drm_gem_mmap(filp, vma); | |
469 | if (ret) | |
470 | return ret; | |
471 | ||
472 | shmem = to_drm_gem_shmem_obj(vma->vm_private_data); | |
473 | ||
474 | ret = drm_gem_shmem_get_pages(shmem); | |
475 | if (ret) { | |
476 | drm_gem_vm_close(vma); | |
477 | return ret; | |
478 | } | |
479 | ||
480 | /* VM_PFNMAP was set by drm_gem_mmap() */ | |
481 | vma->vm_flags &= ~VM_PFNMAP; | |
482 | vma->vm_flags |= VM_MIXEDMAP; | |
483 | ||
484 | /* Remove the fake offset */ | |
485 | vma->vm_pgoff -= drm_vma_node_start(&shmem->base.vma_node); | |
486 | ||
487 | return 0; | |
488 | } | |
489 | EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap); | |
490 | ||
491 | /** | |
492 | * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs | |
493 | * @p: DRM printer | |
494 | * @indent: Tab indentation level | |
495 | * @obj: GEM object | |
496 | */ | |
497 | void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, | |
498 | const struct drm_gem_object *obj) | |
499 | { | |
500 | const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
501 | ||
502 | drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); | |
503 | drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); | |
504 | drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); | |
505 | } | |
506 | EXPORT_SYMBOL(drm_gem_shmem_print_info); | |
507 | ||
508 | /** | |
509 | * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned | |
510 | * pages for a shmem GEM object | |
511 | * @obj: GEM object | |
512 | * | |
513 | * This function exports a scatter/gather table suitable for PRIME usage by | |
514 | * calling the standard DMA mapping API. | |
515 | * | |
516 | * Returns: | |
517 | * A pointer to the scatter/gather table of pinned pages or NULL on failure. | |
518 | */ | |
519 | struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj) | |
520 | { | |
521 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
522 | ||
523 | return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT); | |
524 | } | |
525 | EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table); | |
526 | ||
527 | /** | |
528 | * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a | |
529 | * scatter/gather table for a shmem GEM object. | |
530 | * @obj: GEM object | |
531 | * | |
532 | * This function returns a scatter/gather table suitable for driver usage. If | |
533 | * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg | |
534 | * table created. | |
535 | * | |
536 | * Returns: | |
537 | * A pointer to the scatter/gather table of pinned pages or errno on failure. | |
538 | */ | |
539 | struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj) | |
540 | { | |
541 | int ret; | |
542 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); | |
543 | struct sg_table *sgt; | |
544 | ||
545 | if (shmem->sgt) | |
546 | return shmem->sgt; | |
547 | ||
548 | WARN_ON(obj->import_attach); | |
549 | ||
550 | ret = drm_gem_shmem_get_pages(shmem); | |
551 | if (ret) | |
552 | return ERR_PTR(ret); | |
553 | ||
554 | sgt = drm_gem_shmem_get_sg_table(&shmem->base); | |
555 | if (IS_ERR(sgt)) { | |
556 | ret = PTR_ERR(sgt); | |
557 | goto err_put_pages; | |
558 | } | |
559 | /* Map the pages for use by the h/w. */ | |
560 | dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL); | |
561 | ||
562 | shmem->sgt = sgt; | |
563 | ||
564 | return sgt; | |
565 | ||
566 | err_put_pages: | |
567 | drm_gem_shmem_put_pages(shmem); | |
568 | return ERR_PTR(ret); | |
569 | } | |
570 | EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt); | |
571 | ||
572 | /** | |
573 | * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from | |
574 | * another driver's scatter/gather table of pinned pages | |
575 | * @dev: Device to import into | |
576 | * @attach: DMA-BUF attachment | |
577 | * @sgt: Scatter/gather table of pinned pages | |
578 | * | |
579 | * This function imports a scatter/gather table exported via DMA-BUF by | |
580 | * another driver. Drivers that use the shmem helpers should set this as their | |
581 | * &drm_driver.gem_prime_import_sg_table callback. | |
582 | * | |
583 | * Returns: | |
584 | * A pointer to a newly created GEM object or an ERR_PTR-encoded negative | |
585 | * error code on failure. | |
586 | */ | |
587 | struct drm_gem_object * | |
588 | drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, | |
589 | struct dma_buf_attachment *attach, | |
590 | struct sg_table *sgt) | |
591 | { | |
592 | size_t size = PAGE_ALIGN(attach->dmabuf->size); | |
593 | size_t npages = size >> PAGE_SHIFT; | |
594 | struct drm_gem_shmem_object *shmem; | |
595 | int ret; | |
596 | ||
597 | shmem = drm_gem_shmem_create(dev, size); | |
598 | if (IS_ERR(shmem)) | |
599 | return ERR_CAST(shmem); | |
600 | ||
601 | shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); | |
602 | if (!shmem->pages) { | |
603 | ret = -ENOMEM; | |
604 | goto err_free_gem; | |
605 | } | |
606 | ||
607 | ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages); | |
608 | if (ret < 0) | |
609 | goto err_free_array; | |
610 | ||
611 | shmem->sgt = sgt; | |
612 | shmem->pages_use_count = 1; /* Permanently pinned from our point of view */ | |
613 | ||
614 | DRM_DEBUG_PRIME("size = %zu\n", size); | |
615 | ||
616 | return &shmem->base; | |
617 | ||
618 | err_free_array: | |
619 | kvfree(shmem->pages); | |
620 | err_free_gem: | |
621 | drm_gem_object_put_unlocked(&shmem->base); | |
622 | ||
623 | return ERR_PTR(ret); | |
624 | } | |
625 | EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table); |