1 /*
2 * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
6 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation.
11 */
12
13 #include <linux/module.h>
14 #include <linux/mm.h>
15 #include <linux/scatterlist.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/vmalloc.h>
19
20 #include <media/videobuf2-v4l2.h>
21 #include <media/videobuf2-memops.h>
22 #include <media/videobuf2-dma-sg.h>
23
24 static int debug;
25 module_param(debug, int, 0644);
26
27 #define dprintk(level, fmt, arg...) \
28 do { \
29 if (debug >= level) \
30 printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \
31 } while (0)
32
33 struct vb2_dma_sg_conf {
34 struct device *dev;
35 };
36
37 struct vb2_dma_sg_buf {
38 struct device *dev;
39 void *vaddr;
40 struct page **pages;
41 struct frame_vector *vec;
42 int offset;
43 enum dma_data_direction dma_dir;
44 struct sg_table sg_table;
45 /*
46 * This will point to sg_table when used with the MMAP or USERPTR
47 * memory model, and to the dma_buf sglist when used with the
48 * DMABUF memory model.
49 */
50 struct sg_table *dma_sgt;
51 size_t size;
52 unsigned int num_pages;
53 atomic_t refcount;
54 struct vb2_vmarea_handler handler;
55
56 struct dma_buf_attachment *db_attach;
57 };
58
59 static void vb2_dma_sg_put(void *buf_priv);
60
vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf * buf,gfp_t gfp_flags)61 static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
62 gfp_t gfp_flags)
63 {
64 unsigned int last_page = 0;
65 int size = buf->size;
66
67 while (size > 0) {
68 struct page *pages;
69 int order;
70 int i;
71
72 order = get_order(size);
73 /* Dont over allocate*/
74 if ((PAGE_SIZE << order) > size)
75 order--;
76
77 pages = NULL;
78 while (!pages) {
79 pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
80 __GFP_NOWARN | gfp_flags, order);
81 if (pages)
82 break;
83
84 if (order == 0) {
85 while (last_page--)
86 __free_page(buf->pages[last_page]);
87 return -ENOMEM;
88 }
89 order--;
90 }
91
92 split_page(pages, order);
93 for (i = 0; i < (1 << order); i++)
94 buf->pages[last_page++] = &pages[i];
95
96 size -= PAGE_SIZE << order;
97 }
98
99 return 0;
100 }
101
vb2_dma_sg_alloc(void * alloc_ctx,unsigned long size,enum dma_data_direction dma_dir,gfp_t gfp_flags)102 static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
103 enum dma_data_direction dma_dir, gfp_t gfp_flags)
104 {
105 struct vb2_dma_sg_conf *conf = alloc_ctx;
106 struct vb2_dma_sg_buf *buf;
107 struct sg_table *sgt;
108 int ret;
109 int num_pages;
110 DEFINE_DMA_ATTRS(attrs);
111
112 dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
113
114 if (WARN_ON(alloc_ctx == NULL))
115 return NULL;
116 buf = kzalloc(sizeof *buf, GFP_KERNEL);
117 if (!buf)
118 return NULL;
119
120 buf->vaddr = NULL;
121 buf->dma_dir = dma_dir;
122 buf->offset = 0;
123 buf->size = size;
124 /* size is already page aligned */
125 buf->num_pages = size >> PAGE_SHIFT;
126 buf->dma_sgt = &buf->sg_table;
127
128 buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
129 GFP_KERNEL);
130 if (!buf->pages)
131 goto fail_pages_array_alloc;
132
133 ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
134 if (ret)
135 goto fail_pages_alloc;
136
137 ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
138 buf->num_pages, 0, size, GFP_KERNEL);
139 if (ret)
140 goto fail_table_alloc;
141
142 /* Prevent the device from being released while the buffer is used */
143 buf->dev = get_device(conf->dev);
144
145 sgt = &buf->sg_table;
146 /*
147 * No need to sync to the device, this will happen later when the
148 * prepare() memop is called.
149 */
150 sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
151 buf->dma_dir, &attrs);
152 if (!sgt->nents)
153 goto fail_map;
154
155 buf->handler.refcount = &buf->refcount;
156 buf->handler.put = vb2_dma_sg_put;
157 buf->handler.arg = buf;
158
159 atomic_inc(&buf->refcount);
160
161 dprintk(1, "%s: Allocated buffer of %d pages\n",
162 __func__, buf->num_pages);
163 return buf;
164
165 fail_map:
166 put_device(buf->dev);
167 sg_free_table(buf->dma_sgt);
168 fail_table_alloc:
169 num_pages = buf->num_pages;
170 while (num_pages--)
171 __free_page(buf->pages[num_pages]);
172 fail_pages_alloc:
173 kfree(buf->pages);
174 fail_pages_array_alloc:
175 kfree(buf);
176 return NULL;
177 }
178
vb2_dma_sg_put(void * buf_priv)179 static void vb2_dma_sg_put(void *buf_priv)
180 {
181 struct vb2_dma_sg_buf *buf = buf_priv;
182 struct sg_table *sgt = &buf->sg_table;
183 int i = buf->num_pages;
184
185 if (atomic_dec_and_test(&buf->refcount)) {
186 DEFINE_DMA_ATTRS(attrs);
187
188 dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
189 dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
190 buf->num_pages);
191 dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
192 buf->dma_dir, &attrs);
193 if (buf->vaddr)
194 vm_unmap_ram(buf->vaddr, buf->num_pages);
195 sg_free_table(buf->dma_sgt);
196 while (--i >= 0)
197 __free_page(buf->pages[i]);
198 kfree(buf->pages);
199 put_device(buf->dev);
200 kfree(buf);
201 }
202 }
203
vb2_dma_sg_prepare(void * buf_priv)204 static void vb2_dma_sg_prepare(void *buf_priv)
205 {
206 struct vb2_dma_sg_buf *buf = buf_priv;
207 struct sg_table *sgt = buf->dma_sgt;
208
209 /* DMABUF exporter will flush the cache for us */
210 if (buf->db_attach)
211 return;
212
213 dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
214 buf->dma_dir);
215 }
216
vb2_dma_sg_finish(void * buf_priv)217 static void vb2_dma_sg_finish(void *buf_priv)
218 {
219 struct vb2_dma_sg_buf *buf = buf_priv;
220 struct sg_table *sgt = buf->dma_sgt;
221
222 /* DMABUF exporter will flush the cache for us */
223 if (buf->db_attach)
224 return;
225
226 dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
227 }
228
vb2_dma_sg_get_userptr(void * alloc_ctx,unsigned long vaddr,unsigned long size,enum dma_data_direction dma_dir)229 static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
230 unsigned long size,
231 enum dma_data_direction dma_dir)
232 {
233 struct vb2_dma_sg_conf *conf = alloc_ctx;
234 struct vb2_dma_sg_buf *buf;
235 struct sg_table *sgt;
236 DEFINE_DMA_ATTRS(attrs);
237 struct frame_vector *vec;
238
239 dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
240 buf = kzalloc(sizeof *buf, GFP_KERNEL);
241 if (!buf)
242 return NULL;
243
244 buf->vaddr = NULL;
245 buf->dev = conf->dev;
246 buf->dma_dir = dma_dir;
247 buf->offset = vaddr & ~PAGE_MASK;
248 buf->size = size;
249 buf->dma_sgt = &buf->sg_table;
250 vec = vb2_create_framevec(vaddr, size, buf->dma_dir == DMA_FROM_DEVICE);
251 if (IS_ERR(vec))
252 goto userptr_fail_pfnvec;
253 buf->vec = vec;
254
255 buf->pages = frame_vector_pages(vec);
256 if (IS_ERR(buf->pages))
257 goto userptr_fail_sgtable;
258 buf->num_pages = frame_vector_count(vec);
259
260 if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
261 buf->num_pages, buf->offset, size, 0))
262 goto userptr_fail_sgtable;
263
264 sgt = &buf->sg_table;
265 /*
266 * No need to sync to the device, this will happen later when the
267 * prepare() memop is called.
268 */
269 sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
270 buf->dma_dir, &attrs);
271 if (!sgt->nents)
272 goto userptr_fail_map;
273
274 return buf;
275
276 userptr_fail_map:
277 sg_free_table(&buf->sg_table);
278 userptr_fail_sgtable:
279 vb2_destroy_framevec(vec);
280 userptr_fail_pfnvec:
281 kfree(buf);
282 return NULL;
283 }
284
285 /*
286 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
287 * be used
288 */
vb2_dma_sg_put_userptr(void * buf_priv)289 static void vb2_dma_sg_put_userptr(void *buf_priv)
290 {
291 struct vb2_dma_sg_buf *buf = buf_priv;
292 struct sg_table *sgt = &buf->sg_table;
293 int i = buf->num_pages;
294 DEFINE_DMA_ATTRS(attrs);
295
296 dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
297
298 dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
299 __func__, buf->num_pages);
300 dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
301 &attrs);
302 if (buf->vaddr)
303 vm_unmap_ram(buf->vaddr, buf->num_pages);
304 sg_free_table(buf->dma_sgt);
305 while (--i >= 0) {
306 if (buf->dma_dir == DMA_FROM_DEVICE)
307 set_page_dirty_lock(buf->pages[i]);
308 }
309 vb2_destroy_framevec(buf->vec);
310 kfree(buf);
311 }
312
vb2_dma_sg_vaddr(void * buf_priv)313 static void *vb2_dma_sg_vaddr(void *buf_priv)
314 {
315 struct vb2_dma_sg_buf *buf = buf_priv;
316
317 BUG_ON(!buf);
318
319 if (!buf->vaddr) {
320 if (buf->db_attach)
321 buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
322 else
323 buf->vaddr = vm_map_ram(buf->pages,
324 buf->num_pages, -1, PAGE_KERNEL);
325 }
326
327 /* add offset in case userptr is not page-aligned */
328 return buf->vaddr ? buf->vaddr + buf->offset : NULL;
329 }
330
vb2_dma_sg_num_users(void * buf_priv)331 static unsigned int vb2_dma_sg_num_users(void *buf_priv)
332 {
333 struct vb2_dma_sg_buf *buf = buf_priv;
334
335 return atomic_read(&buf->refcount);
336 }
337
vb2_dma_sg_mmap(void * buf_priv,struct vm_area_struct * vma)338 static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
339 {
340 struct vb2_dma_sg_buf *buf = buf_priv;
341 unsigned long uaddr = vma->vm_start;
342 unsigned long usize = vma->vm_end - vma->vm_start;
343 int i = 0;
344
345 if (!buf) {
346 printk(KERN_ERR "No memory to map\n");
347 return -EINVAL;
348 }
349
350 do {
351 int ret;
352
353 ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
354 if (ret) {
355 printk(KERN_ERR "Remapping memory, error: %d\n", ret);
356 return ret;
357 }
358
359 uaddr += PAGE_SIZE;
360 usize -= PAGE_SIZE;
361 } while (usize > 0);
362
363
364 /*
365 * Use common vm_area operations to track buffer refcount.
366 */
367 vma->vm_private_data = &buf->handler;
368 vma->vm_ops = &vb2_common_vm_ops;
369
370 vma->vm_ops->open(vma);
371
372 return 0;
373 }
374
375 /*********************************************/
376 /* DMABUF ops for exporters */
377 /*********************************************/
378
379 struct vb2_dma_sg_attachment {
380 struct sg_table sgt;
381 enum dma_data_direction dma_dir;
382 };
383
vb2_dma_sg_dmabuf_ops_attach(struct dma_buf * dbuf,struct device * dev,struct dma_buf_attachment * dbuf_attach)384 static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
385 struct dma_buf_attachment *dbuf_attach)
386 {
387 struct vb2_dma_sg_attachment *attach;
388 unsigned int i;
389 struct scatterlist *rd, *wr;
390 struct sg_table *sgt;
391 struct vb2_dma_sg_buf *buf = dbuf->priv;
392 int ret;
393
394 attach = kzalloc(sizeof(*attach), GFP_KERNEL);
395 if (!attach)
396 return -ENOMEM;
397
398 sgt = &attach->sgt;
399 /* Copy the buf->base_sgt scatter list to the attachment, as we can't
400 * map the same scatter list to multiple attachments at the same time.
401 */
402 ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
403 if (ret) {
404 kfree(attach);
405 return -ENOMEM;
406 }
407
408 rd = buf->dma_sgt->sgl;
409 wr = sgt->sgl;
410 for (i = 0; i < sgt->orig_nents; ++i) {
411 sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
412 rd = sg_next(rd);
413 wr = sg_next(wr);
414 }
415
416 attach->dma_dir = DMA_NONE;
417 dbuf_attach->priv = attach;
418
419 return 0;
420 }
421
vb2_dma_sg_dmabuf_ops_detach(struct dma_buf * dbuf,struct dma_buf_attachment * db_attach)422 static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
423 struct dma_buf_attachment *db_attach)
424 {
425 struct vb2_dma_sg_attachment *attach = db_attach->priv;
426 struct sg_table *sgt;
427
428 if (!attach)
429 return;
430
431 sgt = &attach->sgt;
432
433 /* release the scatterlist cache */
434 if (attach->dma_dir != DMA_NONE)
435 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
436 attach->dma_dir);
437 sg_free_table(sgt);
438 kfree(attach);
439 db_attach->priv = NULL;
440 }
441
vb2_dma_sg_dmabuf_ops_map(struct dma_buf_attachment * db_attach,enum dma_data_direction dma_dir)442 static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
443 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
444 {
445 struct vb2_dma_sg_attachment *attach = db_attach->priv;
446 /* stealing dmabuf mutex to serialize map/unmap operations */
447 struct mutex *lock = &db_attach->dmabuf->lock;
448 struct sg_table *sgt;
449
450 mutex_lock(lock);
451
452 sgt = &attach->sgt;
453 /* return previously mapped sg table */
454 if (attach->dma_dir == dma_dir) {
455 mutex_unlock(lock);
456 return sgt;
457 }
458
459 /* release any previous cache */
460 if (attach->dma_dir != DMA_NONE) {
461 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
462 attach->dma_dir);
463 attach->dma_dir = DMA_NONE;
464 }
465
466 /* mapping to the client with new direction */
467 sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
468 dma_dir);
469 if (!sgt->nents) {
470 pr_err("failed to map scatterlist\n");
471 mutex_unlock(lock);
472 return ERR_PTR(-EIO);
473 }
474
475 attach->dma_dir = dma_dir;
476
477 mutex_unlock(lock);
478
479 return sgt;
480 }
481
vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment * db_attach,struct sg_table * sgt,enum dma_data_direction dma_dir)482 static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
483 struct sg_table *sgt, enum dma_data_direction dma_dir)
484 {
485 /* nothing to be done here */
486 }
487
vb2_dma_sg_dmabuf_ops_release(struct dma_buf * dbuf)488 static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
489 {
490 /* drop reference obtained in vb2_dma_sg_get_dmabuf */
491 vb2_dma_sg_put(dbuf->priv);
492 }
493
vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf * dbuf,unsigned long pgnum)494 static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
495 {
496 struct vb2_dma_sg_buf *buf = dbuf->priv;
497
498 return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL;
499 }
500
vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf * dbuf)501 static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
502 {
503 struct vb2_dma_sg_buf *buf = dbuf->priv;
504
505 return vb2_dma_sg_vaddr(buf);
506 }
507
vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf * dbuf,struct vm_area_struct * vma)508 static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
509 struct vm_area_struct *vma)
510 {
511 return vb2_dma_sg_mmap(dbuf->priv, vma);
512 }
513
514 static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
515 .attach = vb2_dma_sg_dmabuf_ops_attach,
516 .detach = vb2_dma_sg_dmabuf_ops_detach,
517 .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
518 .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
519 .kmap = vb2_dma_sg_dmabuf_ops_kmap,
520 .kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap,
521 .vmap = vb2_dma_sg_dmabuf_ops_vmap,
522 .mmap = vb2_dma_sg_dmabuf_ops_mmap,
523 .release = vb2_dma_sg_dmabuf_ops_release,
524 };
525
vb2_dma_sg_get_dmabuf(void * buf_priv,unsigned long flags)526 static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
527 {
528 struct vb2_dma_sg_buf *buf = buf_priv;
529 struct dma_buf *dbuf;
530 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
531
532 exp_info.ops = &vb2_dma_sg_dmabuf_ops;
533 exp_info.size = buf->size;
534 exp_info.flags = flags;
535 exp_info.priv = buf;
536
537 if (WARN_ON(!buf->dma_sgt))
538 return NULL;
539
540 dbuf = dma_buf_export(&exp_info);
541 if (IS_ERR(dbuf))
542 return NULL;
543
544 /* dmabuf keeps reference to vb2 buffer */
545 atomic_inc(&buf->refcount);
546
547 return dbuf;
548 }
549
550 /*********************************************/
551 /* callbacks for DMABUF buffers */
552 /*********************************************/
553
vb2_dma_sg_map_dmabuf(void * mem_priv)554 static int vb2_dma_sg_map_dmabuf(void *mem_priv)
555 {
556 struct vb2_dma_sg_buf *buf = mem_priv;
557 struct sg_table *sgt;
558
559 if (WARN_ON(!buf->db_attach)) {
560 pr_err("trying to pin a non attached buffer\n");
561 return -EINVAL;
562 }
563
564 if (WARN_ON(buf->dma_sgt)) {
565 pr_err("dmabuf buffer is already pinned\n");
566 return 0;
567 }
568
569 /* get the associated scatterlist for this buffer */
570 sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
571 if (IS_ERR(sgt)) {
572 pr_err("Error getting dmabuf scatterlist\n");
573 return -EINVAL;
574 }
575
576 buf->dma_sgt = sgt;
577 buf->vaddr = NULL;
578
579 return 0;
580 }
581
vb2_dma_sg_unmap_dmabuf(void * mem_priv)582 static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
583 {
584 struct vb2_dma_sg_buf *buf = mem_priv;
585 struct sg_table *sgt = buf->dma_sgt;
586
587 if (WARN_ON(!buf->db_attach)) {
588 pr_err("trying to unpin a not attached buffer\n");
589 return;
590 }
591
592 if (WARN_ON(!sgt)) {
593 pr_err("dmabuf buffer is already unpinned\n");
594 return;
595 }
596
597 if (buf->vaddr) {
598 dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr);
599 buf->vaddr = NULL;
600 }
601 dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
602
603 buf->dma_sgt = NULL;
604 }
605
vb2_dma_sg_detach_dmabuf(void * mem_priv)606 static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
607 {
608 struct vb2_dma_sg_buf *buf = mem_priv;
609
610 /* if vb2 works correctly you should never detach mapped buffer */
611 if (WARN_ON(buf->dma_sgt))
612 vb2_dma_sg_unmap_dmabuf(buf);
613
614 /* detach this attachment */
615 dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
616 kfree(buf);
617 }
618
vb2_dma_sg_attach_dmabuf(void * alloc_ctx,struct dma_buf * dbuf,unsigned long size,enum dma_data_direction dma_dir)619 static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
620 unsigned long size, enum dma_data_direction dma_dir)
621 {
622 struct vb2_dma_sg_conf *conf = alloc_ctx;
623 struct vb2_dma_sg_buf *buf;
624 struct dma_buf_attachment *dba;
625
626 if (dbuf->size < size)
627 return ERR_PTR(-EFAULT);
628
629 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
630 if (!buf)
631 return ERR_PTR(-ENOMEM);
632
633 buf->dev = conf->dev;
634 /* create attachment for the dmabuf with the user device */
635 dba = dma_buf_attach(dbuf, buf->dev);
636 if (IS_ERR(dba)) {
637 pr_err("failed to attach dmabuf\n");
638 kfree(buf);
639 return dba;
640 }
641
642 buf->dma_dir = dma_dir;
643 buf->size = size;
644 buf->db_attach = dba;
645
646 return buf;
647 }
648
vb2_dma_sg_cookie(void * buf_priv)649 static void *vb2_dma_sg_cookie(void *buf_priv)
650 {
651 struct vb2_dma_sg_buf *buf = buf_priv;
652
653 return buf->dma_sgt;
654 }
655
656 const struct vb2_mem_ops vb2_dma_sg_memops = {
657 .alloc = vb2_dma_sg_alloc,
658 .put = vb2_dma_sg_put,
659 .get_userptr = vb2_dma_sg_get_userptr,
660 .put_userptr = vb2_dma_sg_put_userptr,
661 .prepare = vb2_dma_sg_prepare,
662 .finish = vb2_dma_sg_finish,
663 .vaddr = vb2_dma_sg_vaddr,
664 .mmap = vb2_dma_sg_mmap,
665 .num_users = vb2_dma_sg_num_users,
666 .get_dmabuf = vb2_dma_sg_get_dmabuf,
667 .map_dmabuf = vb2_dma_sg_map_dmabuf,
668 .unmap_dmabuf = vb2_dma_sg_unmap_dmabuf,
669 .attach_dmabuf = vb2_dma_sg_attach_dmabuf,
670 .detach_dmabuf = vb2_dma_sg_detach_dmabuf,
671 .cookie = vb2_dma_sg_cookie,
672 };
673 EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
674
vb2_dma_sg_init_ctx(struct device * dev)675 void *vb2_dma_sg_init_ctx(struct device *dev)
676 {
677 struct vb2_dma_sg_conf *conf;
678
679 conf = kzalloc(sizeof(*conf), GFP_KERNEL);
680 if (!conf)
681 return ERR_PTR(-ENOMEM);
682
683 conf->dev = dev;
684
685 return conf;
686 }
687 EXPORT_SYMBOL_GPL(vb2_dma_sg_init_ctx);
688
vb2_dma_sg_cleanup_ctx(void * alloc_ctx)689 void vb2_dma_sg_cleanup_ctx(void *alloc_ctx)
690 {
691 if (!IS_ERR_OR_NULL(alloc_ctx))
692 kfree(alloc_ctx);
693 }
694 EXPORT_SYMBOL_GPL(vb2_dma_sg_cleanup_ctx);
695
696 MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
697 MODULE_AUTHOR("Andrzej Pietrasiewicz");
698 MODULE_LICENSE("GPL");
699