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