1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * helper functions for SG DMA video4linux capture buffers
4 *
5 * The functions expect the hardware being able to scatter gather
6 * (i.e. the buffers are not linear in physical memory, but fragmented
7 * into PAGE_SIZE chunks). They also assume the driver does not need
8 * to touch the video data.
9 *
10 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
11 *
12 * Highly based on video-buf written originally by:
13 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
14 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
15 * (c) 2006 Ted Walther and John Sokol
16 */
17
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/sched/mm.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/pgtable.h>
25
26 #include <linux/dma-mapping.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/scatterlist.h>
30 #include <asm/page.h>
31
32 #include <media/videobuf-dma-sg.h>
33
34 #define MAGIC_DMABUF 0x19721112
35 #define MAGIC_SG_MEM 0x17890714
36
37 #define MAGIC_CHECK(is, should) \
38 if (unlikely((is) != (should))) { \
39 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \
40 is, should); \
41 BUG(); \
42 }
43
44 static int debug;
45 module_param(debug, int, 0644);
46
47 MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
48 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@kernel.org>");
49 MODULE_LICENSE("GPL");
50
51 #define dprintk(level, fmt, arg...) \
52 if (debug >= level) \
53 printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
54
55 /* --------------------------------------------------------------------- */
56
57 /*
58 * Return a scatterlist for some page-aligned vmalloc()'ed memory
59 * block (NULL on errors). Memory for the scatterlist is allocated
60 * using kmalloc. The caller must free the memory.
61 */
videobuf_vmalloc_to_sg(unsigned char * virt,int nr_pages)62 static struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt,
63 int nr_pages)
64 {
65 struct scatterlist *sglist;
66 struct page *pg;
67 int i;
68
69 sglist = vzalloc(array_size(nr_pages, sizeof(*sglist)));
70 if (NULL == sglist)
71 return NULL;
72 sg_init_table(sglist, nr_pages);
73 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
74 pg = vmalloc_to_page(virt);
75 if (NULL == pg)
76 goto err;
77 BUG_ON(PageHighMem(pg));
78 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
79 }
80 return sglist;
81
82 err:
83 vfree(sglist);
84 return NULL;
85 }
86
87 /*
88 * Return a scatterlist for a an array of userpages (NULL on errors).
89 * Memory for the scatterlist is allocated using kmalloc. The caller
90 * must free the memory.
91 */
videobuf_pages_to_sg(struct page ** pages,int nr_pages,int offset,size_t size)92 static struct scatterlist *videobuf_pages_to_sg(struct page **pages,
93 int nr_pages, int offset, size_t size)
94 {
95 struct scatterlist *sglist;
96 int i;
97
98 if (NULL == pages[0])
99 return NULL;
100 sglist = vmalloc(array_size(nr_pages, sizeof(*sglist)));
101 if (NULL == sglist)
102 return NULL;
103 sg_init_table(sglist, nr_pages);
104
105 if (PageHighMem(pages[0]))
106 /* DMA to highmem pages might not work */
107 goto highmem;
108 sg_set_page(&sglist[0], pages[0],
109 min_t(size_t, PAGE_SIZE - offset, size), offset);
110 size -= min_t(size_t, PAGE_SIZE - offset, size);
111 for (i = 1; i < nr_pages; i++) {
112 if (NULL == pages[i])
113 goto nopage;
114 if (PageHighMem(pages[i]))
115 goto highmem;
116 sg_set_page(&sglist[i], pages[i], min_t(size_t, PAGE_SIZE, size), 0);
117 size -= min_t(size_t, PAGE_SIZE, size);
118 }
119 return sglist;
120
121 nopage:
122 dprintk(2, "sgl: oops - no page\n");
123 vfree(sglist);
124 return NULL;
125
126 highmem:
127 dprintk(2, "sgl: oops - highmem page\n");
128 vfree(sglist);
129 return NULL;
130 }
131
132 /* --------------------------------------------------------------------- */
133
videobuf_to_dma(struct videobuf_buffer * buf)134 struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf)
135 {
136 struct videobuf_dma_sg_memory *mem = buf->priv;
137 BUG_ON(!mem);
138
139 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
140
141 return &mem->dma;
142 }
143 EXPORT_SYMBOL_GPL(videobuf_to_dma);
144
videobuf_dma_init(struct videobuf_dmabuf * dma)145 static void videobuf_dma_init(struct videobuf_dmabuf *dma)
146 {
147 memset(dma, 0, sizeof(*dma));
148 dma->magic = MAGIC_DMABUF;
149 }
150
videobuf_dma_init_user_locked(struct videobuf_dmabuf * dma,int direction,unsigned long data,unsigned long size)151 static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
152 int direction, unsigned long data, unsigned long size)
153 {
154 unsigned int gup_flags = FOLL_LONGTERM;
155 unsigned long first, last;
156 int err;
157
158 dma->direction = direction;
159 switch (dma->direction) {
160 case DMA_FROM_DEVICE:
161 gup_flags |= FOLL_WRITE;
162 break;
163 case DMA_TO_DEVICE:
164 break;
165 default:
166 BUG();
167 }
168
169 first = (data & PAGE_MASK) >> PAGE_SHIFT;
170 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
171 dma->offset = data & ~PAGE_MASK;
172 dma->size = size;
173 dma->nr_pages = last-first+1;
174 dma->pages = kmalloc_array(dma->nr_pages, sizeof(struct page *),
175 GFP_KERNEL);
176 if (NULL == dma->pages)
177 return -ENOMEM;
178
179 dprintk(1, "init user [0x%lx+0x%lx => %lu pages]\n",
180 data, size, dma->nr_pages);
181
182 err = pin_user_pages(data & PAGE_MASK, dma->nr_pages, gup_flags,
183 dma->pages);
184
185 if (err != dma->nr_pages) {
186 dma->nr_pages = (err >= 0) ? err : 0;
187 dprintk(1, "pin_user_pages: err=%d [%lu]\n", err,
188 dma->nr_pages);
189 return err < 0 ? err : -EINVAL;
190 }
191 return 0;
192 }
193
videobuf_dma_init_user(struct videobuf_dmabuf * dma,int direction,unsigned long data,unsigned long size)194 static int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
195 unsigned long data, unsigned long size)
196 {
197 int ret;
198
199 mmap_read_lock(current->mm);
200 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
201 mmap_read_unlock(current->mm);
202
203 return ret;
204 }
205
videobuf_dma_init_kernel(struct videobuf_dmabuf * dma,int direction,unsigned long nr_pages)206 static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
207 unsigned long nr_pages)
208 {
209 int i;
210
211 dprintk(1, "init kernel [%lu pages]\n", nr_pages);
212
213 dma->direction = direction;
214 dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
215 GFP_KERNEL);
216 if (!dma->vaddr_pages)
217 return -ENOMEM;
218
219 dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
220 if (!dma->dma_addr) {
221 kfree(dma->vaddr_pages);
222 return -ENOMEM;
223 }
224 for (i = 0; i < nr_pages; i++) {
225 void *addr;
226
227 addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
228 &(dma->dma_addr[i]), GFP_KERNEL);
229 if (addr == NULL)
230 goto out_free_pages;
231
232 dma->vaddr_pages[i] = virt_to_page(addr);
233 }
234 dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
235 PAGE_KERNEL);
236 if (NULL == dma->vaddr) {
237 dprintk(1, "vmalloc_32(%lu pages) failed\n", nr_pages);
238 goto out_free_pages;
239 }
240
241 dprintk(1, "vmalloc is at addr %p, size=%lu\n",
242 dma->vaddr, nr_pages << PAGE_SHIFT);
243
244 memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
245 dma->nr_pages = nr_pages;
246
247 return 0;
248 out_free_pages:
249 while (i > 0) {
250 void *addr;
251
252 i--;
253 addr = page_address(dma->vaddr_pages[i]);
254 dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]);
255 }
256 kfree(dma->dma_addr);
257 dma->dma_addr = NULL;
258 kfree(dma->vaddr_pages);
259 dma->vaddr_pages = NULL;
260
261 return -ENOMEM;
262
263 }
264
videobuf_dma_init_overlay(struct videobuf_dmabuf * dma,int direction,dma_addr_t addr,unsigned long nr_pages)265 static int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
266 dma_addr_t addr, unsigned long nr_pages)
267 {
268 dprintk(1, "init overlay [%lu pages @ bus 0x%lx]\n",
269 nr_pages, (unsigned long)addr);
270 dma->direction = direction;
271
272 if (0 == addr)
273 return -EINVAL;
274
275 dma->bus_addr = addr;
276 dma->nr_pages = nr_pages;
277
278 return 0;
279 }
280
videobuf_dma_map(struct device * dev,struct videobuf_dmabuf * dma)281 static int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
282 {
283 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
284 BUG_ON(0 == dma->nr_pages);
285
286 if (dma->pages) {
287 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
288 dma->offset, dma->size);
289 }
290 if (dma->vaddr) {
291 dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr,
292 dma->nr_pages);
293 }
294 if (dma->bus_addr) {
295 dma->sglist = vmalloc(sizeof(*dma->sglist));
296 if (NULL != dma->sglist) {
297 dma->sglen = 1;
298 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
299 & PAGE_MASK;
300 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
301 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
302 }
303 }
304 if (NULL == dma->sglist) {
305 dprintk(1, "scatterlist is NULL\n");
306 return -ENOMEM;
307 }
308 if (!dma->bus_addr) {
309 dma->sglen = dma_map_sg(dev, dma->sglist,
310 dma->nr_pages, dma->direction);
311 if (0 == dma->sglen) {
312 printk(KERN_WARNING
313 "%s: videobuf_map_sg failed\n", __func__);
314 vfree(dma->sglist);
315 dma->sglist = NULL;
316 dma->sglen = 0;
317 return -ENOMEM;
318 }
319 }
320
321 return 0;
322 }
323
videobuf_dma_unmap(struct device * dev,struct videobuf_dmabuf * dma)324 int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
325 {
326 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
327
328 if (!dma->sglen)
329 return 0;
330
331 dma_unmap_sg(dev, dma->sglist, dma->nr_pages, dma->direction);
332
333 vfree(dma->sglist);
334 dma->sglist = NULL;
335 dma->sglen = 0;
336
337 return 0;
338 }
339 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
340
videobuf_dma_free(struct videobuf_dmabuf * dma)341 int videobuf_dma_free(struct videobuf_dmabuf *dma)
342 {
343 int i;
344 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
345 BUG_ON(dma->sglen);
346
347 if (dma->pages) {
348 unpin_user_pages_dirty_lock(dma->pages, dma->nr_pages,
349 dma->direction == DMA_FROM_DEVICE);
350 kfree(dma->pages);
351 dma->pages = NULL;
352 }
353
354 if (dma->dma_addr) {
355 for (i = 0; i < dma->nr_pages; i++) {
356 void *addr;
357
358 addr = page_address(dma->vaddr_pages[i]);
359 dma_free_coherent(dma->dev, PAGE_SIZE, addr,
360 dma->dma_addr[i]);
361 }
362 kfree(dma->dma_addr);
363 dma->dma_addr = NULL;
364 kfree(dma->vaddr_pages);
365 dma->vaddr_pages = NULL;
366 vunmap(dma->vaddr);
367 dma->vaddr = NULL;
368 }
369
370 if (dma->bus_addr)
371 dma->bus_addr = 0;
372 dma->direction = DMA_NONE;
373
374 return 0;
375 }
376 EXPORT_SYMBOL_GPL(videobuf_dma_free);
377
378 /* --------------------------------------------------------------------- */
379
videobuf_vm_open(struct vm_area_struct * vma)380 static void videobuf_vm_open(struct vm_area_struct *vma)
381 {
382 struct videobuf_mapping *map = vma->vm_private_data;
383
384 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
385 map->count, vma->vm_start, vma->vm_end);
386
387 map->count++;
388 }
389
videobuf_vm_close(struct vm_area_struct * vma)390 static void videobuf_vm_close(struct vm_area_struct *vma)
391 {
392 struct videobuf_mapping *map = vma->vm_private_data;
393 struct videobuf_queue *q = map->q;
394 struct videobuf_dma_sg_memory *mem;
395 int i;
396
397 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
398 map->count, vma->vm_start, vma->vm_end);
399
400 map->count--;
401 if (0 == map->count) {
402 dprintk(1, "munmap %p q=%p\n", map, q);
403 videobuf_queue_lock(q);
404 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
405 if (NULL == q->bufs[i])
406 continue;
407 mem = q->bufs[i]->priv;
408 if (!mem)
409 continue;
410
411 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
412
413 if (q->bufs[i]->map != map)
414 continue;
415 q->bufs[i]->map = NULL;
416 q->bufs[i]->baddr = 0;
417 q->ops->buf_release(q, q->bufs[i]);
418 }
419 videobuf_queue_unlock(q);
420 kfree(map);
421 }
422 }
423
424 /*
425 * Get a anonymous page for the mapping. Make sure we can DMA to that
426 * memory location with 32bit PCI devices (i.e. don't use highmem for
427 * now ...). Bounce buffers don't work very well for the data rates
428 * video capture has.
429 */
videobuf_vm_fault(struct vm_fault * vmf)430 static vm_fault_t videobuf_vm_fault(struct vm_fault *vmf)
431 {
432 struct vm_area_struct *vma = vmf->vma;
433 struct page *page;
434
435 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
436 vmf->address, vma->vm_start, vma->vm_end);
437
438 page = alloc_page(GFP_USER | __GFP_DMA32);
439 if (!page)
440 return VM_FAULT_OOM;
441 clear_user_highpage(page, vmf->address);
442 vmf->page = page;
443
444 return 0;
445 }
446
447 static const struct vm_operations_struct videobuf_vm_ops = {
448 .open = videobuf_vm_open,
449 .close = videobuf_vm_close,
450 .fault = videobuf_vm_fault,
451 };
452
453 /* ---------------------------------------------------------------------
454 * SG handlers for the generic methods
455 */
456
457 /* Allocated area consists on 3 parts:
458 struct video_buffer
459 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
460 struct videobuf_dma_sg_memory
461 */
462
__videobuf_alloc_vb(size_t size)463 static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
464 {
465 struct videobuf_dma_sg_memory *mem;
466 struct videobuf_buffer *vb;
467
468 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
469 if (!vb)
470 return vb;
471
472 mem = vb->priv = ((char *)vb) + size;
473 mem->magic = MAGIC_SG_MEM;
474
475 videobuf_dma_init(&mem->dma);
476
477 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
478 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
479 mem, (long)sizeof(*mem));
480
481 return vb;
482 }
483
__videobuf_to_vaddr(struct videobuf_buffer * buf)484 static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
485 {
486 struct videobuf_dma_sg_memory *mem = buf->priv;
487 BUG_ON(!mem);
488
489 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
490
491 return mem->dma.vaddr;
492 }
493
__videobuf_iolock(struct videobuf_queue * q,struct videobuf_buffer * vb,struct v4l2_framebuffer * fbuf)494 static int __videobuf_iolock(struct videobuf_queue *q,
495 struct videobuf_buffer *vb,
496 struct v4l2_framebuffer *fbuf)
497 {
498 struct videobuf_dma_sg_memory *mem = vb->priv;
499 unsigned long pages;
500 dma_addr_t bus;
501 int err;
502
503 BUG_ON(!mem);
504
505 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
506
507 if (!mem->dma.dev)
508 mem->dma.dev = q->dev;
509 else
510 WARN_ON(mem->dma.dev != q->dev);
511
512 switch (vb->memory) {
513 case V4L2_MEMORY_MMAP:
514 case V4L2_MEMORY_USERPTR:
515 if (0 == vb->baddr) {
516 /* no userspace addr -- kernel bounce buffer */
517 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
518 err = videobuf_dma_init_kernel(&mem->dma,
519 DMA_FROM_DEVICE,
520 pages);
521 if (0 != err)
522 return err;
523 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
524 /* dma directly to userspace */
525 err = videobuf_dma_init_user(&mem->dma,
526 DMA_FROM_DEVICE,
527 vb->baddr, vb->bsize);
528 if (0 != err)
529 return err;
530 } else {
531 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
532 buffers can only be called from videobuf_qbuf
533 we take current->mm->mmap_lock there, to prevent
534 locking inversion, so don't take it here */
535
536 err = videobuf_dma_init_user_locked(&mem->dma,
537 DMA_FROM_DEVICE,
538 vb->baddr, vb->bsize);
539 if (0 != err)
540 return err;
541 }
542 break;
543 case V4L2_MEMORY_OVERLAY:
544 if (NULL == fbuf)
545 return -EINVAL;
546 /* FIXME: need sanity checks for vb->boff */
547 /*
548 * Using a double cast to avoid compiler warnings when
549 * building for PAE. Compiler doesn't like direct casting
550 * of a 32 bit ptr to 64 bit integer.
551 */
552 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
553 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
554 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
555 bus, pages);
556 if (0 != err)
557 return err;
558 break;
559 default:
560 BUG();
561 }
562 err = videobuf_dma_map(q->dev, &mem->dma);
563 if (0 != err)
564 return err;
565
566 return 0;
567 }
568
__videobuf_sync(struct videobuf_queue * q,struct videobuf_buffer * buf)569 static int __videobuf_sync(struct videobuf_queue *q,
570 struct videobuf_buffer *buf)
571 {
572 struct videobuf_dma_sg_memory *mem = buf->priv;
573 BUG_ON(!mem || !mem->dma.sglen);
574
575 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
576 MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF);
577
578 dma_sync_sg_for_cpu(q->dev, mem->dma.sglist,
579 mem->dma.nr_pages, mem->dma.direction);
580
581 return 0;
582 }
583
__videobuf_mmap_mapper(struct videobuf_queue * q,struct videobuf_buffer * buf,struct vm_area_struct * vma)584 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
585 struct videobuf_buffer *buf,
586 struct vm_area_struct *vma)
587 {
588 struct videobuf_dma_sg_memory *mem = buf->priv;
589 struct videobuf_mapping *map;
590 unsigned int first, last, size = 0, i;
591 int retval;
592
593 retval = -EINVAL;
594
595 BUG_ON(!mem);
596 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
597
598 /* look for first buffer to map */
599 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
600 if (buf == q->bufs[first]) {
601 size = PAGE_ALIGN(q->bufs[first]->bsize);
602 break;
603 }
604 }
605
606 /* paranoia, should never happen since buf is always valid. */
607 if (!size) {
608 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
609 (vma->vm_pgoff << PAGE_SHIFT));
610 goto done;
611 }
612
613 last = first;
614
615 /* create mapping + update buffer list */
616 retval = -ENOMEM;
617 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
618 if (NULL == map)
619 goto done;
620
621 size = 0;
622 for (i = first; i <= last; i++) {
623 if (NULL == q->bufs[i])
624 continue;
625 q->bufs[i]->map = map;
626 q->bufs[i]->baddr = vma->vm_start + size;
627 size += PAGE_ALIGN(q->bufs[i]->bsize);
628 }
629
630 map->count = 1;
631 map->q = q;
632 vma->vm_ops = &videobuf_vm_ops;
633 /* using shared anonymous pages */
634 vm_flags_mod(vma, VM_DONTEXPAND | VM_DONTDUMP, VM_IO);
635 vma->vm_private_data = map;
636 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
637 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
638 retval = 0;
639
640 done:
641 return retval;
642 }
643
644 static struct videobuf_qtype_ops sg_ops = {
645 .magic = MAGIC_QTYPE_OPS,
646
647 .alloc_vb = __videobuf_alloc_vb,
648 .iolock = __videobuf_iolock,
649 .sync = __videobuf_sync,
650 .mmap_mapper = __videobuf_mmap_mapper,
651 .vaddr = __videobuf_to_vaddr,
652 };
653
videobuf_sg_alloc(size_t size)654 void *videobuf_sg_alloc(size_t size)
655 {
656 struct videobuf_queue q;
657
658 /* Required to make generic handler to call __videobuf_alloc */
659 q.int_ops = &sg_ops;
660
661 q.msize = size;
662
663 return videobuf_alloc_vb(&q);
664 }
665 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
666
videobuf_queue_sg_init(struct videobuf_queue * q,const struct videobuf_queue_ops * ops,struct device * dev,spinlock_t * irqlock,enum v4l2_buf_type type,enum v4l2_field field,unsigned int msize,void * priv,struct mutex * ext_lock)667 void videobuf_queue_sg_init(struct videobuf_queue *q,
668 const struct videobuf_queue_ops *ops,
669 struct device *dev,
670 spinlock_t *irqlock,
671 enum v4l2_buf_type type,
672 enum v4l2_field field,
673 unsigned int msize,
674 void *priv,
675 struct mutex *ext_lock)
676 {
677 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
678 priv, &sg_ops, ext_lock);
679 }
680 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
681
682