1 /*
2 * helper functions for SG DMA video4linux capture buffers
3 *
4 * The functions expect the hardware being able to scatter gather
5 * (i.e. the buffers are not linear in physical memory, but fragmented
6 * into PAGE_SIZE chunks). They also assume the driver does not need
7 * to touch the video data.
8 *
9 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
10 *
11 * Highly based on video-buf written originally by:
12 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
13 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
14 * (c) 2006 Ted Walther and John Sokol
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2
19 */
20
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/interrupt.h>
27
28 #include <linux/dma-mapping.h>
29 #include <linux/vmalloc.h>
30 #include <linux/pagemap.h>
31 #include <linux/scatterlist.h>
32 #include <asm/page.h>
33 #include <asm/pgtable.h>
34
35 #include <media/videobuf-dma-sg.h>
36
37 #define MAGIC_DMABUF 0x19721112
38 #define MAGIC_SG_MEM 0x17890714
39
40 #define MAGIC_CHECK(is, should) \
41 if (unlikely((is) != (should))) { \
42 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \
43 is, should); \
44 BUG(); \
45 }
46
47 static int debug;
48 module_param(debug, int, 0644);
49
50 MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
51 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
52 MODULE_LICENSE("GPL");
53
54 #define dprintk(level, fmt, arg...) \
55 if (debug >= level) \
56 printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
57
58 /* --------------------------------------------------------------------- */
59
60 /*
61 * Return a scatterlist for some page-aligned vmalloc()'ed memory
62 * block (NULL on errors). Memory for the scatterlist is allocated
63 * using kmalloc. The caller must free the memory.
64 */
videobuf_vmalloc_to_sg(unsigned char * virt,int nr_pages)65 static struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt,
66 int nr_pages)
67 {
68 struct scatterlist *sglist;
69 struct page *pg;
70 int i;
71
72 sglist = vzalloc(nr_pages * sizeof(*sglist));
73 if (NULL == sglist)
74 return NULL;
75 sg_init_table(sglist, nr_pages);
76 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
77 pg = vmalloc_to_page(virt);
78 if (NULL == pg)
79 goto err;
80 BUG_ON(PageHighMem(pg));
81 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
82 }
83 return sglist;
84
85 err:
86 vfree(sglist);
87 return NULL;
88 }
89
90 /*
91 * Return a scatterlist for a an array of userpages (NULL on errors).
92 * Memory for the scatterlist is allocated using kmalloc. The caller
93 * must free the memory.
94 */
videobuf_pages_to_sg(struct page ** pages,int nr_pages,int offset,size_t size)95 static struct scatterlist *videobuf_pages_to_sg(struct page **pages,
96 int nr_pages, int offset, size_t size)
97 {
98 struct scatterlist *sglist;
99 int i;
100
101 if (NULL == pages[0])
102 return NULL;
103 sglist = vmalloc(nr_pages * sizeof(*sglist));
104 if (NULL == sglist)
105 return NULL;
106 sg_init_table(sglist, nr_pages);
107
108 if (PageHighMem(pages[0]))
109 /* DMA to highmem pages might not work */
110 goto highmem;
111 sg_set_page(&sglist[0], pages[0],
112 min_t(size_t, PAGE_SIZE - offset, size), offset);
113 size -= min_t(size_t, PAGE_SIZE - offset, size);
114 for (i = 1; i < nr_pages; i++) {
115 if (NULL == pages[i])
116 goto nopage;
117 if (PageHighMem(pages[i]))
118 goto highmem;
119 sg_set_page(&sglist[i], pages[i], min_t(size_t, PAGE_SIZE, size), 0);
120 size -= min_t(size_t, PAGE_SIZE, size);
121 }
122 return sglist;
123
124 nopage:
125 dprintk(2, "sgl: oops - no page\n");
126 vfree(sglist);
127 return NULL;
128
129 highmem:
130 dprintk(2, "sgl: oops - highmem page\n");
131 vfree(sglist);
132 return NULL;
133 }
134
135 /* --------------------------------------------------------------------- */
136
videobuf_to_dma(struct videobuf_buffer * buf)137 struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf)
138 {
139 struct videobuf_dma_sg_memory *mem = buf->priv;
140 BUG_ON(!mem);
141
142 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
143
144 return &mem->dma;
145 }
146 EXPORT_SYMBOL_GPL(videobuf_to_dma);
147
videobuf_dma_init(struct videobuf_dmabuf * dma)148 void videobuf_dma_init(struct videobuf_dmabuf *dma)
149 {
150 memset(dma, 0, sizeof(*dma));
151 dma->magic = MAGIC_DMABUF;
152 }
153 EXPORT_SYMBOL_GPL(videobuf_dma_init);
154
videobuf_dma_init_user_locked(struct videobuf_dmabuf * dma,int direction,unsigned long data,unsigned long size)155 static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
156 int direction, unsigned long data, unsigned long size)
157 {
158 unsigned long first, last;
159 int err, rw = 0;
160
161 dma->direction = direction;
162 switch (dma->direction) {
163 case DMA_FROM_DEVICE:
164 rw = READ;
165 break;
166 case DMA_TO_DEVICE:
167 rw = WRITE;
168 break;
169 default:
170 BUG();
171 }
172
173 first = (data & PAGE_MASK) >> PAGE_SHIFT;
174 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
175 dma->offset = data & ~PAGE_MASK;
176 dma->size = size;
177 dma->nr_pages = last-first+1;
178 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page *), GFP_KERNEL);
179 if (NULL == dma->pages)
180 return -ENOMEM;
181
182 dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
183 data, size, dma->nr_pages);
184
185 err = get_user_pages(current, current->mm,
186 data & PAGE_MASK, dma->nr_pages,
187 rw == READ, 1, /* force */
188 dma->pages, NULL);
189
190 if (err != dma->nr_pages) {
191 dma->nr_pages = (err >= 0) ? err : 0;
192 dprintk(1, "get_user_pages: err=%d [%d]\n", err, dma->nr_pages);
193 return err < 0 ? err : -EINVAL;
194 }
195 return 0;
196 }
197
videobuf_dma_init_user(struct videobuf_dmabuf * dma,int direction,unsigned long data,unsigned long size)198 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
199 unsigned long data, unsigned long size)
200 {
201 int ret;
202
203 down_read(¤t->mm->mmap_sem);
204 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
205 up_read(¤t->mm->mmap_sem);
206
207 return ret;
208 }
209 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
210
videobuf_dma_init_kernel(struct videobuf_dmabuf * dma,int direction,int nr_pages)211 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
212 int nr_pages)
213 {
214 int i;
215
216 dprintk(1, "init kernel [%d pages]\n", nr_pages);
217
218 dma->direction = direction;
219 dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
220 GFP_KERNEL);
221 if (!dma->vaddr_pages)
222 return -ENOMEM;
223
224 dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
225 if (!dma->dma_addr) {
226 kfree(dma->vaddr_pages);
227 return -ENOMEM;
228 }
229 for (i = 0; i < nr_pages; i++) {
230 void *addr;
231
232 addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
233 &(dma->dma_addr[i]), GFP_KERNEL);
234 if (addr == NULL)
235 goto out_free_pages;
236
237 dma->vaddr_pages[i] = virt_to_page(addr);
238 }
239 dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
240 PAGE_KERNEL);
241 if (NULL == dma->vaddr) {
242 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
243 goto out_free_pages;
244 }
245
246 dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
247 (unsigned long)dma->vaddr,
248 nr_pages << PAGE_SHIFT);
249
250 memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
251 dma->nr_pages = nr_pages;
252
253 return 0;
254 out_free_pages:
255 while (i > 0) {
256 void *addr;
257
258 i--;
259 addr = page_address(dma->vaddr_pages[i]);
260 dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]);
261 }
262 kfree(dma->dma_addr);
263 dma->dma_addr = NULL;
264 kfree(dma->vaddr_pages);
265 dma->vaddr_pages = NULL;
266
267 return -ENOMEM;
268
269 }
270 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
271
videobuf_dma_init_overlay(struct videobuf_dmabuf * dma,int direction,dma_addr_t addr,int nr_pages)272 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
273 dma_addr_t addr, int nr_pages)
274 {
275 dprintk(1, "init overlay [%d pages @ bus 0x%lx]\n",
276 nr_pages, (unsigned long)addr);
277 dma->direction = direction;
278
279 if (0 == addr)
280 return -EINVAL;
281
282 dma->bus_addr = addr;
283 dma->nr_pages = nr_pages;
284
285 return 0;
286 }
287 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
288
videobuf_dma_map(struct device * dev,struct videobuf_dmabuf * dma)289 int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
290 {
291 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
292 BUG_ON(0 == dma->nr_pages);
293
294 if (dma->pages) {
295 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
296 dma->offset, dma->size);
297 }
298 if (dma->vaddr) {
299 dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr,
300 dma->nr_pages);
301 }
302 if (dma->bus_addr) {
303 dma->sglist = vmalloc(sizeof(*dma->sglist));
304 if (NULL != dma->sglist) {
305 dma->sglen = 1;
306 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
307 & PAGE_MASK;
308 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
309 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
310 }
311 }
312 if (NULL == dma->sglist) {
313 dprintk(1, "scatterlist is NULL\n");
314 return -ENOMEM;
315 }
316 if (!dma->bus_addr) {
317 dma->sglen = dma_map_sg(dev, dma->sglist,
318 dma->nr_pages, dma->direction);
319 if (0 == dma->sglen) {
320 printk(KERN_WARNING
321 "%s: videobuf_map_sg failed\n", __func__);
322 vfree(dma->sglist);
323 dma->sglist = NULL;
324 dma->sglen = 0;
325 return -ENOMEM;
326 }
327 }
328
329 return 0;
330 }
331 EXPORT_SYMBOL_GPL(videobuf_dma_map);
332
videobuf_dma_unmap(struct device * dev,struct videobuf_dmabuf * dma)333 int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
334 {
335 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
336
337 if (!dma->sglen)
338 return 0;
339
340 dma_unmap_sg(dev, dma->sglist, dma->sglen, dma->direction);
341
342 vfree(dma->sglist);
343 dma->sglist = NULL;
344 dma->sglen = 0;
345
346 return 0;
347 }
348 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
349
videobuf_dma_free(struct videobuf_dmabuf * dma)350 int videobuf_dma_free(struct videobuf_dmabuf *dma)
351 {
352 int i;
353 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
354 BUG_ON(dma->sglen);
355
356 if (dma->pages) {
357 for (i = 0; i < dma->nr_pages; i++)
358 page_cache_release(dma->pages[i]);
359 kfree(dma->pages);
360 dma->pages = NULL;
361 }
362
363 if (dma->dma_addr) {
364 for (i = 0; i < dma->nr_pages; i++) {
365 void *addr;
366
367 addr = page_address(dma->vaddr_pages[i]);
368 dma_free_coherent(dma->dev, PAGE_SIZE, addr,
369 dma->dma_addr[i]);
370 }
371 kfree(dma->dma_addr);
372 dma->dma_addr = NULL;
373 kfree(dma->vaddr_pages);
374 dma->vaddr_pages = NULL;
375 vunmap(dma->vaddr);
376 dma->vaddr = NULL;
377 }
378
379 if (dma->bus_addr)
380 dma->bus_addr = 0;
381 dma->direction = DMA_NONE;
382
383 return 0;
384 }
385 EXPORT_SYMBOL_GPL(videobuf_dma_free);
386
387 /* --------------------------------------------------------------------- */
388
videobuf_vm_open(struct vm_area_struct * vma)389 static void videobuf_vm_open(struct vm_area_struct *vma)
390 {
391 struct videobuf_mapping *map = vma->vm_private_data;
392
393 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
394 map->count, vma->vm_start, vma->vm_end);
395
396 map->count++;
397 }
398
videobuf_vm_close(struct vm_area_struct * vma)399 static void videobuf_vm_close(struct vm_area_struct *vma)
400 {
401 struct videobuf_mapping *map = vma->vm_private_data;
402 struct videobuf_queue *q = map->q;
403 struct videobuf_dma_sg_memory *mem;
404 int i;
405
406 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
407 map->count, vma->vm_start, vma->vm_end);
408
409 map->count--;
410 if (0 == map->count) {
411 dprintk(1, "munmap %p q=%p\n", map, q);
412 videobuf_queue_lock(q);
413 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
414 if (NULL == q->bufs[i])
415 continue;
416 mem = q->bufs[i]->priv;
417 if (!mem)
418 continue;
419
420 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
421
422 if (q->bufs[i]->map != map)
423 continue;
424 q->bufs[i]->map = NULL;
425 q->bufs[i]->baddr = 0;
426 q->ops->buf_release(q, q->bufs[i]);
427 }
428 videobuf_queue_unlock(q);
429 kfree(map);
430 }
431 return;
432 }
433
434 /*
435 * Get a anonymous page for the mapping. Make sure we can DMA to that
436 * memory location with 32bit PCI devices (i.e. don't use highmem for
437 * now ...). Bounce buffers don't work very well for the data rates
438 * video capture has.
439 */
videobuf_vm_fault(struct vm_area_struct * vma,struct vm_fault * vmf)440 static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
441 {
442 struct page *page;
443
444 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
445 (unsigned long)vmf->virtual_address,
446 vma->vm_start, vma->vm_end);
447
448 page = alloc_page(GFP_USER | __GFP_DMA32);
449 if (!page)
450 return VM_FAULT_OOM;
451 clear_user_highpage(page, (unsigned long)vmf->virtual_address);
452 vmf->page = page;
453
454 return 0;
455 }
456
457 static const struct vm_operations_struct videobuf_vm_ops = {
458 .open = videobuf_vm_open,
459 .close = videobuf_vm_close,
460 .fault = videobuf_vm_fault,
461 };
462
463 /* ---------------------------------------------------------------------
464 * SG handlers for the generic methods
465 */
466
467 /* Allocated area consists on 3 parts:
468 struct video_buffer
469 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
470 struct videobuf_dma_sg_memory
471 */
472
__videobuf_alloc_vb(size_t size)473 static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
474 {
475 struct videobuf_dma_sg_memory *mem;
476 struct videobuf_buffer *vb;
477
478 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
479 if (!vb)
480 return vb;
481
482 mem = vb->priv = ((char *)vb) + size;
483 mem->magic = MAGIC_SG_MEM;
484
485 videobuf_dma_init(&mem->dma);
486
487 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
488 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
489 mem, (long)sizeof(*mem));
490
491 return vb;
492 }
493
__videobuf_to_vaddr(struct videobuf_buffer * buf)494 static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
495 {
496 struct videobuf_dma_sg_memory *mem = buf->priv;
497 BUG_ON(!mem);
498
499 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
500
501 return mem->dma.vaddr;
502 }
503
__videobuf_iolock(struct videobuf_queue * q,struct videobuf_buffer * vb,struct v4l2_framebuffer * fbuf)504 static int __videobuf_iolock(struct videobuf_queue *q,
505 struct videobuf_buffer *vb,
506 struct v4l2_framebuffer *fbuf)
507 {
508 int err, pages;
509 dma_addr_t bus;
510 struct videobuf_dma_sg_memory *mem = vb->priv;
511 BUG_ON(!mem);
512
513 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
514
515 if (!mem->dma.dev)
516 mem->dma.dev = q->dev;
517 else
518 WARN_ON(mem->dma.dev != q->dev);
519
520 switch (vb->memory) {
521 case V4L2_MEMORY_MMAP:
522 case V4L2_MEMORY_USERPTR:
523 if (0 == vb->baddr) {
524 /* no userspace addr -- kernel bounce buffer */
525 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
526 err = videobuf_dma_init_kernel(&mem->dma,
527 DMA_FROM_DEVICE,
528 pages);
529 if (0 != err)
530 return err;
531 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
532 /* dma directly to userspace */
533 err = videobuf_dma_init_user(&mem->dma,
534 DMA_FROM_DEVICE,
535 vb->baddr, vb->bsize);
536 if (0 != err)
537 return err;
538 } else {
539 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
540 buffers can only be called from videobuf_qbuf
541 we take current->mm->mmap_sem there, to prevent
542 locking inversion, so don't take it here */
543
544 err = videobuf_dma_init_user_locked(&mem->dma,
545 DMA_FROM_DEVICE,
546 vb->baddr, vb->bsize);
547 if (0 != err)
548 return err;
549 }
550 break;
551 case V4L2_MEMORY_OVERLAY:
552 if (NULL == fbuf)
553 return -EINVAL;
554 /* FIXME: need sanity checks for vb->boff */
555 /*
556 * Using a double cast to avoid compiler warnings when
557 * building for PAE. Compiler doesn't like direct casting
558 * of a 32 bit ptr to 64 bit integer.
559 */
560 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
561 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
562 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
563 bus, pages);
564 if (0 != err)
565 return err;
566 break;
567 default:
568 BUG();
569 }
570 err = videobuf_dma_map(q->dev, &mem->dma);
571 if (0 != err)
572 return err;
573
574 return 0;
575 }
576
__videobuf_sync(struct videobuf_queue * q,struct videobuf_buffer * buf)577 static int __videobuf_sync(struct videobuf_queue *q,
578 struct videobuf_buffer *buf)
579 {
580 struct videobuf_dma_sg_memory *mem = buf->priv;
581 BUG_ON(!mem || !mem->dma.sglen);
582
583 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
584 MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF);
585
586 dma_sync_sg_for_cpu(q->dev, mem->dma.sglist,
587 mem->dma.sglen, mem->dma.direction);
588
589 return 0;
590 }
591
__videobuf_mmap_mapper(struct videobuf_queue * q,struct videobuf_buffer * buf,struct vm_area_struct * vma)592 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
593 struct videobuf_buffer *buf,
594 struct vm_area_struct *vma)
595 {
596 struct videobuf_dma_sg_memory *mem = buf->priv;
597 struct videobuf_mapping *map;
598 unsigned int first, last, size = 0, i;
599 int retval;
600
601 retval = -EINVAL;
602
603 BUG_ON(!mem);
604 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
605
606 /* look for first buffer to map */
607 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
608 if (buf == q->bufs[first]) {
609 size = PAGE_ALIGN(q->bufs[first]->bsize);
610 break;
611 }
612 }
613
614 /* paranoia, should never happen since buf is always valid. */
615 if (!size) {
616 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
617 (vma->vm_pgoff << PAGE_SHIFT));
618 goto done;
619 }
620
621 last = first;
622
623 /* create mapping + update buffer list */
624 retval = -ENOMEM;
625 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
626 if (NULL == map)
627 goto done;
628
629 size = 0;
630 for (i = first; i <= last; i++) {
631 if (NULL == q->bufs[i])
632 continue;
633 q->bufs[i]->map = map;
634 q->bufs[i]->baddr = vma->vm_start + size;
635 size += PAGE_ALIGN(q->bufs[i]->bsize);
636 }
637
638 map->count = 1;
639 map->q = q;
640 vma->vm_ops = &videobuf_vm_ops;
641 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
642 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
643 vma->vm_private_data = map;
644 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
645 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
646 retval = 0;
647
648 done:
649 return retval;
650 }
651
652 static struct videobuf_qtype_ops sg_ops = {
653 .magic = MAGIC_QTYPE_OPS,
654
655 .alloc_vb = __videobuf_alloc_vb,
656 .iolock = __videobuf_iolock,
657 .sync = __videobuf_sync,
658 .mmap_mapper = __videobuf_mmap_mapper,
659 .vaddr = __videobuf_to_vaddr,
660 };
661
videobuf_sg_alloc(size_t size)662 void *videobuf_sg_alloc(size_t size)
663 {
664 struct videobuf_queue q;
665
666 /* Required to make generic handler to call __videobuf_alloc */
667 q.int_ops = &sg_ops;
668
669 q.msize = size;
670
671 return videobuf_alloc_vb(&q);
672 }
673 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
674
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)675 void videobuf_queue_sg_init(struct videobuf_queue *q,
676 const struct videobuf_queue_ops *ops,
677 struct device *dev,
678 spinlock_t *irqlock,
679 enum v4l2_buf_type type,
680 enum v4l2_field field,
681 unsigned int msize,
682 void *priv,
683 struct mutex *ext_lock)
684 {
685 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
686 priv, &sg_ops, ext_lock);
687 }
688 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
689
690