Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / drivers / media / video / videobuf-dma-sg.c
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/slab.h>
25 #include <linux/interrupt.h>
26
27 #include <linux/dma-mapping.h>
28 #include <linux/vmalloc.h>
29 #include <linux/pagemap.h>
30 #include <linux/scatterlist.h>
31 #include <asm/page.h>
32 #include <asm/pgtable.h>
33
34 #include <media/videobuf-dma-sg.h>
35
36 #define MAGIC_DMABUF 0x19721112
37 #define MAGIC_SG_MEM 0x17890714
38
39 #define MAGIC_CHECK(is,should)  if (unlikely((is) != (should))) \
40         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
41
42 static int debug;
43 module_param(debug, int, 0644);
44
45 MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
46 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
47 MODULE_LICENSE("GPL");
48
49 #define dprintk(level, fmt, arg...)     if (debug >= level) \
50         printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
51
52 /* --------------------------------------------------------------------- */
53
54 struct scatterlist*
55 videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
56 {
57         struct scatterlist *sglist;
58         struct page *pg;
59         int i;
60
61         sglist = vmalloc(nr_pages * sizeof(*sglist));
62         if (NULL == sglist)
63                 return NULL;
64         memset(sglist, 0, nr_pages * sizeof(*sglist));
65         sg_init_table(sglist, nr_pages);
66         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
67                 pg = vmalloc_to_page(virt);
68                 if (NULL == pg)
69                         goto err;
70                 BUG_ON(PageHighMem(pg));
71                 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
72         }
73         return sglist;
74
75  err:
76         vfree(sglist);
77         return NULL;
78 }
79
80 struct scatterlist*
81 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
82 {
83         struct scatterlist *sglist;
84         int i;
85
86         if (NULL == pages[0])
87                 return NULL;
88         sglist = vmalloc(nr_pages * sizeof(*sglist));
89         if (NULL == sglist)
90                 return NULL;
91         sg_init_table(sglist, nr_pages);
92
93         if (PageHighMem(pages[0]))
94                 /* DMA to highmem pages might not work */
95                 goto highmem;
96         sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
97         for (i = 1; i < nr_pages; i++) {
98                 if (NULL == pages[i])
99                         goto nopage;
100                 if (PageHighMem(pages[i]))
101                         goto highmem;
102                 sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
103         }
104         return sglist;
105
106  nopage:
107         dprintk(2,"sgl: oops - no page\n");
108         vfree(sglist);
109         return NULL;
110
111  highmem:
112         dprintk(2,"sgl: oops - highmem page\n");
113         vfree(sglist);
114         return NULL;
115 }
116
117 /* --------------------------------------------------------------------- */
118
119 struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf)
120 {
121         struct videobuf_dma_sg_memory *mem = buf->priv;
122         BUG_ON(!mem);
123
124         MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
125
126         return &mem->dma;
127 }
128
129 void videobuf_dma_init(struct videobuf_dmabuf *dma)
130 {
131         memset(dma,0,sizeof(*dma));
132         dma->magic = MAGIC_DMABUF;
133 }
134
135 static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
136                         int direction, unsigned long data, unsigned long size)
137 {
138         unsigned long first,last;
139         int err, rw = 0;
140
141         dma->direction = direction;
142         switch (dma->direction) {
143         case DMA_FROM_DEVICE:
144                 rw = READ;
145                 break;
146         case DMA_TO_DEVICE:
147                 rw = WRITE;
148                 break;
149         default:
150                 BUG();
151         }
152
153         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
154         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
155         dma->offset   = data & ~PAGE_MASK;
156         dma->nr_pages = last-first+1;
157         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
158                              GFP_KERNEL);
159         if (NULL == dma->pages)
160                 return -ENOMEM;
161         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
162                 data,size,dma->nr_pages);
163
164         err = get_user_pages(current,current->mm,
165                              data & PAGE_MASK, dma->nr_pages,
166                              rw == READ, 1, /* force */
167                              dma->pages, NULL);
168
169         if (err != dma->nr_pages) {
170                 dma->nr_pages = (err >= 0) ? err : 0;
171                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
172                 return err < 0 ? err : -EINVAL;
173         }
174         return 0;
175 }
176
177 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
178                            unsigned long data, unsigned long size)
179 {
180         int ret;
181         down_read(&current->mm->mmap_sem);
182         ret = videobuf_dma_init_user_locked(dma, direction, data, size);
183         up_read(&current->mm->mmap_sem);
184
185         return ret;
186 }
187
188 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
189                              int nr_pages)
190 {
191         dprintk(1,"init kernel [%d pages]\n",nr_pages);
192         dma->direction = direction;
193         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
194         if (NULL == dma->vmalloc) {
195                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
196                 return -ENOMEM;
197         }
198         dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
199                                 (unsigned long)dma->vmalloc,
200                                 nr_pages << PAGE_SHIFT);
201         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
202         dma->nr_pages = nr_pages;
203         return 0;
204 }
205
206 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
207                               dma_addr_t addr, int nr_pages)
208 {
209         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
210                 nr_pages,(unsigned long)addr);
211         dma->direction = direction;
212         if (0 == addr)
213                 return -EINVAL;
214
215         dma->bus_addr = addr;
216         dma->nr_pages = nr_pages;
217         return 0;
218 }
219
220 int videobuf_dma_map(struct videobuf_queue* q, struct videobuf_dmabuf *dma)
221 {
222         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
223         BUG_ON(0 == dma->nr_pages);
224
225         if (dma->pages) {
226                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
227                                                    dma->offset);
228         }
229         if (dma->vmalloc) {
230                 dma->sglist = videobuf_vmalloc_to_sg
231                                                 (dma->vmalloc,dma->nr_pages);
232         }
233         if (dma->bus_addr) {
234                 dma->sglist = vmalloc(sizeof(*dma->sglist));
235                 if (NULL != dma->sglist) {
236                         dma->sglen  = 1;
237                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
238                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
239                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
240                 }
241         }
242         if (NULL == dma->sglist) {
243                 dprintk(1,"scatterlist is NULL\n");
244                 return -ENOMEM;
245         }
246         if (!dma->bus_addr) {
247                 dma->sglen = dma_map_sg(q->dev, dma->sglist,
248                                         dma->nr_pages, dma->direction);
249                 if (0 == dma->sglen) {
250                         printk(KERN_WARNING
251                                "%s: videobuf_map_sg failed\n",__func__);
252                         vfree(dma->sglist);
253                         dma->sglist = NULL;
254                         dma->sglen = 0;
255                         return -ENOMEM;
256                 }
257         }
258         return 0;
259 }
260
261 int videobuf_dma_sync(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
262 {
263         MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
264         BUG_ON(!dma->sglen);
265
266         dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->nr_pages, dma->direction);
267         return 0;
268 }
269
270 int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
271 {
272         MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
273         if (!dma->sglen)
274                 return 0;
275
276         dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
277
278         vfree(dma->sglist);
279         dma->sglist = NULL;
280         dma->sglen = 0;
281         return 0;
282 }
283
284 int videobuf_dma_free(struct videobuf_dmabuf *dma)
285 {
286         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
287         BUG_ON(dma->sglen);
288
289         if (dma->pages) {
290                 int i;
291                 for (i=0; i < dma->nr_pages; i++)
292                         page_cache_release(dma->pages[i]);
293                 kfree(dma->pages);
294                 dma->pages = NULL;
295         }
296
297         vfree(dma->vmalloc);
298         dma->vmalloc = NULL;
299
300         if (dma->bus_addr) {
301                 dma->bus_addr = 0;
302         }
303         dma->direction = DMA_NONE;
304         return 0;
305 }
306
307 /* --------------------------------------------------------------------- */
308
309 int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
310 {
311         struct videobuf_queue q;
312
313         q.dev = dev;
314
315         return videobuf_dma_map(&q, dma);
316 }
317
318 int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
319 {
320         struct videobuf_queue q;
321
322         q.dev = dev;
323
324         return videobuf_dma_unmap(&q, dma);
325 }
326
327 /* --------------------------------------------------------------------- */
328
329 static void
330 videobuf_vm_open(struct vm_area_struct *vma)
331 {
332         struct videobuf_mapping *map = vma->vm_private_data;
333
334         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
335                 map->count,vma->vm_start,vma->vm_end);
336         map->count++;
337 }
338
339 static void
340 videobuf_vm_close(struct vm_area_struct *vma)
341 {
342         struct videobuf_mapping *map = vma->vm_private_data;
343         struct videobuf_queue *q = map->q;
344         struct videobuf_dma_sg_memory *mem;
345         int i;
346
347         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
348                 map->count,vma->vm_start,vma->vm_end);
349
350         map->count--;
351         if (0 == map->count) {
352                 dprintk(1,"munmap %p q=%p\n",map,q);
353                 mutex_lock(&q->vb_lock);
354                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
355                         if (NULL == q->bufs[i])
356                                 continue;
357                         mem=q->bufs[i]->priv;
358
359                         if (!mem)
360                                 continue;
361
362                         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
363
364                         if (q->bufs[i]->map != map)
365                                 continue;
366                         q->bufs[i]->map   = NULL;
367                         q->bufs[i]->baddr = 0;
368                         q->ops->buf_release(q,q->bufs[i]);
369                 }
370                 mutex_unlock(&q->vb_lock);
371                 kfree(map);
372         }
373         return;
374 }
375
376 /*
377  * Get a anonymous page for the mapping.  Make sure we can DMA to that
378  * memory location with 32bit PCI devices (i.e. don't use highmem for
379  * now ...).  Bounce buffers don't work very well for the data rates
380  * video capture has.
381  */
382 static int
383 videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
384 {
385         struct page *page;
386
387         dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
388                 (unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
389         page = alloc_page(GFP_USER | __GFP_DMA32);
390         if (!page)
391                 return VM_FAULT_OOM;
392         clear_user_highpage(page, (unsigned long)vmf->virtual_address);
393         vmf->page = page;
394         return 0;
395 }
396
397 static struct vm_operations_struct videobuf_vm_ops =
398 {
399         .open     = videobuf_vm_open,
400         .close    = videobuf_vm_close,
401         .fault    = videobuf_vm_fault,
402 };
403
404 /* ---------------------------------------------------------------------
405  * SG handlers for the generic methods
406  */
407
408 /* Allocated area consists on 3 parts:
409         struct video_buffer
410         struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
411         struct videobuf_dma_sg_memory
412  */
413
414 static void *__videobuf_alloc(size_t size)
415 {
416         struct videobuf_dma_sg_memory *mem;
417         struct videobuf_buffer *vb;
418
419         vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);
420
421         mem = vb->priv = ((char *)vb)+size;
422         mem->magic=MAGIC_SG_MEM;
423
424         videobuf_dma_init(&mem->dma);
425
426         dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
427                 __func__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
428                 mem,(long)sizeof(*mem));
429
430         return vb;
431 }
432
433 static void *__videobuf_to_vmalloc (struct videobuf_buffer *buf)
434 {
435         struct videobuf_dma_sg_memory *mem = buf->priv;
436         BUG_ON(!mem);
437
438         MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
439
440         return mem->dma.vmalloc;
441 }
442
443 static int __videobuf_iolock (struct videobuf_queue* q,
444                               struct videobuf_buffer *vb,
445                               struct v4l2_framebuffer *fbuf)
446 {
447         int err,pages;
448         dma_addr_t bus;
449         struct videobuf_dma_sg_memory *mem = vb->priv;
450         BUG_ON(!mem);
451
452         MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
453
454         switch (vb->memory) {
455         case V4L2_MEMORY_MMAP:
456         case V4L2_MEMORY_USERPTR:
457                 if (0 == vb->baddr) {
458                         /* no userspace addr -- kernel bounce buffer */
459                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
460                         err = videobuf_dma_init_kernel( &mem->dma,
461                                                         DMA_FROM_DEVICE,
462                                                         pages );
463                         if (0 != err)
464                                 return err;
465                 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
466                         /* dma directly to userspace */
467                         err = videobuf_dma_init_user( &mem->dma,
468                                                       DMA_FROM_DEVICE,
469                                                       vb->baddr,vb->bsize );
470                         if (0 != err)
471                                 return err;
472                 } else {
473                         /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
474                         buffers can only be called from videobuf_qbuf
475                         we take current->mm->mmap_sem there, to prevent
476                         locking inversion, so don't take it here */
477
478                         err = videobuf_dma_init_user_locked(&mem->dma,
479                                                       DMA_FROM_DEVICE,
480                                                       vb->baddr, vb->bsize);
481                         if (0 != err)
482                                 return err;
483                 }
484                 break;
485         case V4L2_MEMORY_OVERLAY:
486                 if (NULL == fbuf)
487                         return -EINVAL;
488                 /* FIXME: need sanity checks for vb->boff */
489                 /*
490                  * Using a double cast to avoid compiler warnings when
491                  * building for PAE. Compiler doesn't like direct casting
492                  * of a 32 bit ptr to 64 bit integer.
493                  */
494                 bus   = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
495                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
496                 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
497                                                 bus, pages);
498                 if (0 != err)
499                         return err;
500                 break;
501         default:
502                 BUG();
503         }
504         err = videobuf_dma_map(q, &mem->dma);
505         if (0 != err)
506                 return err;
507
508         return 0;
509 }
510
511 static int __videobuf_sync(struct videobuf_queue *q,
512                            struct videobuf_buffer *buf)
513 {
514         struct videobuf_dma_sg_memory *mem = buf->priv;
515         BUG_ON(!mem);
516         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
517
518         return  videobuf_dma_sync(q,&mem->dma);
519 }
520
521 static int __videobuf_mmap_free(struct videobuf_queue *q)
522 {
523         int i;
524
525         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
526                 if (q->bufs[i]) {
527                         if (q->bufs[i]->map)
528                                 return -EBUSY;
529                 }
530         }
531
532         return 0;
533 }
534
535 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
536                          struct vm_area_struct *vma)
537 {
538         struct videobuf_dma_sg_memory *mem;
539         struct videobuf_mapping *map;
540         unsigned int first,last,size,i;
541         int retval;
542
543         retval = -EINVAL;
544         if (!(vma->vm_flags & VM_WRITE)) {
545                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
546                 goto done;
547         }
548         if (!(vma->vm_flags & VM_SHARED)) {
549                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
550                 goto done;
551         }
552
553         /* This function maintains backwards compatibility with V4L1 and will
554          * map more than one buffer if the vma length is equal to the combined
555          * size of multiple buffers than it will map them together.  See
556          * VIDIOCGMBUF in the v4l spec
557          *
558          * TODO: Allow drivers to specify if they support this mode
559          */
560
561         /* look for first buffer to map */
562         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
563                 if (NULL == q->bufs[first])
564                         continue;
565                 mem=q->bufs[first]->priv;
566                 BUG_ON(!mem);
567                 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
568
569                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
570                         continue;
571                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
572                         break;
573         }
574         if (VIDEO_MAX_FRAME == first) {
575                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
576                         (vma->vm_pgoff << PAGE_SHIFT));
577                 goto done;
578         }
579
580         /* look for last buffer to map */
581         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
582                 if (NULL == q->bufs[last])
583                         continue;
584                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
585                         continue;
586                 if (q->bufs[last]->map) {
587                         retval = -EBUSY;
588                         goto done;
589                 }
590                 size += q->bufs[last]->bsize;
591                 if (size == (vma->vm_end - vma->vm_start))
592                         break;
593         }
594         if (VIDEO_MAX_FRAME == last) {
595                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
596                         (vma->vm_end - vma->vm_start));
597                 goto done;
598         }
599
600         /* create mapping + update buffer list */
601         retval = -ENOMEM;
602         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
603         if (NULL == map)
604                 goto done;
605
606         size = 0;
607         for (i = first; i <= last; i++) {
608                 if (NULL == q->bufs[i])
609                         continue;
610                 q->bufs[i]->map   = map;
611                 q->bufs[i]->baddr = vma->vm_start + size;
612                 size += q->bufs[i]->bsize;
613         }
614
615         map->count    = 1;
616         map->start    = vma->vm_start;
617         map->end      = vma->vm_end;
618         map->q        = q;
619         vma->vm_ops   = &videobuf_vm_ops;
620         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
621         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
622         vma->vm_private_data = map;
623         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
624                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
625         retval = 0;
626
627  done:
628         return retval;
629 }
630
631 static int __videobuf_copy_to_user ( struct videobuf_queue *q,
632                                 char __user *data, size_t count,
633                                 int nonblocking )
634 {
635         struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
636         BUG_ON(!mem);
637         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
638
639         /* copy to userspace */
640         if (count > q->read_buf->size - q->read_off)
641                 count = q->read_buf->size - q->read_off;
642
643         if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
644                 return -EFAULT;
645
646         return count;
647 }
648
649 static int __videobuf_copy_stream ( struct videobuf_queue *q,
650                                 char __user *data, size_t count, size_t pos,
651                                 int vbihack, int nonblocking )
652 {
653         unsigned int  *fc;
654         struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
655         BUG_ON(!mem);
656         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
657
658         if (vbihack) {
659                 /* dirty, undocumented hack -- pass the frame counter
660                         * within the last four bytes of each vbi data block.
661                         * We need that one to maintain backward compatibility
662                         * to all vbi decoding software out there ... */
663                 fc  = (unsigned int*)mem->dma.vmalloc;
664                 fc += (q->read_buf->size>>2) -1;
665                 *fc = q->read_buf->field_count >> 1;
666                 dprintk(1,"vbihack: %d\n",*fc);
667         }
668
669         /* copy stuff using the common method */
670         count = __videobuf_copy_to_user (q,data,count,nonblocking);
671
672         if ( (count==-EFAULT) && (0 == pos) )
673                 return -EFAULT;
674
675         return count;
676 }
677
678 static struct videobuf_qtype_ops sg_ops = {
679         .magic        = MAGIC_QTYPE_OPS,
680
681         .alloc        = __videobuf_alloc,
682         .iolock       = __videobuf_iolock,
683         .sync         = __videobuf_sync,
684         .mmap_free    = __videobuf_mmap_free,
685         .mmap_mapper  = __videobuf_mmap_mapper,
686         .video_copy_to_user = __videobuf_copy_to_user,
687         .copy_stream  = __videobuf_copy_stream,
688         .vmalloc      = __videobuf_to_vmalloc,
689 };
690
691 void *videobuf_sg_alloc(size_t size)
692 {
693         struct videobuf_queue q;
694
695         /* Required to make generic handler to call __videobuf_alloc */
696         q.int_ops = &sg_ops;
697
698         q.msize = size;
699
700         return videobuf_alloc(&q);
701 }
702
703 void videobuf_queue_sg_init(struct videobuf_queue* q,
704                          struct videobuf_queue_ops *ops,
705                          struct device *dev,
706                          spinlock_t *irqlock,
707                          enum v4l2_buf_type type,
708                          enum v4l2_field field,
709                          unsigned int msize,
710                          void *priv)
711 {
712         videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
713                                  priv, &sg_ops);
714 }
715
716 /* --------------------------------------------------------------------- */
717
718 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
719
720 EXPORT_SYMBOL_GPL(videobuf_to_dma);
721 EXPORT_SYMBOL_GPL(videobuf_dma_init);
722 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
723 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
724 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
725 EXPORT_SYMBOL_GPL(videobuf_dma_map);
726 EXPORT_SYMBOL_GPL(videobuf_dma_sync);
727 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
728 EXPORT_SYMBOL_GPL(videobuf_dma_free);
729
730 EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
731 EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
732 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
733
734 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
735
736 /*
737  * Local variables:
738  * c-basic-offset: 8
739  * End:
740  */