?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
V4L/DVB: v4l videobuf: use struct videobuf_buffer * instead of void * for videobuf_alloc
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / media / video / videobuf-dma-sg.c
blob014eb63c096034dfc7c26d903de5dbc8dee9189b
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 struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
61 {
62 struct scatterlist *sglist;
63 struct page *pg;
64 int i;
65
66 sglist = vmalloc(nr_pages * sizeof(*sglist));
67 if (NULL == sglist)
68 return NULL;
69 memset(sglist, 0, nr_pages * sizeof(*sglist));
70 sg_init_table(sglist, nr_pages);
71 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
72 pg = vmalloc_to_page(virt);
73 if (NULL == pg)
74 goto err;
75 BUG_ON(PageHighMem(pg));
76 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
77 }
78 return sglist;
79
80 err:
81 vfree(sglist);
82 return NULL;
83 }
84 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
85
86 struct scatterlist *videobuf_pages_to_sg(struct page **pages, int nr_pages,
87 int offset)
88 {
89 struct scatterlist *sglist;
90 int i;
91
92 if (NULL == pages[0])
93 return NULL;
94 sglist = vmalloc(nr_pages * sizeof(*sglist));
95 if (NULL == sglist)
96 return NULL;
97 sg_init_table(sglist, nr_pages);
98
99 if (PageHighMem(pages[0]))
100 /* DMA to highmem pages might not work */
101 goto highmem;
102 sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
103 for (i = 1; i < nr_pages; i++) {
104 if (NULL == pages[i])
105 goto nopage;
106 if (PageHighMem(pages[i]))
107 goto highmem;
108 sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
109 }
110 return sglist;
111
112 nopage:
113 dprintk(2, "sgl: oops - no page\n");
114 vfree(sglist);
115 return NULL;
116
117 highmem:
118 dprintk(2, "sgl: oops - highmem page\n");
119 vfree(sglist);
120 return NULL;
121 }
122
123 /* --------------------------------------------------------------------- */
124
125 struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf)
126 {
127 struct videobuf_dma_sg_memory *mem = buf->priv;
128 BUG_ON(!mem);
129
130 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
131
132 return &mem->dma;
133 }
134 EXPORT_SYMBOL_GPL(videobuf_to_dma);
135
136 void videobuf_dma_init(struct videobuf_dmabuf *dma)
137 {
138 memset(dma, 0, sizeof(*dma));
139 dma->magic = MAGIC_DMABUF;
140 }
141 EXPORT_SYMBOL_GPL(videobuf_dma_init);
142
143 static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
144 int direction, unsigned long data, unsigned long size)
145 {
146 unsigned long first, last;
147 int err, rw = 0;
148
149 dma->direction = direction;
150 switch (dma->direction) {
151 case DMA_FROM_DEVICE:
152 rw = READ;
153 break;
154 case DMA_TO_DEVICE:
155 rw = WRITE;
156 break;
157 default:
158 BUG();
159 }
160
161 first = (data & PAGE_MASK) >> PAGE_SHIFT;
162 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
163 dma->offset = data & ~PAGE_MASK;
164 dma->nr_pages = last-first+1;
165 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page *), GFP_KERNEL);
166 if (NULL == dma->pages)
167 return -ENOMEM;
168
169 dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
170 data, size, dma->nr_pages);
171
172 err = get_user_pages(current, current->mm,
173 data & PAGE_MASK, dma->nr_pages,
174 rw == READ, 1, /* force */
175 dma->pages, NULL);
176
177 if (err != dma->nr_pages) {
178 dma->nr_pages = (err >= 0) ? err : 0;
179 dprintk(1, "get_user_pages: err=%d [%d]\n", err, dma->nr_pages);
180 return err < 0 ? err : -EINVAL;
181 }
182 return 0;
183 }
184
185 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
186 unsigned long data, unsigned long size)
187 {
188 int ret;
189
190 down_read(&current->mm->mmap_sem);
191 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
192 up_read(&current->mm->mmap_sem);
193
194 return ret;
195 }
196 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
197
198 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
199 int nr_pages)
200 {
201 dprintk(1, "init kernel [%d pages]\n", nr_pages);
202
203 dma->direction = direction;
204 dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
205 if (NULL == dma->vmalloc) {
206 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
207 return -ENOMEM;
208 }
209
210 dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
211 (unsigned long)dma->vmalloc,
212 nr_pages << PAGE_SHIFT);
213
214 memset(dma->vmalloc, 0, nr_pages << PAGE_SHIFT);
215 dma->nr_pages = nr_pages;
216
217 return 0;
218 }
219 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
220
221 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
222 dma_addr_t addr, int nr_pages)
223 {
224 dprintk(1, "init overlay [%d pages @ bus 0x%lx]\n",
225 nr_pages, (unsigned long)addr);
226 dma->direction = direction;
227
228 if (0 == addr)
229 return -EINVAL;
230
231 dma->bus_addr = addr;
232 dma->nr_pages = nr_pages;
233
234 return 0;
235 }
236 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
237
238 int videobuf_dma_map(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
239 {
240 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
241 BUG_ON(0 == dma->nr_pages);
242
243 if (dma->pages) {
244 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
245 dma->offset);
246 }
247 if (dma->vmalloc) {
248 dma->sglist = videobuf_vmalloc_to_sg(dma->vmalloc,
249 dma->nr_pages);
250 }
251 if (dma->bus_addr) {
252 dma->sglist = vmalloc(sizeof(*dma->sglist));
253 if (NULL != dma->sglist) {
254 dma->sglen = 1;
255 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
256 & PAGE_MASK;
257 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
258 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
259 }
260 }
261 if (NULL == dma->sglist) {
262 dprintk(1, "scatterlist is NULL\n");
263 return -ENOMEM;
264 }
265 if (!dma->bus_addr) {
266 dma->sglen = dma_map_sg(q->dev, dma->sglist,
267 dma->nr_pages, dma->direction);
268 if (0 == dma->sglen) {
269 printk(KERN_WARNING
270 "%s: videobuf_map_sg failed\n", __func__);
271 vfree(dma->sglist);
272 dma->sglist = NULL;
273 dma->sglen = 0;
274 return -ENOMEM;
275 }
276 }
277
278 return 0;
279 }
280 EXPORT_SYMBOL_GPL(videobuf_dma_map);
281
282 int videobuf_dma_sync(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
283 {
284 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
285 BUG_ON(!dma->sglen);
286
287 dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->nr_pages, dma->direction);
288
289 return 0;
290 }
291 EXPORT_SYMBOL_GPL(videobuf_dma_sync);
292
293 int videobuf_dma_unmap(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
294 {
295 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
296
297 if (!dma->sglen)
298 return 0;
299
300 dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
301
302 vfree(dma->sglist);
303 dma->sglist = NULL;
304 dma->sglen = 0;
305
306 return 0;
307 }
308 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
309
310 int videobuf_dma_free(struct videobuf_dmabuf *dma)
311 {
312 int i;
313 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
314 BUG_ON(dma->sglen);
315
316 if (dma->pages) {
317 for (i = 0; i < dma->nr_pages; i++)
318 page_cache_release(dma->pages[i]);
319 kfree(dma->pages);
320 dma->pages = NULL;
321 }
322
323 vfree(dma->vmalloc);
324 dma->vmalloc = NULL;
325
326 if (dma->bus_addr)
327 dma->bus_addr = 0;
328 dma->direction = DMA_NONE;
329
330 return 0;
331 }
332 EXPORT_SYMBOL_GPL(videobuf_dma_free);
333
334 /* --------------------------------------------------------------------- */
335
336 int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
337 {
338 struct videobuf_queue q;
339
340 q.dev = dev;
341
342 return videobuf_dma_map(&q, dma);
343 }
344 EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
345
346 int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
347 {
348 struct videobuf_queue q;
349
350 q.dev = dev;
351
352 return videobuf_dma_unmap(&q, dma);
353 }
354 EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
355
356 /* --------------------------------------------------------------------- */
357
358 static void videobuf_vm_open(struct vm_area_struct *vma)
359 {
360 struct videobuf_mapping *map = vma->vm_private_data;
361
362 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
363 map->count, vma->vm_start, vma->vm_end);
364
365 map->count++;
366 }
367
368 static void videobuf_vm_close(struct vm_area_struct *vma)
369 {
370 struct videobuf_mapping *map = vma->vm_private_data;
371 struct videobuf_queue *q = map->q;
372 struct videobuf_dma_sg_memory *mem;
373 int i;
374
375 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
376 map->count, vma->vm_start, vma->vm_end);
377
378 map->count--;
379 if (0 == map->count) {
380 dprintk(1, "munmap %p q=%p\n", map, q);
381 mutex_lock(&q->vb_lock);
382 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
383 if (NULL == q->bufs[i])
384 continue;
385 mem = q->bufs[i]->priv;
386 if (!mem)
387 continue;
388
389 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
390
391 if (q->bufs[i]->map != map)
392 continue;
393 q->bufs[i]->map = NULL;
394 q->bufs[i]->baddr = 0;
395 q->ops->buf_release(q, q->bufs[i]);
396 }
397 mutex_unlock(&q->vb_lock);
398 kfree(map);
399 }
400 return;
401 }
402
403 /*
404 * Get a anonymous page for the mapping. Make sure we can DMA to that
405 * memory location with 32bit PCI devices (i.e. don't use highmem for
406 * now ...). Bounce buffers don't work very well for the data rates
407 * video capture has.
408 */
409 static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
410 {
411 struct page *page;
412
413 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
414 (unsigned long)vmf->virtual_address,
415 vma->vm_start, vma->vm_end);
416
417 page = alloc_page(GFP_USER | __GFP_DMA32);
418 if (!page)
419 return VM_FAULT_OOM;
420 clear_user_highpage(page, (unsigned long)vmf->virtual_address);
421 vmf->page = page;
422
423 return 0;
424 }
425
426 static const struct vm_operations_struct videobuf_vm_ops = {
427 .open = videobuf_vm_open,
428 .close = videobuf_vm_close,
429 .fault = videobuf_vm_fault,
430 };
431
432 /* ---------------------------------------------------------------------
433 * SG handlers for the generic methods
434 */
435
436 /* Allocated area consists on 3 parts:
437 struct video_buffer
438 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
439 struct videobuf_dma_sg_memory
440 */
441
442 static struct videobuf_buffer *__videobuf_alloc(size_t size)
443 {
444 struct videobuf_dma_sg_memory *mem;
445 struct videobuf_buffer *vb;
446
447 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
448 if (!vb)
449 return vb;
450
451 mem = vb->priv = ((char *)vb) + size;
452 mem->magic = MAGIC_SG_MEM;
453
454 videobuf_dma_init(&mem->dma);
455
456 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
457 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
458 mem, (long)sizeof(*mem));
459
460 return vb;
461 }
462
463 static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf)
464 {
465 struct videobuf_dma_sg_memory *mem = buf->priv;
466 BUG_ON(!mem);
467
468 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
469
470 return mem->dma.vmalloc;
471 }
472
473 static int __videobuf_iolock(struct videobuf_queue *q,
474 struct videobuf_buffer *vb,
475 struct v4l2_framebuffer *fbuf)
476 {
477 int err, pages;
478 dma_addr_t bus;
479 struct videobuf_dma_sg_memory *mem = vb->priv;
480 BUG_ON(!mem);
481
482 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
483
484 switch (vb->memory) {
485 case V4L2_MEMORY_MMAP:
486 case V4L2_MEMORY_USERPTR:
487 if (0 == vb->baddr) {
488 /* no userspace addr -- kernel bounce buffer */
489 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
490 err = videobuf_dma_init_kernel(&mem->dma,
491 DMA_FROM_DEVICE,
492 pages);
493 if (0 != err)
494 return err;
495 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
496 /* dma directly to userspace */
497 err = videobuf_dma_init_user(&mem->dma,
498 DMA_FROM_DEVICE,
499 vb->baddr, vb->bsize);
500 if (0 != err)
501 return err;
502 } else {
503 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
504 buffers can only be called from videobuf_qbuf
505 we take current->mm->mmap_sem there, to prevent
506 locking inversion, so don't take it here */
507
508 err = videobuf_dma_init_user_locked(&mem->dma,
509 DMA_FROM_DEVICE,
510 vb->baddr, vb->bsize);
511 if (0 != err)
512 return err;
513 }
514 break;
515 case V4L2_MEMORY_OVERLAY:
516 if (NULL == fbuf)
517 return -EINVAL;
518 /* FIXME: need sanity checks for vb->boff */
519 /*
520 * Using a double cast to avoid compiler warnings when
521 * building for PAE. Compiler doesn't like direct casting
522 * of a 32 bit ptr to 64 bit integer.
523 */
524 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
525 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
526 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
527 bus, pages);
528 if (0 != err)
529 return err;
530 break;
531 default:
532 BUG();
533 }
534 err = videobuf_dma_map(q, &mem->dma);
535 if (0 != err)
536 return err;
537
538 return 0;
539 }
540
541 static int __videobuf_sync(struct videobuf_queue *q,
542 struct videobuf_buffer *buf)
543 {
544 struct videobuf_dma_sg_memory *mem = buf->priv;
545 BUG_ON(!mem);
546 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
547
548 return videobuf_dma_sync(q, &mem->dma);
549 }
550
551 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
552 struct vm_area_struct *vma)
553 {
554 struct videobuf_dma_sg_memory *mem;
555 struct videobuf_mapping *map;
556 unsigned int first, last, size, i;
557 int retval;
558
559 retval = -EINVAL;
560 if (!(vma->vm_flags & VM_WRITE)) {
561 dprintk(1, "mmap app bug: PROT_WRITE please\n");
562 goto done;
563 }
564 if (!(vma->vm_flags & VM_SHARED)) {
565 dprintk(1, "mmap app bug: MAP_SHARED please\n");
566 goto done;
567 }
568
569 /* This function maintains backwards compatibility with V4L1 and will
570 * map more than one buffer if the vma length is equal to the combined
571 * size of multiple buffers than it will map them together. See
572 * VIDIOCGMBUF in the v4l spec
573 *
574 * TODO: Allow drivers to specify if they support this mode
575 */
576
577 /* look for first buffer to map */
578 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
579 if (NULL == q->bufs[first])
580 continue;
581 mem = q->bufs[first]->priv;
582 BUG_ON(!mem);
583 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
584
585 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
586 continue;
587 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
588 break;
589 }
590 if (VIDEO_MAX_FRAME == first) {
591 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
592 (vma->vm_pgoff << PAGE_SHIFT));
593 goto done;
594 }
595
596 /* look for last buffer to map */
597 for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
598 if (NULL == q->bufs[last])
599 continue;
600 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
601 continue;
602 if (q->bufs[last]->map) {
603 retval = -EBUSY;
604 goto done;
605 }
606 size += PAGE_ALIGN(q->bufs[last]->bsize);
607 if (size == (vma->vm_end - vma->vm_start))
608 break;
609 }
610 if (VIDEO_MAX_FRAME == last) {
611 dprintk(1, "mmap app bug: size invalid [size=0x%lx]\n",
612 (vma->vm_end - vma->vm_start));
613 goto done;
614 }
615
616 /* create mapping + update buffer list */
617 retval = -ENOMEM;
618 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
619 if (NULL == map)
620 goto done;
621
622 size = 0;
623 for (i = first; i <= last; i++) {
624 if (NULL == q->bufs[i])
625 continue;
626 q->bufs[i]->map = map;
627 q->bufs[i]->baddr = vma->vm_start + size;
628 size += PAGE_ALIGN(q->bufs[i]->bsize);
629 }
630
631 map->count = 1;
632 map->start = vma->vm_start;
633 map->end = vma->vm_end;
634 map->q = q;
635 vma->vm_ops = &videobuf_vm_ops;
636 vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
637 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
638 vma->vm_private_data = map;
639 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
640 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
641 retval = 0;
642
643 done:
644 return retval;
645 }
646
647 static int __videobuf_copy_to_user(struct videobuf_queue *q,
648 char __user *data, size_t count,
649 int nonblocking)
650 {
651 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
652 BUG_ON(!mem);
653 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
654
655 /* copy to userspace */
656 if (count > q->read_buf->size - q->read_off)
657 count = q->read_buf->size - q->read_off;
658
659 if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
660 return -EFAULT;
661
662 return count;
663 }
664
665 static int __videobuf_copy_stream(struct videobuf_queue *q,
666 char __user *data, size_t count, size_t pos,
667 int vbihack, int nonblocking)
668 {
669 unsigned int *fc;
670 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
671 BUG_ON(!mem);
672 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
673
674 if (vbihack) {
675 /* dirty, undocumented hack -- pass the frame counter
676 * within the last four bytes of each vbi data block.
677 * We need that one to maintain backward compatibility
678 * to all vbi decoding software out there ... */
679 fc = (unsigned int *)mem->dma.vmalloc;
680 fc += (q->read_buf->size >> 2) - 1;
681 *fc = q->read_buf->field_count >> 1;
682 dprintk(1, "vbihack: %d\n", *fc);
683 }
684
685 /* copy stuff using the common method */
686 count = __videobuf_copy_to_user(q, data, count, nonblocking);
687
688 if ((count == -EFAULT) && (0 == pos))
689 return -EFAULT;
690
691 return count;
692 }
693
694 static struct videobuf_qtype_ops sg_ops = {
695 .magic = MAGIC_QTYPE_OPS,
696
697 .alloc = __videobuf_alloc,
698 .iolock = __videobuf_iolock,
699 .sync = __videobuf_sync,
700 .mmap_mapper = __videobuf_mmap_mapper,
701 .video_copy_to_user = __videobuf_copy_to_user,
702 .copy_stream = __videobuf_copy_stream,
703 .vmalloc = __videobuf_to_vmalloc,
704 };
705
706 void *videobuf_sg_alloc(size_t size)
707 {
708 struct videobuf_queue q;
709
710 /* Required to make generic handler to call __videobuf_alloc */
711 q.int_ops = &sg_ops;
712
713 q.msize = size;
714
715 return videobuf_alloc(&q);
716 }
717 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
718
719 void videobuf_queue_sg_init(struct videobuf_queue *q,
720 const struct videobuf_queue_ops *ops,
721 struct device *dev,
722 spinlock_t *irqlock,
723 enum v4l2_buf_type type,
724 enum v4l2_field field,
725 unsigned int msize,
726 void *priv)
727 {
728 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
729 priv, &sg_ops);
730 }
731 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
732
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree