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V4L/DVB (7493): videobuf: Avoid deadlock with QBUF and bring up to spec for empty...
[linux-2.6-block.git] / drivers / media / video / videobuf-dma-sg.c
CommitLineData
7a7d9a89 1/*
0705135e 2 * helper functions for SG DMA video4linux capture buffers
7a7d9a89
MCC		 3 *
4 * The functions expect the hardware being able to scatter gatter
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
0705135e 27#include <linux/dma-mapping.h>
7a7d9a89
MCC		 28#include <linux/vmalloc.h>
29#include <linux/pagemap.h>
11763609 30#include <linux/scatterlist.h>
7a7d9a89
MCC		 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
ff699e6b 42static int debug;
7a7d9a89
MCC		 43module_param(debug, int, 0644);
44
0705135e 45MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
7a7d9a89
MCC		 46MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
47MODULE_LICENSE("GPL");
48
49#define dprintk(level, fmt, arg...) if (debug >= level) \
50 printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
51
52/* --------------------------------------------------------------------- */
53
54struct scatterlist*
55videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
56{
57 struct scatterlist *sglist;
58 struct page *pg;
59 int i;
60
61 sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
62 if (NULL == sglist)
63 return NULL;
45711f1a 64 sg_init_table(sglist, nr_pages);
7a7d9a89
MCC		 65 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
66 pg = vmalloc_to_page(virt);
67 if (NULL == pg)
68 goto err;
69 BUG_ON(PageHighMem(pg));
642f1490 70 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
7a7d9a89
MCC		 71 }
72 return sglist;
73
74 err:
75 kfree(sglist);
76 return NULL;
77}
78
79struct scatterlist*
80videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
81{
82 struct scatterlist *sglist;
83 int i = 0;
84
85 if (NULL == pages[0])
86 return NULL;
87 sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL);
88 if (NULL == sglist)
89 return NULL;
45711f1a 90 sg_init_table(sglist, nr_pages);
7a7d9a89
MCC		 91
92 if (NULL == pages[0])
93 goto nopage;
94 if (PageHighMem(pages[0]))
95 /* DMA to highmem pages might not work */
96 goto highmem;
642f1490 97 sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
7a7d9a89
MCC		 98 for (i = 1; i < nr_pages; i++) {
99 if (NULL == pages[i])
100 goto nopage;
101 if (PageHighMem(pages[i]))
102 goto highmem;
642f1490 103 sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
7a7d9a89
MCC		 104 }
105 return sglist;
106
107 nopage:
108 dprintk(2,"sgl: oops - no page\n");
109 kfree(sglist);
110 return NULL;
111
112 highmem:
113 dprintk(2,"sgl: oops - highmem page\n");
114 kfree(sglist);
115 return NULL;
116}
117
118/* --------------------------------------------------------------------- */
119
120struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf)
121{
0705135e
GL		 122 struct videobuf_dma_sg_memory *mem = buf->priv;
123 BUG_ON(!mem);
7a7d9a89 124
0705135e 125 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
7a7d9a89
MCC		 126
127 return &mem->dma;
128}
129
130void videobuf_dma_init(struct videobuf_dmabuf *dma)
131{
132 memset(dma,0,sizeof(*dma));
133 dma->magic = MAGIC_DMABUF;
134}
135
9900132f
ML		 136static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
137 int direction, unsigned long data, unsigned long size)
7a7d9a89
MCC		 138{
139 unsigned long first,last;
140 int err, rw = 0;
141
142 dma->direction = direction;
143 switch (dma->direction) {
0705135e
GL		 144 case DMA_FROM_DEVICE:
145 rw = READ;
146 break;
147 case DMA_TO_DEVICE:
148 rw = WRITE;
149 break;
150 default:
151 BUG();
7a7d9a89
MCC		 152 }
153
154 first = (data & PAGE_MASK) >> PAGE_SHIFT;
155 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
156 dma->offset = data & ~PAGE_MASK;
157 dma->nr_pages = last-first+1;
158 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
159 GFP_KERNEL);
160 if (NULL == dma->pages)
161 return -ENOMEM;
162 dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
163 data,size,dma->nr_pages);
164
165 dma->varea = (void *) data;
166
9900132f 167
7a7d9a89
MCC		 168 err = get_user_pages(current,current->mm,
169 data & PAGE_MASK, dma->nr_pages,
170 rw == READ, 1, /* force */
171 dma->pages, NULL);
9900132f 172
7a7d9a89
MCC		 173 if (err != dma->nr_pages) {
174 dma->nr_pages = (err >= 0) ? err : 0;
175 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
176 return err < 0 ? err : -EINVAL;
177 }
178 return 0;
179}
180
9900132f
ML		 181int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
182 unsigned long data, unsigned long size)
183{
184 int ret;
185 down_read(&current->mm->mmap_sem);
186 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
187 up_read(&current->mm->mmap_sem);
188
189 return ret;
190}
191
7a7d9a89
MCC		 192int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
193 int nr_pages)
194{
195 dprintk(1,"init kernel [%d pages]\n",nr_pages);
196 dma->direction = direction;
197 dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
198 if (NULL == dma->vmalloc) {
199 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
200 return -ENOMEM;
201 }
202 dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
203 (unsigned long)dma->vmalloc,
204 nr_pages << PAGE_SHIFT);
205 memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
206 dma->nr_pages = nr_pages;
207 return 0;
208}
209
210int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
211 dma_addr_t addr, int nr_pages)
212{
213 dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
214 nr_pages,(unsigned long)addr);
215 dma->direction = direction;
216 if (0 == addr)
217 return -EINVAL;
218
219 dma->bus_addr = addr;
220 dma->nr_pages = nr_pages;
221 return 0;
222}
223
0705135e 224int videobuf_dma_map(struct videobuf_queue* q, struct videobuf_dmabuf *dma)
7a7d9a89 225{
7a7d9a89
MCC		 226 MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
227 BUG_ON(0 == dma->nr_pages);
228
229 if (dma->pages) {
230 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
231 dma->offset);
232 }
233 if (dma->vmalloc) {
234 dma->sglist = videobuf_vmalloc_to_sg
235 (dma->vmalloc,dma->nr_pages);
236 }
237 if (dma->bus_addr) {
238 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
239 if (NULL != dma->sglist) {
240 dma->sglen = 1;
241 sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
242 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
243 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
244 }
245 }
246 if (NULL == dma->sglist) {
247 dprintk(1,"scatterlist is NULL\n");
248 return -ENOMEM;
249 }
250 if (!dma->bus_addr) {
0705135e 251 dma->sglen = dma_map_sg(q->dev, dma->sglist,
7a7d9a89 252 dma->nr_pages, dma->direction);
7a7d9a89
MCC		 253 if (0 == dma->sglen) {
254 printk(KERN_WARNING
255 "%s: videobuf_map_sg failed\n",__FUNCTION__);
256 kfree(dma->sglist);
257 dma->sglist = NULL;
258 dma->sglen = 0;
259 return -EIO;
260 }
261 }
262 return 0;
263}
264
0705135e 265int videobuf_dma_sync(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
7a7d9a89 266{
0705135e 267 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
7a7d9a89
MCC		 268 BUG_ON(!dma->sglen);
269
0705135e 270 dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->nr_pages, dma->direction);
7a7d9a89
MCC		 271 return 0;
272}
273
274int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
275{
0705135e 276 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
7a7d9a89
MCC		 277 if (!dma->sglen)
278 return 0;
279
0705135e 280 dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
5ddff434 281
7a7d9a89
MCC		 282 kfree(dma->sglist);
283 dma->sglist = NULL;
284 dma->sglen = 0;
285 return 0;
286}
287
288int videobuf_dma_free(struct videobuf_dmabuf *dma)
289{
290 MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
291 BUG_ON(dma->sglen);
292
293 if (dma->pages) {
294 int i;
295 for (i=0; i < dma->nr_pages; i++)
296 page_cache_release(dma->pages[i]);
297 kfree(dma->pages);
298 dma->pages = NULL;
299 }
300
301 vfree(dma->vmalloc);
302 dma->vmalloc = NULL;
303 dma->varea = NULL;
304
305 if (dma->bus_addr) {
306 dma->bus_addr = 0;
307 }
0705135e 308 dma->direction = DMA_NONE;
7a7d9a89
MCC		 309 return 0;
310}
311
312/* --------------------------------------------------------------------- */
313
0705135e 314int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
7a7d9a89
MCC		 315{
316 struct videobuf_queue q;
7a7d9a89 317
0705135e 318 q.dev = dev;
7a7d9a89 319
0705135e 320 return videobuf_dma_map(&q, dma);
7a7d9a89
MCC		 321}
322
0705135e 323int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
7a7d9a89
MCC		 324{
325 struct videobuf_queue q;
7a7d9a89 326
0705135e 327 q.dev = dev;
7a7d9a89 328
0705135e 329 return videobuf_dma_unmap(&q, dma);
7a7d9a89
MCC		 330}
331
332/* --------------------------------------------------------------------- */
333
334static void
335videobuf_vm_open(struct vm_area_struct *vma)
336{
337 struct videobuf_mapping *map = vma->vm_private_data;
338
339 dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
340 map->count,vma->vm_start,vma->vm_end);
341 map->count++;
342}
343
344static void
345videobuf_vm_close(struct vm_area_struct *vma)
346{
347 struct videobuf_mapping *map = vma->vm_private_data;
348 struct videobuf_queue *q = map->q;
0705135e 349 struct videobuf_dma_sg_memory *mem;
7a7d9a89
MCC		 350 int i;
351
352 dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
353 map->count,vma->vm_start,vma->vm_end);
354
355 map->count--;
356 if (0 == map->count) {
357 dprintk(1,"munmap %p q=%p\n",map,q);
64f9477f 358 mutex_lock(&q->vb_lock);
7a7d9a89
MCC		 359 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
360 if (NULL == q->bufs[i])
361 continue;
362 mem=q->bufs[i]->priv;
363
364 if (!mem)
365 continue;
366
367 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
368
851c0c96 369 if (q->bufs[i]->map != map)
7a7d9a89 370 continue;
851c0c96 371 q->bufs[i]->map = NULL;
7a7d9a89
MCC		 372 q->bufs[i]->baddr = 0;
373 q->ops->buf_release(q,q->bufs[i]);
374 }
64f9477f 375 mutex_unlock(&q->vb_lock);
7a7d9a89
MCC		 376 kfree(map);
377 }
378 return;
379}
380
381/*
382 * Get a anonymous page for the mapping. Make sure we can DMA to that
383 * memory location with 32bit PCI devices (i.e. don't use highmem for
384 * now ...). Bounce buffers don't work very well for the data rates
385 * video capture has.
386 */
105354a0
NP		 387static int
388videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
7a7d9a89
MCC		 389{
390 struct page *page;
391
105354a0
NP		 392 dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
393 (unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
7a7d9a89
MCC		 394 page = alloc_page(GFP_USER | __GFP_DMA32);
395 if (!page)
105354a0 396 return VM_FAULT_OOM;
d172b8bd
AM		 397 clear_user_page(page_address(page), (unsigned long)vmf->virtual_address,
398 page);
105354a0
NP		 399 vmf->page = page;
400 return 0;
7a7d9a89
MCC		 401}
402
403static struct vm_operations_struct videobuf_vm_ops =
404{
405 .open = videobuf_vm_open,
406 .close = videobuf_vm_close,
105354a0 407 .fault = videobuf_vm_fault,
7a7d9a89
MCC		 408};
409
410/* ---------------------------------------------------------------------
0705135e 411 * SG handlers for the generic methods
7a7d9a89
MCC		 412 */
413
414/* Allocated area consists on 3 parts:
415 struct video_buffer
416 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
0705135e 417 struct videobuf_dma_sg_memory
7a7d9a89
MCC		 418 */
419
420static void *__videobuf_alloc(size_t size)
421{
0705135e 422 struct videobuf_dma_sg_memory *mem;
7a7d9a89
MCC		 423 struct videobuf_buffer *vb;
424
425 vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);
426
427 mem = vb->priv = ((char *)vb)+size;
428 mem->magic=MAGIC_SG_MEM;
429
430 videobuf_dma_init(&mem->dma);
431
432 dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
433 __FUNCTION__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
434 mem,(long)sizeof(*mem));
435
436 return vb;
437}
438
439static int __videobuf_iolock (struct videobuf_queue* q,
440 struct videobuf_buffer *vb,
441 struct v4l2_framebuffer *fbuf)
442{
443 int err,pages;
444 dma_addr_t bus;
0705135e 445 struct videobuf_dma_sg_memory *mem = vb->priv;
7a7d9a89
MCC		 446 BUG_ON(!mem);
447
0705135e 448 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
7a7d9a89
MCC		 449
450 switch (vb->memory) {
451 case V4L2_MEMORY_MMAP:
452 case V4L2_MEMORY_USERPTR:
453 if (0 == vb->baddr) {
454 /* no userspace addr -- kernel bounce buffer */
455 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
456 err = videobuf_dma_init_kernel( &mem->dma,
0705135e 457 DMA_FROM_DEVICE,
7a7d9a89
MCC		 458 pages );
459 if (0 != err)
460 return err;
9900132f 461 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
7a7d9a89
MCC		 462 /* dma directly to userspace */
463 err = videobuf_dma_init_user( &mem->dma,
0705135e 464 DMA_FROM_DEVICE,
7a7d9a89
MCC		 465 vb->baddr,vb->bsize );
466 if (0 != err)
467 return err;
9900132f
ML		 468 } else {
469 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
470 buffers can only be called from videobuf_qbuf
471 we take current->mm->mmap_sem there, to prevent
472 locking inversion, so don't take it here */
473
474 err = videobuf_dma_init_user_locked(&mem->dma,
0705135e 475 DMA_FROM_DEVICE,
9900132f
ML		 476 vb->baddr, vb->bsize);
477 if (0 != err)
478 return err;
7a7d9a89
MCC		 479 }
480 break;
481 case V4L2_MEMORY_OVERLAY:
482 if (NULL == fbuf)
483 return -EINVAL;
484 /* FIXME: need sanity checks for vb->boff */
485 /*
486 * Using a double cast to avoid compiler warnings when
487 * building for PAE. Compiler doesn't like direct casting
488 * of a 32 bit ptr to 64 bit integer.
489 */
490 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
491 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
0705135e 492 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
7a7d9a89
MCC		 493 bus, pages);
494 if (0 != err)
495 return err;
496 break;
497 default:
498 BUG();
499 }
0705135e 500 err = videobuf_dma_map(q, &mem->dma);
7a7d9a89
MCC		 501 if (0 != err)
502 return err;
503
504 return 0;
505}
506
507static int __videobuf_sync(struct videobuf_queue *q,
508 struct videobuf_buffer *buf)
509{
0705135e
GL		 510 struct videobuf_dma_sg_memory *mem = buf->priv;
511 BUG_ON(!mem);
7a7d9a89
MCC		 512 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
513
514 return videobuf_dma_sync(q,&mem->dma);
515}
516
517static int __videobuf_mmap_free(struct videobuf_queue *q)
518{
519 int i;
520
521 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
522 if (q->bufs[i]) {
851c0c96 523 if (q->bufs[i]->map)
7a7d9a89
MCC		 524 return -EBUSY;
525 }
526 }
527
528 return 0;
529}
530
531static int __videobuf_mmap_mapper(struct videobuf_queue *q,
532 struct vm_area_struct *vma)
533{
0705135e 534 struct videobuf_dma_sg_memory *mem;
7a7d9a89
MCC		 535 struct videobuf_mapping *map;
536 unsigned int first,last,size,i;
537 int retval;
538
539 retval = -EINVAL;
540 if (!(vma->vm_flags & VM_WRITE)) {
541 dprintk(1,"mmap app bug: PROT_WRITE please\n");
542 goto done;
543 }
544 if (!(vma->vm_flags & VM_SHARED)) {
545 dprintk(1,"mmap app bug: MAP_SHARED please\n");
546 goto done;
547 }
548
549 /* look for first buffer to map */
550 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
551 if (NULL == q->bufs[first])
552 continue;
553 mem=q->bufs[first]->priv;
0705135e 554 BUG_ON(!mem);
7a7d9a89
MCC		 555 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
556
557 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
558 continue;
559 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
560 break;
561 }
562 if (VIDEO_MAX_FRAME == first) {
563 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
564 (vma->vm_pgoff << PAGE_SHIFT));
565 goto done;
566 }
567
568 /* look for last buffer to map */
569 for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
570 if (NULL == q->bufs[last])
571 continue;
572 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
573 continue;
851c0c96 574 if (q->bufs[last]->map) {
7a7d9a89
MCC		 575 retval = -EBUSY;
576 goto done;
577 }
578 size += q->bufs[last]->bsize;
579 if (size == (vma->vm_end - vma->vm_start))
580 break;
581 }
582 if (VIDEO_MAX_FRAME == last) {
583 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
584 (vma->vm_end - vma->vm_start));
585 goto done;
586 }
587
588 /* create mapping + update buffer list */
589 retval = -ENOMEM;
590 map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
591 if (NULL == map)
592 goto done;
593 for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
851c0c96 594 q->bufs[i]->map = map;
7a7d9a89
MCC		 595 q->bufs[i]->baddr = vma->vm_start + size;
596 }
597 map->count = 1;
598 map->start = vma->vm_start;
599 map->end = vma->vm_end;
600 map->q = q;
601 vma->vm_ops = &videobuf_vm_ops;
602 vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
603 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
604 vma->vm_private_data = map;
605 dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
606 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
607 retval = 0;
608
609 done:
610 return retval;
611}
612
7a7d9a89
MCC		 613static int __videobuf_copy_to_user ( struct videobuf_queue *q,
614 char __user *data, size_t count,
615 int nonblocking )
616{
0705135e
GL		 617 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
618 BUG_ON(!mem);
7a7d9a89
MCC		 619 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
620
621 /* copy to userspace */
622 if (count > q->read_buf->size - q->read_off)
623 count = q->read_buf->size - q->read_off;
624
625 if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
626 return -EFAULT;
627
628 return count;
629}
630
631static int __videobuf_copy_stream ( struct videobuf_queue *q,
632 char __user *data, size_t count, size_t pos,
633 int vbihack, int nonblocking )
634{
635 unsigned int *fc;
0705135e
GL		 636 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
637 BUG_ON(!mem);
7a7d9a89
MCC		 638 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
639
640 if (vbihack) {
641 /* dirty, undocumented hack -- pass the frame counter
642 * within the last four bytes of each vbi data block.
643 * We need that one to maintain backward compatibility
644 * to all vbi decoding software out there ... */
645 fc = (unsigned int*)mem->dma.vmalloc;
646 fc += (q->read_buf->size>>2) -1;
647 *fc = q->read_buf->field_count >> 1;
648 dprintk(1,"vbihack: %d\n",*fc);
649 }
650
651 /* copy stuff using the common method */
652 count = __videobuf_copy_to_user (q,data,count,nonblocking);
653
654 if ( (count==-EFAULT) && (0 == pos) )
655 return -EFAULT;
656
657 return count;
658}
659
0705135e 660static struct videobuf_qtype_ops sg_ops = {
7a7d9a89
MCC		 661 .magic = MAGIC_QTYPE_OPS,
662
663 .alloc = __videobuf_alloc,
664 .iolock = __videobuf_iolock,
665 .sync = __videobuf_sync,
666 .mmap_free = __videobuf_mmap_free,
667 .mmap_mapper = __videobuf_mmap_mapper,
13bcd5d0 668 .video_copy_to_user = __videobuf_copy_to_user,
7a7d9a89
MCC		 669 .copy_stream = __videobuf_copy_stream,
670};
671
0705135e 672void *videobuf_sg_alloc(size_t size)
7a7d9a89
MCC		 673{
674 struct videobuf_queue q;
675
676 /* Required to make generic handler to call __videobuf_alloc */
0705135e 677 q.int_ops = &sg_ops;
7a7d9a89 678
0705135e 679 q.msize = size;
7a7d9a89 680
0705135e 681 return videobuf_alloc(&q);
7a7d9a89
MCC		 682}
683
0705135e 684void videobuf_queue_sg_init(struct videobuf_queue* q,
7a7d9a89 685 struct videobuf_queue_ops *ops,
0705135e 686 struct device *dev,
7a7d9a89
MCC		 687 spinlock_t *irqlock,
688 enum v4l2_buf_type type,
689 enum v4l2_field field,
690 unsigned int msize,
691 void *priv)
692{
d4cae5a5 693 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
0705135e 694 priv, &sg_ops);
7a7d9a89
MCC		 695}
696
7a7d9a89
MCC		 697/* --------------------------------------------------------------------- */
698
699EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
700
701EXPORT_SYMBOL_GPL(videobuf_to_dma);
702EXPORT_SYMBOL_GPL(videobuf_dma_init);
703EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
704EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
705EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
706EXPORT_SYMBOL_GPL(videobuf_dma_map);
707EXPORT_SYMBOL_GPL(videobuf_dma_sync);
708EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
709EXPORT_SYMBOL_GPL(videobuf_dma_free);
710
0705135e
GL		 711EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
712EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
713EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
7a7d9a89 714
0705135e 715EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
7a7d9a89
MCC		 716
717/*
718 * Local variables:
719 * c-basic-offset: 8
720 * End:
721 */
Linux 6.x block layer and io_uring tree(s)