drivers/media/video/videobuf-dma-sg.c

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