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