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