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 <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         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
  64                 pg = vmalloc_to_page(virt);
  65                 if (NULL == pg)
  66                         goto err;
  67                 BUG_ON(PageHighMem(pg));
  68                 sglist[i].page   = pg;
  69                 sglist[i].length = PAGE_SIZE;
  70         }
  71         return sglist;
  72
  73  err:
  74         kfree(sglist);
  75         return NULL;
  76 }
  77
  78 struct scatterlist*
  79 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
  80 {
  81         struct scatterlist *sglist;
  82         int i = 0;
  83
  84         if (NULL == pages[0])
  85                 return NULL;
  86         sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL);
  87         if (NULL == sglist)
  88                 return NULL;
  89
  90         if (NULL == pages[0])
  91                 goto nopage;
  92         if (PageHighMem(pages[0]))
  93                 /* DMA to highmem pages might not work */
  94                 goto highmem;
  95         sglist[0].page   = pages[0];
  96         sglist[0].offset = offset;
  97         sglist[0].length = PAGE_SIZE - 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                 sglist[i].page   = pages[i];
 104                 sglist[i].length = PAGE_SIZE;
 105         }
 106         return sglist;
 107
 108  nopage:
 109         dprintk(2,"sgl: oops - no page\n");
 110         kfree(sglist);
 111         return NULL;
 112
 113  highmem:
 114         dprintk(2,"sgl: oops - highmem page\n");
 115         kfree(sglist);
 116         return NULL;
 117 }
 118
 119 /* --------------------------------------------------------------------- */
 120
 121 struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf)
 122 {
 123         struct videbuf_pci_sg_memory *mem=buf->priv;
 124         BUG_ON (!mem);
 125
 126         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 127
 128         return &mem->dma;
 129 }
 130
 131 void videobuf_dma_init(struct videobuf_dmabuf *dma)
 132 {
 133         memset(dma,0,sizeof(*dma));
 134         dma->magic = MAGIC_DMABUF;
 135 }
 136
 137 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 138                            unsigned long data, unsigned long size)
 139 {
 140         unsigned long first,last;
 141         int err, rw = 0;
 142
 143         dma->direction = direction;
 144         switch (dma->direction) {
 145         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 146         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 147         default:                 BUG();
 148         }
 149
 150         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 151         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 152         dma->offset   = data & ~PAGE_MASK;
 153         dma->nr_pages = last-first+1;
 154         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 155                              GFP_KERNEL);
 156         if (NULL == dma->pages)
 157                 return -ENOMEM;
 158         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 159                 data,size,dma->nr_pages);
 160
 161         dma->varea = (void *) data;
 162
 163         down_read(&current->mm->mmap_sem);
 164         err = get_user_pages(current,current->mm,
 165                              data & PAGE_MASK, dma->nr_pages,
 166                              rw == READ, 1, /* force */
 167                              dma->pages, NULL);
 168         up_read(&current->mm->mmap_sem);
 169         if (err != dma->nr_pages) {
 170                 dma->nr_pages = (err >= 0) ? err : 0;
 171                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 172                 return err < 0 ? err : -EINVAL;
 173         }
 174         return 0;
 175 }
 176
 177 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 178                              int nr_pages)
 179 {
 180         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 181         dma->direction = direction;
 182         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 183         if (NULL == dma->vmalloc) {
 184                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 185                 return -ENOMEM;
 186         }
 187         dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
 188                                 (unsigned long)dma->vmalloc,
 189                                 nr_pages << PAGE_SHIFT);
 190         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 191         dma->nr_pages = nr_pages;
 192         return 0;
 193 }
 194
 195 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 196                               dma_addr_t addr, int nr_pages)
 197 {
 198         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 199                 nr_pages,(unsigned long)addr);
 200         dma->direction = direction;
 201         if (0 == addr)
 202                 return -EINVAL;
 203
 204         dma->bus_addr = addr;
 205         dma->nr_pages = nr_pages;
 206         return 0;
 207 }
 208
 209 int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 210 {
 211         void                   *dev=q->dev;
 212         struct videobuf_dma_sg_ops *ops=q->priv_ops;
 213
 214         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 215         BUG_ON(0 == dma->nr_pages);
 216
 217         if (dma->pages) {
 218                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 219                                                    dma->offset);
 220         }
 221         if (dma->vmalloc) {
 222                 dma->sglist = videobuf_vmalloc_to_sg
 223                                                 (dma->vmalloc,dma->nr_pages);
 224         }
 225         if (dma->bus_addr) {
 226                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 227                 if (NULL != dma->sglist) {
 228                         dma->sglen  = 1;
 229                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 230                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 231                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 232                 }
 233         }
 234         if (NULL == dma->sglist) {
 235                 dprintk(1,"scatterlist is NULL\n");
 236                 return -ENOMEM;
 237         }
 238         if (!dma->bus_addr) {
 239                 if (ops && ops->vb_map_sg) {
 240                         dma->sglen = ops->vb_map_sg(dev,dma->sglist,
 241                                         dma->nr_pages, dma->direction);
 242                 }
 243                 if (0 == dma->sglen) {
 244                         printk(KERN_WARNING
 245                                "%s: videobuf_map_sg failed\n",__FUNCTION__);
 246                         kfree(dma->sglist);
 247                         dma->sglist = NULL;
 248                         dma->sglen = 0;
 249                         return -EIO;
 250                 }
 251         }
 252         return 0;
 253 }
 254
 255 int videobuf_dma_sync(struct videobuf_queue *q,struct videobuf_dmabuf *dma)
 256 {
 257         void                   *dev=q->dev;
 258         struct videobuf_dma_sg_ops *ops=q->priv_ops;
 259
 260         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 261         BUG_ON(!dma->sglen);
 262
 263         if (!dma->bus_addr && ops && ops->vb_dma_sync_sg)
 264                 ops->vb_dma_sync_sg(dev,dma->sglist,dma->nr_pages,
 265                                                         dma->direction);
 266
 267         return 0;
 268 }
 269
 270 int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 271 {
 272         void                   *dev=q->dev;
 273         struct videobuf_dma_sg_ops *ops=q->priv_ops;
 274
 275         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 276         if (!dma->sglen)
 277                 return 0;
 278
 279         if (!dma->bus_addr && ops && ops->vb_unmap_sg)
 280                         ops->vb_unmap_sg(dev,dma->sglist,dma->nr_pages,
 281                                                         dma->direction);
 282         kfree(dma->sglist);
 283         dma->sglist = NULL;
 284         dma->sglen = 0;
 285         return 0;
 286 }
 287
 288 int 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         }
 308         dma->direction = PCI_DMA_NONE;
 309         return 0;
 310 }
 311
 312 /* --------------------------------------------------------------------- */
 313
 314 int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma)
 315 {
 316         struct videobuf_queue q;
 317         struct videobuf_dma_sg_ops qops;
 318
 319         q.dev=pci;
 320         qops.vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 321         qops.vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 322         q.priv_ops = &qops;
 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         struct videobuf_dma_sg_ops qops;
 331
 332         q.dev=pci;
 333         qops.vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 334         qops.vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 335         q.priv_ops = &qops;
 336
 337         return (videobuf_dma_unmap(&q,dma));
 338 }
 339
 340 /* --------------------------------------------------------------------- */
 341
 342 static void
 343 videobuf_vm_open(struct vm_area_struct *vma)
 344 {
 345         struct videobuf_mapping *map = vma->vm_private_data;
 346
 347         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
 348                 map->count,vma->vm_start,vma->vm_end);
 349         map->count++;
 350 }
 351
 352 static void
 353 videobuf_vm_close(struct vm_area_struct *vma)
 354 {
 355         struct videobuf_mapping *map = vma->vm_private_data;
 356         struct videobuf_queue *q = map->q;
 357         struct videbuf_pci_sg_memory *mem;
 358         int i;
 359
 360         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
 361                 map->count,vma->vm_start,vma->vm_end);
 362
 363         map->count--;
 364         if (0 == map->count) {
 365                 dprintk(1,"munmap %p q=%p\n",map,q);
 366                 mutex_lock(&q->lock);
 367                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 368                         if (NULL == q->bufs[i])
 369                                 continue;
 370                         mem=q->bufs[i]->priv;
 371
 372                         if (!mem)
 373                                 continue;
 374
 375                         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 376
 377                         if (mem->map != map)
 378                                 continue;
 379                         mem->map   = NULL;
 380                         q->bufs[i]->baddr = 0;
 381                         q->ops->buf_release(q,q->bufs[i]);
 382                 }
 383                 mutex_unlock(&q->lock);
 384                 kfree(map);
 385         }
 386         return;
 387 }
 388
 389 /*
 390  * Get a anonymous page for the mapping.  Make sure we can DMA to that
 391  * memory location with 32bit PCI devices (i.e. don't use highmem for
 392  * now ...).  Bounce buffers don't work very well for the data rates
 393  * video capture has.
 394  */
 395 static struct page*
 396 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
 397                    int *type)
 398 {
 399         struct page *page;
 400
 401         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
 402                 vaddr,vma->vm_start,vma->vm_end);
 403         if (vaddr > vma->vm_end)
 404                 return NOPAGE_SIGBUS;
 405         page = alloc_page(GFP_USER | __GFP_DMA32);
 406         if (!page)
 407                 return NOPAGE_OOM;
 408         clear_user_page(page_address(page), vaddr, page);
 409         if (type)
 410                 *type = VM_FAULT_MINOR;
 411         return page;
 412 }
 413
 414 static struct vm_operations_struct videobuf_vm_ops =
 415 {
 416         .open     = videobuf_vm_open,
 417         .close    = videobuf_vm_close,
 418         .nopage   = videobuf_vm_nopage,
 419 };
 420
 421 /* ---------------------------------------------------------------------
 422  * PCI handlers for the generic methods
 423  */
 424
 425 /* Allocated area consists on 3 parts:
 426         struct video_buffer
 427         struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
 428         struct videobuf_pci_sg_memory
 429  */
 430
 431 static void *__videobuf_alloc(size_t size)
 432 {
 433         struct videbuf_pci_sg_memory *mem;
 434         struct videobuf_buffer *vb;
 435
 436         vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);
 437
 438         mem = vb->priv = ((char *)vb)+size;
 439         mem->magic=MAGIC_SG_MEM;
 440
 441         videobuf_dma_init(&mem->dma);
 442
 443         dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
 444                 __FUNCTION__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
 445                 mem,(long)sizeof(*mem));
 446
 447         return vb;
 448 }
 449
 450 static int __videobuf_iolock (struct videobuf_queue* q,
 451                               struct videobuf_buffer *vb,
 452                               struct v4l2_framebuffer *fbuf)
 453 {
 454         int err,pages;
 455         dma_addr_t bus;
 456         struct videbuf_pci_sg_memory *mem=vb->priv;
 457         BUG_ON(!mem);
 458
 459         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 460
 461         switch (vb->memory) {
 462         case V4L2_MEMORY_MMAP:
 463         case V4L2_MEMORY_USERPTR:
 464                 if (0 == vb->baddr) {
 465                         /* no userspace addr -- kernel bounce buffer */
 466                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 467                         err = videobuf_dma_init_kernel( &mem->dma,
 468                                                         PCI_DMA_FROMDEVICE,
 469                                                         pages );
 470                         if (0 != err)
 471                                 return err;
 472                 } else {
 473                         /* dma directly to userspace */
 474                         err = videobuf_dma_init_user( &mem->dma,
 475                                                       PCI_DMA_FROMDEVICE,
 476                                                       vb->baddr,vb->bsize );
 477                         if (0 != err)
 478                                 return err;
 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;
 492                 err = videobuf_dma_init_overlay(&mem->dma,PCI_DMA_FROMDEVICE,
 493                                                 bus, pages);
 494                 if (0 != err)
 495                         return err;
 496                 break;
 497         default:
 498                 BUG();
 499         }
 500         err = videobuf_dma_map(q,&mem->dma);
 501         if (0 != err)
 502                 return err;
 503
 504         return 0;
 505 }
 506
 507 static int __videobuf_sync(struct videobuf_queue *q,
 508                            struct videobuf_buffer *buf)
 509 {
 510         struct videbuf_pci_sg_memory *mem=buf->priv;
 511         BUG_ON (!mem);
 512         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 513
 514         return  videobuf_dma_sync(q,&mem->dma);
 515 }
 516
 517 static 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]) {
 523                         struct videbuf_pci_sg_memory *mem=q->bufs[i]->priv;
 524                         if (mem && mem->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                 mem=q->bufs[last]->priv;
 576                 if (mem->map) {
 577                         retval = -EBUSY;
 578                         goto done;
 579                 }
 580                 size += q->bufs[last]->bsize;
 581                 if (size == (vma->vm_end - vma->vm_start))
 582                         break;
 583         }
 584         if (VIDEO_MAX_FRAME == last) {
 585                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
 586                         (vma->vm_end - vma->vm_start));
 587                 goto done;
 588         }
 589
 590         /* create mapping + update buffer list */
 591         retval = -ENOMEM;
 592         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
 593         if (NULL == map)
 594                 goto done;
 595         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
 596                 mem=q->bufs[i]->priv;
 597                 mem->map   = map;
 598                 q->bufs[i]->baddr = vma->vm_start + size;
 599         }
 600         map->count    = 1;
 601         map->start    = vma->vm_start;
 602         map->end      = vma->vm_end;
 603         map->q        = q;
 604         vma->vm_ops   = &videobuf_vm_ops;
 605         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
 606         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
 607         vma->vm_private_data = map;
 608         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
 609                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
 610         retval = 0;
 611
 612  done:
 613         return retval;
 614 }
 615
 616 static int __videobuf_is_mmapped (struct videobuf_buffer *buf)
 617 {
 618         struct videbuf_pci_sg_memory *mem=buf->priv;
 619
 620         BUG_ON (!mem);
 621         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 622
 623         return (mem->map)?1:0;
 624 }
 625
 626 static int __videobuf_copy_to_user ( struct videobuf_queue *q,
 627                                 char __user *data, size_t count,
 628                                 int nonblocking )
 629 {
 630         struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
 631         BUG_ON (!mem);
 632         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 633
 634         /* copy to userspace */
 635         if (count > q->read_buf->size - q->read_off)
 636                 count = q->read_buf->size - q->read_off;
 637
 638         if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
 639                 return -EFAULT;
 640
 641         return count;
 642 }
 643
 644 static int __videobuf_copy_stream ( struct videobuf_queue *q,
 645                                 char __user *data, size_t count, size_t pos,
 646                                 int vbihack, int nonblocking )
 647 {
 648         unsigned int  *fc;
 649         struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
 650         BUG_ON (!mem);
 651         MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
 652
 653         if (vbihack) {
 654                 /* dirty, undocumented hack -- pass the frame counter
 655                         * within the last four bytes of each vbi data block.
 656                         * We need that one to maintain backward compatibility
 657                         * to all vbi decoding software out there ... */
 658                 fc  = (unsigned int*)mem->dma.vmalloc;
 659                 fc += (q->read_buf->size>>2) -1;
 660                 *fc = q->read_buf->field_count >> 1;
 661                 dprintk(1,"vbihack: %d\n",*fc);
 662         }
 663
 664         /* copy stuff using the common method */
 665         count = __videobuf_copy_to_user (q,data,count,nonblocking);
 666
 667         if ( (count==-EFAULT) && (0 == pos) )
 668                 return -EFAULT;
 669
 670         return count;
 671 }
 672
 673 static struct videobuf_qtype_ops pci_ops = {
 674         .magic        = MAGIC_QTYPE_OPS,
 675
 676         .alloc        = __videobuf_alloc,
 677         .iolock       = __videobuf_iolock,
 678         .sync         = __videobuf_sync,
 679         .mmap_free    = __videobuf_mmap_free,
 680         .mmap_mapper  = __videobuf_mmap_mapper,
 681         .is_mmapped   = __videobuf_is_mmapped,
 682         .copy_to_user = __videobuf_copy_to_user,
 683         .copy_stream  = __videobuf_copy_stream,
 684 };
 685
 686 void *videobuf_pci_alloc (size_t size)
 687 {
 688         struct videobuf_queue q;
 689
 690         /* Required to make generic handler to call __videobuf_alloc */
 691         q.int_ops=&pci_ops;
 692
 693         q.msize=size;
 694
 695         return videobuf_alloc (&q);
 696 }
 697
 698 void videobuf_queue_pci_init(struct videobuf_queue* q,
 699                          struct videobuf_queue_ops *ops,
 700                          void *dev,
 701                          spinlock_t *irqlock,
 702                          enum v4l2_buf_type type,
 703                          enum v4l2_field field,
 704                          unsigned int msize,
 705                          void *priv)
 706 {
 707         struct videobuf_dma_sg_ops *priv_ops;
 708
 709         videobuf_queue_init(q, ops, dev, irqlock, type, field, msize, priv);
 710         q->int_ops=&pci_ops;
 711
 712         /* FIXME: the code bellow should be removed after having a proper
 713          * memory allocation method for vivi and tm6000
 714          */
 715         q->priv_ops= kzalloc(sizeof(struct videobuf_dma_sg_ops), GFP_KERNEL);
 716         BUG_ON (!q->priv_ops);
 717
 718         priv_ops=q->priv_ops;
 719
 720         /* Sets default methods for handling Scatter Gather mapping */
 721         priv_ops->vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 722         priv_ops->vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 723         priv_ops->vb_dma_sync_sg=(vb_map_sg_t *)pci_dma_sync_sg_for_cpu;
 724 }
 725
 726 void videobuf_set_pci_ops (struct videobuf_queue* q,
 727                                 struct videobuf_dma_sg_ops *ops)
 728 {
 729         kfree (q->priv_ops);
 730
 731         q->priv_ops=ops;
 732
 733         if (!ops)
 734                 return;
 735
 736         /* If not specified, defaults to PCI map sg */
 737         if (!ops->vb_map_sg)
 738                 ops->vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 739
 740         if (!ops->vb_dma_sync_sg)
 741                 ops->vb_dma_sync_sg=(vb_map_sg_t *)pci_dma_sync_sg_for_cpu;
 742         if (!ops->vb_unmap_sg)
 743                 ops->vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 744 }
 745
 746
 747 /* --------------------------------------------------------------------- */
 748
 749 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
 750
 751 EXPORT_SYMBOL_GPL(videobuf_to_dma);
 752 EXPORT_SYMBOL_GPL(videobuf_dma_init);
 753 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
 754 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
 755 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
 756 EXPORT_SYMBOL_GPL(videobuf_dma_map);
 757 EXPORT_SYMBOL_GPL(videobuf_dma_sync);
 758 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
 759 EXPORT_SYMBOL_GPL(videobuf_dma_free);
 760
 761 EXPORT_SYMBOL_GPL(videobuf_pci_dma_map);
 762 EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap);
 763 EXPORT_SYMBOL_GPL(videobuf_pci_alloc);
 764
 765 EXPORT_SYMBOL_GPL(videobuf_queue_pci_init);
 766 EXPORT_SYMBOL_GPL(videobuf_set_pci_ops);
 767
 768 /*
 769  * Local variables:
 770  * c-basic-offset: 8
 771  * End:
 772  */