drivers/media/video/video-buf.c

   1 /*
   2  *
   3  * generic helper functions for video4linux capture buffers, to handle
   4  * memory management and PCI DMA.
   5  * Right now, bttv, saa7134, saa7146 and cx88 use it.
   6  *
   7  * The functions expect the hardware being able to scatter gatter
   8  * (i.e. the buffers are not linear in physical memory, but fragmented
   9  * into PAGE_SIZE chunks).  They also assume the driver does not need
  10  * to touch the video data.
  11  *
  12  * device specific map/unmap/sync stuff now are mapped as operations
  13  * to allow its usage by USB and virtual devices.
  14  *
  15  * (c) 2001-2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  16  * (c) 2006 Mauro Carvalho Chehab <mchehab@infradead.org>
  17  * (c) 2006 Ted Walther and John Sokol
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/slab.h>
  31 #include <linux/pci.h>
  32 #include <linux/interrupt.h>
  33 #include <asm/page.h>
  34 #include <asm/pgtable.h>
  35
  36 #include <media/video-buf.h>
  37
  38 #define MAGIC_DMABUF 0x19721112
  39 #define MAGIC_BUFFER 0x20040302
  40 #define MAGIC_CHECK(is,should)  if (unlikely((is) != (should))) \
  41         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
  42
  43 static int debug = 0;
  44 module_param(debug, int, 0644);
  45
  46 MODULE_DESCRIPTION("helper module to manage video4linux pci dma buffers");
  47 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  48 MODULE_LICENSE("GPL");
  49
  50 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  51         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  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 void videobuf_dma_init(struct videobuf_dmabuf *dma)
 122 {
 123         memset(dma,0,sizeof(*dma));
 124         dma->magic = MAGIC_DMABUF;
 125 }
 126
 127 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 128                            unsigned long data, unsigned long size)
 129 {
 130         unsigned long first,last;
 131         int err, rw = 0;
 132
 133         dma->direction = direction;
 134         switch (dma->direction) {
 135         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 136         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 137         default:                 BUG();
 138         }
 139
 140         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 141         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 142         dma->offset   = data & ~PAGE_MASK;
 143         dma->nr_pages = last-first+1;
 144         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 145                              GFP_KERNEL);
 146         if (NULL == dma->pages)
 147                 return -ENOMEM;
 148         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 149                 data,size,dma->nr_pages);
 150
 151         down_read(&current->mm->mmap_sem);
 152         err = get_user_pages(current,current->mm,
 153                              data & PAGE_MASK, dma->nr_pages,
 154                              rw == READ, 1, /* force */
 155                              dma->pages, NULL);
 156         up_read(&current->mm->mmap_sem);
 157         if (err != dma->nr_pages) {
 158                 dma->nr_pages = (err >= 0) ? err : 0;
 159                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 160                 return err < 0 ? err : -EINVAL;
 161         }
 162         return 0;
 163 }
 164
 165 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 166                              int nr_pages)
 167 {
 168         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 169         dma->direction = direction;
 170         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 171         if (NULL == dma->vmalloc) {
 172                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 173                 return -ENOMEM;
 174         }
 175         dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
 176                                 (unsigned long)dma->vmalloc,
 177                                 nr_pages << PAGE_SHIFT);
 178         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 179         dma->nr_pages = nr_pages;
 180         return 0;
 181 }
 182
 183 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 184                               dma_addr_t addr, int nr_pages)
 185 {
 186         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 187                 nr_pages,(unsigned long)addr);
 188         dma->direction = direction;
 189         if (0 == addr)
 190                 return -EINVAL;
 191
 192         dma->bus_addr = addr;
 193         dma->nr_pages = nr_pages;
 194         return 0;
 195 }
 196
 197 int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 198 {
 199         void                   *dev=q->dev;
 200
 201         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 202         BUG_ON(0 == dma->nr_pages);
 203
 204         if (dma->pages) {
 205                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 206                                                    dma->offset);
 207         }
 208         if (dma->vmalloc) {
 209                 dma->sglist = videobuf_vmalloc_to_sg
 210                                                 (dma->vmalloc,dma->nr_pages);
 211         }
 212         if (dma->bus_addr) {
 213                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 214                 if (NULL != dma->sglist) {
 215                         dma->sglen  = 1;
 216                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 217                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 218                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 219                 }
 220         }
 221         if (NULL == dma->sglist) {
 222                 dprintk(1,"scatterlist is NULL\n");
 223                 return -ENOMEM;
 224         }
 225         if (!dma->bus_addr) {
 226                 if (q->ops->vb_map_sg) {
 227                         dma->sglen = q->ops->vb_map_sg(dev,dma->sglist,
 228                                         dma->nr_pages, dma->direction);
 229                 }
 230                 if (0 == dma->sglen) {
 231                         printk(KERN_WARNING
 232                                "%s: videobuf_map_sg failed\n",__FUNCTION__);
 233                         kfree(dma->sglist);
 234                         dma->sglist = NULL;
 235                         dma->sglen = 0;
 236                         return -EIO;
 237                 }
 238         }
 239         return 0;
 240 }
 241
 242 int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 243 {
 244         void                   *dev=q->dev;
 245
 246         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 247         BUG_ON(!dma->sglen);
 248
 249         if (!dma->bus_addr && q->ops->vb_dma_sync_sg)
 250                 q->ops->vb_dma_sync_sg(dev,dma->sglist,dma->nr_pages,
 251                                                         dma->direction);
 252
 253         return 0;
 254 }
 255
 256 int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 257 {
 258         void                   *dev=q->dev;
 259
 260         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 261         if (!dma->sglen)
 262                 return 0;
 263
 264         if (!dma->bus_addr && q->ops->vb_unmap_sg)
 265                         q->ops->vb_unmap_sg(dev,dma->sglist,dma->nr_pages,
 266                                                         dma->direction);
 267         kfree(dma->sglist);
 268         dma->sglist = NULL;
 269         dma->sglen = 0;
 270         return 0;
 271 }
 272
 273 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 274 {
 275         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 276         BUG_ON(dma->sglen);
 277
 278         if (dma->pages) {
 279                 int i;
 280                 for (i=0; i < dma->nr_pages; i++)
 281                         page_cache_release(dma->pages[i]);
 282                 kfree(dma->pages);
 283                 dma->pages = NULL;
 284         }
 285
 286         vfree(dma->vmalloc);
 287         dma->vmalloc = NULL;
 288
 289         if (dma->bus_addr) {
 290                 dma->bus_addr = 0;
 291         }
 292         dma->direction = PCI_DMA_NONE;
 293         return 0;
 294 }
 295
 296 /* --------------------------------------------------------------------- */
 297
 298 void* videobuf_alloc(unsigned int size)
 299 {
 300         struct videobuf_buffer *vb;
 301
 302         vb = kzalloc(size,GFP_KERNEL);
 303         if (NULL != vb) {
 304                 videobuf_dma_init(&vb->dma);
 305                 init_waitqueue_head(&vb->done);
 306                 vb->magic     = MAGIC_BUFFER;
 307         }
 308         return vb;
 309 }
 310
 311 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 312 {
 313         int retval = 0;
 314         DECLARE_WAITQUEUE(wait, current);
 315
 316         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 317         add_wait_queue(&vb->done, &wait);
 318         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 319                 if (non_blocking) {
 320                         retval = -EAGAIN;
 321                         break;
 322                 }
 323                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 324                                         : TASK_UNINTERRUPTIBLE);
 325                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 326                         schedule();
 327                 set_current_state(TASK_RUNNING);
 328                 if (intr && signal_pending(current)) {
 329                         dprintk(1,"buffer waiton: -EINTR\n");
 330                         retval = -EINTR;
 331                         break;
 332                 }
 333         }
 334         remove_wait_queue(&vb->done, &wait);
 335         return retval;
 336 }
 337
 338 int
 339 videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
 340                 struct v4l2_framebuffer *fbuf)
 341 {
 342         int err,pages;
 343         dma_addr_t bus;
 344
 345         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 346         switch (vb->memory) {
 347         case V4L2_MEMORY_MMAP:
 348         case V4L2_MEMORY_USERPTR:
 349                 if (0 == vb->baddr) {
 350                         /* no userspace addr -- kernel bounce buffer */
 351                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 352                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 353                                                        pages);
 354                         if (0 != err)
 355                                 return err;
 356                 } else {
 357                         /* dma directly to userspace */
 358                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 359                                                      vb->baddr,vb->bsize);
 360                         if (0 != err)
 361                                 return err;
 362                 }
 363                 break;
 364         case V4L2_MEMORY_OVERLAY:
 365                 if (NULL == fbuf)
 366                         return -EINVAL;
 367                 /* FIXME: need sanity checks for vb->boff */
 368                 /*
 369                  * Using a double cast to avoid compiler warnings when
 370                  * building for PAE. Compiler doesn't like direct casting
 371                  * of a 32 bit ptr to 64 bit integer.
 372                  */
 373                 bus   = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
 374                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 375                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 376                                                 bus, pages);
 377                 if (0 != err)
 378                         return err;
 379                 break;
 380         default:
 381                 BUG();
 382         }
 383         err = videobuf_dma_map(q,&vb->dma);
 384         if (0 != err)
 385                 return err;
 386
 387         return 0;
 388 }
 389
 390 /* --------------------------------------------------------------------- */
 391
 392 void videobuf_queue_pci(struct videobuf_queue* q)
 393 {
 394         /* If not specified, defaults to PCI map sg */
 395         if (!q->ops->vb_map_sg)
 396                 q->ops->vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 397
 398         if (!q->ops->vb_dma_sync_sg)
 399                 q->ops->vb_dma_sync_sg=(vb_map_sg_t *)pci_dma_sync_sg_for_cpu;
 400         if (!q->ops->vb_unmap_sg)
 401                 q->ops->vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 402 }
 403
 404 int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma)
 405 {
 406         struct videobuf_queue q;
 407         struct videobuf_queue_ops qops;
 408
 409         q.dev=pci;
 410         qops.vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 411         qops.vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 412         q.ops = &qops;
 413
 414         return (videobuf_dma_map(&q,dma));
 415 }
 416
 417 int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma)
 418 {
 419         struct videobuf_queue q;
 420         struct videobuf_queue_ops qops;
 421
 422         q.dev=pci;
 423         qops.vb_map_sg=(vb_map_sg_t *)pci_map_sg;
 424         qops.vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
 425         q.ops = &qops;
 426
 427         return (videobuf_dma_unmap(&q,dma));
 428 }
 429
 430 void videobuf_queue_init(struct videobuf_queue* q,
 431                          struct videobuf_queue_ops *ops,
 432                          void *dev,
 433                          spinlock_t *irqlock,
 434                          enum v4l2_buf_type type,
 435                          enum v4l2_field field,
 436                          unsigned int msize,
 437                          void *priv)
 438 {
 439         memset(q,0,sizeof(*q));
 440         q->irqlock = irqlock;
 441         q->dev     = dev;
 442         q->type    = type;
 443         q->field   = field;
 444         q->msize   = msize;
 445         q->ops     = ops;
 446         q->priv_data = priv;
 447
 448         videobuf_queue_pci(q);
 449
 450         mutex_init(&q->lock);
 451         INIT_LIST_HEAD(&q->stream);
 452 }
 453
 454 int
 455 videobuf_queue_is_busy(struct videobuf_queue *q)
 456 {
 457         int i;
 458
 459         if (q->streaming) {
 460                 dprintk(1,"busy: streaming active\n");
 461                 return 1;
 462         }
 463         if (q->reading) {
 464                 dprintk(1,"busy: pending read #1\n");
 465                 return 1;
 466         }
 467         if (q->read_buf) {
 468                 dprintk(1,"busy: pending read #2\n");
 469                 return 1;
 470         }
 471         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 472                 if (NULL == q->bufs[i])
 473                         continue;
 474                 if (q->bufs[i]->map) {
 475                         dprintk(1,"busy: buffer #%d mapped\n",i);
 476                         return 1;
 477                 }
 478                 if (q->bufs[i]->state == STATE_QUEUED) {
 479                         dprintk(1,"busy: buffer #%d queued\n",i);
 480                         return 1;
 481                 }
 482                 if (q->bufs[i]->state == STATE_ACTIVE) {
 483                         dprintk(1,"busy: buffer #%d avtive\n",i);
 484                         return 1;
 485                 }
 486         }
 487         return 0;
 488 }
 489
 490 void
 491 videobuf_queue_cancel(struct videobuf_queue *q)
 492 {
 493         unsigned long flags=0;
 494         int i;
 495
 496         /* remove queued buffers from list */
 497         if (q->irqlock)
 498                 spin_lock_irqsave(q->irqlock,flags);
 499         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 500                 if (NULL == q->bufs[i])
 501                         continue;
 502                 if (q->bufs[i]->state == STATE_QUEUED) {
 503                         list_del(&q->bufs[i]->queue);
 504                         q->bufs[i]->state = STATE_ERROR;
 505                 }
 506         }
 507         if (q->irqlock)
 508                 spin_unlock_irqrestore(q->irqlock,flags);
 509
 510         /* free all buffers + clear queue */
 511         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 512                 if (NULL == q->bufs[i])
 513                         continue;
 514                 q->ops->buf_release(q,q->bufs[i]);
 515         }
 516         INIT_LIST_HEAD(&q->stream);
 517 }
 518
 519 /* --------------------------------------------------------------------- */
 520
 521 enum v4l2_field
 522 videobuf_next_field(struct videobuf_queue *q)
 523 {
 524         enum v4l2_field field = q->field;
 525
 526         BUG_ON(V4L2_FIELD_ANY == field);
 527
 528         if (V4L2_FIELD_ALTERNATE == field) {
 529                 if (V4L2_FIELD_TOP == q->last) {
 530                         field   = V4L2_FIELD_BOTTOM;
 531                         q->last = V4L2_FIELD_BOTTOM;
 532                 } else {
 533                         field   = V4L2_FIELD_TOP;
 534                         q->last = V4L2_FIELD_TOP;
 535                 }
 536         }
 537         return field;
 538 }
 539
 540 void
 541 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 542                 enum v4l2_buf_type type)
 543 {
 544         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 545
 546         b->index    = vb->i;
 547         b->type     = type;
 548
 549         b->memory   = vb->memory;
 550         switch (b->memory) {
 551         case V4L2_MEMORY_MMAP:
 552                 b->m.offset  = vb->boff;
 553                 b->length    = vb->bsize;
 554                 break;
 555         case V4L2_MEMORY_USERPTR:
 556                 b->m.userptr = vb->baddr;
 557                 b->length    = vb->bsize;
 558                 break;
 559         case V4L2_MEMORY_OVERLAY:
 560                 b->m.offset  = vb->boff;
 561                 break;
 562         }
 563
 564         b->flags    = 0;
 565         if (vb->map)
 566                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 567
 568         switch (vb->state) {
 569         case STATE_PREPARED:
 570         case STATE_QUEUED:
 571         case STATE_ACTIVE:
 572                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 573                 break;
 574         case STATE_DONE:
 575         case STATE_ERROR:
 576                 b->flags |= V4L2_BUF_FLAG_DONE;
 577                 break;
 578         case STATE_NEEDS_INIT:
 579         case STATE_IDLE:
 580                 /* nothing */
 581                 break;
 582         }
 583
 584         if (vb->input != UNSET) {
 585                 b->flags |= V4L2_BUF_FLAG_INPUT;
 586                 b->input  = vb->input;
 587         }
 588
 589         b->field     = vb->field;
 590         b->timestamp = vb->ts;
 591         b->bytesused = vb->size;
 592         b->sequence  = vb->field_count >> 1;
 593 }
 594
 595 int
 596 videobuf_reqbufs(struct videobuf_queue *q,
 597                  struct v4l2_requestbuffers *req)
 598 {
 599         unsigned int size,count;
 600         int retval;
 601
 602         if (req->type != q->type) {
 603                 dprintk(1,"reqbufs: queue type invalid\n");
 604                 return -EINVAL;
 605         }
 606         if (req->count < 1) {
 607                 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
 608                 return -EINVAL;
 609         }
 610         if (req->memory != V4L2_MEMORY_MMAP     &&
 611             req->memory != V4L2_MEMORY_USERPTR  &&
 612             req->memory != V4L2_MEMORY_OVERLAY) {
 613                 dprintk(1,"reqbufs: memory type invalid\n");
 614                 return -EINVAL;
 615         }
 616
 617         if (q->streaming) {
 618                 dprintk(1,"reqbufs: streaming already exists\n");
 619                 return -EBUSY;
 620         }
 621         if (!list_empty(&q->stream)) {
 622                 dprintk(1,"reqbufs: stream running\n");
 623                 return -EBUSY;
 624         }
 625
 626         mutex_lock(&q->lock);
 627         count = req->count;
 628         if (count > VIDEO_MAX_FRAME)
 629                 count = VIDEO_MAX_FRAME;
 630         size = 0;
 631         q->ops->buf_setup(q,&count,&size);
 632         size = PAGE_ALIGN(size);
 633         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 634                 count, size, (count*size)>>PAGE_SHIFT);
 635
 636         retval = videobuf_mmap_setup(q,count,size,req->memory);
 637         if (retval < 0) {
 638                 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
 639                 goto done;
 640         }
 641
 642         req->count = count;
 643
 644  done:
 645         mutex_unlock(&q->lock);
 646         return retval;
 647 }
 648
 649 int
 650 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 651 {
 652         if (unlikely(b->type != q->type)) {
 653                 dprintk(1,"querybuf: Wrong type.\n");
 654                 return -EINVAL;
 655         }
 656         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 657                 dprintk(1,"querybuf: index out of range.\n");
 658                 return -EINVAL;
 659         }
 660         if (unlikely(NULL == q->bufs[b->index])) {
 661                 dprintk(1,"querybuf: buffer is null.\n");
 662                 return -EINVAL;
 663         }
 664         videobuf_status(b,q->bufs[b->index],q->type);
 665         return 0;
 666 }
 667
 668 int
 669 videobuf_qbuf(struct videobuf_queue *q,
 670               struct v4l2_buffer *b)
 671 {
 672         struct videobuf_buffer *buf;
 673         enum v4l2_field field;
 674         unsigned long flags=0;
 675         int retval;
 676
 677         mutex_lock(&q->lock);
 678         retval = -EBUSY;
 679         if (q->reading) {
 680                 dprintk(1,"qbuf: Reading running...\n");
 681                 goto done;
 682         }
 683         retval = -EINVAL;
 684         if (b->type != q->type) {
 685                 dprintk(1,"qbuf: Wrong type.\n");
 686                 goto done;
 687         }
 688         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 689                 dprintk(1,"qbuf: index out of range.\n");
 690                 goto done;
 691         }
 692         buf = q->bufs[b->index];
 693         if (NULL == buf) {
 694                 dprintk(1,"qbuf: buffer is null.\n");
 695                 goto done;
 696         }
 697         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 698         if (buf->memory != b->memory) {
 699                 dprintk(1,"qbuf: memory type is wrong.\n");
 700                 goto done;
 701         }
 702         if (buf->state == STATE_QUEUED ||
 703             buf->state == STATE_PREPARED ||
 704             buf->state == STATE_ACTIVE) {
 705                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 706                 goto done;
 707         }
 708
 709         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 710                 if (b->input >= q->inputs) {
 711                         dprintk(1,"qbuf: wrong input.\n");
 712                         goto done;
 713                 }
 714                 buf->input = b->input;
 715         } else {
 716                 buf->input = UNSET;
 717         }
 718
 719         switch (b->memory) {
 720         case V4L2_MEMORY_MMAP:
 721                 if (0 == buf->baddr) {
 722                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 723                         goto done;
 724                 }
 725                 break;
 726         case V4L2_MEMORY_USERPTR:
 727                 if (b->length < buf->bsize) {
 728                         dprintk(1,"qbuf: buffer length is not enough\n");
 729                         goto done;
 730                 }
 731                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 732                         q->ops->buf_release(q,buf);
 733                 buf->baddr = b->m.userptr;
 734                 break;
 735         case V4L2_MEMORY_OVERLAY:
 736                 buf->boff = b->m.offset;
 737                 break;
 738         default:
 739                 dprintk(1,"qbuf: wrong memory type\n");
 740                 goto done;
 741         }
 742
 743         dprintk(1,"qbuf: requesting next field\n");
 744         field = videobuf_next_field(q);
 745         retval = q->ops->buf_prepare(q,buf,field);
 746         if (0 != retval) {
 747                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 748                 goto done;
 749         }
 750
 751         list_add_tail(&buf->stream,&q->stream);
 752         if (q->streaming) {
 753                 if (q->irqlock)
 754                         spin_lock_irqsave(q->irqlock,flags);
 755                 q->ops->buf_queue(q,buf);
 756                 if (q->irqlock)
 757                         spin_unlock_irqrestore(q->irqlock,flags);
 758         }
 759         dprintk(1,"qbuf: succeded\n");
 760         retval = 0;
 761
 762  done:
 763         mutex_unlock(&q->lock);
 764         return retval;
 765 }
 766
 767 int
 768 videobuf_dqbuf(struct videobuf_queue *q,
 769                struct v4l2_buffer *b, int nonblocking)
 770 {
 771         struct videobuf_buffer *buf;
 772         int retval;
 773
 774         mutex_lock(&q->lock);
 775         retval = -EBUSY;
 776         if (q->reading) {
 777                 dprintk(1,"dqbuf: Reading running...\n");
 778                 goto done;
 779         }
 780         retval = -EINVAL;
 781         if (b->type != q->type) {
 782                 dprintk(1,"dqbuf: Wrong type.\n");
 783                 goto done;
 784         }
 785         if (list_empty(&q->stream)) {
 786                 dprintk(1,"dqbuf: stream running\n");
 787                 goto done;
 788         }
 789         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 790         retval = videobuf_waiton(buf, nonblocking, 1);
 791         if (retval < 0) {
 792                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 793                 goto done;
 794         }
 795         switch (buf->state) {
 796         case STATE_ERROR:
 797                 dprintk(1,"dqbuf: state is error\n");
 798                 retval = -EIO;
 799                 videobuf_dma_sync(q,&buf->dma);
 800                 buf->state = STATE_IDLE;
 801                 break;
 802         case STATE_DONE:
 803                 dprintk(1,"dqbuf: state is done\n");
 804                 videobuf_dma_sync(q,&buf->dma);
 805                 buf->state = STATE_IDLE;
 806                 break;
 807         default:
 808                 dprintk(1,"dqbuf: state invalid\n");
 809                 retval = -EINVAL;
 810                 goto done;
 811         }
 812         list_del(&buf->stream);
 813         memset(b,0,sizeof(*b));
 814         videobuf_status(b,buf,q->type);
 815
 816  done:
 817         mutex_unlock(&q->lock);
 818         return retval;
 819 }
 820
 821 int videobuf_streamon(struct videobuf_queue *q)
 822 {
 823         struct videobuf_buffer *buf;
 824         struct list_head *list;
 825         unsigned long flags=0;
 826         int retval;
 827
 828         mutex_lock(&q->lock);
 829         retval = -EBUSY;
 830         if (q->reading)
 831                 goto done;
 832         retval = 0;
 833         if (q->streaming)
 834                 goto done;
 835         q->streaming = 1;
 836         if (q->irqlock)
 837                 spin_lock_irqsave(q->irqlock,flags);
 838         list_for_each(list,&q->stream) {
 839                 buf = list_entry(list, struct videobuf_buffer, stream);
 840                 if (buf->state == STATE_PREPARED)
 841                         q->ops->buf_queue(q,buf);
 842         }
 843         if (q->irqlock)
 844                 spin_unlock_irqrestore(q->irqlock,flags);
 845
 846  done:
 847         mutex_unlock(&q->lock);
 848         return retval;
 849 }
 850
 851 int videobuf_streamoff(struct videobuf_queue *q)
 852 {
 853         int retval = -EINVAL;
 854
 855         mutex_lock(&q->lock);
 856         if (!q->streaming)
 857                 goto done;
 858         videobuf_queue_cancel(q);
 859         q->streaming = 0;
 860         retval = 0;
 861
 862  done:
 863         mutex_unlock(&q->lock);
 864         return retval;
 865 }
 866
 867 static ssize_t
 868 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 869                        size_t count, loff_t *ppos)
 870 {
 871         enum v4l2_field field;
 872         unsigned long flags=0;
 873         int retval;
 874
 875         /* setup stuff */
 876         q->read_buf = videobuf_alloc(q->msize);
 877         if (NULL == q->read_buf)
 878                 return -ENOMEM;
 879
 880         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 881         q->read_buf->baddr  = (unsigned long)data;
 882         q->read_buf->bsize  = count;
 883         field = videobuf_next_field(q);
 884         retval = q->ops->buf_prepare(q,q->read_buf,field);
 885         if (0 != retval)
 886                 goto done;
 887
 888         /* start capture & wait */
 889         if (q->irqlock)
 890                 spin_lock_irqsave(q->irqlock,flags);
 891         q->ops->buf_queue(q,q->read_buf);
 892         if (q->irqlock)
 893                 spin_unlock_irqrestore(q->irqlock,flags);
 894         retval = videobuf_waiton(q->read_buf,0,0);
 895         if (0 == retval) {
 896                 videobuf_dma_sync(q,&q->read_buf->dma);
 897                 if (STATE_ERROR == q->read_buf->state)
 898                         retval = -EIO;
 899                 else
 900                         retval = q->read_buf->size;
 901         }
 902
 903  done:
 904         /* cleanup */
 905         q->ops->buf_release(q,q->read_buf);
 906         kfree(q->read_buf);
 907         q->read_buf = NULL;
 908         return retval;
 909 }
 910
 911 ssize_t videobuf_read_one(struct videobuf_queue *q,
 912                           char __user *data, size_t count, loff_t *ppos,
 913                           int nonblocking)
 914 {
 915         enum v4l2_field field;
 916         unsigned long flags=0;
 917         unsigned size, nbufs, bytes;
 918         int retval;
 919
 920         mutex_lock(&q->lock);
 921
 922         nbufs = 1; size = 0;
 923         q->ops->buf_setup(q,&nbufs,&size);
 924         if (NULL == q->read_buf  &&
 925             count >= size        &&
 926             !nonblocking) {
 927                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 928                 if (retval >= 0  ||  retval == -EIO)
 929                         /* ok, all done */
 930                         goto done;
 931                 /* fallback to kernel bounce buffer on failures */
 932         }
 933
 934         if (NULL == q->read_buf) {
 935                 /* need to capture a new frame */
 936                 retval = -ENOMEM;
 937                 q->read_buf = videobuf_alloc(q->msize);
 938                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 939                 if (NULL == q->read_buf)
 940                         goto done;
 941                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 942                 q->read_buf->bsize = count; /* preferred size */
 943                 field = videobuf_next_field(q);
 944                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 945                 if (0 != retval) {
 946                         kfree (q->read_buf);
 947                         q->read_buf = NULL;
 948                         goto done;
 949                 }
 950                 if (q->irqlock)
 951                         spin_lock_irqsave(q->irqlock,flags);
 952                 q->ops->buf_queue(q,q->read_buf);
 953                 if (q->irqlock)
 954                         spin_unlock_irqrestore(q->irqlock,flags);
 955                 q->read_off = 0;
 956         }
 957
 958         /* wait until capture is done */
 959         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 960         if (0 != retval)
 961                 goto done;
 962         videobuf_dma_sync(q,&q->read_buf->dma);
 963
 964         if (STATE_ERROR == q->read_buf->state) {
 965                 /* catch I/O errors */
 966                 q->ops->buf_release(q,q->read_buf);
 967                 kfree(q->read_buf);
 968                 q->read_buf = NULL;
 969                 retval = -EIO;
 970                 goto done;
 971         }
 972
 973         /* copy to userspace */
 974         bytes = count;
 975         if (bytes > q->read_buf->size - q->read_off)
 976                 bytes = q->read_buf->size - q->read_off;
 977         retval = -EFAULT;
 978         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 979                 goto done;
 980
 981         retval = bytes;
 982         q->read_off += bytes;
 983         if (q->read_off == q->read_buf->size) {
 984                 /* all data copied, cleanup */
 985                 q->ops->buf_release(q,q->read_buf);
 986                 kfree(q->read_buf);
 987                 q->read_buf = NULL;
 988         }
 989
 990  done:
 991         mutex_unlock(&q->lock);
 992         return retval;
 993 }
 994
 995 int videobuf_read_start(struct videobuf_queue *q)
 996 {
 997         enum v4l2_field field;
 998         unsigned long flags=0;
 999         int count = 0, size = 0;
1000         int err, i;
1001
1002         q->ops->buf_setup(q,&count,&size);
1003         if (count < 2)
1004                 count = 2;
1005         if (count > VIDEO_MAX_FRAME)
1006                 count = VIDEO_MAX_FRAME;
1007         size = PAGE_ALIGN(size);
1008
1009         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
1010         if (err)
1011                 return err;
1012         for (i = 0; i < count; i++) {
1013                 field = videobuf_next_field(q);
1014                 err = q->ops->buf_prepare(q,q->bufs[i],field);
1015                 if (err)
1016                         return err;
1017                 list_add_tail(&q->bufs[i]->stream, &q->stream);
1018         }
1019         if (q->irqlock)
1020                 spin_lock_irqsave(q->irqlock,flags);
1021         for (i = 0; i < count; i++)
1022                 q->ops->buf_queue(q,q->bufs[i]);
1023         if (q->irqlock)
1024                 spin_unlock_irqrestore(q->irqlock,flags);
1025         q->reading = 1;
1026         return 0;
1027 }
1028
1029 void videobuf_read_stop(struct videobuf_queue *q)
1030 {
1031         int i;
1032
1033         videobuf_queue_cancel(q);
1034         videobuf_mmap_free(q);
1035         INIT_LIST_HEAD(&q->stream);
1036         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1037                 if (NULL == q->bufs[i])
1038                         continue;
1039                 kfree(q->bufs[i]);
1040                 q->bufs[i] = NULL;
1041         }
1042         q->read_buf = NULL;
1043         q->reading  = 0;
1044 }
1045
1046 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1047                              char __user *data, size_t count, loff_t *ppos,
1048                              int vbihack, int nonblocking)
1049 {
1050         unsigned int *fc, bytes;
1051         int err, retval;
1052         unsigned long flags=0;
1053
1054         dprintk(2,"%s\n",__FUNCTION__);
1055         mutex_lock(&q->lock);
1056         retval = -EBUSY;
1057         if (q->streaming)
1058                 goto done;
1059         if (!q->reading) {
1060                 retval = videobuf_read_start(q);
1061                 if (retval < 0)
1062                         goto done;
1063         }
1064
1065         retval = 0;
1066         while (count > 0) {
1067                 /* get / wait for data */
1068                 if (NULL == q->read_buf) {
1069                         q->read_buf = list_entry(q->stream.next,
1070                                                  struct videobuf_buffer,
1071                                                  stream);
1072                         list_del(&q->read_buf->stream);
1073                         q->read_off = 0;
1074                 }
1075                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
1076                 if (err < 0) {
1077                         if (0 == retval)
1078                                 retval = err;
1079                         break;
1080                 }
1081
1082                 if (q->read_buf->state == STATE_DONE) {
1083                         if (vbihack) {
1084                                 /* dirty, undocumented hack -- pass the frame counter
1085                                  * within the last four bytes of each vbi data block.
1086                                  * We need that one to maintain backward compatibility
1087                                  * to all vbi decoding software out there ... */
1088                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
1089                                 fc += (q->read_buf->size>>2) -1;
1090                                 *fc = q->read_buf->field_count >> 1;
1091                                 dprintk(1,"vbihack: %d\n",*fc);
1092                         }
1093
1094                         /* copy stuff */
1095                         bytes = count;
1096                         if (bytes > q->read_buf->size - q->read_off)
1097                                 bytes = q->read_buf->size - q->read_off;
1098                         if (copy_to_user(data + retval,
1099                                          q->read_buf->dma.vmalloc + q->read_off,
1100                                          bytes)) {
1101                                 if (0 == retval)
1102                                         retval = -EFAULT;
1103                                 break;
1104                         }
1105                         count       -= bytes;
1106                         retval      += bytes;
1107                         q->read_off += bytes;
1108                 } else {
1109                         /* some error */
1110                         q->read_off = q->read_buf->size;
1111                         if (0 == retval)
1112                                 retval = -EIO;
1113                 }
1114
1115                 /* requeue buffer when done with copying */
1116                 if (q->read_off == q->read_buf->size) {
1117                         list_add_tail(&q->read_buf->stream,
1118                                       &q->stream);
1119                         if (q->irqlock)
1120                                 spin_lock_irqsave(q->irqlock,flags);
1121                         q->ops->buf_queue(q,q->read_buf);
1122                         if (q->irqlock)
1123                                 spin_unlock_irqrestore(q->irqlock,flags);
1124                         q->read_buf = NULL;
1125                 }
1126                 if (retval < 0)
1127                         break;
1128         }
1129
1130  done:
1131         mutex_unlock(&q->lock);
1132         return retval;
1133 }
1134
1135 unsigned int videobuf_poll_stream(struct file *file,
1136                                   struct videobuf_queue *q,
1137                                   poll_table *wait)
1138 {
1139         struct videobuf_buffer *buf = NULL;
1140         unsigned int rc = 0;
1141
1142         mutex_lock(&q->lock);
1143         if (q->streaming) {
1144                 if (!list_empty(&q->stream))
1145                         buf = list_entry(q->stream.next,
1146                                          struct videobuf_buffer, stream);
1147         } else {
1148                 if (!q->reading)
1149                         videobuf_read_start(q);
1150                 if (!q->reading) {
1151                         rc = POLLERR;
1152                 } else if (NULL == q->read_buf) {
1153                         q->read_buf = list_entry(q->stream.next,
1154                                                  struct videobuf_buffer,
1155                                                  stream);
1156                         list_del(&q->read_buf->stream);
1157                         q->read_off = 0;
1158                 }
1159                 buf = q->read_buf;
1160         }
1161         if (!buf)
1162                 rc = POLLERR;
1163
1164         if (0 == rc) {
1165                 poll_wait(file, &buf->done, wait);
1166                 if (buf->state == STATE_DONE ||
1167                     buf->state == STATE_ERROR)
1168                         rc = POLLIN|POLLRDNORM;
1169         }
1170         mutex_unlock(&q->lock);
1171         return rc;
1172 }
1173
1174 /* --------------------------------------------------------------------- */
1175
1176 static void
1177 videobuf_vm_open(struct vm_area_struct *vma)
1178 {
1179         struct videobuf_mapping *map = vma->vm_private_data;
1180
1181         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1182                 map->count,vma->vm_start,vma->vm_end);
1183         map->count++;
1184 }
1185
1186 static void
1187 videobuf_vm_close(struct vm_area_struct *vma)
1188 {
1189         struct videobuf_mapping *map = vma->vm_private_data;
1190         struct videobuf_queue *q = map->q;
1191         int i;
1192
1193         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1194                 map->count,vma->vm_start,vma->vm_end);
1195
1196         map->count--;
1197         if (0 == map->count) {
1198                 dprintk(1,"munmap %p q=%p\n",map,q);
1199                 mutex_lock(&q->lock);
1200                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1201                         if (NULL == q->bufs[i])
1202                                 continue;
1203                         if (q->bufs[i])
1204                                 ;
1205                         if (q->bufs[i]->map != map)
1206                                 continue;
1207                         q->bufs[i]->map   = NULL;
1208                         q->bufs[i]->baddr = 0;
1209                         q->ops->buf_release(q,q->bufs[i]);
1210                 }
1211                 mutex_unlock(&q->lock);
1212                 kfree(map);
1213         }
1214         return;
1215 }
1216
1217 /*
1218  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1219  * memory location with 32bit PCI devices (i.e. don't use highmem for
1220  * now ...).  Bounce buffers don't work very well for the data rates
1221  * video capture has.
1222  */
1223 static struct page*
1224 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1225                    int *type)
1226 {
1227         struct page *page;
1228
1229         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1230                 vaddr,vma->vm_start,vma->vm_end);
1231         if (vaddr > vma->vm_end)
1232                 return NOPAGE_SIGBUS;
1233         page = alloc_page(GFP_USER | __GFP_DMA32);
1234         if (!page)
1235                 return NOPAGE_OOM;
1236         clear_user_page(page_address(page), vaddr, page);
1237         if (type)
1238                 *type = VM_FAULT_MINOR;
1239         return page;
1240 }
1241
1242 static struct vm_operations_struct videobuf_vm_ops =
1243 {
1244         .open     = videobuf_vm_open,
1245         .close    = videobuf_vm_close,
1246         .nopage   = videobuf_vm_nopage,
1247 };
1248
1249 int videobuf_mmap_setup(struct videobuf_queue *q,
1250                         unsigned int bcount, unsigned int bsize,
1251                         enum v4l2_memory memory)
1252 {
1253         unsigned int i;
1254         int err;
1255
1256         err = videobuf_mmap_free(q);
1257         if (0 != err)
1258                 return err;
1259
1260         for (i = 0; i < bcount; i++) {
1261                 q->bufs[i] = videobuf_alloc(q->msize);
1262                 q->bufs[i]->i      = i;
1263                 q->bufs[i]->input  = UNSET;
1264                 q->bufs[i]->memory = memory;
1265                 q->bufs[i]->bsize  = bsize;
1266                 switch (memory) {
1267                 case V4L2_MEMORY_MMAP:
1268                         q->bufs[i]->boff  = bsize * i;
1269                         break;
1270                 case V4L2_MEMORY_USERPTR:
1271                 case V4L2_MEMORY_OVERLAY:
1272                         /* nothing */
1273                         break;
1274                 }
1275         }
1276         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1277                 bcount,bsize);
1278         return 0;
1279 }
1280
1281 int videobuf_mmap_free(struct videobuf_queue *q)
1282 {
1283         int i;
1284
1285         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1286                 if (q->bufs[i] && q->bufs[i]->map)
1287                         return -EBUSY;
1288         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1289                 if (NULL == q->bufs[i])
1290                         continue;
1291                 q->ops->buf_release(q,q->bufs[i]);
1292                 kfree(q->bufs[i]);
1293                 q->bufs[i] = NULL;
1294         }
1295         return 0;
1296 }
1297
1298 int videobuf_mmap_mapper(struct videobuf_queue *q,
1299                          struct vm_area_struct *vma)
1300 {
1301         struct videobuf_mapping *map;
1302         unsigned int first,last,size,i;
1303         int retval;
1304
1305         mutex_lock(&q->lock);
1306         retval = -EINVAL;
1307         if (!(vma->vm_flags & VM_WRITE)) {
1308                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1309                 goto done;
1310         }
1311         if (!(vma->vm_flags & VM_SHARED)) {
1312                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1313                 goto done;
1314         }
1315
1316         /* look for first buffer to map */
1317         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1318                 if (NULL == q->bufs[first])
1319                         continue;
1320                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1321                         continue;
1322                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1323                         break;
1324         }
1325         if (VIDEO_MAX_FRAME == first) {
1326                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1327                         (vma->vm_pgoff << PAGE_SHIFT));
1328                 goto done;
1329         }
1330
1331         /* look for last buffer to map */
1332         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1333                 if (NULL == q->bufs[last])
1334                         continue;
1335                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1336                         continue;
1337                 if (q->bufs[last]->map) {
1338                         retval = -EBUSY;
1339                         goto done;
1340                 }
1341                 size += q->bufs[last]->bsize;
1342                 if (size == (vma->vm_end - vma->vm_start))
1343                         break;
1344         }
1345         if (VIDEO_MAX_FRAME == last) {
1346                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1347                         (vma->vm_end - vma->vm_start));
1348                 goto done;
1349         }
1350
1351         /* create mapping + update buffer list */
1352         retval = -ENOMEM;
1353         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1354         if (NULL == map)
1355                 goto done;
1356         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1357                 q->bufs[i]->map   = map;
1358                 q->bufs[i]->baddr = vma->vm_start + size;
1359         }
1360         map->count    = 1;
1361         map->start    = vma->vm_start;
1362         map->end      = vma->vm_end;
1363         map->q        = q;
1364         vma->vm_ops   = &videobuf_vm_ops;
1365         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1366         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1367         vma->vm_private_data = map;
1368         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1369                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1370         retval = 0;
1371
1372  done:
1373         mutex_unlock(&q->lock);
1374         return retval;
1375 }
1376
1377 /* --------------------------------------------------------------------- */
1378
1379 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1380
1381 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1382 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1383 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1384 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1385 EXPORT_SYMBOL_GPL(videobuf_dma_map);
1386 EXPORT_SYMBOL_GPL(videobuf_dma_sync);
1387 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
1388 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1389
1390 EXPORT_SYMBOL_GPL(videobuf_pci_dma_map);
1391 EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap);
1392
1393 EXPORT_SYMBOL_GPL(videobuf_alloc);
1394 EXPORT_SYMBOL_GPL(videobuf_waiton);
1395 EXPORT_SYMBOL_GPL(videobuf_iolock);
1396
1397 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1398 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1399 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1400
1401 EXPORT_SYMBOL_GPL(videobuf_next_field);
1402 EXPORT_SYMBOL_GPL(videobuf_status);
1403 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1404 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1405 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1406 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1407 EXPORT_SYMBOL_GPL(videobuf_streamon);
1408 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1409
1410 EXPORT_SYMBOL_GPL(videobuf_read_start);
1411 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1412 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1413 EXPORT_SYMBOL_GPL(videobuf_read_one);
1414 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1415
1416 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1417 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1418 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1419
1420 /*
1421  * Local variables:
1422  * c-basic-offset: 8
1423  * End:
1424  */