drivers/media/video/video-buf.c

   1 /*
   2  * generic helper functions for video4linux capture buffers, to handle
   3  * memory management and PCI DMA.  Right now bttv + saa7134 use it.
   4  *
   5  * The functions expect the hardware being able to scatter gatter
   6  * (i.e. the buffers are not linear in physical memory, but fragmented
   7  * into PAGE_SIZE chunks).  They also assume the driver does not need
   8  * to touch the video data (thus it is probably not useful for USB as
   9  * data often must be uncompressed by the drivers).
  10  *
  11  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  */
  18
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/slab.h>
  24 #include <linux/pci.h>
  25 #include <linux/interrupt.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28
  29 #include <media/video-buf.h>
  30
  31 static int debug = 0;
  32
  33 MODULE_DESCRIPTION("helper module to manage video4linux pci dma buffers");
  34 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  35 MODULE_LICENSE("GPL");
  36 MODULE_PARM(debug,"i");
  37
  38 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  39         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  40
  41 struct scatterlist*
  42 videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
  43 {
  44         struct scatterlist *sglist;
  45         struct page *pg;
  46         int i;
  47
  48         sglist = kmalloc(sizeof(struct scatterlist)*nr_pages, GFP_KERNEL);
  49         if (NULL == sglist)
  50                 return NULL;
  51         memset(sglist,0,sizeof(struct scatterlist)*nr_pages);
  52         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
  53                 pg = vmalloc_to_page(virt);
  54                 if (NULL == pg)
  55                         goto err;
  56                 if (PageHighMem(pg))
  57                         BUG();
  58                 sglist[i].page   = pg;
  59                 sglist[i].length = PAGE_SIZE;
  60         }
  61         return sglist;
  62
  63  err:
  64         kfree(sglist);
  65         return NULL;
  66 }
  67
  68 struct scatterlist*
  69 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
  70 {
  71         struct scatterlist *sglist;
  72         int i = 0;
  73
  74         if (NULL == pages[0])
  75                 return NULL;
  76         sglist = kmalloc(sizeof(*sglist) * nr_pages, GFP_KERNEL);
  77         if (NULL == sglist)
  78                 return NULL;
  79         memset(sglist, 0, sizeof(*sglist) * nr_pages);
  80
  81         if (NULL == pages[0])
  82                 goto nopage;
  83         if (PageHighMem(pages[0]))
  84                 /* DMA to highmem pages might not work */
  85                 goto highmem;
  86         sglist[0].page   = pages[0];
  87         sglist[0].offset = offset;
  88         sglist[0].length = PAGE_SIZE - offset;
  89         for (i = 1; i < nr_pages; i++) {
  90                 if (NULL == pages[i])
  91                         goto nopage;
  92                 if (PageHighMem(pages[i]))
  93                         goto highmem;
  94                 sglist[i].page   = pages[i];
  95                 sglist[i].length = PAGE_SIZE;
  96         }
  97         return sglist;
  98
  99  nopage:
 100         dprintk(2,"sgl: oops - no page\n");
 101         kfree(sglist);
 102         return NULL;
 103
 104  highmem:
 105         dprintk(2,"sgl: oops - highmem page\n");
 106         kfree(sglist);
 107         return NULL;
 108 }
 109
 110 /* --------------------------------------------------------------------- */
 111
 112 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 113                            unsigned long data, unsigned long size)
 114 {
 115         unsigned long first,last;
 116         int err, rw = 0;
 117
 118         dma->direction = direction;
 119         switch (dma->direction) {
 120         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 121         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 122         default:                 BUG();
 123         }
 124
 125         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 126         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 127         dma->offset   = data & ~PAGE_MASK;
 128         dma->nr_pages = last-first+1;
 129         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 130                              GFP_KERNEL);
 131         if (NULL == dma->pages)
 132                 return -ENOMEM;
 133         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 134                 data,size,dma->nr_pages);
 135
 136         down_read(&current->mm->mmap_sem);
 137         err = get_user_pages(current,current->mm,
 138                              data & PAGE_MASK, dma->nr_pages,
 139                              rw == READ, 1, /* force */
 140                              dma->pages, NULL);
 141         up_read(&current->mm->mmap_sem);
 142         if (err != dma->nr_pages) {
 143                 dma->nr_pages = (err >= 0) ? err : 0;
 144                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 145                 return err < 0 ? err : -EINVAL;
 146         }
 147         return 0;
 148 }
 149
 150 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 151                              int nr_pages)
 152 {
 153         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 154         dma->direction = direction;
 155         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 156         if (NULL == dma->vmalloc) {
 157                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 158                 return -ENOMEM;
 159         }
 160         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 161         dma->nr_pages = nr_pages;
 162         return 0;
 163 }
 164
 165 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 166                               dma_addr_t addr, int nr_pages)
 167 {
 168         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 169                 nr_pages,(unsigned long)addr);
 170         dma->direction = direction;
 171         if (0 == addr)
 172                 return -EINVAL;
 173
 174         dma->bus_addr = addr;
 175         dma->nr_pages = nr_pages;
 176         return 0;
 177 }
 178
 179 int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 180 {
 181         if (0 == dma->nr_pages)
 182                 BUG();
 183
 184         if (dma->pages) {
 185                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 186                                                    dma->offset);
 187         }
 188         if (dma->vmalloc) {
 189                 dma->sglist = videobuf_vmalloc_to_sg
 190                         (dma->vmalloc,dma->nr_pages);
 191         }
 192         if (dma->bus_addr) {
 193                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 194                 if (NULL != dma->sglist) {
 195                         dma->sglen  = 1;
 196                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 197                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 198                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 199                 }
 200         }
 201         if (NULL == dma->sglist) {
 202                 dprintk(1,"scatterlist is NULL\n");
 203                 return -ENOMEM;
 204         }
 205
 206         if (!dma->bus_addr)
 207                 dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
 208                                         dma->direction);
 209         return 0;
 210 }
 211
 212 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 213 {
 214         if (!dma->sglen)
 215                 BUG();
 216
 217         if (!dma->bus_addr)
 218                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 219         return 0;
 220 }
 221
 222 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 223 {
 224         if (!dma->sglen)
 225                 return 0;
 226
 227         if (!dma->bus_addr)
 228                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 229         kfree(dma->sglist);
 230         dma->sglist = NULL;
 231         dma->sglen = 0;
 232         return 0;
 233 }
 234
 235 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 236 {
 237         if (dma->sglen)
 238                 BUG();
 239
 240         if (dma->pages) {
 241                 int i;
 242                 for (i=0; i < dma->nr_pages; i++)
 243                         page_cache_release(dma->pages[i]);
 244                 kfree(dma->pages);
 245                 dma->pages = NULL;
 246         }
 247         if (dma->vmalloc) {
 248                 vfree(dma->vmalloc);
 249                 dma->vmalloc = NULL;
 250         }
 251         if (dma->bus_addr) {
 252                 dma->bus_addr = 0;
 253         }
 254         dma->direction = PCI_DMA_NONE;
 255         return 0;
 256 }
 257
 258 /* --------------------------------------------------------------------- */
 259
 260 void* videobuf_alloc(unsigned int size)
 261 {
 262         struct videobuf_buffer *vb;
 263
 264         vb = kmalloc(size,GFP_KERNEL);
 265         if (NULL != vb) {
 266                 memset(vb,0,size);
 267                 init_waitqueue_head(&vb->done);
 268         }
 269         return vb;
 270 }
 271
 272 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 273 {
 274         int retval = 0;
 275         DECLARE_WAITQUEUE(wait, current);
 276
 277         add_wait_queue(&vb->done, &wait);
 278         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 279                 if (non_blocking) {
 280                         retval = -EAGAIN;
 281                         break;
 282                 }
 283                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 284                                         : TASK_UNINTERRUPTIBLE);
 285                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 286                         schedule();
 287                 set_current_state(TASK_RUNNING);
 288                 if (intr && signal_pending(current)) {
 289                         dprintk(1,"buffer waiton: -EINTR\n");
 290                         retval = -EINTR;
 291                         break;
 292                 }
 293         }
 294         remove_wait_queue(&vb->done, &wait);
 295         return retval;
 296 }
 297
 298 int
 299 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 300                 struct v4l2_framebuffer *fbuf)
 301 {
 302         int err,pages;
 303         dma_addr_t bus;
 304
 305         switch (vb->memory) {
 306         case V4L2_MEMORY_MMAP:
 307         case V4L2_MEMORY_USERPTR:
 308                 if (0 == vb->baddr) {
 309                         /* no userspace addr -- kernel bounce buffer */
 310                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 311                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 312                                                        pages);
 313                         if (0 != err)
 314                                 return err;
 315                 } else {
 316                         /* dma directly to userspace */
 317                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 318                                                      vb->baddr,vb->bsize);
 319                         if (0 != err)
 320                                 return err;
 321                 }
 322                 break;
 323         case V4L2_MEMORY_OVERLAY:
 324                 if (NULL == fbuf)
 325                         return -EINVAL;
 326                 /* FIXME: need sanity checks for vb->boff */
 327                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 328                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 329                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 330                                                 bus, pages);
 331                 if (0 != err)
 332                         return err;
 333                 break;
 334         default:
 335                 BUG();
 336         }
 337         err = videobuf_dma_pci_map(pci,&vb->dma);
 338         if (0 != err)
 339                 return err;
 340
 341         return 0;
 342 }
 343
 344 /* --------------------------------------------------------------------- */
 345
 346 void
 347 videobuf_queue_init(struct videobuf_queue *q,
 348                     struct videobuf_queue_ops *ops,
 349                     struct pci_dev *pci,
 350                     spinlock_t *irqlock,
 351                     enum v4l2_buf_type type,
 352                     enum v4l2_field field,
 353                     unsigned int msize)
 354 {
 355         memset(q,0,sizeof(*q));
 356
 357         q->irqlock = irqlock;
 358         q->pci     = pci;
 359         q->type    = type;
 360         q->field   = field;
 361         q->msize   = msize;
 362         q->ops     = ops;
 363
 364         init_MUTEX(&q->lock);
 365         INIT_LIST_HEAD(&q->stream);
 366 }
 367
 368 int
 369 videobuf_queue_is_busy(struct videobuf_queue *q)
 370 {
 371         int i;
 372
 373         if (q->streaming) {
 374                 dprintk(1,"busy: streaming active\n");
 375                 return 1;
 376         }
 377         if (q->reading) {
 378                 dprintk(1,"busy: pending read #1\n");
 379                 return 1;
 380         }
 381         if (q->read_buf) {
 382                 dprintk(1,"busy: pending read #2\n");
 383                 return 1;
 384         }
 385         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 386                 if (NULL == q->bufs[i])
 387                         continue;
 388                 if (q->bufs[i]->map) {
 389                         dprintk(1,"busy: buffer #%d mapped\n",i);
 390                         return 1;
 391                 }
 392                 if (q->bufs[i]->state == STATE_QUEUED) {
 393                         dprintk(1,"busy: buffer #%d queued\n",i);
 394                         return 1;
 395                 }
 396                 if (q->bufs[i]->state == STATE_ACTIVE) {
 397                         dprintk(1,"busy: buffer #%d avtive\n",i);
 398                         return 1;
 399                 }
 400         }
 401         return 0;
 402 }
 403
 404 void
 405 videobuf_queue_cancel(struct file *file, struct videobuf_queue *q)
 406 {
 407         unsigned long flags;
 408         int i;
 409
 410         /* remove queued buffers from list */
 411         spin_lock_irqsave(q->irqlock,flags);
 412         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 413                 if (NULL == q->bufs[i])
 414                         continue;
 415                 if (q->bufs[i]->state == STATE_QUEUED) {
 416                         list_del(&q->bufs[i]->queue);
 417                         q->bufs[i]->state = STATE_ERROR;
 418                 }
 419         }
 420         spin_unlock_irqrestore(q->irqlock,flags);
 421
 422         /* free all buffers + clear queue */
 423         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 424                 if (NULL == q->bufs[i])
 425                         continue;
 426                 q->ops->buf_release(file,q->bufs[i]);
 427         }
 428         INIT_LIST_HEAD(&q->stream);
 429 }
 430
 431 /* --------------------------------------------------------------------- */
 432
 433 enum v4l2_field
 434 videobuf_next_field(struct videobuf_queue *q)
 435 {
 436         enum v4l2_field field = q->field;
 437
 438         BUG_ON(V4L2_FIELD_ANY == field);
 439
 440         if (V4L2_FIELD_ALTERNATE == field) {
 441                 if (V4L2_FIELD_TOP == q->last) {
 442                         field   = V4L2_FIELD_BOTTOM;
 443                         q->last = V4L2_FIELD_BOTTOM;
 444                 } else {
 445                         field   = V4L2_FIELD_TOP;
 446                         q->last = V4L2_FIELD_TOP;
 447                 }
 448         }
 449         return field;
 450 }
 451
 452 void
 453 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 454                 enum v4l2_buf_type type)
 455 {
 456         b->index    = vb->i;
 457         b->type     = type;
 458
 459         b->memory   = vb->memory;
 460         switch (b->memory) {
 461         case V4L2_MEMORY_MMAP:
 462                 b->m.offset  = vb->boff;
 463                 b->length    = vb->bsize;
 464                 break;
 465         case V4L2_MEMORY_USERPTR:
 466                 b->m.userptr = vb->baddr;
 467                 b->length    = vb->bsize;
 468                 break;
 469         case V4L2_MEMORY_OVERLAY:
 470                 b->m.offset  = vb->boff;
 471                 break;
 472         }
 473
 474         b->flags    = 0;
 475         if (vb->map)
 476                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 477
 478         switch (vb->state) {
 479         case STATE_PREPARED:
 480         case STATE_QUEUED:
 481         case STATE_ACTIVE:
 482                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 483                 break;
 484         case STATE_DONE:
 485         case STATE_ERROR:
 486                 b->flags |= V4L2_BUF_FLAG_DONE;
 487                 break;
 488         case STATE_NEEDS_INIT:
 489         case STATE_IDLE:
 490                 /* nothing */
 491                 break;
 492         }
 493
 494         b->field     = vb->field;
 495         b->timestamp = vb->ts;
 496         b->bytesused = vb->size;
 497         b->sequence  = vb->field_count >> 1;
 498 }
 499
 500 int
 501 videobuf_reqbufs(struct file *file, struct videobuf_queue *q,
 502                  struct v4l2_requestbuffers *req)
 503 {
 504         unsigned int size,count;
 505         int retval;
 506
 507         if (req->type != q->type)
 508                 return -EINVAL;
 509         if (req->count < 1)
 510                 return -EINVAL;
 511         if (req->memory != V4L2_MEMORY_MMAP     &&
 512             req->memory != V4L2_MEMORY_USERPTR  &&
 513             req->memory != V4L2_MEMORY_OVERLAY)
 514                 return -EINVAL;
 515
 516         down(&q->lock);
 517         count = req->count;
 518         if (count > VIDEO_MAX_FRAME)
 519                 count = VIDEO_MAX_FRAME;
 520         size = 0;
 521         q->ops->buf_setup(file,&count,&size);
 522         size = PAGE_ALIGN(size);
 523         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 524                 count, size, (count*size)>>PAGE_SHIFT);
 525
 526         retval = videobuf_mmap_setup(file,q,count,size,req->memory);
 527         if (retval < 0)
 528                 goto done;
 529
 530         req->count = count;
 531
 532  done:
 533         up(&q->lock);
 534         return retval;
 535 }
 536
 537 int
 538 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 539 {
 540         if (unlikely(b->type != q->type))
 541                 return -EINVAL;
 542         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 543                 return -EINVAL;
 544         if (unlikely(NULL == q->bufs[b->index]))
 545                 return -EINVAL;
 546         videobuf_status(b,q->bufs[b->index],q->type);
 547         return 0;
 548 }
 549
 550 int
 551 videobuf_qbuf(struct file *file, struct videobuf_queue *q,
 552               struct v4l2_buffer *b)
 553 {
 554         struct videobuf_buffer *buf;
 555         enum v4l2_field field;
 556         unsigned long flags;
 557         int retval;
 558
 559         down(&q->lock);
 560         retval = -EBUSY;
 561         if (q->reading)
 562                 goto done;
 563         retval = -EINVAL;
 564         if (b->type != q->type)
 565                 goto done;
 566         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 567                 goto done;
 568         buf = q->bufs[b->index];
 569         if (NULL == buf)
 570                 goto done;
 571         if (buf->memory != b->memory)
 572                 goto done;
 573         if (buf->state == STATE_QUEUED ||
 574             buf->state == STATE_ACTIVE)
 575                 goto done;
 576
 577         switch (b->memory) {
 578         case V4L2_MEMORY_MMAP:
 579                 if (0 == buf->baddr)
 580                         goto done;
 581                 break;
 582         case V4L2_MEMORY_USERPTR:
 583                 if (b->length < buf->bsize)
 584                         goto done;
 585                 buf->baddr = b->m.userptr;
 586                 break;
 587         case V4L2_MEMORY_OVERLAY:
 588                 buf->boff = b->m.offset;
 589                 break;
 590         default:
 591                 goto done;
 592         }
 593
 594         field = videobuf_next_field(q);
 595         retval = q->ops->buf_prepare(file,buf,field);
 596         if (0 != retval)
 597                 goto done;
 598
 599         list_add_tail(&buf->stream,&q->stream);
 600         if (q->streaming) {
 601                 spin_lock_irqsave(q->irqlock,flags);
 602                 q->ops->buf_queue(file,buf);
 603                 spin_unlock_irqrestore(q->irqlock,flags);
 604         }
 605         retval = 0;
 606
 607  done:
 608         up(&q->lock);
 609         return retval;
 610 }
 611
 612 int
 613 videobuf_dqbuf(struct file *file, struct videobuf_queue *q,
 614                struct v4l2_buffer *b)
 615 {
 616         struct videobuf_buffer *buf;
 617         int retval;
 618
 619         down(&q->lock);
 620         retval = -EBUSY;
 621         if (q->reading)
 622                 goto done;
 623         retval = -EINVAL;
 624         if (b->type != q->type)
 625                 goto done;
 626         if (list_empty(&q->stream))
 627                 goto done;
 628         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 629         retval = videobuf_waiton(buf, file->f_flags & O_NONBLOCK, 1);
 630         if (retval < 0)
 631                 goto done;
 632         switch (buf->state) {
 633         case STATE_ERROR:
 634                 retval = -EIO;
 635                 /* fall through */
 636         case STATE_DONE:
 637                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 638                 buf->state = STATE_IDLE;
 639                 break;
 640         default:
 641                 retval = -EINVAL;
 642                 goto done;
 643         }
 644         list_del(&buf->stream);
 645         memset(b,0,sizeof(*b));
 646         videobuf_status(b,buf,q->type);
 647
 648  done:
 649         up(&q->lock);
 650         return retval;
 651 }
 652
 653 int videobuf_streamon(struct file *file, struct videobuf_queue *q)
 654 {
 655         struct videobuf_buffer *buf;
 656         struct list_head *list;
 657         unsigned long flags;
 658         int retval;
 659
 660         down(&q->lock);
 661         retval = -EBUSY;
 662         if (q->reading)
 663                 goto done;
 664         retval = 0;
 665         if (q->streaming)
 666                 goto done;
 667         q->streaming = 1;
 668         spin_lock_irqsave(q->irqlock,flags);
 669         list_for_each(list,&q->stream) {
 670                 buf = list_entry(list, struct videobuf_buffer, stream);
 671                 if (buf->state == STATE_PREPARED)
 672                         q->ops->buf_queue(file,buf);
 673         }
 674         spin_unlock_irqrestore(q->irqlock,flags);
 675
 676  done:
 677         up(&q->lock);
 678         return retval;
 679 }
 680
 681 int videobuf_streamoff(struct file *file, struct videobuf_queue *q)
 682 {
 683         int retval = -EINVAL;
 684
 685         down(&q->lock);
 686         if (!q->streaming)
 687                 goto done;
 688         videobuf_queue_cancel(file,q);
 689         q->streaming = 0;
 690         retval = 0;
 691
 692  done:
 693         up(&q->lock);
 694         return retval;
 695 }
 696
 697 static ssize_t
 698 videobuf_read_zerocopy(struct file *file, struct videobuf_queue *q,
 699                        char *data, size_t count, loff_t *ppos)
 700 {
 701         enum v4l2_field field;
 702         unsigned long flags;
 703         int retval;
 704
 705         /* setup stuff */
 706         retval = -ENOMEM;
 707         q->read_buf = videobuf_alloc(q->msize);
 708         if (NULL == q->read_buf)
 709                 goto done;
 710
 711         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 712         q->read_buf->baddr  = (unsigned long)data;
 713         q->read_buf->bsize  = count;
 714         field = videobuf_next_field(q);
 715         retval = q->ops->buf_prepare(file,q->read_buf,field);
 716         if (0 != retval)
 717                 goto done;
 718
 719         /* start capture & wait */
 720         spin_lock_irqsave(q->irqlock,flags);
 721         q->ops->buf_queue(file,q->read_buf);
 722         spin_unlock_irqrestore(q->irqlock,flags);
 723         retval = videobuf_waiton(q->read_buf,0,0);
 724         if (0 == retval) {
 725                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 726                 if (STATE_ERROR == q->read_buf->state)
 727                         retval = -EIO;
 728                 else
 729                         retval = q->read_buf->size;
 730         }
 731
 732  done:
 733         /* cleanup */
 734         q->ops->buf_release(file,q->read_buf);
 735         kfree(q->read_buf);
 736         q->read_buf = NULL;
 737         return retval;
 738 }
 739
 740 ssize_t videobuf_read_one(struct file *file, struct videobuf_queue *q,
 741                           char *data, size_t count, loff_t *ppos)
 742 {
 743         enum v4l2_field field;
 744         unsigned long flags;
 745         unsigned size, nbufs, bytes;
 746         int retval;
 747
 748         down(&q->lock);
 749
 750         nbufs = 1; size = 0;
 751         q->ops->buf_setup(file,&nbufs,&size);
 752         if (NULL == q->read_buf  &&
 753             count >= size        &&
 754             !(file->f_flags & O_NONBLOCK)) {
 755                 retval = videobuf_read_zerocopy(file,q,data,count,ppos);
 756                 if (retval >= 0  ||  retval == -EIO)
 757                         /* ok, all done */
 758                         goto done;
 759                 /* fallback to kernel bounce buffer on failures */
 760         }
 761
 762         if (NULL == q->read_buf) {
 763                 /* need to capture a new frame */
 764                 retval = -ENOMEM;
 765                 q->read_buf = videobuf_alloc(q->msize);
 766                 if (NULL == q->read_buf)
 767                         goto done;
 768                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 769                 field = videobuf_next_field(q);
 770                 retval = q->ops->buf_prepare(file,q->read_buf,field);
 771                 if (0 != retval)
 772                         goto done;
 773                 spin_lock_irqsave(q->irqlock,flags);
 774                 q->ops->buf_queue(file,q->read_buf);
 775                 spin_unlock_irqrestore(q->irqlock,flags);
 776                 q->read_off = 0;
 777         }
 778
 779         /* wait until capture is done */
 780         retval = videobuf_waiton(q->read_buf, file->f_flags & O_NONBLOCK, 1);
 781         if (0 != retval)
 782                 goto done;
 783         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 784
 785         if (STATE_ERROR == q->read_buf->state) {
 786                 /* catch I/O errors */
 787                 q->ops->buf_release(file,q->read_buf);
 788                 kfree(q->read_buf);
 789                 q->read_buf = NULL;
 790                 retval = -EIO;
 791                 goto done;
 792         }
 793
 794         /* copy to userspace */
 795         bytes = count;
 796         if (bytes > q->read_buf->size - q->read_off)
 797                 bytes = q->read_buf->size - q->read_off;
 798         retval = -EFAULT;
 799         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 800                 goto done;
 801
 802         retval = bytes;
 803         q->read_off += bytes;
 804         if (q->read_off == q->read_buf->size) {
 805                 /* all data copied, cleanup */
 806                 q->ops->buf_release(file,q->read_buf);
 807                 kfree(q->read_buf);
 808                 q->read_buf = NULL;
 809         }
 810
 811  done:
 812         up(&q->lock);
 813         return retval;
 814 }
 815
 816 int videobuf_read_start(struct file *file, struct videobuf_queue *q)
 817 {
 818         enum v4l2_field field;
 819         unsigned long flags;
 820         int count = 0, size = 0;
 821         int err, i;
 822
 823         q->ops->buf_setup(file,&count,&size);
 824         if (count < 2)
 825                 count = 2;
 826         if (count > VIDEO_MAX_FRAME)
 827                 count = VIDEO_MAX_FRAME;
 828         size = PAGE_ALIGN(size);
 829
 830         err = videobuf_mmap_setup(file, q, count, size, V4L2_MEMORY_USERPTR);
 831         if (err)
 832                 return err;
 833         for (i = 0; i < count; i++) {
 834                 field = videobuf_next_field(q);
 835                 err = q->ops->buf_prepare(file,q->bufs[i],field);
 836                 if (err)
 837                         return err;
 838                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 839         }
 840         spin_lock_irqsave(q->irqlock,flags);
 841         for (i = 0; i < count; i++)
 842                 q->ops->buf_queue(file,q->bufs[i]);
 843         spin_unlock_irqrestore(q->irqlock,flags);
 844         q->reading = 1;
 845         return 0;
 846 }
 847
 848 void videobuf_read_stop(struct file *file, struct videobuf_queue *q)
 849 {
 850         int i;
 851
 852         videobuf_queue_cancel(file,q);
 853         INIT_LIST_HEAD(&q->stream);
 854         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 855                 if (NULL == q->bufs[i])
 856                         continue;
 857                 kfree(q->bufs[i]);
 858                 q->bufs[i] = NULL;
 859         }
 860         q->read_buf = NULL;
 861         q->reading  = 0;
 862 }
 863
 864 ssize_t videobuf_read_stream(struct file *file, struct videobuf_queue *q,
 865                              char *data, size_t count, loff_t *ppos,
 866                              int vbihack)
 867 {
 868         unsigned int *fc, bytes;
 869         int err, retval;
 870         unsigned long flags;
 871
 872         down(&q->lock);
 873         retval = -EBUSY;
 874         if (q->streaming)
 875                 goto done;
 876         if (!q->reading) {
 877                 retval = videobuf_read_start(file,q);
 878                 if (retval < 0)
 879                         goto done;
 880         }
 881
 882         retval = 0;
 883         while (count > 0) {
 884                 /* get / wait for data */
 885                 if (NULL == q->read_buf) {
 886                         q->read_buf = list_entry(q->stream.next,
 887                                                  struct videobuf_buffer,
 888                                                  stream);
 889                         list_del(&q->read_buf->stream);
 890                         q->read_off = 0;
 891                 }
 892                 err = videobuf_waiton(q->read_buf,
 893                                       file->f_flags & O_NONBLOCK,1);
 894                 if (err < 0) {
 895                         if (0 == retval)
 896                                 retval = err;
 897                         break;
 898                 }
 899
 900                 if (q->read_buf->state == STATE_DONE) {
 901                         if (vbihack) {
 902                                 /* dirty, undocumented hack -- pass the frame counter
 903                                  * within the last four bytes of each vbi data block.
 904                                  * We need that one to maintain backward compatibility
 905                                  * to all vbi decoding software out there ... */
 906                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 907                                 fc += (q->read_buf->size>>2) -1;
 908                                 *fc = q->read_buf->field_count >> 1;
 909                                 dprintk(1,"vbihack: %d\n",*fc);
 910                         }
 911
 912                         /* copy stuff */
 913                         bytes = count;
 914                         if (bytes > q->read_buf->size - q->read_off)
 915                                 bytes = q->read_buf->size - q->read_off;
 916                         if (copy_to_user(data + retval,
 917                                          q->read_buf->dma.vmalloc + q->read_off,
 918                                          bytes)) {
 919                                 if (0 == retval)
 920                                         retval = -EFAULT;
 921                                 break;
 922                         }
 923                         count       -= bytes;
 924                         retval      += bytes;
 925                         q->read_off += bytes;
 926                 } else {
 927                         /* some error */
 928                         q->read_off = q->read_buf->size;
 929                         if (0 == retval)
 930                                 retval = -EIO;
 931                 }
 932
 933                 /* requeue buffer when done with copying */
 934                 if (q->read_off == q->read_buf->size) {
 935                         list_add_tail(&q->read_buf->stream,
 936                                       &q->stream);
 937                         spin_lock_irqsave(q->irqlock,flags);
 938                         q->ops->buf_queue(file,q->read_buf);
 939                         spin_unlock_irqrestore(q->irqlock,flags);
 940                         q->read_buf = NULL;
 941                 }
 942                 if (retval < 0)
 943                         break;
 944         }
 945
 946  done:
 947         up(&q->lock);
 948         return retval;
 949 }
 950
 951 unsigned int videobuf_poll_stream(struct file *file,
 952                                   struct videobuf_queue *q,
 953                                   poll_table *wait)
 954 {
 955         struct videobuf_buffer *buf = NULL;
 956         unsigned int rc = 0;
 957
 958         down(&q->lock);
 959         if (q->streaming) {
 960                 if (!list_empty(&q->stream))
 961                         buf = list_entry(q->stream.next,
 962                                          struct videobuf_buffer, stream);
 963         } else {
 964                 if (!q->reading)
 965                         videobuf_read_start(file,q);
 966                 if (!q->reading) {
 967                         rc = POLLERR;
 968                 } else if (NULL == q->read_buf) {
 969                         q->read_buf = list_entry(q->stream.next,
 970                                                  struct videobuf_buffer,
 971                                                  stream);
 972                         list_del(&q->read_buf->stream);
 973                         q->read_off = 0;
 974                 }
 975                 buf = q->read_buf;
 976         }
 977         if (!buf)
 978                 rc = POLLERR;
 979
 980         if (0 == rc) {
 981                 poll_wait(file, &buf->done, wait);
 982                 if (buf->state == STATE_DONE ||
 983                     buf->state == STATE_ERROR)
 984                         rc = POLLIN|POLLRDNORM;
 985         }
 986         up(&q->lock);
 987         return rc;
 988 }
 989
 990 /* --------------------------------------------------------------------- */
 991
 992 static void
 993 videobuf_vm_open(struct vm_area_struct *vma)
 994 {
 995         struct videobuf_mapping *map = vma->vm_private_data;
 996
 997         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
 998                 map->count,vma->vm_start,vma->vm_end);
 999         map->count++;
1000 }
1001
1002 static void
1003 videobuf_vm_close(struct vm_area_struct *vma)
1004 {
1005         struct videobuf_mapping *map = vma->vm_private_data;
1006         int i;
1007
1008         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1009                 map->count,vma->vm_start,vma->vm_end);
1010
1011         /* down(&fh->lock); FIXME */
1012         map->count--;
1013         if (0 == map->count) {
1014                 dprintk(1,"munmap %p\n",map);
1015                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1016                         if (NULL == map->q->bufs[i])
1017                                 continue;
1018                         if (map->q->bufs[i])
1019                                 ;
1020                         if (map->q->bufs[i]->map != map)
1021                                 continue;
1022                         map->q->bufs[i]->map   = NULL;
1023                         map->q->bufs[i]->baddr = 0;
1024                         map->q->ops->buf_release(vma->vm_file,map->q->bufs[i]);
1025                 }
1026                 kfree(map);
1027         }
1028         /* up(&fh->lock); FIXME */
1029         return;
1030 }
1031
1032 /*
1033  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1034  * memory location with 32bit PCI devices (i.e. don't use highmem for
1035  * now ...).  Bounce buffers don't work very well for the data rates
1036  * video capture has.
1037  */
1038 static struct page*
1039 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1040                    int *type)
1041 {
1042         struct page *page;
1043
1044         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1045                 vaddr,vma->vm_start,vma->vm_end);
1046         if (vaddr > vma->vm_end)
1047                 return NOPAGE_SIGBUS;
1048         page = alloc_page(GFP_USER);
1049         if (!page)
1050                 return NOPAGE_OOM;
1051         clear_user_page(page_address(page), vaddr, page);
1052         if (type)
1053                 *type = VM_FAULT_MINOR;
1054         return page;
1055 }
1056
1057 static struct vm_operations_struct videobuf_vm_ops =
1058 {
1059         .open     = videobuf_vm_open,
1060         .close    = videobuf_vm_close,
1061         .nopage   = videobuf_vm_nopage,
1062 };
1063
1064 int videobuf_mmap_setup(struct file *file, struct videobuf_queue *q,
1065                         unsigned int bcount, unsigned int bsize,
1066                         enum v4l2_memory memory)
1067 {
1068         unsigned int i;
1069         int err;
1070
1071         err = videobuf_mmap_free(file,q);
1072         if (0 != err)
1073                 return err;
1074
1075         for (i = 0; i < bcount; i++) {
1076                 q->bufs[i] = videobuf_alloc(q->msize);
1077                 q->bufs[i]->i      = i;
1078                 q->bufs[i]->memory = memory;
1079                 q->bufs[i]->bsize  = bsize;
1080                 switch (memory) {
1081                 case V4L2_MEMORY_MMAP:
1082                         q->bufs[i]->boff  = bsize * i;
1083                         break;
1084                 case V4L2_MEMORY_USERPTR:
1085                 case V4L2_MEMORY_OVERLAY:
1086                         /* nothing */
1087                         break;
1088                 };
1089         }
1090         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1091                 bcount,bsize);
1092         return 0;
1093 }
1094
1095 int videobuf_mmap_free(struct file *file, struct videobuf_queue *q)
1096 {
1097         int i;
1098
1099         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1100                 if (q->bufs[i] && q->bufs[i]->map)
1101                         return -EBUSY;
1102         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1103                 if (NULL == q->bufs[i])
1104                         continue;
1105                 q->ops->buf_release(file,q->bufs[i]);
1106                 kfree(q->bufs[i]);
1107                 q->bufs[i] = NULL;
1108         }
1109         return 0;
1110 }
1111
1112 int videobuf_mmap_mapper(struct vm_area_struct *vma,
1113                          struct videobuf_queue *q)
1114 {
1115         struct videobuf_mapping *map;
1116         unsigned int first,last,size,i;
1117         int retval;
1118
1119         down(&q->lock);
1120         retval = -EINVAL;
1121         if (!(vma->vm_flags & VM_WRITE)) {
1122                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1123                 goto done;
1124         }
1125         if (!(vma->vm_flags & VM_SHARED)) {
1126                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1127                 goto done;
1128         }
1129
1130         /* look for first buffer to map */
1131         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1132                 if (NULL == q->bufs[first])
1133                         continue;
1134                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1135                         continue;
1136                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1137                         break;
1138         }
1139         if (VIDEO_MAX_FRAME == first) {
1140                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1141                         (vma->vm_pgoff << PAGE_SHIFT));
1142                 goto done;
1143         }
1144
1145         /* look for last buffer to map */
1146         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1147                 if (NULL == q->bufs[last])
1148                         continue;
1149                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1150                         continue;
1151                 if (q->bufs[last]->map) {
1152                         retval = -EBUSY;
1153                         goto done;
1154                 }
1155                 size += q->bufs[last]->bsize;
1156                 if (size == (vma->vm_end - vma->vm_start))
1157                         break;
1158         }
1159         if (VIDEO_MAX_FRAME == last) {
1160                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1161                         (vma->vm_end - vma->vm_start));
1162                 goto done;
1163         }
1164
1165         /* create mapping + update buffer list */
1166         retval = -ENOMEM;
1167         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1168         if (NULL == map)
1169                 goto done;
1170         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1171                 q->bufs[i]->map   = map;
1172                 q->bufs[i]->baddr = vma->vm_start + size;
1173         }
1174         map->count    = 1;
1175         map->start    = vma->vm_start;
1176         map->end      = vma->vm_end;
1177         map->q        = q;
1178         vma->vm_ops   = &videobuf_vm_ops;
1179         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1180         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1181         vma->vm_private_data = map;
1182         dprintk(1,"mmap %p: %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1183                 map,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1184         retval = 0;
1185
1186  done:
1187         up(&q->lock);
1188         return retval;
1189 }
1190
1191 /* --------------------------------------------------------------------- */
1192
1193 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1194
1195 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1196 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1197 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1198 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1199 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1200 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1201 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1202
1203 EXPORT_SYMBOL_GPL(videobuf_alloc);
1204 EXPORT_SYMBOL_GPL(videobuf_waiton);
1205 EXPORT_SYMBOL_GPL(videobuf_iolock);
1206
1207 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1208 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1209 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1210
1211 EXPORT_SYMBOL_GPL(videobuf_next_field);
1212 EXPORT_SYMBOL_GPL(videobuf_status);
1213 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1214 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1215 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1216 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1217 EXPORT_SYMBOL_GPL(videobuf_streamon);
1218 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1219
1220 EXPORT_SYMBOL_GPL(videobuf_read_start);
1221 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1222 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1223 EXPORT_SYMBOL_GPL(videobuf_read_one);
1224 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1225
1226 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1227 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1228 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1229
1230 /*
1231  * Local variables:
1232  * c-basic-offset: 8
1233  * End:
1234  */