git.oblomov.eu Git - linux-2.6/blob - drivers/media/video/video-buf.c

   1 /*
   2  *
   3  * generic helper functions for video4linux capture buffers, to handle
   4  * memory management and PCI DMA.  Right now bttv + saa7134 use it.
   5  *
   6  * The functions expect the hardware being able to scatter gatter
   7  * (i.e. the buffers are not linear in physical memory, but fragmented
   8  * into PAGE_SIZE chunks).  They also assume the driver does not need
   9  * to touch the video data (thus it is probably not useful for USB 1.1
  10  * as data often must be uncompressed by the drivers).
  11  *
  12  * (c) 2001-2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/slab.h>
  26 #include <linux/pci.h>
  27 #include <linux/interrupt.h>
  28 #include <asm/page.h>
  29 #include <asm/pgtable.h>
  30
  31 #include <media/video-buf.h>
  32
  33 #define MAGIC_DMABUF 0x19721112
  34 #define MAGIC_BUFFER 0x20040302
  35 #define MAGIC_CHECK(is,should)  if (unlikely((is) != (should))) \
  36         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
  37
  38 static int debug = 0;
  39 module_param(debug, int, 0644);
  40
  41 MODULE_DESCRIPTION("helper module to manage video4linux pci dma buffers");
  42 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  43 MODULE_LICENSE("GPL");
  44
  45 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  46         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  47
  48 struct scatterlist*
  49 videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
  50 {
  51         struct scatterlist *sglist;
  52         struct page *pg;
  53         int i;
  54
  55         sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
  56         if (NULL == sglist)
  57                 return NULL;
  58         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
  59                 pg = vmalloc_to_page(virt);
  60                 if (NULL == pg)
  61                         goto err;
  62                 if (PageHighMem(pg))
  63                         BUG();
  64                 sglist[i].page   = pg;
  65                 sglist[i].length = PAGE_SIZE;
  66         }
  67         return sglist;
  68
  69  err:
  70         kfree(sglist);
  71         return NULL;
  72 }
  73
  74 struct scatterlist*
  75 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
  76 {
  77         struct scatterlist *sglist;
  78         int i = 0;
  79
  80         if (NULL == pages[0])
  81                 return NULL;
  82         sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL);
  83         if (NULL == sglist)
  84                 return NULL;
  85
  86         if (NULL == pages[0])
  87                 goto nopage;
  88         if (PageHighMem(pages[0]))
  89                 /* DMA to highmem pages might not work */
  90                 goto highmem;
  91         sglist[0].page   = pages[0];
  92         sglist[0].offset = offset;
  93         sglist[0].length = PAGE_SIZE - offset;
  94         for (i = 1; i < nr_pages; i++) {
  95                 if (NULL == pages[i])
  96                         goto nopage;
  97                 if (PageHighMem(pages[i]))
  98                         goto highmem;
  99                 sglist[i].page   = pages[i];
 100                 sglist[i].length = PAGE_SIZE;
 101         }
 102         return sglist;
 103
 104  nopage:
 105         dprintk(2,"sgl: oops - no page\n");
 106         kfree(sglist);
 107         return NULL;
 108
 109  highmem:
 110         dprintk(2,"sgl: oops - highmem page\n");
 111         kfree(sglist);
 112         return NULL;
 113 }
 114
 115 /* --------------------------------------------------------------------- */
 116
 117 void videobuf_dma_init(struct videobuf_dmabuf *dma)
 118 {
 119         memset(dma,0,sizeof(*dma));
 120         dma->magic = MAGIC_DMABUF;
 121 }
 122
 123 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 124                            unsigned long data, unsigned long size)
 125 {
 126         unsigned long first,last;
 127         int err, rw = 0;
 128
 129         dma->direction = direction;
 130         switch (dma->direction) {
 131         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 132         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 133         default:                 BUG();
 134         }
 135
 136         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 137         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 138         dma->offset   = data & ~PAGE_MASK;
 139         dma->nr_pages = last-first+1;
 140         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 141                              GFP_KERNEL);
 142         if (NULL == dma->pages)
 143                 return -ENOMEM;
 144         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 145                 data,size,dma->nr_pages);
 146
 147         down_read(&current->mm->mmap_sem);
 148         err = get_user_pages(current,current->mm,
 149                              data & PAGE_MASK, dma->nr_pages,
 150                              rw == READ, 1, /* force */
 151                              dma->pages, NULL);
 152         up_read(&current->mm->mmap_sem);
 153         if (err != dma->nr_pages) {
 154                 dma->nr_pages = (err >= 0) ? err : 0;
 155                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 156                 return err < 0 ? err : -EINVAL;
 157         }
 158         return 0;
 159 }
 160
 161 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 162                              int nr_pages)
 163 {
 164         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 165         dma->direction = direction;
 166         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 167         if (NULL == dma->vmalloc) {
 168                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 169                 return -ENOMEM;
 170         }
 171         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 172         dma->nr_pages = nr_pages;
 173         return 0;
 174 }
 175
 176 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 177                               dma_addr_t addr, int nr_pages)
 178 {
 179         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 180                 nr_pages,(unsigned long)addr);
 181         dma->direction = direction;
 182         if (0 == addr)
 183                 return -EINVAL;
 184
 185         dma->bus_addr = addr;
 186         dma->nr_pages = nr_pages;
 187         return 0;
 188 }
 189
 190 int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 191 {
 192         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 193         BUG_ON(0 == dma->nr_pages);
 194
 195         if (dma->pages) {
 196                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 197                                                    dma->offset);
 198         }
 199         if (dma->vmalloc) {
 200                 dma->sglist = videobuf_vmalloc_to_sg
 201                         (dma->vmalloc,dma->nr_pages);
 202         }
 203         if (dma->bus_addr) {
 204                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 205                 if (NULL != dma->sglist) {
 206                         dma->sglen  = 1;
 207                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 208                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 209                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 210                 }
 211         }
 212         if (NULL == dma->sglist) {
 213                 dprintk(1,"scatterlist is NULL\n");
 214                 return -ENOMEM;
 215         }
 216
 217         if (!dma->bus_addr) {
 218                 dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
 219                                         dma->direction);
 220                 if (0 == dma->sglen) {
 221                         printk(KERN_WARNING
 222                                "%s: pci_map_sg failed\n",__FUNCTION__);
 223                         kfree(dma->sglist);
 224                         dma->sglist = NULL;
 225                         dma->sglen = 0;
 226                         return -EIO;
 227                 }
 228         }
 229         return 0;
 230 }
 231
 232 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 233 {
 234         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 235         BUG_ON(!dma->sglen);
 236
 237         if (!dma->bus_addr)
 238                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 239         return 0;
 240 }
 241
 242 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 243 {
 244         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 245         if (!dma->sglen)
 246                 return 0;
 247
 248         if (!dma->bus_addr)
 249                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 250         kfree(dma->sglist);
 251         dma->sglist = NULL;
 252         dma->sglen = 0;
 253         return 0;
 254 }
 255
 256 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 257 {
 258         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 259         BUG_ON(dma->sglen);
 260
 261         if (dma->pages) {
 262                 int i;
 263                 for (i=0; i < dma->nr_pages; i++)
 264                         page_cache_release(dma->pages[i]);
 265                 kfree(dma->pages);
 266                 dma->pages = NULL;
 267         }
 268
 269         vfree(dma->vmalloc);
 270         dma->vmalloc = NULL;
 271
 272         if (dma->bus_addr) {
 273                 dma->bus_addr = 0;
 274         }
 275         dma->direction = PCI_DMA_NONE;
 276         return 0;
 277 }
 278
 279 /* --------------------------------------------------------------------- */
 280
 281 void* videobuf_alloc(unsigned int size)
 282 {
 283         struct videobuf_buffer *vb;
 284
 285         vb = kzalloc(size,GFP_KERNEL);
 286         if (NULL != vb) {
 287                 videobuf_dma_init(&vb->dma);
 288                 init_waitqueue_head(&vb->done);
 289                 vb->magic     = MAGIC_BUFFER;
 290         }
 291         return vb;
 292 }
 293
 294 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 295 {
 296         int retval = 0;
 297         DECLARE_WAITQUEUE(wait, current);
 298
 299         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 300         add_wait_queue(&vb->done, &wait);
 301         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 302                 if (non_blocking) {
 303                         retval = -EAGAIN;
 304                         break;
 305                 }
 306                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 307                                         : TASK_UNINTERRUPTIBLE);
 308                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 309                         schedule();
 310                 set_current_state(TASK_RUNNING);
 311                 if (intr && signal_pending(current)) {
 312                         dprintk(1,"buffer waiton: -EINTR\n");
 313                         retval = -EINTR;
 314                         break;
 315                 }
 316         }
 317         remove_wait_queue(&vb->done, &wait);
 318         return retval;
 319 }
 320
 321 int
 322 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 323                 struct v4l2_framebuffer *fbuf)
 324 {
 325         int err,pages;
 326         dma_addr_t bus;
 327
 328         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 329         switch (vb->memory) {
 330         case V4L2_MEMORY_MMAP:
 331         case V4L2_MEMORY_USERPTR:
 332                 if (0 == vb->baddr) {
 333                         /* no userspace addr -- kernel bounce buffer */
 334                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 335                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 336                                                        pages);
 337                         if (0 != err)
 338                                 return err;
 339                 } else {
 340                         /* dma directly to userspace */
 341                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 342                                                      vb->baddr,vb->bsize);
 343                         if (0 != err)
 344                                 return err;
 345                 }
 346                 break;
 347         case V4L2_MEMORY_OVERLAY:
 348                 if (NULL == fbuf)
 349                         return -EINVAL;
 350                 /* FIXME: need sanity checks for vb->boff */
 351                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 352                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 353                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 354                                                 bus, pages);
 355                 if (0 != err)
 356                         return err;
 357                 break;
 358         default:
 359                 BUG();
 360         }
 361         err = videobuf_dma_pci_map(pci,&vb->dma);
 362         if (0 != err)
 363                 return err;
 364
 365         return 0;
 366 }
 367
 368 /* --------------------------------------------------------------------- */
 369
 370 void videobuf_queue_init(struct videobuf_queue* q,
 371                          struct videobuf_queue_ops *ops,
 372                          struct pci_dev *pci,
 373                          spinlock_t *irqlock,
 374                          enum v4l2_buf_type type,
 375                          enum v4l2_field field,
 376                          unsigned int msize,
 377                          void *priv)
 378 {
 379         memset(q,0,sizeof(*q));
 380         q->irqlock = irqlock;
 381         q->pci     = pci;
 382         q->type    = type;
 383         q->field   = field;
 384         q->msize   = msize;
 385         q->ops     = ops;
 386         q->priv_data = priv;
 387
 388         mutex_init(&q->lock);
 389         INIT_LIST_HEAD(&q->stream);
 390 }
 391
 392 int
 393 videobuf_queue_is_busy(struct videobuf_queue *q)
 394 {
 395         int i;
 396
 397         if (q->streaming) {
 398                 dprintk(1,"busy: streaming active\n");
 399                 return 1;
 400         }
 401         if (q->reading) {
 402                 dprintk(1,"busy: pending read #1\n");
 403                 return 1;
 404         }
 405         if (q->read_buf) {
 406                 dprintk(1,"busy: pending read #2\n");
 407                 return 1;
 408         }
 409         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 410                 if (NULL == q->bufs[i])
 411                         continue;
 412                 if (q->bufs[i]->map) {
 413                         dprintk(1,"busy: buffer #%d mapped\n",i);
 414                         return 1;
 415                 }
 416                 if (q->bufs[i]->state == STATE_QUEUED) {
 417                         dprintk(1,"busy: buffer #%d queued\n",i);
 418                         return 1;
 419                 }
 420                 if (q->bufs[i]->state == STATE_ACTIVE) {
 421                         dprintk(1,"busy: buffer #%d avtive\n",i);
 422                         return 1;
 423                 }
 424         }
 425         return 0;
 426 }
 427
 428 void
 429 videobuf_queue_cancel(struct videobuf_queue *q)
 430 {
 431         unsigned long flags;
 432         int i;
 433
 434         /* remove queued buffers from list */
 435         spin_lock_irqsave(q->irqlock,flags);
 436         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 437                 if (NULL == q->bufs[i])
 438                         continue;
 439                 if (q->bufs[i]->state == STATE_QUEUED) {
 440                         list_del(&q->bufs[i]->queue);
 441                         q->bufs[i]->state = STATE_ERROR;
 442                 }
 443         }
 444         spin_unlock_irqrestore(q->irqlock,flags);
 445
 446         /* free all buffers + clear queue */
 447         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 448                 if (NULL == q->bufs[i])
 449                         continue;
 450                 q->ops->buf_release(q,q->bufs[i]);
 451         }
 452         INIT_LIST_HEAD(&q->stream);
 453 }
 454
 455 /* --------------------------------------------------------------------- */
 456
 457 enum v4l2_field
 458 videobuf_next_field(struct videobuf_queue *q)
 459 {
 460         enum v4l2_field field = q->field;
 461
 462         BUG_ON(V4L2_FIELD_ANY == field);
 463
 464         if (V4L2_FIELD_ALTERNATE == field) {
 465                 if (V4L2_FIELD_TOP == q->last) {
 466                         field   = V4L2_FIELD_BOTTOM;
 467                         q->last = V4L2_FIELD_BOTTOM;
 468                 } else {
 469                         field   = V4L2_FIELD_TOP;
 470                         q->last = V4L2_FIELD_TOP;
 471                 }
 472         }
 473         return field;
 474 }
 475
 476 void
 477 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 478                 enum v4l2_buf_type type)
 479 {
 480         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 481
 482         b->index    = vb->i;
 483         b->type     = type;
 484
 485         b->memory   = vb->memory;
 486         switch (b->memory) {
 487         case V4L2_MEMORY_MMAP:
 488                 b->m.offset  = vb->boff;
 489                 b->length    = vb->bsize;
 490                 break;
 491         case V4L2_MEMORY_USERPTR:
 492                 b->m.userptr = vb->baddr;
 493                 b->length    = vb->bsize;
 494                 break;
 495         case V4L2_MEMORY_OVERLAY:
 496                 b->m.offset  = vb->boff;
 497                 break;
 498         }
 499
 500         b->flags    = 0;
 501         if (vb->map)
 502                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 503
 504         switch (vb->state) {
 505         case STATE_PREPARED:
 506         case STATE_QUEUED:
 507         case STATE_ACTIVE:
 508                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 509                 break;
 510         case STATE_DONE:
 511         case STATE_ERROR:
 512                 b->flags |= V4L2_BUF_FLAG_DONE;
 513                 break;
 514         case STATE_NEEDS_INIT:
 515         case STATE_IDLE:
 516                 /* nothing */
 517                 break;
 518         }
 519
 520         if (vb->input != UNSET) {
 521                 b->flags |= V4L2_BUF_FLAG_INPUT;
 522                 b->input  = vb->input;
 523         }
 524
 525         b->field     = vb->field;
 526         b->timestamp = vb->ts;
 527         b->bytesused = vb->size;
 528         b->sequence  = vb->field_count >> 1;
 529 }
 530
 531 int
 532 videobuf_reqbufs(struct videobuf_queue *q,
 533                  struct v4l2_requestbuffers *req)
 534 {
 535         unsigned int size,count;
 536         int retval;
 537
 538         if (req->type != q->type)
 539                 return -EINVAL;
 540         if (req->count < 1)
 541                 return -EINVAL;
 542         if (req->memory != V4L2_MEMORY_MMAP     &&
 543             req->memory != V4L2_MEMORY_USERPTR  &&
 544             req->memory != V4L2_MEMORY_OVERLAY)
 545                 return -EINVAL;
 546
 547         if (q->streaming)
 548                 return -EBUSY;
 549         if (!list_empty(&q->stream))
 550                 return -EBUSY;
 551
 552         mutex_lock(&q->lock);
 553         count = req->count;
 554         if (count > VIDEO_MAX_FRAME)
 555                 count = VIDEO_MAX_FRAME;
 556         size = 0;
 557         q->ops->buf_setup(q,&count,&size);
 558         size = PAGE_ALIGN(size);
 559         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 560                 count, size, (count*size)>>PAGE_SHIFT);
 561
 562         retval = videobuf_mmap_setup(q,count,size,req->memory);
 563         if (retval < 0)
 564                 goto done;
 565
 566         req->count = count;
 567
 568  done:
 569         mutex_unlock(&q->lock);
 570         return retval;
 571 }
 572
 573 int
 574 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 575 {
 576         if (unlikely(b->type != q->type))
 577                 return -EINVAL;
 578         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 579                 return -EINVAL;
 580         if (unlikely(NULL == q->bufs[b->index]))
 581                 return -EINVAL;
 582         videobuf_status(b,q->bufs[b->index],q->type);
 583         return 0;
 584 }
 585
 586 int
 587 videobuf_qbuf(struct videobuf_queue *q,
 588               struct v4l2_buffer *b)
 589 {
 590         struct videobuf_buffer *buf;
 591         enum v4l2_field field;
 592         unsigned long flags;
 593         int retval;
 594
 595         mutex_lock(&q->lock);
 596         retval = -EBUSY;
 597         if (q->reading)
 598                 goto done;
 599         retval = -EINVAL;
 600         if (b->type != q->type)
 601                 goto done;
 602         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 603                 goto done;
 604         buf = q->bufs[b->index];
 605         if (NULL == buf)
 606                 goto done;
 607         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 608         if (buf->memory != b->memory)
 609                 goto done;
 610         if (buf->state == STATE_QUEUED ||
 611             buf->state == STATE_ACTIVE)
 612                 goto done;
 613
 614         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 615                 if (b->input >= q->inputs)
 616                         goto done;
 617                 buf->input = b->input;
 618         } else {
 619                 buf->input = UNSET;
 620         }
 621
 622         switch (b->memory) {
 623         case V4L2_MEMORY_MMAP:
 624                 if (0 == buf->baddr)
 625                         goto done;
 626                 break;
 627         case V4L2_MEMORY_USERPTR:
 628                 if (b->length < buf->bsize)
 629                         goto done;
 630                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 631                         q->ops->buf_release(q,buf);
 632                 buf->baddr = b->m.userptr;
 633                 break;
 634         case V4L2_MEMORY_OVERLAY:
 635                 buf->boff = b->m.offset;
 636                 break;
 637         default:
 638                 goto done;
 639         }
 640
 641         field = videobuf_next_field(q);
 642         retval = q->ops->buf_prepare(q,buf,field);
 643         if (0 != retval)
 644                 goto done;
 645
 646         list_add_tail(&buf->stream,&q->stream);
 647         if (q->streaming) {
 648                 spin_lock_irqsave(q->irqlock,flags);
 649                 q->ops->buf_queue(q,buf);
 650                 spin_unlock_irqrestore(q->irqlock,flags);
 651         }
 652         retval = 0;
 653
 654  done:
 655         mutex_unlock(&q->lock);
 656         return retval;
 657 }
 658
 659 int
 660 videobuf_dqbuf(struct videobuf_queue *q,
 661                struct v4l2_buffer *b, int nonblocking)
 662 {
 663         struct videobuf_buffer *buf;
 664         int retval;
 665
 666         mutex_lock(&q->lock);
 667         retval = -EBUSY;
 668         if (q->reading)
 669                 goto done;
 670         retval = -EINVAL;
 671         if (b->type != q->type)
 672                 goto done;
 673         if (list_empty(&q->stream))
 674                 goto done;
 675         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 676         retval = videobuf_waiton(buf, nonblocking, 1);
 677         if (retval < 0)
 678                 goto done;
 679         switch (buf->state) {
 680         case STATE_ERROR:
 681                 retval = -EIO;
 682                 /* fall through */
 683         case STATE_DONE:
 684                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 685                 buf->state = STATE_IDLE;
 686                 break;
 687         default:
 688                 retval = -EINVAL;
 689                 goto done;
 690         }
 691         list_del(&buf->stream);
 692         memset(b,0,sizeof(*b));
 693         videobuf_status(b,buf,q->type);
 694
 695  done:
 696         mutex_unlock(&q->lock);
 697         return retval;
 698 }
 699
 700 int videobuf_streamon(struct videobuf_queue *q)
 701 {
 702         struct videobuf_buffer *buf;
 703         struct list_head *list;
 704         unsigned long flags;
 705         int retval;
 706
 707         mutex_lock(&q->lock);
 708         retval = -EBUSY;
 709         if (q->reading)
 710                 goto done;
 711         retval = 0;
 712         if (q->streaming)
 713                 goto done;
 714         q->streaming = 1;
 715         spin_lock_irqsave(q->irqlock,flags);
 716         list_for_each(list,&q->stream) {
 717                 buf = list_entry(list, struct videobuf_buffer, stream);
 718                 if (buf->state == STATE_PREPARED)
 719                         q->ops->buf_queue(q,buf);
 720         }
 721         spin_unlock_irqrestore(q->irqlock,flags);
 722
 723  done:
 724         mutex_unlock(&q->lock);
 725         return retval;
 726 }
 727
 728 int videobuf_streamoff(struct videobuf_queue *q)
 729 {
 730         int retval = -EINVAL;
 731
 732         mutex_lock(&q->lock);
 733         if (!q->streaming)
 734                 goto done;
 735         videobuf_queue_cancel(q);
 736         q->streaming = 0;
 737         retval = 0;
 738
 739  done:
 740         mutex_unlock(&q->lock);
 741         return retval;
 742 }
 743
 744 static ssize_t
 745 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 746                        size_t count, loff_t *ppos)
 747 {
 748         enum v4l2_field field;
 749         unsigned long flags;
 750         int retval;
 751
 752         /* setup stuff */
 753         q->read_buf = videobuf_alloc(q->msize);
 754         if (NULL == q->read_buf)
 755                 return -ENOMEM;
 756
 757         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 758         q->read_buf->baddr  = (unsigned long)data;
 759         q->read_buf->bsize  = count;
 760         field = videobuf_next_field(q);
 761         retval = q->ops->buf_prepare(q,q->read_buf,field);
 762         if (0 != retval)
 763                 goto done;
 764
 765         /* start capture & wait */
 766         spin_lock_irqsave(q->irqlock,flags);
 767         q->ops->buf_queue(q,q->read_buf);
 768         spin_unlock_irqrestore(q->irqlock,flags);
 769         retval = videobuf_waiton(q->read_buf,0,0);
 770         if (0 == retval) {
 771                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 772                 if (STATE_ERROR == q->read_buf->state)
 773                         retval = -EIO;
 774                 else
 775                         retval = q->read_buf->size;
 776         }
 777
 778  done:
 779         /* cleanup */
 780         q->ops->buf_release(q,q->read_buf);
 781         kfree(q->read_buf);
 782         q->read_buf = NULL;
 783         return retval;
 784 }
 785
 786 ssize_t videobuf_read_one(struct videobuf_queue *q,
 787                           char __user *data, size_t count, loff_t *ppos,
 788                           int nonblocking)
 789 {
 790         enum v4l2_field field;
 791         unsigned long flags;
 792         unsigned size, nbufs, bytes;
 793         int retval;
 794
 795         mutex_lock(&q->lock);
 796
 797         nbufs = 1; size = 0;
 798         q->ops->buf_setup(q,&nbufs,&size);
 799         if (NULL == q->read_buf  &&
 800             count >= size        &&
 801             !nonblocking) {
 802                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 803                 if (retval >= 0  ||  retval == -EIO)
 804                         /* ok, all done */
 805                         goto done;
 806                 /* fallback to kernel bounce buffer on failures */
 807         }
 808
 809         if (NULL == q->read_buf) {
 810                 /* need to capture a new frame */
 811                 retval = -ENOMEM;
 812                 q->read_buf = videobuf_alloc(q->msize);
 813                 if (NULL == q->read_buf)
 814                         goto done;
 815                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 816                 q->read_buf->bsize = count; /* preferred size */
 817                 field = videobuf_next_field(q);
 818                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 819                 if (0 != retval) {
 820                         kfree (q->read_buf);
 821                         q->read_buf = NULL;
 822                         goto done;
 823                 }
 824                 spin_lock_irqsave(q->irqlock,flags);
 825                 q->ops->buf_queue(q,q->read_buf);
 826                 spin_unlock_irqrestore(q->irqlock,flags);
 827                 q->read_off = 0;
 828         }
 829
 830         /* wait until capture is done */
 831         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 832         if (0 != retval)
 833                 goto done;
 834         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 835
 836         if (STATE_ERROR == q->read_buf->state) {
 837                 /* catch I/O errors */
 838                 q->ops->buf_release(q,q->read_buf);
 839                 kfree(q->read_buf);
 840                 q->read_buf = NULL;
 841                 retval = -EIO;
 842                 goto done;
 843         }
 844
 845         /* copy to userspace */
 846         bytes = count;
 847         if (bytes > q->read_buf->size - q->read_off)
 848                 bytes = q->read_buf->size - q->read_off;
 849         retval = -EFAULT;
 850         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 851                 goto done;
 852
 853         retval = bytes;
 854         q->read_off += bytes;
 855         if (q->read_off == q->read_buf->size) {
 856                 /* all data copied, cleanup */
 857                 q->ops->buf_release(q,q->read_buf);
 858                 kfree(q->read_buf);
 859                 q->read_buf = NULL;
 860         }
 861
 862  done:
 863         mutex_unlock(&q->lock);
 864         return retval;
 865 }
 866
 867 int videobuf_read_start(struct videobuf_queue *q)
 868 {
 869         enum v4l2_field field;
 870         unsigned long flags;
 871         int count = 0, size = 0;
 872         int err, i;
 873
 874         q->ops->buf_setup(q,&count,&size);
 875         if (count < 2)
 876                 count = 2;
 877         if (count > VIDEO_MAX_FRAME)
 878                 count = VIDEO_MAX_FRAME;
 879         size = PAGE_ALIGN(size);
 880
 881         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 882         if (err)
 883                 return err;
 884         for (i = 0; i < count; i++) {
 885                 field = videobuf_next_field(q);
 886                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 887                 if (err)
 888                         return err;
 889                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 890         }
 891         spin_lock_irqsave(q->irqlock,flags);
 892         for (i = 0; i < count; i++)
 893                 q->ops->buf_queue(q,q->bufs[i]);
 894         spin_unlock_irqrestore(q->irqlock,flags);
 895         q->reading = 1;
 896         return 0;
 897 }
 898
 899 void videobuf_read_stop(struct videobuf_queue *q)
 900 {
 901         int i;
 902
 903         videobuf_queue_cancel(q);
 904         videobuf_mmap_free(q);
 905         INIT_LIST_HEAD(&q->stream);
 906         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 907                 if (NULL == q->bufs[i])
 908                         continue;
 909                 kfree(q->bufs[i]);
 910                 q->bufs[i] = NULL;
 911         }
 912         q->read_buf = NULL;
 913         q->reading  = 0;
 914 }
 915
 916 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 917                              char __user *data, size_t count, loff_t *ppos,
 918                              int vbihack, int nonblocking)
 919 {
 920         unsigned int *fc, bytes;
 921         int err, retval;
 922         unsigned long flags;
 923
 924         dprintk(2,"%s\n",__FUNCTION__);
 925         mutex_lock(&q->lock);
 926         retval = -EBUSY;
 927         if (q->streaming)
 928                 goto done;
 929         if (!q->reading) {
 930                 retval = videobuf_read_start(q);
 931                 if (retval < 0)
 932                         goto done;
 933         }
 934
 935         retval = 0;
 936         while (count > 0) {
 937                 /* get / wait for data */
 938                 if (NULL == q->read_buf) {
 939                         q->read_buf = list_entry(q->stream.next,
 940                                                  struct videobuf_buffer,
 941                                                  stream);
 942                         list_del(&q->read_buf->stream);
 943                         q->read_off = 0;
 944                 }
 945                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
 946                 if (err < 0) {
 947                         if (0 == retval)
 948                                 retval = err;
 949                         break;
 950                 }
 951
 952                 if (q->read_buf->state == STATE_DONE) {
 953                         if (vbihack) {
 954                                 /* dirty, undocumented hack -- pass the frame counter
 955                                  * within the last four bytes of each vbi data block.
 956                                  * We need that one to maintain backward compatibility
 957                                  * to all vbi decoding software out there ... */
 958                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 959                                 fc += (q->read_buf->size>>2) -1;
 960                                 *fc = q->read_buf->field_count >> 1;
 961                                 dprintk(1,"vbihack: %d\n",*fc);
 962                         }
 963
 964                         /* copy stuff */
 965                         bytes = count;
 966                         if (bytes > q->read_buf->size - q->read_off)
 967                                 bytes = q->read_buf->size - q->read_off;
 968                         if (copy_to_user(data + retval,
 969                                          q->read_buf->dma.vmalloc + q->read_off,
 970                                          bytes)) {
 971                                 if (0 == retval)
 972                                         retval = -EFAULT;
 973                                 break;
 974                         }
 975                         count       -= bytes;
 976                         retval      += bytes;
 977                         q->read_off += bytes;
 978                 } else {
 979                         /* some error */
 980                         q->read_off = q->read_buf->size;
 981                         if (0 == retval)
 982                                 retval = -EIO;
 983                 }
 984
 985                 /* requeue buffer when done with copying */
 986                 if (q->read_off == q->read_buf->size) {
 987                         list_add_tail(&q->read_buf->stream,
 988                                       &q->stream);
 989                         spin_lock_irqsave(q->irqlock,flags);
 990                         q->ops->buf_queue(q,q->read_buf);
 991                         spin_unlock_irqrestore(q->irqlock,flags);
 992                         q->read_buf = NULL;
 993                 }
 994                 if (retval < 0)
 995                         break;
 996         }
 997
 998  done:
 999         mutex_unlock(&q->lock);
1000         return retval;
1001 }
1002
1003 unsigned int videobuf_poll_stream(struct file *file,
1004                                   struct videobuf_queue *q,
1005                                   poll_table *wait)
1006 {
1007         struct videobuf_buffer *buf = NULL;
1008         unsigned int rc = 0;
1009
1010         mutex_lock(&q->lock);
1011         if (q->streaming) {
1012                 if (!list_empty(&q->stream))
1013                         buf = list_entry(q->stream.next,
1014                                          struct videobuf_buffer, stream);
1015         } else {
1016                 if (!q->reading)
1017                         videobuf_read_start(q);
1018                 if (!q->reading) {
1019                         rc = POLLERR;
1020                 } else if (NULL == q->read_buf) {
1021                         q->read_buf = list_entry(q->stream.next,
1022                                                  struct videobuf_buffer,
1023                                                  stream);
1024                         list_del(&q->read_buf->stream);
1025                         q->read_off = 0;
1026                 }
1027                 buf = q->read_buf;
1028         }
1029         if (!buf)
1030                 rc = POLLERR;
1031
1032         if (0 == rc) {
1033                 poll_wait(file, &buf->done, wait);
1034                 if (buf->state == STATE_DONE ||
1035                     buf->state == STATE_ERROR)
1036                         rc = POLLIN|POLLRDNORM;
1037         }
1038         mutex_unlock(&q->lock);
1039         return rc;
1040 }
1041
1042 /* --------------------------------------------------------------------- */
1043
1044 static void
1045 videobuf_vm_open(struct vm_area_struct *vma)
1046 {
1047         struct videobuf_mapping *map = vma->vm_private_data;
1048
1049         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1050                 map->count,vma->vm_start,vma->vm_end);
1051         map->count++;
1052 }
1053
1054 static void
1055 videobuf_vm_close(struct vm_area_struct *vma)
1056 {
1057         struct videobuf_mapping *map = vma->vm_private_data;
1058         struct videobuf_queue *q = map->q;
1059         int i;
1060
1061         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1062                 map->count,vma->vm_start,vma->vm_end);
1063
1064         map->count--;
1065         if (0 == map->count) {
1066                 dprintk(1,"munmap %p q=%p\n",map,q);
1067                 mutex_lock(&q->lock);
1068                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1069                         if (NULL == q->bufs[i])
1070                                 continue;
1071                         if (q->bufs[i])
1072                                 ;
1073                         if (q->bufs[i]->map != map)
1074                                 continue;
1075                         q->bufs[i]->map   = NULL;
1076                         q->bufs[i]->baddr = 0;
1077                         q->ops->buf_release(q,q->bufs[i]);
1078                 }
1079                 mutex_unlock(&q->lock);
1080                 kfree(map);
1081         }
1082         return;
1083 }
1084
1085 /*
1086  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1087  * memory location with 32bit PCI devices (i.e. don't use highmem for
1088  * now ...).  Bounce buffers don't work very well for the data rates
1089  * video capture has.
1090  */
1091 static struct page*
1092 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1093                    int *type)
1094 {
1095         struct page *page;
1096
1097         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1098                 vaddr,vma->vm_start,vma->vm_end);
1099         if (vaddr > vma->vm_end)
1100                 return NOPAGE_SIGBUS;
1101         page = alloc_page(GFP_USER);
1102         if (!page)
1103                 return NOPAGE_OOM;
1104         clear_user_page(page_address(page), vaddr, page);
1105         if (type)
1106                 *type = VM_FAULT_MINOR;
1107         return page;
1108 }
1109
1110 static struct vm_operations_struct videobuf_vm_ops =
1111 {
1112         .open     = videobuf_vm_open,
1113         .close    = videobuf_vm_close,
1114         .nopage   = videobuf_vm_nopage,
1115 };
1116
1117 int videobuf_mmap_setup(struct videobuf_queue *q,
1118                         unsigned int bcount, unsigned int bsize,
1119                         enum v4l2_memory memory)
1120 {
1121         unsigned int i;
1122         int err;
1123
1124         err = videobuf_mmap_free(q);
1125         if (0 != err)
1126                 return err;
1127
1128         for (i = 0; i < bcount; i++) {
1129                 q->bufs[i] = videobuf_alloc(q->msize);
1130                 q->bufs[i]->i      = i;
1131                 q->bufs[i]->input  = UNSET;
1132                 q->bufs[i]->memory = memory;
1133                 q->bufs[i]->bsize  = bsize;
1134                 switch (memory) {
1135                 case V4L2_MEMORY_MMAP:
1136                         q->bufs[i]->boff  = bsize * i;
1137                         break;
1138                 case V4L2_MEMORY_USERPTR:
1139                 case V4L2_MEMORY_OVERLAY:
1140                         /* nothing */
1141                         break;
1142                 }
1143         }
1144         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1145                 bcount,bsize);
1146         return 0;
1147 }
1148
1149 int videobuf_mmap_free(struct videobuf_queue *q)
1150 {
1151         int i;
1152
1153         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1154                 if (q->bufs[i] && q->bufs[i]->map)
1155                         return -EBUSY;
1156         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1157                 if (NULL == q->bufs[i])
1158                         continue;
1159                 q->ops->buf_release(q,q->bufs[i]);
1160                 kfree(q->bufs[i]);
1161                 q->bufs[i] = NULL;
1162         }
1163         return 0;
1164 }
1165
1166 int videobuf_mmap_mapper(struct videobuf_queue *q,
1167                          struct vm_area_struct *vma)
1168 {
1169         struct videobuf_mapping *map;
1170         unsigned int first,last,size,i;
1171         int retval;
1172
1173         mutex_lock(&q->lock);
1174         retval = -EINVAL;
1175         if (!(vma->vm_flags & VM_WRITE)) {
1176                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1177                 goto done;
1178         }
1179         if (!(vma->vm_flags & VM_SHARED)) {
1180                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1181                 goto done;
1182         }
1183
1184         /* look for first buffer to map */
1185         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1186                 if (NULL == q->bufs[first])
1187                         continue;
1188                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1189                         continue;
1190                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1191                         break;
1192         }
1193         if (VIDEO_MAX_FRAME == first) {
1194                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1195                         (vma->vm_pgoff << PAGE_SHIFT));
1196                 goto done;
1197         }
1198
1199         /* look for last buffer to map */
1200         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1201                 if (NULL == q->bufs[last])
1202                         continue;
1203                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1204                         continue;
1205                 if (q->bufs[last]->map) {
1206                         retval = -EBUSY;
1207                         goto done;
1208                 }
1209                 size += q->bufs[last]->bsize;
1210                 if (size == (vma->vm_end - vma->vm_start))
1211                         break;
1212         }
1213         if (VIDEO_MAX_FRAME == last) {
1214                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1215                         (vma->vm_end - vma->vm_start));
1216                 goto done;
1217         }
1218
1219         /* create mapping + update buffer list */
1220         retval = -ENOMEM;
1221         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1222         if (NULL == map)
1223                 goto done;
1224         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1225                 q->bufs[i]->map   = map;
1226                 q->bufs[i]->baddr = vma->vm_start + size;
1227         }
1228         map->count    = 1;
1229         map->start    = vma->vm_start;
1230         map->end      = vma->vm_end;
1231         map->q        = q;
1232         vma->vm_ops   = &videobuf_vm_ops;
1233         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1234         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1235         vma->vm_private_data = map;
1236         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1237                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1238         retval = 0;
1239
1240  done:
1241         mutex_unlock(&q->lock);
1242         return retval;
1243 }
1244
1245 /* --------------------------------------------------------------------- */
1246
1247 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1248
1249 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1250 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1251 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1252 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1253 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1254 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1255 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1256 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1257
1258 EXPORT_SYMBOL_GPL(videobuf_alloc);
1259 EXPORT_SYMBOL_GPL(videobuf_waiton);
1260 EXPORT_SYMBOL_GPL(videobuf_iolock);
1261
1262 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1263 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1264 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1265
1266 EXPORT_SYMBOL_GPL(videobuf_next_field);
1267 EXPORT_SYMBOL_GPL(videobuf_status);
1268 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1269 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1270 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1271 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1272 EXPORT_SYMBOL_GPL(videobuf_streamon);
1273 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1274
1275 EXPORT_SYMBOL_GPL(videobuf_read_start);
1276 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1277 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1278 EXPORT_SYMBOL_GPL(videobuf_read_one);
1279 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1280
1281 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1282 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1283 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1284
1285 /*
1286  * Local variables:
1287  * c-basic-offset: 8
1288  * End:
1289  */