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