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 = kmalloc(sizeof(struct scatterlist)*nr_pages, GFP_KERNEL);
  56         if (NULL == sglist)
  57                 return NULL;
  58         memset(sglist,0,sizeof(struct scatterlist)*nr_pages);
  59         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
  60                 pg = vmalloc_to_page(virt);
  61                 if (NULL == pg)
  62                         goto err;
  63                 if (PageHighMem(pg))
  64                         BUG();
  65                 sglist[i].page   = pg;
  66                 sglist[i].length = PAGE_SIZE;
  67         }
  68         return sglist;
  69
  70  err:
  71         kfree(sglist);
  72         return NULL;
  73 }
  74
  75 struct scatterlist*
  76 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
  77 {
  78         struct scatterlist *sglist;
  79         int i = 0;
  80
  81         if (NULL == pages[0])
  82                 return NULL;
  83         sglist = kmalloc(sizeof(*sglist) * nr_pages, GFP_KERNEL);
  84         if (NULL == sglist)
  85                 return NULL;
  86         memset(sglist, 0, sizeof(*sglist) * nr_pages);
  87
  88         if (NULL == pages[0])
  89                 goto nopage;
  90         if (PageHighMem(pages[0]))
  91                 /* DMA to highmem pages might not work */
  92                 goto highmem;
  93         sglist[0].page   = pages[0];
  94         sglist[0].offset = offset;
  95         sglist[0].length = PAGE_SIZE - offset;
  96         for (i = 1; i < nr_pages; i++) {
  97                 if (NULL == pages[i])
  98                         goto nopage;
  99                 if (PageHighMem(pages[i]))
 100                         goto highmem;
 101                 sglist[i].page   = pages[i];
 102                 sglist[i].length = PAGE_SIZE;
 103         }
 104         return sglist;
 105
 106  nopage:
 107         dprintk(2,"sgl: oops - no page\n");
 108         kfree(sglist);
 109         return NULL;
 110
 111  highmem:
 112         dprintk(2,"sgl: oops - highmem page\n");
 113         kfree(sglist);
 114         return NULL;
 115 }
 116
 117 /* --------------------------------------------------------------------- */
 118
 119 void videobuf_dma_init(struct videobuf_dmabuf *dma)
 120 {
 121         memset(dma,0,sizeof(*dma));
 122         dma->magic = MAGIC_DMABUF;
 123 }
 124
 125 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 126                            unsigned long data, unsigned long size)
 127 {
 128         unsigned long first,last;
 129         int err, rw = 0;
 130
 131         dma->direction = direction;
 132         switch (dma->direction) {
 133         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 134         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 135         default:                 BUG();
 136         }
 137
 138         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 139         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 140         dma->offset   = data & ~PAGE_MASK;
 141         dma->nr_pages = last-first+1;
 142         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 143                              GFP_KERNEL);
 144         if (NULL == dma->pages)
 145                 return -ENOMEM;
 146         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 147                 data,size,dma->nr_pages);
 148
 149         down_read(&current->mm->mmap_sem);
 150         err = get_user_pages(current,current->mm,
 151                              data & PAGE_MASK, dma->nr_pages,
 152                              rw == READ, 1, /* force */
 153                              dma->pages, NULL);
 154         up_read(&current->mm->mmap_sem);
 155         if (err != dma->nr_pages) {
 156                 dma->nr_pages = (err >= 0) ? err : 0;
 157                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 158                 return err < 0 ? err : -EINVAL;
 159         }
 160         return 0;
 161 }
 162
 163 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 164                              int nr_pages)
 165 {
 166         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 167         dma->direction = direction;
 168         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 169         if (NULL == dma->vmalloc) {
 170                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 171                 return -ENOMEM;
 172         }
 173         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 174         dma->nr_pages = nr_pages;
 175         return 0;
 176 }
 177
 178 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 179                               dma_addr_t addr, int nr_pages)
 180 {
 181         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 182                 nr_pages,(unsigned long)addr);
 183         dma->direction = direction;
 184         if (0 == addr)
 185                 return -EINVAL;
 186
 187         dma->bus_addr = addr;
 188         dma->nr_pages = nr_pages;
 189         return 0;
 190 }
 191
 192 int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 193 {
 194         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 195         BUG_ON(0 == dma->nr_pages);
 196
 197         if (dma->pages) {
 198                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 199                                                    dma->offset);
 200         }
 201         if (dma->vmalloc) {
 202                 dma->sglist = videobuf_vmalloc_to_sg
 203                         (dma->vmalloc,dma->nr_pages);
 204         }
 205         if (dma->bus_addr) {
 206                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 207                 if (NULL != dma->sglist) {
 208                         dma->sglen  = 1;
 209                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 210                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 211                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 212                 }
 213         }
 214         if (NULL == dma->sglist) {
 215                 dprintk(1,"scatterlist is NULL\n");
 216                 return -ENOMEM;
 217         }
 218
 219         if (!dma->bus_addr) {
 220                 dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
 221                                         dma->direction);
 222                 if (0 == dma->sglen) {
 223                         printk(KERN_WARNING
 224                                "%s: pci_map_sg failed\n",__FUNCTION__);
 225                         kfree(dma->sglist);
 226                         dma->sglist = NULL;
 227                         dma->sglen = 0;
 228                         return -EIO;
 229                 }
 230         }
 231         return 0;
 232 }
 233
 234 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 235 {
 236         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 237         BUG_ON(!dma->sglen);
 238
 239         if (!dma->bus_addr)
 240                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 241         return 0;
 242 }
 243
 244 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 245 {
 246         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 247         if (!dma->sglen)
 248                 return 0;
 249
 250         if (!dma->bus_addr)
 251                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 252         kfree(dma->sglist);
 253         dma->sglist = NULL;
 254         dma->sglen = 0;
 255         return 0;
 256 }
 257
 258 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 259 {
 260         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 261         BUG_ON(dma->sglen);
 262
 263         if (dma->pages) {
 264                 int i;
 265                 for (i=0; i < dma->nr_pages; i++)
 266                         page_cache_release(dma->pages[i]);
 267                 kfree(dma->pages);
 268                 dma->pages = NULL;
 269         }
 270
 271         vfree(dma->vmalloc);
 272         dma->vmalloc = NULL;
 273
 274         if (dma->bus_addr) {
 275                 dma->bus_addr = 0;
 276         }
 277         dma->direction = PCI_DMA_NONE;
 278         return 0;
 279 }
 280
 281 /* --------------------------------------------------------------------- */
 282
 283 void* videobuf_alloc(unsigned int size)
 284 {
 285         struct videobuf_buffer *vb;
 286
 287         vb = kmalloc(size,GFP_KERNEL);
 288         if (NULL != vb) {
 289                 memset(vb,0,size);
 290                 videobuf_dma_init(&vb->dma);
 291                 init_waitqueue_head(&vb->done);
 292                 vb->magic     = MAGIC_BUFFER;
 293         }
 294         return vb;
 295 }
 296
 297 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 298 {
 299         int retval = 0;
 300         DECLARE_WAITQUEUE(wait, current);
 301
 302         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 303         add_wait_queue(&vb->done, &wait);
 304         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 305                 if (non_blocking) {
 306                         retval = -EAGAIN;
 307                         break;
 308                 }
 309                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 310                                         : TASK_UNINTERRUPTIBLE);
 311                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 312                         schedule();
 313                 set_current_state(TASK_RUNNING);
 314                 if (intr && signal_pending(current)) {
 315                         dprintk(1,"buffer waiton: -EINTR\n");
 316                         retval = -EINTR;
 317                         break;
 318                 }
 319         }
 320         remove_wait_queue(&vb->done, &wait);
 321         return retval;
 322 }
 323
 324 int
 325 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 326                 struct v4l2_framebuffer *fbuf)
 327 {
 328         int err,pages;
 329         dma_addr_t bus;
 330
 331         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 332         switch (vb->memory) {
 333         case V4L2_MEMORY_MMAP:
 334         case V4L2_MEMORY_USERPTR:
 335                 if (0 == vb->baddr) {
 336                         /* no userspace addr -- kernel bounce buffer */
 337                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 338                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 339                                                        pages);
 340                         if (0 != err)
 341                                 return err;
 342                 } else {
 343                         /* dma directly to userspace */
 344                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 345                                                      vb->baddr,vb->bsize);
 346                         if (0 != err)
 347                                 return err;
 348                 }
 349                 break;
 350         case V4L2_MEMORY_OVERLAY:
 351                 if (NULL == fbuf)
 352                         return -EINVAL;
 353                 /* FIXME: need sanity checks for vb->boff */
 354                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 355                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 356                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 357                                                 bus, pages);
 358                 if (0 != err)
 359                         return err;
 360                 break;
 361         default:
 362                 BUG();
 363         }
 364         err = videobuf_dma_pci_map(pci,&vb->dma);
 365         if (0 != err)
 366                 return err;
 367
 368         return 0;
 369 }
 370
 371 /* --------------------------------------------------------------------- */
 372
 373 void videobuf_queue_init(struct videobuf_queue* q,
 374                          struct videobuf_queue_ops *ops,
 375                          struct pci_dev *pci,
 376                          spinlock_t *irqlock,
 377                          enum v4l2_buf_type type,
 378                          enum v4l2_field field,
 379                          unsigned int msize,
 380                          void *priv)
 381 {
 382         memset(q,0,sizeof(*q));
 383         q->irqlock = irqlock;
 384         q->pci     = pci;
 385         q->type    = type;
 386         q->field   = field;
 387         q->msize   = msize;
 388         q->ops     = ops;
 389         q->priv_data = priv;
 390
 391         init_MUTEX(&q->lock);
 392         INIT_LIST_HEAD(&q->stream);
 393 }
 394
 395 int
 396 videobuf_queue_is_busy(struct videobuf_queue *q)
 397 {
 398         int i;
 399
 400         if (q->streaming) {
 401                 dprintk(1,"busy: streaming active\n");
 402                 return 1;
 403         }
 404         if (q->reading) {
 405                 dprintk(1,"busy: pending read #1\n");
 406                 return 1;
 407         }
 408         if (q->read_buf) {
 409                 dprintk(1,"busy: pending read #2\n");
 410                 return 1;
 411         }
 412         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 413                 if (NULL == q->bufs[i])
 414                         continue;
 415                 if (q->bufs[i]->map) {
 416                         dprintk(1,"busy: buffer #%d mapped\n",i);
 417                         return 1;
 418                 }
 419                 if (q->bufs[i]->state == STATE_QUEUED) {
 420                         dprintk(1,"busy: buffer #%d queued\n",i);
 421                         return 1;
 422                 }
 423                 if (q->bufs[i]->state == STATE_ACTIVE) {
 424                         dprintk(1,"busy: buffer #%d avtive\n",i);
 425                         return 1;
 426                 }
 427         }
 428         return 0;
 429 }
 430
 431 void
 432 videobuf_queue_cancel(struct videobuf_queue *q)
 433 {
 434         unsigned long flags;
 435         int i;
 436
 437         /* remove queued buffers from list */
 438         spin_lock_irqsave(q->irqlock,flags);
 439         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 440                 if (NULL == q->bufs[i])
 441                         continue;
 442                 if (q->bufs[i]->state == STATE_QUEUED) {
 443                         list_del(&q->bufs[i]->queue);
 444                         q->bufs[i]->state = STATE_ERROR;
 445                 }
 446         }
 447         spin_unlock_irqrestore(q->irqlock,flags);
 448
 449         /* free all buffers + clear queue */
 450         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 451                 if (NULL == q->bufs[i])
 452                         continue;
 453                 q->ops->buf_release(q,q->bufs[i]);
 454         }
 455         INIT_LIST_HEAD(&q->stream);
 456 }
 457
 458 /* --------------------------------------------------------------------- */
 459
 460 enum v4l2_field
 461 videobuf_next_field(struct videobuf_queue *q)
 462 {
 463         enum v4l2_field field = q->field;
 464
 465         BUG_ON(V4L2_FIELD_ANY == field);
 466
 467         if (V4L2_FIELD_ALTERNATE == field) {
 468                 if (V4L2_FIELD_TOP == q->last) {
 469                         field   = V4L2_FIELD_BOTTOM;
 470                         q->last = V4L2_FIELD_BOTTOM;
 471                 } else {
 472                         field   = V4L2_FIELD_TOP;
 473                         q->last = V4L2_FIELD_TOP;
 474                 }
 475         }
 476         return field;
 477 }
 478
 479 void
 480 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 481                 enum v4l2_buf_type type)
 482 {
 483         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 484
 485         b->index    = vb->i;
 486         b->type     = type;
 487
 488         b->memory   = vb->memory;
 489         switch (b->memory) {
 490         case V4L2_MEMORY_MMAP:
 491                 b->m.offset  = vb->boff;
 492                 b->length    = vb->bsize;
 493                 break;
 494         case V4L2_MEMORY_USERPTR:
 495                 b->m.userptr = vb->baddr;
 496                 b->length    = vb->bsize;
 497                 break;
 498         case V4L2_MEMORY_OVERLAY:
 499                 b->m.offset  = vb->boff;
 500                 break;
 501         }
 502
 503         b->flags    = 0;
 504         if (vb->map)
 505                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 506
 507         switch (vb->state) {
 508         case STATE_PREPARED:
 509         case STATE_QUEUED:
 510         case STATE_ACTIVE:
 511                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 512                 break;
 513         case STATE_DONE:
 514         case STATE_ERROR:
 515                 b->flags |= V4L2_BUF_FLAG_DONE;
 516                 break;
 517         case STATE_NEEDS_INIT:
 518         case STATE_IDLE:
 519                 /* nothing */
 520                 break;
 521         }
 522
 523         if (vb->input != UNSET) {
 524                 b->flags |= V4L2_BUF_FLAG_INPUT;
 525                 b->input  = vb->input;
 526         }
 527
 528         b->field     = vb->field;
 529         b->timestamp = vb->ts;
 530         b->bytesused = vb->size;
 531         b->sequence  = vb->field_count >> 1;
 532 }
 533
 534 int
 535 videobuf_reqbufs(struct videobuf_queue *q,
 536                  struct v4l2_requestbuffers *req)
 537 {
 538         unsigned int size,count;
 539         int retval;
 540
 541         if (req->type != q->type)
 542                 return -EINVAL;
 543         if (req->count < 1)
 544                 return -EINVAL;
 545         if (req->memory != V4L2_MEMORY_MMAP     &&
 546             req->memory != V4L2_MEMORY_USERPTR  &&
 547             req->memory != V4L2_MEMORY_OVERLAY)
 548                 return -EINVAL;
 549
 550         if (q->streaming)
 551                 return -EBUSY;
 552         if (!list_empty(&q->stream))
 553                 return -EBUSY;
 554
 555         down(&q->lock);
 556         count = req->count;
 557         if (count > VIDEO_MAX_FRAME)
 558                 count = VIDEO_MAX_FRAME;
 559         size = 0;
 560         q->ops->buf_setup(q,&count,&size);
 561         size = PAGE_ALIGN(size);
 562         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 563                 count, size, (count*size)>>PAGE_SHIFT);
 564
 565         retval = videobuf_mmap_setup(q,count,size,req->memory);
 566         if (retval < 0)
 567                 goto done;
 568
 569         req->count = count;
 570
 571  done:
 572         up(&q->lock);
 573         return retval;
 574 }
 575
 576 int
 577 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 578 {
 579         if (unlikely(b->type != q->type))
 580                 return -EINVAL;
 581         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 582                 return -EINVAL;
 583         if (unlikely(NULL == q->bufs[b->index]))
 584                 return -EINVAL;
 585         videobuf_status(b,q->bufs[b->index],q->type);
 586         return 0;
 587 }
 588
 589 int
 590 videobuf_qbuf(struct videobuf_queue *q,
 591               struct v4l2_buffer *b)
 592 {
 593         struct videobuf_buffer *buf;
 594         enum v4l2_field field;
 595         unsigned long flags;
 596         int retval;
 597
 598         down(&q->lock);
 599         retval = -EBUSY;
 600         if (q->reading)
 601                 goto done;
 602         retval = -EINVAL;
 603         if (b->type != q->type)
 604                 goto done;
 605         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 606                 goto done;
 607         buf = q->bufs[b->index];
 608         if (NULL == buf)
 609                 goto done;
 610         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 611         if (buf->memory != b->memory)
 612                 goto done;
 613         if (buf->state == STATE_QUEUED ||
 614             buf->state == STATE_ACTIVE)
 615                 goto done;
 616
 617         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 618                 if (b->input >= q->inputs)
 619                         goto done;
 620                 buf->input = b->input;
 621         } else {
 622                 buf->input = UNSET;
 623         }
 624
 625         switch (b->memory) {
 626         case V4L2_MEMORY_MMAP:
 627                 if (0 == buf->baddr)
 628                         goto done;
 629                 break;
 630         case V4L2_MEMORY_USERPTR:
 631                 if (b->length < buf->bsize)
 632                         goto done;
 633                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 634                         q->ops->buf_release(q,buf);
 635                 buf->baddr = b->m.userptr;
 636                 break;
 637         case V4L2_MEMORY_OVERLAY:
 638                 buf->boff = b->m.offset;
 639                 break;
 640         default:
 641                 goto done;
 642         }
 643
 644         field = videobuf_next_field(q);
 645         retval = q->ops->buf_prepare(q,buf,field);
 646         if (0 != retval)
 647                 goto done;
 648
 649         list_add_tail(&buf->stream,&q->stream);
 650         if (q->streaming) {
 651                 spin_lock_irqsave(q->irqlock,flags);
 652                 q->ops->buf_queue(q,buf);
 653                 spin_unlock_irqrestore(q->irqlock,flags);
 654         }
 655         retval = 0;
 656
 657  done:
 658         up(&q->lock);
 659         return retval;
 660 }
 661
 662 int
 663 videobuf_dqbuf(struct videobuf_queue *q,
 664                struct v4l2_buffer *b, int nonblocking)
 665 {
 666         struct videobuf_buffer *buf;
 667         int retval;
 668
 669         down(&q->lock);
 670         retval = -EBUSY;
 671         if (q->reading)
 672                 goto done;
 673         retval = -EINVAL;
 674         if (b->type != q->type)
 675                 goto done;
 676         if (list_empty(&q->stream))
 677                 goto done;
 678         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 679         retval = videobuf_waiton(buf, nonblocking, 1);
 680         if (retval < 0)
 681                 goto done;
 682         switch (buf->state) {
 683         case STATE_ERROR:
 684                 retval = -EIO;
 685                 /* fall through */
 686         case STATE_DONE:
 687                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 688                 buf->state = STATE_IDLE;
 689                 break;
 690         default:
 691                 retval = -EINVAL;
 692                 goto done;
 693         }
 694         list_del(&buf->stream);
 695         memset(b,0,sizeof(*b));
 696         videobuf_status(b,buf,q->type);
 697
 698  done:
 699         up(&q->lock);
 700         return retval;
 701 }
 702
 703 int videobuf_streamon(struct videobuf_queue *q)
 704 {
 705         struct videobuf_buffer *buf;
 706         struct list_head *list;
 707         unsigned long flags;
 708         int retval;
 709
 710         down(&q->lock);
 711         retval = -EBUSY;
 712         if (q->reading)
 713                 goto done;
 714         retval = 0;
 715         if (q->streaming)
 716                 goto done;
 717         q->streaming = 1;
 718         spin_lock_irqsave(q->irqlock,flags);
 719         list_for_each(list,&q->stream) {
 720                 buf = list_entry(list, struct videobuf_buffer, stream);
 721                 if (buf->state == STATE_PREPARED)
 722                         q->ops->buf_queue(q,buf);
 723         }
 724         spin_unlock_irqrestore(q->irqlock,flags);
 725
 726  done:
 727         up(&q->lock);
 728         return retval;
 729 }
 730
 731 int videobuf_streamoff(struct videobuf_queue *q)
 732 {
 733         int retval = -EINVAL;
 734
 735         down(&q->lock);
 736         if (!q->streaming)
 737                 goto done;
 738         videobuf_queue_cancel(q);
 739         q->streaming = 0;
 740         retval = 0;
 741
 742  done:
 743         up(&q->lock);
 744         return retval;
 745 }
 746
 747 static ssize_t
 748 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 749                        size_t count, loff_t *ppos)
 750 {
 751         enum v4l2_field field;
 752         unsigned long flags;
 753         int retval;
 754
 755         /* setup stuff */
 756         q->read_buf = videobuf_alloc(q->msize);
 757         if (NULL == q->read_buf)
 758                 return -ENOMEM;
 759
 760         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 761         q->read_buf->baddr  = (unsigned long)data;
 762         q->read_buf->bsize  = count;
 763         field = videobuf_next_field(q);
 764         retval = q->ops->buf_prepare(q,q->read_buf,field);
 765         if (0 != retval)
 766                 goto done;
 767
 768         /* start capture & wait */
 769         spin_lock_irqsave(q->irqlock,flags);
 770         q->ops->buf_queue(q,q->read_buf);
 771         spin_unlock_irqrestore(q->irqlock,flags);
 772         retval = videobuf_waiton(q->read_buf,0,0);
 773         if (0 == retval) {
 774                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 775                 if (STATE_ERROR == q->read_buf->state)
 776                         retval = -EIO;
 777                 else
 778                         retval = q->read_buf->size;
 779         }
 780
 781  done:
 782         /* cleanup */
 783         q->ops->buf_release(q,q->read_buf);
 784         kfree(q->read_buf);
 785         q->read_buf = NULL;
 786         return retval;
 787 }
 788
 789 ssize_t videobuf_read_one(struct videobuf_queue *q,
 790                           char __user *data, size_t count, loff_t *ppos,
 791                           int nonblocking)
 792 {
 793         enum v4l2_field field;
 794         unsigned long flags;
 795         unsigned size, nbufs, bytes;
 796         int retval;
 797
 798         down(&q->lock);
 799
 800         nbufs = 1; size = 0;
 801         q->ops->buf_setup(q,&nbufs,&size);
 802         if (NULL == q->read_buf  &&
 803             count >= size        &&
 804             !nonblocking) {
 805                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 806                 if (retval >= 0  ||  retval == -EIO)
 807                         /* ok, all done */
 808                         goto done;
 809                 /* fallback to kernel bounce buffer on failures */
 810         }
 811
 812         if (NULL == q->read_buf) {
 813                 /* need to capture a new frame */
 814                 retval = -ENOMEM;
 815                 q->read_buf = videobuf_alloc(q->msize);
 816                 if (NULL == q->read_buf)
 817                         goto done;
 818                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 819                 q->read_buf->bsize = count; /* preferred size */
 820                 field = videobuf_next_field(q);
 821                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 822                 if (0 != retval) {
 823                         kfree (q->read_buf);
 824                         q->read_buf = NULL;
 825                         goto done;
 826                 }
 827                 spin_lock_irqsave(q->irqlock,flags);
 828                 q->ops->buf_queue(q,q->read_buf);
 829                 spin_unlock_irqrestore(q->irqlock,flags);
 830                 q->read_off = 0;
 831         }
 832
 833         /* wait until capture is done */
 834         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 835         if (0 != retval)
 836                 goto done;
 837         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 838
 839         if (STATE_ERROR == q->read_buf->state) {
 840                 /* catch I/O errors */
 841                 q->ops->buf_release(q,q->read_buf);
 842                 kfree(q->read_buf);
 843                 q->read_buf = NULL;
 844                 retval = -EIO;
 845                 goto done;
 846         }
 847
 848         /* copy to userspace */
 849         bytes = count;
 850         if (bytes > q->read_buf->size - q->read_off)
 851                 bytes = q->read_buf->size - q->read_off;
 852         retval = -EFAULT;
 853         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 854                 goto done;
 855
 856         retval = bytes;
 857         q->read_off += bytes;
 858         if (q->read_off == q->read_buf->size) {
 859                 /* all data copied, cleanup */
 860                 q->ops->buf_release(q,q->read_buf);
 861                 kfree(q->read_buf);
 862                 q->read_buf = NULL;
 863         }
 864
 865  done:
 866         up(&q->lock);
 867         return retval;
 868 }
 869
 870 int videobuf_read_start(struct videobuf_queue *q)
 871 {
 872         enum v4l2_field field;
 873         unsigned long flags;
 874         int count = 0, size = 0;
 875         int err, i;
 876
 877         q->ops->buf_setup(q,&count,&size);
 878         if (count < 2)
 879                 count = 2;
 880         if (count > VIDEO_MAX_FRAME)
 881                 count = VIDEO_MAX_FRAME;
 882         size = PAGE_ALIGN(size);
 883
 884         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 885         if (err)
 886                 return err;
 887         for (i = 0; i < count; i++) {
 888                 field = videobuf_next_field(q);
 889                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 890                 if (err)
 891                         return err;
 892                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 893         }
 894         spin_lock_irqsave(q->irqlock,flags);
 895         for (i = 0; i < count; i++)
 896                 q->ops->buf_queue(q,q->bufs[i]);
 897         spin_unlock_irqrestore(q->irqlock,flags);
 898         q->reading = 1;
 899         return 0;
 900 }
 901
 902 void videobuf_read_stop(struct videobuf_queue *q)
 903 {
 904         int i;
 905
 906         videobuf_queue_cancel(q);
 907         videobuf_mmap_free(q);
 908         INIT_LIST_HEAD(&q->stream);
 909         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 910                 if (NULL == q->bufs[i])
 911                         continue;
 912                 kfree(q->bufs[i]);
 913                 q->bufs[i] = NULL;
 914         }
 915         q->read_buf = NULL;
 916         q->reading  = 0;
 917 }
 918
 919 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 920                              char __user *data, size_t count, loff_t *ppos,
 921                              int vbihack, int nonblocking)
 922 {
 923         unsigned int *fc, bytes;
 924         int err, retval;
 925         unsigned long flags;
 926
 927         dprintk(2,"%s\n",__FUNCTION__);
 928         down(&q->lock);
 929         retval = -EBUSY;
 930         if (q->streaming)
 931                 goto done;
 932         if (!q->reading) {
 933                 retval = videobuf_read_start(q);
 934                 if (retval < 0)
 935                         goto done;
 936         }
 937
 938         retval = 0;
 939         while (count > 0) {
 940                 /* get / wait for data */
 941                 if (NULL == q->read_buf) {
 942                         q->read_buf = list_entry(q->stream.next,
 943                                                  struct videobuf_buffer,
 944                                                  stream);
 945                         list_del(&q->read_buf->stream);
 946                         q->read_off = 0;
 947                 }
 948                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
 949                 if (err < 0) {
 950                         if (0 == retval)
 951                                 retval = err;
 952                         break;
 953                 }
 954
 955                 if (q->read_buf->state == STATE_DONE) {
 956                         if (vbihack) {
 957                                 /* dirty, undocumented hack -- pass the frame counter
 958                                  * within the last four bytes of each vbi data block.
 959                                  * We need that one to maintain backward compatibility
 960                                  * to all vbi decoding software out there ... */
 961                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 962                                 fc += (q->read_buf->size>>2) -1;
 963                                 *fc = q->read_buf->field_count >> 1;
 964                                 dprintk(1,"vbihack: %d\n",*fc);
 965                         }
 966
 967                         /* copy stuff */
 968                         bytes = count;
 969                         if (bytes > q->read_buf->size - q->read_off)
 970                                 bytes = q->read_buf->size - q->read_off;
 971                         if (copy_to_user(data + retval,
 972                                          q->read_buf->dma.vmalloc + q->read_off,
 973                                          bytes)) {
 974                                 if (0 == retval)
 975                                         retval = -EFAULT;
 976                                 break;
 977                         }
 978                         count       -= bytes;
 979                         retval      += bytes;
 980                         q->read_off += bytes;
 981                 } else {
 982                         /* some error */
 983                         q->read_off = q->read_buf->size;
 984                         if (0 == retval)
 985                                 retval = -EIO;
 986                 }
 987
 988                 /* requeue buffer when done with copying */
 989                 if (q->read_off == q->read_buf->size) {
 990                         list_add_tail(&q->read_buf->stream,
 991                                       &q->stream);
 992                         spin_lock_irqsave(q->irqlock,flags);
 993                         q->ops->buf_queue(q,q->read_buf);
 994                         spin_unlock_irqrestore(q->irqlock,flags);
 995                         q->read_buf = NULL;
 996                 }
 997                 if (retval < 0)
 998                         break;
 999         }
1000
1001  done:
1002         up(&q->lock);
1003         return retval;
1004 }
1005
1006 unsigned int videobuf_poll_stream(struct file *file,
1007                                   struct videobuf_queue *q,
1008                                   poll_table *wait)
1009 {
1010         struct videobuf_buffer *buf = NULL;
1011         unsigned int rc = 0;
1012
1013         down(&q->lock);
1014         if (q->streaming) {
1015                 if (!list_empty(&q->stream))
1016                         buf = list_entry(q->stream.next,
1017                                          struct videobuf_buffer, stream);
1018         } else {
1019                 if (!q->reading)
1020                         videobuf_read_start(q);
1021                 if (!q->reading) {
1022                         rc = POLLERR;
1023                 } else if (NULL == q->read_buf) {
1024                         q->read_buf = list_entry(q->stream.next,
1025                                                  struct videobuf_buffer,
1026                                                  stream);
1027                         list_del(&q->read_buf->stream);
1028                         q->read_off = 0;
1029                 }
1030                 buf = q->read_buf;
1031         }
1032         if (!buf)
1033                 rc = POLLERR;
1034
1035         if (0 == rc) {
1036                 poll_wait(file, &buf->done, wait);
1037                 if (buf->state == STATE_DONE ||
1038                     buf->state == STATE_ERROR)
1039                         rc = POLLIN|POLLRDNORM;
1040         }
1041         up(&q->lock);
1042         return rc;
1043 }
1044
1045 /* --------------------------------------------------------------------- */
1046
1047 static void
1048 videobuf_vm_open(struct vm_area_struct *vma)
1049 {
1050         struct videobuf_mapping *map = vma->vm_private_data;
1051
1052         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1053                 map->count,vma->vm_start,vma->vm_end);
1054         map->count++;
1055 }
1056
1057 static void
1058 videobuf_vm_close(struct vm_area_struct *vma)
1059 {
1060         struct videobuf_mapping *map = vma->vm_private_data;
1061         struct videobuf_queue *q = map->q;
1062         int i;
1063
1064         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1065                 map->count,vma->vm_start,vma->vm_end);
1066
1067         map->count--;
1068         if (0 == map->count) {
1069                 dprintk(1,"munmap %p q=%p\n",map,q);
1070                 down(&q->lock);
1071                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1072                         if (NULL == q->bufs[i])
1073                                 continue;
1074                         if (q->bufs[i])
1075                                 ;
1076                         if (q->bufs[i]->map != map)
1077                                 continue;
1078                         q->bufs[i]->map   = NULL;
1079                         q->bufs[i]->baddr = 0;
1080                         q->ops->buf_release(q,q->bufs[i]);
1081                 }
1082                 up(&q->lock);
1083                 kfree(map);
1084         }
1085         return;
1086 }
1087
1088 /*
1089  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1090  * memory location with 32bit PCI devices (i.e. don't use highmem for
1091  * now ...).  Bounce buffers don't work very well for the data rates
1092  * video capture has.
1093  */
1094 static struct page*
1095 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1096                    int *type)
1097 {
1098         struct page *page;
1099
1100         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1101                 vaddr,vma->vm_start,vma->vm_end);
1102         if (vaddr > vma->vm_end)
1103                 return NOPAGE_SIGBUS;
1104         page = alloc_page(GFP_USER);
1105         if (!page)
1106                 return NOPAGE_OOM;
1107         clear_user_page(page_address(page), vaddr, page);
1108         if (type)
1109                 *type = VM_FAULT_MINOR;
1110         return page;
1111 }
1112
1113 static struct vm_operations_struct videobuf_vm_ops =
1114 {
1115         .open     = videobuf_vm_open,
1116         .close    = videobuf_vm_close,
1117         .nopage   = videobuf_vm_nopage,
1118 };
1119
1120 int videobuf_mmap_setup(struct videobuf_queue *q,
1121                         unsigned int bcount, unsigned int bsize,
1122                         enum v4l2_memory memory)
1123 {
1124         unsigned int i;
1125         int err;
1126
1127         err = videobuf_mmap_free(q);
1128         if (0 != err)
1129                 return err;
1130
1131         for (i = 0; i < bcount; i++) {
1132                 q->bufs[i] = videobuf_alloc(q->msize);
1133                 q->bufs[i]->i      = i;
1134                 q->bufs[i]->input  = UNSET;
1135                 q->bufs[i]->memory = memory;
1136                 q->bufs[i]->bsize  = bsize;
1137                 switch (memory) {
1138                 case V4L2_MEMORY_MMAP:
1139                         q->bufs[i]->boff  = bsize * i;
1140                         break;
1141                 case V4L2_MEMORY_USERPTR:
1142                 case V4L2_MEMORY_OVERLAY:
1143                         /* nothing */
1144                         break;
1145                 }
1146         }
1147         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1148                 bcount,bsize);
1149         return 0;
1150 }
1151
1152 int videobuf_mmap_free(struct videobuf_queue *q)
1153 {
1154         int i;
1155
1156         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1157                 if (q->bufs[i] && q->bufs[i]->map)
1158                         return -EBUSY;
1159         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1160                 if (NULL == q->bufs[i])
1161                         continue;
1162                 q->ops->buf_release(q,q->bufs[i]);
1163                 kfree(q->bufs[i]);
1164                 q->bufs[i] = NULL;
1165         }
1166         return 0;
1167 }
1168
1169 int videobuf_mmap_mapper(struct videobuf_queue *q,
1170                          struct vm_area_struct *vma)
1171 {
1172         struct videobuf_mapping *map;
1173         unsigned int first,last,size,i;
1174         int retval;
1175
1176         down(&q->lock);
1177         retval = -EINVAL;
1178         if (!(vma->vm_flags & VM_WRITE)) {
1179                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1180                 goto done;
1181         }
1182         if (!(vma->vm_flags & VM_SHARED)) {
1183                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1184                 goto done;
1185         }
1186
1187         /* look for first buffer to map */
1188         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1189                 if (NULL == q->bufs[first])
1190                         continue;
1191                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1192                         continue;
1193                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1194                         break;
1195         }
1196         if (VIDEO_MAX_FRAME == first) {
1197                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1198                         (vma->vm_pgoff << PAGE_SHIFT));
1199                 goto done;
1200         }
1201
1202         /* look for last buffer to map */
1203         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1204                 if (NULL == q->bufs[last])
1205                         continue;
1206                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1207                         continue;
1208                 if (q->bufs[last]->map) {
1209                         retval = -EBUSY;
1210                         goto done;
1211                 }
1212                 size += q->bufs[last]->bsize;
1213                 if (size == (vma->vm_end - vma->vm_start))
1214                         break;
1215         }
1216         if (VIDEO_MAX_FRAME == last) {
1217                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1218                         (vma->vm_end - vma->vm_start));
1219                 goto done;
1220         }
1221
1222         /* create mapping + update buffer list */
1223         retval = -ENOMEM;
1224         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1225         if (NULL == map)
1226                 goto done;
1227         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1228                 q->bufs[i]->map   = map;
1229                 q->bufs[i]->baddr = vma->vm_start + size;
1230         }
1231         map->count    = 1;
1232         map->start    = vma->vm_start;
1233         map->end      = vma->vm_end;
1234         map->q        = q;
1235         vma->vm_ops   = &videobuf_vm_ops;
1236         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1237         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1238         vma->vm_private_data = map;
1239         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1240                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1241         retval = 0;
1242
1243  done:
1244         up(&q->lock);
1245         return retval;
1246 }
1247
1248 /* --------------------------------------------------------------------- */
1249
1250 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1251
1252 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1253 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1254 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1255 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1256 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1257 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1258 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1259 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1260
1261 EXPORT_SYMBOL_GPL(videobuf_alloc);
1262 EXPORT_SYMBOL_GPL(videobuf_waiton);
1263 EXPORT_SYMBOL_GPL(videobuf_iolock);
1264
1265 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1266 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1267 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1268
1269 EXPORT_SYMBOL_GPL(videobuf_next_field);
1270 EXPORT_SYMBOL_GPL(videobuf_status);
1271 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1272 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1273 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1274 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1275 EXPORT_SYMBOL_GPL(videobuf_streamon);
1276 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1277
1278 EXPORT_SYMBOL_GPL(videobuf_read_start);
1279 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1280 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1281 EXPORT_SYMBOL_GPL(videobuf_read_one);
1282 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1283
1284 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1285 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1286 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1287
1288 /*
1289  * Local variables:
1290  * c-basic-offset: 8
1291  * End:
1292  */