drivers/media/video/video-buf.c

   1 /*
   2  * $Id: video-buf.c,v 1.15 2004/11/07 14:45:00 kraxel Exp $
   3  *
   4  * generic helper functions for video4linux capture buffers, to handle
   5  * memory management and PCI DMA.  Right now bttv + saa7134 use it.
   6  *
   7  * The functions expect the hardware being able to scatter gatter
   8  * (i.e. the buffers are not linear in physical memory, but fragmented
   9  * into PAGE_SIZE chunks).  They also assume the driver does not need
  10  * to touch the video data (thus it is probably not useful for USB 1.1
  11  * as data often must be uncompressed by the drivers).
  12  *
  13  * (c) 2001-2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/module.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         return 0;
 223 }
 224
 225 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 226 {
 227         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 228         BUG_ON(!dma->sglen);
 229
 230         if (!dma->bus_addr)
 231                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 232         return 0;
 233 }
 234
 235 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 236 {
 237         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 238         if (!dma->sglen)
 239                 return 0;
 240
 241         if (!dma->bus_addr)
 242                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 243         kfree(dma->sglist);
 244         dma->sglist = NULL;
 245         dma->sglen = 0;
 246         return 0;
 247 }
 248
 249 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 250 {
 251         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 252         BUG_ON(dma->sglen);
 253
 254         if (dma->pages) {
 255                 int i;
 256                 for (i=0; i < dma->nr_pages; i++)
 257                         page_cache_release(dma->pages[i]);
 258                 kfree(dma->pages);
 259                 dma->pages = NULL;
 260         }
 261         if (dma->vmalloc) {
 262                 vfree(dma->vmalloc);
 263                 dma->vmalloc = NULL;
 264         }
 265         if (dma->bus_addr) {
 266                 dma->bus_addr = 0;
 267         }
 268         dma->direction = PCI_DMA_NONE;
 269         return 0;
 270 }
 271
 272 /* --------------------------------------------------------------------- */
 273
 274 void* videobuf_alloc(unsigned int size)
 275 {
 276         struct videobuf_buffer *vb;
 277
 278         vb = kmalloc(size,GFP_KERNEL);
 279         if (NULL != vb) {
 280                 memset(vb,0,size);
 281                 videobuf_dma_init(&vb->dma);
 282                 init_waitqueue_head(&vb->done);
 283                 vb->magic     = MAGIC_BUFFER;
 284         }
 285         return vb;
 286 }
 287
 288 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 289 {
 290         int retval = 0;
 291         DECLARE_WAITQUEUE(wait, current);
 292
 293         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 294         add_wait_queue(&vb->done, &wait);
 295         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 296                 if (non_blocking) {
 297                         retval = -EAGAIN;
 298                         break;
 299                 }
 300                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 301                                         : TASK_UNINTERRUPTIBLE);
 302                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 303                         schedule();
 304                 set_current_state(TASK_RUNNING);
 305                 if (intr && signal_pending(current)) {
 306                         dprintk(1,"buffer waiton: -EINTR\n");
 307                         retval = -EINTR;
 308                         break;
 309                 }
 310         }
 311         remove_wait_queue(&vb->done, &wait);
 312         return retval;
 313 }
 314
 315 int
 316 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 317                 struct v4l2_framebuffer *fbuf)
 318 {
 319         int err,pages;
 320         dma_addr_t bus;
 321
 322         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 323         switch (vb->memory) {
 324         case V4L2_MEMORY_MMAP:
 325         case V4L2_MEMORY_USERPTR:
 326                 if (0 == vb->baddr) {
 327                         /* no userspace addr -- kernel bounce buffer */
 328                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 329                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 330                                                        pages);
 331                         if (0 != err)
 332                                 return err;
 333                 } else {
 334                         /* dma directly to userspace */
 335                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 336                                                      vb->baddr,vb->bsize);
 337                         if (0 != err)
 338                                 return err;
 339                 }
 340                 break;
 341         case V4L2_MEMORY_OVERLAY:
 342                 if (NULL == fbuf)
 343                         return -EINVAL;
 344                 /* FIXME: need sanity checks for vb->boff */
 345                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 346                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 347                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 348                                                 bus, pages);
 349                 if (0 != err)
 350                         return err;
 351                 break;
 352         default:
 353                 BUG();
 354         }
 355         err = videobuf_dma_pci_map(pci,&vb->dma);
 356         if (0 != err)
 357                 return err;
 358
 359         return 0;
 360 }
 361
 362 /* --------------------------------------------------------------------- */
 363
 364 void videobuf_queue_init(struct videobuf_queue* q,
 365                          struct videobuf_queue_ops *ops,
 366                          struct pci_dev *pci,
 367                          spinlock_t *irqlock,
 368                          enum v4l2_buf_type type,
 369                          enum v4l2_field field,
 370                          unsigned int msize,
 371                          void *priv)
 372 {
 373         memset(q,0,sizeof(*q));
 374         q->irqlock = irqlock;
 375         q->pci     = pci;
 376         q->type    = type;
 377         q->field   = field;
 378         q->msize   = msize;
 379         q->ops     = ops;
 380         q->priv_data = priv;
 381
 382         init_MUTEX(&q->lock);
 383         INIT_LIST_HEAD(&q->stream);
 384 }
 385
 386 int
 387 videobuf_queue_is_busy(struct videobuf_queue *q)
 388 {
 389         int i;
 390
 391         if (q->streaming) {
 392                 dprintk(1,"busy: streaming active\n");
 393                 return 1;
 394         }
 395         if (q->reading) {
 396                 dprintk(1,"busy: pending read #1\n");
 397                 return 1;
 398         }
 399         if (q->read_buf) {
 400                 dprintk(1,"busy: pending read #2\n");
 401                 return 1;
 402         }
 403         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 404                 if (NULL == q->bufs[i])
 405                         continue;
 406                 if (q->bufs[i]->map) {
 407                         dprintk(1,"busy: buffer #%d mapped\n",i);
 408                         return 1;
 409                 }
 410                 if (q->bufs[i]->state == STATE_QUEUED) {
 411                         dprintk(1,"busy: buffer #%d queued\n",i);
 412                         return 1;
 413                 }
 414                 if (q->bufs[i]->state == STATE_ACTIVE) {
 415                         dprintk(1,"busy: buffer #%d avtive\n",i);
 416                         return 1;
 417                 }
 418         }
 419         return 0;
 420 }
 421
 422 void
 423 videobuf_queue_cancel(struct videobuf_queue *q)
 424 {
 425         unsigned long flags;
 426         int i;
 427
 428         /* remove queued buffers from list */
 429         spin_lock_irqsave(q->irqlock,flags);
 430         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 431                 if (NULL == q->bufs[i])
 432                         continue;
 433                 if (q->bufs[i]->state == STATE_QUEUED) {
 434                         list_del(&q->bufs[i]->queue);
 435                         q->bufs[i]->state = STATE_ERROR;
 436                 }
 437         }
 438         spin_unlock_irqrestore(q->irqlock,flags);
 439
 440         /* free all buffers + clear queue */
 441         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 442                 if (NULL == q->bufs[i])
 443                         continue;
 444                 q->ops->buf_release(q,q->bufs[i]);
 445         }
 446         INIT_LIST_HEAD(&q->stream);
 447 }
 448
 449 /* --------------------------------------------------------------------- */
 450
 451 enum v4l2_field
 452 videobuf_next_field(struct videobuf_queue *q)
 453 {
 454         enum v4l2_field field = q->field;
 455
 456         BUG_ON(V4L2_FIELD_ANY == field);
 457
 458         if (V4L2_FIELD_ALTERNATE == field) {
 459                 if (V4L2_FIELD_TOP == q->last) {
 460                         field   = V4L2_FIELD_BOTTOM;
 461                         q->last = V4L2_FIELD_BOTTOM;
 462                 } else {
 463                         field   = V4L2_FIELD_TOP;
 464                         q->last = V4L2_FIELD_TOP;
 465                 }
 466         }
 467         return field;
 468 }
 469
 470 void
 471 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 472                 enum v4l2_buf_type type)
 473 {
 474         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 475
 476         b->index    = vb->i;
 477         b->type     = type;
 478
 479         b->memory   = vb->memory;
 480         switch (b->memory) {
 481         case V4L2_MEMORY_MMAP:
 482                 b->m.offset  = vb->boff;
 483                 b->length    = vb->bsize;
 484                 break;
 485         case V4L2_MEMORY_USERPTR:
 486                 b->m.userptr = vb->baddr;
 487                 b->length    = vb->bsize;
 488                 break;
 489         case V4L2_MEMORY_OVERLAY:
 490                 b->m.offset  = vb->boff;
 491                 break;
 492         }
 493
 494         b->flags    = 0;
 495         if (vb->map)
 496                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 497
 498         switch (vb->state) {
 499         case STATE_PREPARED:
 500         case STATE_QUEUED:
 501         case STATE_ACTIVE:
 502                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 503                 break;
 504         case STATE_DONE:
 505         case STATE_ERROR:
 506                 b->flags |= V4L2_BUF_FLAG_DONE;
 507                 break;
 508         case STATE_NEEDS_INIT:
 509         case STATE_IDLE:
 510                 /* nothing */
 511                 break;
 512         }
 513
 514         if (vb->input != UNSET) {
 515                 b->flags |= V4L2_BUF_FLAG_INPUT;
 516                 b->input  = vb->input;
 517         }
 518
 519         b->field     = vb->field;
 520         b->timestamp = vb->ts;
 521         b->bytesused = vb->size;
 522         b->sequence  = vb->field_count >> 1;
 523 }
 524
 525 int
 526 videobuf_reqbufs(struct videobuf_queue *q,
 527                  struct v4l2_requestbuffers *req)
 528 {
 529         unsigned int size,count;
 530         int retval;
 531
 532         if (req->type != q->type)
 533                 return -EINVAL;
 534         if (req->count < 1)
 535                 return -EINVAL;
 536         if (req->memory != V4L2_MEMORY_MMAP     &&
 537             req->memory != V4L2_MEMORY_USERPTR  &&
 538             req->memory != V4L2_MEMORY_OVERLAY)
 539                 return -EINVAL;
 540
 541         if (q->streaming)
 542                 return -EBUSY;
 543         if (!list_empty(&q->stream))
 544                 return -EBUSY;
 545
 546         down(&q->lock);
 547         count = req->count;
 548         if (count > VIDEO_MAX_FRAME)
 549                 count = VIDEO_MAX_FRAME;
 550         size = 0;
 551         q->ops->buf_setup(q,&count,&size);
 552         size = PAGE_ALIGN(size);
 553         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 554                 count, size, (count*size)>>PAGE_SHIFT);
 555
 556         retval = videobuf_mmap_setup(q,count,size,req->memory);
 557         if (retval < 0)
 558                 goto done;
 559
 560         req->count = count;
 561
 562  done:
 563         up(&q->lock);
 564         return retval;
 565 }
 566
 567 int
 568 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 569 {
 570         if (unlikely(b->type != q->type))
 571                 return -EINVAL;
 572         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 573                 return -EINVAL;
 574         if (unlikely(NULL == q->bufs[b->index]))
 575                 return -EINVAL;
 576         videobuf_status(b,q->bufs[b->index],q->type);
 577         return 0;
 578 }
 579
 580 int
 581 videobuf_qbuf(struct videobuf_queue *q,
 582               struct v4l2_buffer *b)
 583 {
 584         struct videobuf_buffer *buf;
 585         enum v4l2_field field;
 586         unsigned long flags;
 587         int retval;
 588
 589         down(&q->lock);
 590         retval = -EBUSY;
 591         if (q->reading)
 592                 goto done;
 593         retval = -EINVAL;
 594         if (b->type != q->type)
 595                 goto done;
 596         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 597                 goto done;
 598         buf = q->bufs[b->index];
 599         if (NULL == buf)
 600                 goto done;
 601         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 602         if (buf->memory != b->memory)
 603                 goto done;
 604         if (buf->state == STATE_QUEUED ||
 605             buf->state == STATE_ACTIVE)
 606                 goto done;
 607
 608         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 609                 if (b->input >= q->inputs)
 610                         goto done;
 611                 buf->input = b->input;
 612         } else {
 613                 buf->input = UNSET;
 614         }
 615
 616         switch (b->memory) {
 617         case V4L2_MEMORY_MMAP:
 618                 if (0 == buf->baddr)
 619                         goto done;
 620                 break;
 621         case V4L2_MEMORY_USERPTR:
 622                 if (b->length < buf->bsize)
 623                         goto done;
 624                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 625                         q->ops->buf_release(q,buf);
 626                 buf->baddr = b->m.userptr;
 627                 break;
 628         case V4L2_MEMORY_OVERLAY:
 629                 buf->boff = b->m.offset;
 630                 break;
 631         default:
 632                 goto done;
 633         }
 634
 635         field = videobuf_next_field(q);
 636         retval = q->ops->buf_prepare(q,buf,field);
 637         if (0 != retval)
 638                 goto done;
 639
 640         list_add_tail(&buf->stream,&q->stream);
 641         if (q->streaming) {
 642                 spin_lock_irqsave(q->irqlock,flags);
 643                 q->ops->buf_queue(q,buf);
 644                 spin_unlock_irqrestore(q->irqlock,flags);
 645         }
 646         retval = 0;
 647
 648  done:
 649         up(&q->lock);
 650         return retval;
 651 }
 652
 653 int
 654 videobuf_dqbuf(struct videobuf_queue *q,
 655                struct v4l2_buffer *b, int nonblocking)
 656 {
 657         struct videobuf_buffer *buf;
 658         int retval;
 659
 660         down(&q->lock);
 661         retval = -EBUSY;
 662         if (q->reading)
 663                 goto done;
 664         retval = -EINVAL;
 665         if (b->type != q->type)
 666                 goto done;
 667         if (list_empty(&q->stream))
 668                 goto done;
 669         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 670         retval = videobuf_waiton(buf, nonblocking, 1);
 671         if (retval < 0)
 672                 goto done;
 673         switch (buf->state) {
 674         case STATE_ERROR:
 675                 retval = -EIO;
 676                 /* fall through */
 677         case STATE_DONE:
 678                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 679                 buf->state = STATE_IDLE;
 680                 break;
 681         default:
 682                 retval = -EINVAL;
 683                 goto done;
 684         }
 685         list_del(&buf->stream);
 686         memset(b,0,sizeof(*b));
 687         videobuf_status(b,buf,q->type);
 688
 689  done:
 690         up(&q->lock);
 691         return retval;
 692 }
 693
 694 int videobuf_streamon(struct videobuf_queue *q)
 695 {
 696         struct videobuf_buffer *buf;
 697         struct list_head *list;
 698         unsigned long flags;
 699         int retval;
 700
 701         down(&q->lock);
 702         retval = -EBUSY;
 703         if (q->reading)
 704                 goto done;
 705         retval = 0;
 706         if (q->streaming)
 707                 goto done;
 708         q->streaming = 1;
 709         spin_lock_irqsave(q->irqlock,flags);
 710         list_for_each(list,&q->stream) {
 711                 buf = list_entry(list, struct videobuf_buffer, stream);
 712                 if (buf->state == STATE_PREPARED)
 713                         q->ops->buf_queue(q,buf);
 714         }
 715         spin_unlock_irqrestore(q->irqlock,flags);
 716
 717  done:
 718         up(&q->lock);
 719         return retval;
 720 }
 721
 722 int videobuf_streamoff(struct videobuf_queue *q)
 723 {
 724         int retval = -EINVAL;
 725
 726         down(&q->lock);
 727         if (!q->streaming)
 728                 goto done;
 729         videobuf_queue_cancel(q);
 730         q->streaming = 0;
 731         retval = 0;
 732
 733  done:
 734         up(&q->lock);
 735         return retval;
 736 }
 737
 738 static ssize_t
 739 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 740                        size_t count, loff_t *ppos)
 741 {
 742         enum v4l2_field field;
 743         unsigned long flags;
 744         int retval;
 745
 746         /* setup stuff */
 747         retval = -ENOMEM;
 748         q->read_buf = videobuf_alloc(q->msize);
 749         if (NULL == q->read_buf)
 750                 goto done;
 751
 752         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 753         q->read_buf->baddr  = (unsigned long)data;
 754         q->read_buf->bsize  = count;
 755         field = videobuf_next_field(q);
 756         retval = q->ops->buf_prepare(q,q->read_buf,field);
 757         if (0 != retval)
 758                 goto done;
 759
 760         /* start capture & wait */
 761         spin_lock_irqsave(q->irqlock,flags);
 762         q->ops->buf_queue(q,q->read_buf);
 763         spin_unlock_irqrestore(q->irqlock,flags);
 764         retval = videobuf_waiton(q->read_buf,0,0);
 765         if (0 == retval) {
 766                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 767                 if (STATE_ERROR == q->read_buf->state)
 768                         retval = -EIO;
 769                 else
 770                         retval = q->read_buf->size;
 771         }
 772
 773  done:
 774         /* cleanup */
 775         q->ops->buf_release(q,q->read_buf);
 776         kfree(q->read_buf);
 777         q->read_buf = NULL;
 778         return retval;
 779 }
 780
 781 ssize_t videobuf_read_one(struct videobuf_queue *q,
 782                           char __user *data, size_t count, loff_t *ppos,
 783                           int nonblocking)
 784 {
 785         enum v4l2_field field;
 786         unsigned long flags;
 787         unsigned size, nbufs, bytes;
 788         int retval;
 789
 790         down(&q->lock);
 791
 792         nbufs = 1; size = 0;
 793         q->ops->buf_setup(q,&nbufs,&size);
 794         if (NULL == q->read_buf  &&
 795             count >= size        &&
 796             !nonblocking) {
 797                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 798                 if (retval >= 0  ||  retval == -EIO)
 799                         /* ok, all done */
 800                         goto done;
 801                 /* fallback to kernel bounce buffer on failures */
 802         }
 803
 804         if (NULL == q->read_buf) {
 805                 /* need to capture a new frame */
 806                 retval = -ENOMEM;
 807                 q->read_buf = videobuf_alloc(q->msize);
 808                 if (NULL == q->read_buf)
 809                         goto done;
 810                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 811                 field = videobuf_next_field(q);
 812                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 813                 if (0 != retval)
 814                         goto done;
 815                 spin_lock_irqsave(q->irqlock,flags);
 816                 q->ops->buf_queue(q,q->read_buf);
 817                 spin_unlock_irqrestore(q->irqlock,flags);
 818                 q->read_off = 0;
 819         }
 820
 821         /* wait until capture is done */
 822         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 823         if (0 != retval)
 824                 goto done;
 825         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 826
 827         if (STATE_ERROR == q->read_buf->state) {
 828                 /* catch I/O errors */
 829                 q->ops->buf_release(q,q->read_buf);
 830                 kfree(q->read_buf);
 831                 q->read_buf = NULL;
 832                 retval = -EIO;
 833                 goto done;
 834         }
 835
 836         /* copy to userspace */
 837         bytes = count;
 838         if (bytes > q->read_buf->size - q->read_off)
 839                 bytes = q->read_buf->size - q->read_off;
 840         retval = -EFAULT;
 841         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 842                 goto done;
 843
 844         retval = bytes;
 845         q->read_off += bytes;
 846         if (q->read_off == q->read_buf->size) {
 847                 /* all data copied, cleanup */
 848                 q->ops->buf_release(q,q->read_buf);
 849                 kfree(q->read_buf);
 850                 q->read_buf = NULL;
 851         }
 852
 853  done:
 854         up(&q->lock);
 855         return retval;
 856 }
 857
 858 int videobuf_read_start(struct videobuf_queue *q)
 859 {
 860         enum v4l2_field field;
 861         unsigned long flags;
 862         int count = 0, size = 0;
 863         int err, i;
 864
 865         q->ops->buf_setup(q,&count,&size);
 866         if (count < 2)
 867                 count = 2;
 868         if (count > VIDEO_MAX_FRAME)
 869                 count = VIDEO_MAX_FRAME;
 870         size = PAGE_ALIGN(size);
 871
 872         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 873         if (err)
 874                 return err;
 875         for (i = 0; i < count; i++) {
 876                 field = videobuf_next_field(q);
 877                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 878                 if (err)
 879                         return err;
 880                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 881         }
 882         spin_lock_irqsave(q->irqlock,flags);
 883         for (i = 0; i < count; i++)
 884                 q->ops->buf_queue(q,q->bufs[i]);
 885         spin_unlock_irqrestore(q->irqlock,flags);
 886         q->reading = 1;
 887         return 0;
 888 }
 889
 890 void videobuf_read_stop(struct videobuf_queue *q)
 891 {
 892         int i;
 893
 894         videobuf_queue_cancel(q);
 895         INIT_LIST_HEAD(&q->stream);
 896         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 897                 if (NULL == q->bufs[i])
 898                         continue;
 899                 kfree(q->bufs[i]);
 900                 q->bufs[i] = NULL;
 901         }
 902         q->read_buf = NULL;
 903         q->reading  = 0;
 904 }
 905
 906 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 907                              char __user *data, size_t count, loff_t *ppos,
 908                              int vbihack, int nonblocking)
 909 {
 910         unsigned int *fc, bytes;
 911         int err, retval;
 912         unsigned long flags;
 913
 914         dprintk(2,"%s\n",__FUNCTION__);
 915         down(&q->lock);
 916         retval = -EBUSY;
 917         if (q->streaming)
 918                 goto done;
 919         if (!q->reading) {
 920                 retval = videobuf_read_start(q);
 921                 if (retval < 0)
 922                         goto done;
 923         }
 924
 925         retval = 0;
 926         while (count > 0) {
 927                 /* get / wait for data */
 928                 if (NULL == q->read_buf) {
 929                         q->read_buf = list_entry(q->stream.next,
 930                                                  struct videobuf_buffer,
 931                                                  stream);
 932                         list_del(&q->read_buf->stream);
 933                         q->read_off = 0;
 934                 }
 935                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
 936                 if (err < 0) {
 937                         if (0 == retval)
 938                                 retval = err;
 939                         break;
 940                 }
 941
 942                 if (q->read_buf->state == STATE_DONE) {
 943                         if (vbihack) {
 944                                 /* dirty, undocumented hack -- pass the frame counter
 945                                  * within the last four bytes of each vbi data block.
 946                                  * We need that one to maintain backward compatibility
 947                                  * to all vbi decoding software out there ... */
 948                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 949                                 fc += (q->read_buf->size>>2) -1;
 950                                 *fc = q->read_buf->field_count >> 1;
 951                                 dprintk(1,"vbihack: %d\n",*fc);
 952                         }
 953
 954                         /* copy stuff */
 955                         bytes = count;
 956                         if (bytes > q->read_buf->size - q->read_off)
 957                                 bytes = q->read_buf->size - q->read_off;
 958                         if (copy_to_user(data + retval,
 959                                          q->read_buf->dma.vmalloc + q->read_off,
 960                                          bytes)) {
 961                                 if (0 == retval)
 962                                         retval = -EFAULT;
 963                                 break;
 964                         }
 965                         count       -= bytes;
 966                         retval      += bytes;
 967                         q->read_off += bytes;
 968                 } else {
 969                         /* some error */
 970                         q->read_off = q->read_buf->size;
 971                         if (0 == retval)
 972                                 retval = -EIO;
 973                 }
 974
 975                 /* requeue buffer when done with copying */
 976                 if (q->read_off == q->read_buf->size) {
 977                         list_add_tail(&q->read_buf->stream,
 978                                       &q->stream);
 979                         spin_lock_irqsave(q->irqlock,flags);
 980                         q->ops->buf_queue(q,q->read_buf);
 981                         spin_unlock_irqrestore(q->irqlock,flags);
 982                         q->read_buf = NULL;
 983                 }
 984                 if (retval < 0)
 985                         break;
 986         }
 987
 988  done:
 989         up(&q->lock);
 990         return retval;
 991 }
 992
 993 unsigned int videobuf_poll_stream(struct file *file,
 994                                   struct videobuf_queue *q,
 995                                   poll_table *wait)
 996 {
 997         struct videobuf_buffer *buf = NULL;
 998         unsigned int rc = 0;
 999
1000         down(&q->lock);
1001         if (q->streaming) {
1002                 if (!list_empty(&q->stream))
1003                         buf = list_entry(q->stream.next,
1004                                          struct videobuf_buffer, stream);
1005         } else {
1006                 if (!q->reading)
1007                         videobuf_read_start(q);
1008                 if (!q->reading) {
1009                         rc = POLLERR;
1010                 } else if (NULL == q->read_buf) {
1011                         q->read_buf = list_entry(q->stream.next,
1012                                                  struct videobuf_buffer,
1013                                                  stream);
1014                         list_del(&q->read_buf->stream);
1015                         q->read_off = 0;
1016                 }
1017                 buf = q->read_buf;
1018         }
1019         if (!buf)
1020                 rc = POLLERR;
1021
1022         if (0 == rc) {
1023                 poll_wait(file, &buf->done, wait);
1024                 if (buf->state == STATE_DONE ||
1025                     buf->state == STATE_ERROR)
1026                         rc = POLLIN|POLLRDNORM;
1027         }
1028         up(&q->lock);
1029         return rc;
1030 }
1031
1032 /* --------------------------------------------------------------------- */
1033
1034 static void
1035 videobuf_vm_open(struct vm_area_struct *vma)
1036 {
1037         struct videobuf_mapping *map = vma->vm_private_data;
1038
1039         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1040                 map->count,vma->vm_start,vma->vm_end);
1041         map->count++;
1042 }
1043
1044 static void
1045 videobuf_vm_close(struct vm_area_struct *vma)
1046 {
1047         struct videobuf_mapping *map = vma->vm_private_data;
1048         struct videobuf_queue *q = map->q;
1049         int i;
1050
1051         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1052                 map->count,vma->vm_start,vma->vm_end);
1053
1054         map->count--;
1055         if (0 == map->count) {
1056                 dprintk(1,"munmap %p q=%p\n",map,q);
1057                 down(&q->lock);
1058                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1059                         if (NULL == q->bufs[i])
1060                                 continue;
1061                         if (q->bufs[i])
1062                                 ;
1063                         if (q->bufs[i]->map != map)
1064                                 continue;
1065                         q->bufs[i]->map   = NULL;
1066                         q->bufs[i]->baddr = 0;
1067                         q->ops->buf_release(q,q->bufs[i]);
1068                 }
1069                 up(&q->lock);
1070                 kfree(map);
1071         }
1072         return;
1073 }
1074
1075 /*
1076  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1077  * memory location with 32bit PCI devices (i.e. don't use highmem for
1078  * now ...).  Bounce buffers don't work very well for the data rates
1079  * video capture has.
1080  */
1081 static struct page*
1082 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1083                    int *type)
1084 {
1085         struct page *page;
1086
1087         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1088                 vaddr,vma->vm_start,vma->vm_end);
1089         if (vaddr > vma->vm_end)
1090                 return NOPAGE_SIGBUS;
1091         page = alloc_page(GFP_USER);
1092         if (!page)
1093                 return NOPAGE_OOM;
1094         clear_user_page(page_address(page), vaddr, page);
1095         if (type)
1096                 *type = VM_FAULT_MINOR;
1097         return page;
1098 }
1099
1100 static struct vm_operations_struct videobuf_vm_ops =
1101 {
1102         .open     = videobuf_vm_open,
1103         .close    = videobuf_vm_close,
1104         .nopage   = videobuf_vm_nopage,
1105 };
1106
1107 int videobuf_mmap_setup(struct videobuf_queue *q,
1108                         unsigned int bcount, unsigned int bsize,
1109                         enum v4l2_memory memory)
1110 {
1111         unsigned int i;
1112         int err;
1113
1114         err = videobuf_mmap_free(q);
1115         if (0 != err)
1116                 return err;
1117
1118         for (i = 0; i < bcount; i++) {
1119                 q->bufs[i] = videobuf_alloc(q->msize);
1120                 q->bufs[i]->i      = i;
1121                 q->bufs[i]->input  = UNSET;
1122                 q->bufs[i]->memory = memory;
1123                 q->bufs[i]->bsize  = bsize;
1124                 switch (memory) {
1125                 case V4L2_MEMORY_MMAP:
1126                         q->bufs[i]->boff  = bsize * i;
1127                         break;
1128                 case V4L2_MEMORY_USERPTR:
1129                 case V4L2_MEMORY_OVERLAY:
1130                         /* nothing */
1131                         break;
1132                 }
1133         }
1134         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1135                 bcount,bsize);
1136         return 0;
1137 }
1138
1139 int videobuf_mmap_free(struct videobuf_queue *q)
1140 {
1141         int i;
1142
1143         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1144                 if (q->bufs[i] && q->bufs[i]->map)
1145                         return -EBUSY;
1146         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1147                 if (NULL == q->bufs[i])
1148                         continue;
1149                 q->ops->buf_release(q,q->bufs[i]);
1150                 kfree(q->bufs[i]);
1151                 q->bufs[i] = NULL;
1152         }
1153         return 0;
1154 }
1155
1156 int videobuf_mmap_mapper(struct videobuf_queue *q,
1157                          struct vm_area_struct *vma)
1158 {
1159         struct videobuf_mapping *map;
1160         unsigned int first,last,size,i;
1161         int retval;
1162
1163         down(&q->lock);
1164         retval = -EINVAL;
1165         if (!(vma->vm_flags & VM_WRITE)) {
1166                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1167                 goto done;
1168         }
1169         if (!(vma->vm_flags & VM_SHARED)) {
1170                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1171                 goto done;
1172         }
1173
1174         /* look for first buffer to map */
1175         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1176                 if (NULL == q->bufs[first])
1177                         continue;
1178                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1179                         continue;
1180                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1181                         break;
1182         }
1183         if (VIDEO_MAX_FRAME == first) {
1184                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1185                         (vma->vm_pgoff << PAGE_SHIFT));
1186                 goto done;
1187         }
1188
1189         /* look for last buffer to map */
1190         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1191                 if (NULL == q->bufs[last])
1192                         continue;
1193                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1194                         continue;
1195                 if (q->bufs[last]->map) {
1196                         retval = -EBUSY;
1197                         goto done;
1198                 }
1199                 size += q->bufs[last]->bsize;
1200                 if (size == (vma->vm_end - vma->vm_start))
1201                         break;
1202         }
1203         if (VIDEO_MAX_FRAME == last) {
1204                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1205                         (vma->vm_end - vma->vm_start));
1206                 goto done;
1207         }
1208
1209         /* create mapping + update buffer list */
1210         retval = -ENOMEM;
1211         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1212         if (NULL == map)
1213                 goto done;
1214         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1215                 q->bufs[i]->map   = map;
1216                 q->bufs[i]->baddr = vma->vm_start + size;
1217         }
1218         map->count    = 1;
1219         map->start    = vma->vm_start;
1220         map->end      = vma->vm_end;
1221         map->q        = q;
1222         vma->vm_ops   = &videobuf_vm_ops;
1223         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1224         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1225         vma->vm_private_data = map;
1226         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1227                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1228         retval = 0;
1229
1230  done:
1231         up(&q->lock);
1232         return retval;
1233 }
1234
1235 /* --------------------------------------------------------------------- */
1236
1237 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1238
1239 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1240 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1241 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1242 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1243 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1244 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1245 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1246 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1247
1248 EXPORT_SYMBOL_GPL(videobuf_alloc);
1249 EXPORT_SYMBOL_GPL(videobuf_waiton);
1250 EXPORT_SYMBOL_GPL(videobuf_iolock);
1251
1252 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1253 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1254 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1255
1256 EXPORT_SYMBOL_GPL(videobuf_next_field);
1257 EXPORT_SYMBOL_GPL(videobuf_status);
1258 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1259 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1260 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1261 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1262 EXPORT_SYMBOL_GPL(videobuf_streamon);
1263 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1264
1265 EXPORT_SYMBOL_GPL(videobuf_read_start);
1266 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1267 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1268 EXPORT_SYMBOL_GPL(videobuf_read_one);
1269 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1270
1271 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1272 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1273 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1274
1275 /*
1276  * Local variables:
1277  * c-basic-offset: 8
1278  * End:
1279  */