drivers/media/video/video-buf.c

   1 /*
   2  * $Id: video-buf.c,v 1.17 2004/12/10 12:33:40 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/moduleparam.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/slab.h>
  27 #include <linux/pci.h>
  28 #include <linux/interrupt.h>
  29 #include <asm/page.h>
  30 #include <asm/pgtable.h>
  31
  32 #include <media/video-buf.h>
  33
  34 #define MAGIC_DMABUF 0x19721112
  35 #define MAGIC_BUFFER 0x20040302
  36 #define MAGIC_CHECK(is,should)  if (unlikely((is) != (should))) \
  37         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
  38
  39 static int debug = 0;
  40 module_param(debug, int, 0644);
  41
  42 MODULE_DESCRIPTION("helper module to manage video4linux pci dma buffers");
  43 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  44 MODULE_LICENSE("GPL");
  45
  46 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  47         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  48
  49 struct scatterlist*
  50 videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
  51 {
  52         struct scatterlist *sglist;
  53         struct page *pg;
  54         int i;
  55
  56         sglist = kmalloc(sizeof(struct scatterlist)*nr_pages, GFP_KERNEL);
  57         if (NULL == sglist)
  58                 return NULL;
  59         memset(sglist,0,sizeof(struct scatterlist)*nr_pages);
  60         for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
  61                 pg = vmalloc_to_page(virt);
  62                 if (NULL == pg)
  63                         goto err;
  64                 if (PageHighMem(pg))
  65                         BUG();
  66                 sglist[i].page   = pg;
  67                 sglist[i].length = PAGE_SIZE;
  68         }
  69         return sglist;
  70
  71  err:
  72         kfree(sglist);
  73         return NULL;
  74 }
  75
  76 struct scatterlist*
  77 videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
  78 {
  79         struct scatterlist *sglist;
  80         int i = 0;
  81
  82         if (NULL == pages[0])
  83                 return NULL;
  84         sglist = kmalloc(sizeof(*sglist) * nr_pages, GFP_KERNEL);
  85         if (NULL == sglist)
  86                 return NULL;
  87         memset(sglist, 0, sizeof(*sglist) * nr_pages);
  88
  89         if (NULL == pages[0])
  90                 goto nopage;
  91         if (PageHighMem(pages[0]))
  92                 /* DMA to highmem pages might not work */
  93                 goto highmem;
  94         sglist[0].page   = pages[0];
  95         sglist[0].offset = offset;
  96         sglist[0].length = PAGE_SIZE - offset;
  97         for (i = 1; i < nr_pages; i++) {
  98                 if (NULL == pages[i])
  99                         goto nopage;
 100                 if (PageHighMem(pages[i]))
 101                         goto highmem;
 102                 sglist[i].page   = pages[i];
 103                 sglist[i].length = PAGE_SIZE;
 104         }
 105         return sglist;
 106
 107  nopage:
 108         dprintk(2,"sgl: oops - no page\n");
 109         kfree(sglist);
 110         return NULL;
 111
 112  highmem:
 113         dprintk(2,"sgl: oops - highmem page\n");
 114         kfree(sglist);
 115         return NULL;
 116 }
 117
 118 /* --------------------------------------------------------------------- */
 119
 120 void videobuf_dma_init(struct videobuf_dmabuf *dma)
 121 {
 122         memset(dma,0,sizeof(*dma));
 123         dma->magic = MAGIC_DMABUF;
 124 }
 125
 126 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 127                            unsigned long data, unsigned long size)
 128 {
 129         unsigned long first,last;
 130         int err, rw = 0;
 131
 132         dma->direction = direction;
 133         switch (dma->direction) {
 134         case PCI_DMA_FROMDEVICE: rw = READ;  break;
 135         case PCI_DMA_TODEVICE:   rw = WRITE; break;
 136         default:                 BUG();
 137         }
 138
 139         first = (data          & PAGE_MASK) >> PAGE_SHIFT;
 140         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
 141         dma->offset   = data & ~PAGE_MASK;
 142         dma->nr_pages = last-first+1;
 143         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
 144                              GFP_KERNEL);
 145         if (NULL == dma->pages)
 146                 return -ENOMEM;
 147         dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
 148                 data,size,dma->nr_pages);
 149
 150         down_read(&current->mm->mmap_sem);
 151         err = get_user_pages(current,current->mm,
 152                              data & PAGE_MASK, dma->nr_pages,
 153                              rw == READ, 1, /* force */
 154                              dma->pages, NULL);
 155         up_read(&current->mm->mmap_sem);
 156         if (err != dma->nr_pages) {
 157                 dma->nr_pages = (err >= 0) ? err : 0;
 158                 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
 159                 return err < 0 ? err : -EINVAL;
 160         }
 161         return 0;
 162 }
 163
 164 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
 165                              int nr_pages)
 166 {
 167         dprintk(1,"init kernel [%d pages]\n",nr_pages);
 168         dma->direction = direction;
 169         dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
 170         if (NULL == dma->vmalloc) {
 171                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
 172                 return -ENOMEM;
 173         }
 174         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
 175         dma->nr_pages = nr_pages;
 176         return 0;
 177 }
 178
 179 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
 180                               dma_addr_t addr, int nr_pages)
 181 {
 182         dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
 183                 nr_pages,(unsigned long)addr);
 184         dma->direction = direction;
 185         if (0 == addr)
 186                 return -EINVAL;
 187
 188         dma->bus_addr = addr;
 189         dma->nr_pages = nr_pages;
 190         return 0;
 191 }
 192
 193 int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 194 {
 195         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 196         BUG_ON(0 == dma->nr_pages);
 197
 198         if (dma->pages) {
 199                 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
 200                                                    dma->offset);
 201         }
 202         if (dma->vmalloc) {
 203                 dma->sglist = videobuf_vmalloc_to_sg
 204                         (dma->vmalloc,dma->nr_pages);
 205         }
 206         if (dma->bus_addr) {
 207                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
 208                 if (NULL != dma->sglist) {
 209                         dma->sglen  = 1;
 210                         sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
 211                         dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
 212                         sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
 213                 }
 214         }
 215         if (NULL == dma->sglist) {
 216                 dprintk(1,"scatterlist is NULL\n");
 217                 return -ENOMEM;
 218         }
 219
 220         if (!dma->bus_addr)
 221                 dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
 222                                         dma->direction);
 223         return 0;
 224 }
 225
 226 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 227 {
 228         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 229         BUG_ON(!dma->sglen);
 230
 231         if (!dma->bus_addr)
 232                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 233         return 0;
 234 }
 235
 236 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 237 {
 238         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 239         if (!dma->sglen)
 240                 return 0;
 241
 242         if (!dma->bus_addr)
 243                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 244         kfree(dma->sglist);
 245         dma->sglist = NULL;
 246         dma->sglen = 0;
 247         return 0;
 248 }
 249
 250 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 251 {
 252         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 253         BUG_ON(dma->sglen);
 254
 255         if (dma->pages) {
 256                 int i;
 257                 for (i=0; i < dma->nr_pages; i++)
 258                         page_cache_release(dma->pages[i]);
 259                 kfree(dma->pages);
 260                 dma->pages = NULL;
 261         }
 262         if (dma->vmalloc) {
 263                 vfree(dma->vmalloc);
 264                 dma->vmalloc = NULL;
 265         }
 266         if (dma->bus_addr) {
 267                 dma->bus_addr = 0;
 268         }
 269         dma->direction = PCI_DMA_NONE;
 270         return 0;
 271 }
 272
 273 /* --------------------------------------------------------------------- */
 274
 275 void* videobuf_alloc(unsigned int size)
 276 {
 277         struct videobuf_buffer *vb;
 278
 279         vb = kmalloc(size,GFP_KERNEL);
 280         if (NULL != vb) {
 281                 memset(vb,0,size);
 282                 videobuf_dma_init(&vb->dma);
 283                 init_waitqueue_head(&vb->done);
 284                 vb->magic     = MAGIC_BUFFER;
 285         }
 286         return vb;
 287 }
 288
 289 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 290 {
 291         int retval = 0;
 292         DECLARE_WAITQUEUE(wait, current);
 293
 294         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 295         add_wait_queue(&vb->done, &wait);
 296         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 297                 if (non_blocking) {
 298                         retval = -EAGAIN;
 299                         break;
 300                 }
 301                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 302                                         : TASK_UNINTERRUPTIBLE);
 303                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 304                         schedule();
 305                 set_current_state(TASK_RUNNING);
 306                 if (intr && signal_pending(current)) {
 307                         dprintk(1,"buffer waiton: -EINTR\n");
 308                         retval = -EINTR;
 309                         break;
 310                 }
 311         }
 312         remove_wait_queue(&vb->done, &wait);
 313         return retval;
 314 }
 315
 316 int
 317 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 318                 struct v4l2_framebuffer *fbuf)
 319 {
 320         int err,pages;
 321         dma_addr_t bus;
 322
 323         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 324         switch (vb->memory) {
 325         case V4L2_MEMORY_MMAP:
 326         case V4L2_MEMORY_USERPTR:
 327                 if (0 == vb->baddr) {
 328                         /* no userspace addr -- kernel bounce buffer */
 329                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 330                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 331                                                        pages);
 332                         if (0 != err)
 333                                 return err;
 334                 } else {
 335                         /* dma directly to userspace */
 336                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 337                                                      vb->baddr,vb->bsize);
 338                         if (0 != err)
 339                                 return err;
 340                 }
 341                 break;
 342         case V4L2_MEMORY_OVERLAY:
 343                 if (NULL == fbuf)
 344                         return -EINVAL;
 345                 /* FIXME: need sanity checks for vb->boff */
 346                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 347                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 348                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 349                                                 bus, pages);
 350                 if (0 != err)
 351                         return err;
 352                 break;
 353         default:
 354                 BUG();
 355         }
 356         err = videobuf_dma_pci_map(pci,&vb->dma);
 357         if (0 != err)
 358                 return err;
 359
 360         return 0;
 361 }
 362
 363 /* --------------------------------------------------------------------- */
 364
 365 void videobuf_queue_init(struct videobuf_queue* q,
 366                          struct videobuf_queue_ops *ops,
 367                          struct pci_dev *pci,
 368                          spinlock_t *irqlock,
 369                          enum v4l2_buf_type type,
 370                          enum v4l2_field field,
 371                          unsigned int msize,
 372                          void *priv)
 373 {
 374         memset(q,0,sizeof(*q));
 375         q->irqlock = irqlock;
 376         q->pci     = pci;
 377         q->type    = type;
 378         q->field   = field;
 379         q->msize   = msize;
 380         q->ops     = ops;
 381         q->priv_data = priv;
 382
 383         init_MUTEX(&q->lock);
 384         INIT_LIST_HEAD(&q->stream);
 385 }
 386
 387 int
 388 videobuf_queue_is_busy(struct videobuf_queue *q)
 389 {
 390         int i;
 391
 392         if (q->streaming) {
 393                 dprintk(1,"busy: streaming active\n");
 394                 return 1;
 395         }
 396         if (q->reading) {
 397                 dprintk(1,"busy: pending read #1\n");
 398                 return 1;
 399         }
 400         if (q->read_buf) {
 401                 dprintk(1,"busy: pending read #2\n");
 402                 return 1;
 403         }
 404         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 405                 if (NULL == q->bufs[i])
 406                         continue;
 407                 if (q->bufs[i]->map) {
 408                         dprintk(1,"busy: buffer #%d mapped\n",i);
 409                         return 1;
 410                 }
 411                 if (q->bufs[i]->state == STATE_QUEUED) {
 412                         dprintk(1,"busy: buffer #%d queued\n",i);
 413                         return 1;
 414                 }
 415                 if (q->bufs[i]->state == STATE_ACTIVE) {
 416                         dprintk(1,"busy: buffer #%d avtive\n",i);
 417                         return 1;
 418                 }
 419         }
 420         return 0;
 421 }
 422
 423 void
 424 videobuf_queue_cancel(struct videobuf_queue *q)
 425 {
 426         unsigned long flags;
 427         int i;
 428
 429         /* remove queued buffers from list */
 430         spin_lock_irqsave(q->irqlock,flags);
 431         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 432                 if (NULL == q->bufs[i])
 433                         continue;
 434                 if (q->bufs[i]->state == STATE_QUEUED) {
 435                         list_del(&q->bufs[i]->queue);
 436                         q->bufs[i]->state = STATE_ERROR;
 437                 }
 438         }
 439         spin_unlock_irqrestore(q->irqlock,flags);
 440
 441         /* free all buffers + clear queue */
 442         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 443                 if (NULL == q->bufs[i])
 444                         continue;
 445                 q->ops->buf_release(q,q->bufs[i]);
 446         }
 447         INIT_LIST_HEAD(&q->stream);
 448 }
 449
 450 /* --------------------------------------------------------------------- */
 451
 452 enum v4l2_field
 453 videobuf_next_field(struct videobuf_queue *q)
 454 {
 455         enum v4l2_field field = q->field;
 456
 457         BUG_ON(V4L2_FIELD_ANY == field);
 458
 459         if (V4L2_FIELD_ALTERNATE == field) {
 460                 if (V4L2_FIELD_TOP == q->last) {
 461                         field   = V4L2_FIELD_BOTTOM;
 462                         q->last = V4L2_FIELD_BOTTOM;
 463                 } else {
 464                         field   = V4L2_FIELD_TOP;
 465                         q->last = V4L2_FIELD_TOP;
 466                 }
 467         }
 468         return field;
 469 }
 470
 471 void
 472 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 473                 enum v4l2_buf_type type)
 474 {
 475         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 476
 477         b->index    = vb->i;
 478         b->type     = type;
 479
 480         b->memory   = vb->memory;
 481         switch (b->memory) {
 482         case V4L2_MEMORY_MMAP:
 483                 b->m.offset  = vb->boff;
 484                 b->length    = vb->bsize;
 485                 break;
 486         case V4L2_MEMORY_USERPTR:
 487                 b->m.userptr = vb->baddr;
 488                 b->length    = vb->bsize;
 489                 break;
 490         case V4L2_MEMORY_OVERLAY:
 491                 b->m.offset  = vb->boff;
 492                 break;
 493         }
 494
 495         b->flags    = 0;
 496         if (vb->map)
 497                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 498
 499         switch (vb->state) {
 500         case STATE_PREPARED:
 501         case STATE_QUEUED:
 502         case STATE_ACTIVE:
 503                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 504                 break;
 505         case STATE_DONE:
 506         case STATE_ERROR:
 507                 b->flags |= V4L2_BUF_FLAG_DONE;
 508                 break;
 509         case STATE_NEEDS_INIT:
 510         case STATE_IDLE:
 511                 /* nothing */
 512                 break;
 513         }
 514
 515         if (vb->input != UNSET) {
 516                 b->flags |= V4L2_BUF_FLAG_INPUT;
 517                 b->input  = vb->input;
 518         }
 519
 520         b->field     = vb->field;
 521         b->timestamp = vb->ts;
 522         b->bytesused = vb->size;
 523         b->sequence  = vb->field_count >> 1;
 524 }
 525
 526 int
 527 videobuf_reqbufs(struct videobuf_queue *q,
 528                  struct v4l2_requestbuffers *req)
 529 {
 530         unsigned int size,count;
 531         int retval;
 532
 533         if (req->type != q->type)
 534                 return -EINVAL;
 535         if (req->count < 1)
 536                 return -EINVAL;
 537         if (req->memory != V4L2_MEMORY_MMAP     &&
 538             req->memory != V4L2_MEMORY_USERPTR  &&
 539             req->memory != V4L2_MEMORY_OVERLAY)
 540                 return -EINVAL;
 541
 542         if (q->streaming)
 543                 return -EBUSY;
 544         if (!list_empty(&q->stream))
 545                 return -EBUSY;
 546
 547         down(&q->lock);
 548         count = req->count;
 549         if (count > VIDEO_MAX_FRAME)
 550                 count = VIDEO_MAX_FRAME;
 551         size = 0;
 552         q->ops->buf_setup(q,&count,&size);
 553         size = PAGE_ALIGN(size);
 554         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 555                 count, size, (count*size)>>PAGE_SHIFT);
 556
 557         retval = videobuf_mmap_setup(q,count,size,req->memory);
 558         if (retval < 0)
 559                 goto done;
 560
 561         req->count = count;
 562
 563  done:
 564         up(&q->lock);
 565         return retval;
 566 }
 567
 568 int
 569 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 570 {
 571         if (unlikely(b->type != q->type))
 572                 return -EINVAL;
 573         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 574                 return -EINVAL;
 575         if (unlikely(NULL == q->bufs[b->index]))
 576                 return -EINVAL;
 577         videobuf_status(b,q->bufs[b->index],q->type);
 578         return 0;
 579 }
 580
 581 int
 582 videobuf_qbuf(struct videobuf_queue *q,
 583               struct v4l2_buffer *b)
 584 {
 585         struct videobuf_buffer *buf;
 586         enum v4l2_field field;
 587         unsigned long flags;
 588         int retval;
 589
 590         down(&q->lock);
 591         retval = -EBUSY;
 592         if (q->reading)
 593                 goto done;
 594         retval = -EINVAL;
 595         if (b->type != q->type)
 596                 goto done;
 597         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 598                 goto done;
 599         buf = q->bufs[b->index];
 600         if (NULL == buf)
 601                 goto done;
 602         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 603         if (buf->memory != b->memory)
 604                 goto done;
 605         if (buf->state == STATE_QUEUED ||
 606             buf->state == STATE_ACTIVE)
 607                 goto done;
 608
 609         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 610                 if (b->input >= q->inputs)
 611                         goto done;
 612                 buf->input = b->input;
 613         } else {
 614                 buf->input = UNSET;
 615         }
 616
 617         switch (b->memory) {
 618         case V4L2_MEMORY_MMAP:
 619                 if (0 == buf->baddr)
 620                         goto done;
 621                 break;
 622         case V4L2_MEMORY_USERPTR:
 623                 if (b->length < buf->bsize)
 624                         goto done;
 625                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 626                         q->ops->buf_release(q,buf);
 627                 buf->baddr = b->m.userptr;
 628                 break;
 629         case V4L2_MEMORY_OVERLAY:
 630                 buf->boff = b->m.offset;
 631                 break;
 632         default:
 633                 goto done;
 634         }
 635
 636         field = videobuf_next_field(q);
 637         retval = q->ops->buf_prepare(q,buf,field);
 638         if (0 != retval)
 639                 goto done;
 640
 641         list_add_tail(&buf->stream,&q->stream);
 642         if (q->streaming) {
 643                 spin_lock_irqsave(q->irqlock,flags);
 644                 q->ops->buf_queue(q,buf);
 645                 spin_unlock_irqrestore(q->irqlock,flags);
 646         }
 647         retval = 0;
 648
 649  done:
 650         up(&q->lock);
 651         return retval;
 652 }
 653
 654 int
 655 videobuf_dqbuf(struct videobuf_queue *q,
 656                struct v4l2_buffer *b, int nonblocking)
 657 {
 658         struct videobuf_buffer *buf;
 659         int retval;
 660
 661         down(&q->lock);
 662         retval = -EBUSY;
 663         if (q->reading)
 664                 goto done;
 665         retval = -EINVAL;
 666         if (b->type != q->type)
 667                 goto done;
 668         if (list_empty(&q->stream))
 669                 goto done;
 670         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 671         retval = videobuf_waiton(buf, nonblocking, 1);
 672         if (retval < 0)
 673                 goto done;
 674         switch (buf->state) {
 675         case STATE_ERROR:
 676                 retval = -EIO;
 677                 /* fall through */
 678         case STATE_DONE:
 679                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 680                 buf->state = STATE_IDLE;
 681                 break;
 682         default:
 683                 retval = -EINVAL;
 684                 goto done;
 685         }
 686         list_del(&buf->stream);
 687         memset(b,0,sizeof(*b));
 688         videobuf_status(b,buf,q->type);
 689
 690  done:
 691         up(&q->lock);
 692         return retval;
 693 }
 694
 695 int videobuf_streamon(struct videobuf_queue *q)
 696 {
 697         struct videobuf_buffer *buf;
 698         struct list_head *list;
 699         unsigned long flags;
 700         int retval;
 701
 702         down(&q->lock);
 703         retval = -EBUSY;
 704         if (q->reading)
 705                 goto done;
 706         retval = 0;
 707         if (q->streaming)
 708                 goto done;
 709         q->streaming = 1;
 710         spin_lock_irqsave(q->irqlock,flags);
 711         list_for_each(list,&q->stream) {
 712                 buf = list_entry(list, struct videobuf_buffer, stream);
 713                 if (buf->state == STATE_PREPARED)
 714                         q->ops->buf_queue(q,buf);
 715         }
 716         spin_unlock_irqrestore(q->irqlock,flags);
 717
 718  done:
 719         up(&q->lock);
 720         return retval;
 721 }
 722
 723 int videobuf_streamoff(struct videobuf_queue *q)
 724 {
 725         int retval = -EINVAL;
 726
 727         down(&q->lock);
 728         if (!q->streaming)
 729                 goto done;
 730         videobuf_queue_cancel(q);
 731         q->streaming = 0;
 732         retval = 0;
 733
 734  done:
 735         up(&q->lock);
 736         return retval;
 737 }
 738
 739 static ssize_t
 740 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 741                        size_t count, loff_t *ppos)
 742 {
 743         enum v4l2_field field;
 744         unsigned long flags;
 745         int retval;
 746
 747         /* setup stuff */
 748         retval = -ENOMEM;
 749         q->read_buf = videobuf_alloc(q->msize);
 750         if (NULL == q->read_buf)
 751                 goto done;
 752
 753         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 754         q->read_buf->baddr  = (unsigned long)data;
 755         q->read_buf->bsize  = count;
 756         field = videobuf_next_field(q);
 757         retval = q->ops->buf_prepare(q,q->read_buf,field);
 758         if (0 != retval)
 759                 goto done;
 760
 761         /* start capture & wait */
 762         spin_lock_irqsave(q->irqlock,flags);
 763         q->ops->buf_queue(q,q->read_buf);
 764         spin_unlock_irqrestore(q->irqlock,flags);
 765         retval = videobuf_waiton(q->read_buf,0,0);
 766         if (0 == retval) {
 767                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 768                 if (STATE_ERROR == q->read_buf->state)
 769                         retval = -EIO;
 770                 else
 771                         retval = q->read_buf->size;
 772         }
 773
 774  done:
 775         /* cleanup */
 776         q->ops->buf_release(q,q->read_buf);
 777         kfree(q->read_buf);
 778         q->read_buf = NULL;
 779         return retval;
 780 }
 781
 782 ssize_t videobuf_read_one(struct videobuf_queue *q,
 783                           char __user *data, size_t count, loff_t *ppos,
 784                           int nonblocking)
 785 {
 786         enum v4l2_field field;
 787         unsigned long flags;
 788         unsigned size, nbufs, bytes;
 789         int retval;
 790
 791         down(&q->lock);
 792
 793         nbufs = 1; size = 0;
 794         q->ops->buf_setup(q,&nbufs,&size);
 795         if (NULL == q->read_buf  &&
 796             count >= size        &&
 797             !nonblocking) {
 798                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 799                 if (retval >= 0  ||  retval == -EIO)
 800                         /* ok, all done */
 801                         goto done;
 802                 /* fallback to kernel bounce buffer on failures */
 803         }
 804
 805         if (NULL == q->read_buf) {
 806                 /* need to capture a new frame */
 807                 retval = -ENOMEM;
 808                 q->read_buf = videobuf_alloc(q->msize);
 809                 if (NULL == q->read_buf)
 810                         goto done;
 811                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 812                 field = videobuf_next_field(q);
 813                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 814                 if (0 != retval)
 815                         goto done;
 816                 spin_lock_irqsave(q->irqlock,flags);
 817                 q->ops->buf_queue(q,q->read_buf);
 818                 spin_unlock_irqrestore(q->irqlock,flags);
 819                 q->read_off = 0;
 820         }
 821
 822         /* wait until capture is done */
 823         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 824         if (0 != retval)
 825                 goto done;
 826         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 827
 828         if (STATE_ERROR == q->read_buf->state) {
 829                 /* catch I/O errors */
 830                 q->ops->buf_release(q,q->read_buf);
 831                 kfree(q->read_buf);
 832                 q->read_buf = NULL;
 833                 retval = -EIO;
 834                 goto done;
 835         }
 836
 837         /* copy to userspace */
 838         bytes = count;
 839         if (bytes > q->read_buf->size - q->read_off)
 840                 bytes = q->read_buf->size - q->read_off;
 841         retval = -EFAULT;
 842         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 843                 goto done;
 844
 845         retval = bytes;
 846         q->read_off += bytes;
 847         if (q->read_off == q->read_buf->size) {
 848                 /* all data copied, cleanup */
 849                 q->ops->buf_release(q,q->read_buf);
 850                 kfree(q->read_buf);
 851                 q->read_buf = NULL;
 852         }
 853
 854  done:
 855         up(&q->lock);
 856         return retval;
 857 }
 858
 859 int videobuf_read_start(struct videobuf_queue *q)
 860 {
 861         enum v4l2_field field;
 862         unsigned long flags;
 863         int count = 0, size = 0;
 864         int err, i;
 865
 866         q->ops->buf_setup(q,&count,&size);
 867         if (count < 2)
 868                 count = 2;
 869         if (count > VIDEO_MAX_FRAME)
 870                 count = VIDEO_MAX_FRAME;
 871         size = PAGE_ALIGN(size);
 872
 873         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 874         if (err)
 875                 return err;
 876         for (i = 0; i < count; i++) {
 877                 field = videobuf_next_field(q);
 878                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 879                 if (err)
 880                         return err;
 881                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 882         }
 883         spin_lock_irqsave(q->irqlock,flags);
 884         for (i = 0; i < count; i++)
 885                 q->ops->buf_queue(q,q->bufs[i]);
 886         spin_unlock_irqrestore(q->irqlock,flags);
 887         q->reading = 1;
 888         return 0;
 889 }
 890
 891 void videobuf_read_stop(struct videobuf_queue *q)
 892 {
 893         int i;
 894
 895         videobuf_queue_cancel(q);
 896         videobuf_mmap_free(q);
 897         INIT_LIST_HEAD(&q->stream);
 898         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 899                 if (NULL == q->bufs[i])
 900                         continue;
 901                 kfree(q->bufs[i]);
 902                 q->bufs[i] = NULL;
 903         }
 904         q->read_buf = NULL;
 905         q->reading  = 0;
 906 }
 907
 908 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 909                              char __user *data, size_t count, loff_t *ppos,
 910                              int vbihack, int nonblocking)
 911 {
 912         unsigned int *fc, bytes;
 913         int err, retval;
 914         unsigned long flags;
 915
 916         dprintk(2,"%s\n",__FUNCTION__);
 917         down(&q->lock);
 918         retval = -EBUSY;
 919         if (q->streaming)
 920                 goto done;
 921         if (!q->reading) {
 922                 retval = videobuf_read_start(q);
 923                 if (retval < 0)
 924                         goto done;
 925         }
 926
 927         retval = 0;
 928         while (count > 0) {
 929                 /* get / wait for data */
 930                 if (NULL == q->read_buf) {
 931                         q->read_buf = list_entry(q->stream.next,
 932                                                  struct videobuf_buffer,
 933                                                  stream);
 934                         list_del(&q->read_buf->stream);
 935                         q->read_off = 0;
 936                 }
 937                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
 938                 if (err < 0) {
 939                         if (0 == retval)
 940                                 retval = err;
 941                         break;
 942                 }
 943
 944                 if (q->read_buf->state == STATE_DONE) {
 945                         if (vbihack) {
 946                                 /* dirty, undocumented hack -- pass the frame counter
 947                                  * within the last four bytes of each vbi data block.
 948                                  * We need that one to maintain backward compatibility
 949                                  * to all vbi decoding software out there ... */
 950                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 951                                 fc += (q->read_buf->size>>2) -1;
 952                                 *fc = q->read_buf->field_count >> 1;
 953                                 dprintk(1,"vbihack: %d\n",*fc);
 954                         }
 955
 956                         /* copy stuff */
 957                         bytes = count;
 958                         if (bytes > q->read_buf->size - q->read_off)
 959                                 bytes = q->read_buf->size - q->read_off;
 960                         if (copy_to_user(data + retval,
 961                                          q->read_buf->dma.vmalloc + q->read_off,
 962                                          bytes)) {
 963                                 if (0 == retval)
 964                                         retval = -EFAULT;
 965                                 break;
 966                         }
 967                         count       -= bytes;
 968                         retval      += bytes;
 969                         q->read_off += bytes;
 970                 } else {
 971                         /* some error */
 972                         q->read_off = q->read_buf->size;
 973                         if (0 == retval)
 974                                 retval = -EIO;
 975                 }
 976
 977                 /* requeue buffer when done with copying */
 978                 if (q->read_off == q->read_buf->size) {
 979                         list_add_tail(&q->read_buf->stream,
 980                                       &q->stream);
 981                         spin_lock_irqsave(q->irqlock,flags);
 982                         q->ops->buf_queue(q,q->read_buf);
 983                         spin_unlock_irqrestore(q->irqlock,flags);
 984                         q->read_buf = NULL;
 985                 }
 986                 if (retval < 0)
 987                         break;
 988         }
 989
 990  done:
 991         up(&q->lock);
 992         return retval;
 993 }
 994
 995 unsigned int videobuf_poll_stream(struct file *file,
 996                                   struct videobuf_queue *q,
 997                                   poll_table *wait)
 998 {
 999         struct videobuf_buffer *buf = NULL;
1000         unsigned int rc = 0;
1001
1002         down(&q->lock);
1003         if (q->streaming) {
1004                 if (!list_empty(&q->stream))
1005                         buf = list_entry(q->stream.next,
1006                                          struct videobuf_buffer, stream);
1007         } else {
1008                 if (!q->reading)
1009                         videobuf_read_start(q);
1010                 if (!q->reading) {
1011                         rc = POLLERR;
1012                 } else if (NULL == q->read_buf) {
1013                         q->read_buf = list_entry(q->stream.next,
1014                                                  struct videobuf_buffer,
1015                                                  stream);
1016                         list_del(&q->read_buf->stream);
1017                         q->read_off = 0;
1018                 }
1019                 buf = q->read_buf;
1020         }
1021         if (!buf)
1022                 rc = POLLERR;
1023
1024         if (0 == rc) {
1025                 poll_wait(file, &buf->done, wait);
1026                 if (buf->state == STATE_DONE ||
1027                     buf->state == STATE_ERROR)
1028                         rc = POLLIN|POLLRDNORM;
1029         }
1030         up(&q->lock);
1031         return rc;
1032 }
1033
1034 /* --------------------------------------------------------------------- */
1035
1036 static void
1037 videobuf_vm_open(struct vm_area_struct *vma)
1038 {
1039         struct videobuf_mapping *map = vma->vm_private_data;
1040
1041         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1042                 map->count,vma->vm_start,vma->vm_end);
1043         map->count++;
1044 }
1045
1046 static void
1047 videobuf_vm_close(struct vm_area_struct *vma)
1048 {
1049         struct videobuf_mapping *map = vma->vm_private_data;
1050         struct videobuf_queue *q = map->q;
1051         int i;
1052
1053         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1054                 map->count,vma->vm_start,vma->vm_end);
1055
1056         map->count--;
1057         if (0 == map->count) {
1058                 dprintk(1,"munmap %p q=%p\n",map,q);
1059                 down(&q->lock);
1060                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1061                         if (NULL == q->bufs[i])
1062                                 continue;
1063                         if (q->bufs[i])
1064                                 ;
1065                         if (q->bufs[i]->map != map)
1066                                 continue;
1067                         q->bufs[i]->map   = NULL;
1068                         q->bufs[i]->baddr = 0;
1069                         q->ops->buf_release(q,q->bufs[i]);
1070                 }
1071                 up(&q->lock);
1072                 kfree(map);
1073         }
1074         return;
1075 }
1076
1077 /*
1078  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1079  * memory location with 32bit PCI devices (i.e. don't use highmem for
1080  * now ...).  Bounce buffers don't work very well for the data rates
1081  * video capture has.
1082  */
1083 static struct page*
1084 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1085                    int *type)
1086 {
1087         struct page *page;
1088
1089         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1090                 vaddr,vma->vm_start,vma->vm_end);
1091         if (vaddr > vma->vm_end)
1092                 return NOPAGE_SIGBUS;
1093         page = alloc_page(GFP_USER);
1094         if (!page)
1095                 return NOPAGE_OOM;
1096         clear_user_page(page_address(page), vaddr, page);
1097         if (type)
1098                 *type = VM_FAULT_MINOR;
1099         return page;
1100 }
1101
1102 static struct vm_operations_struct videobuf_vm_ops =
1103 {
1104         .open     = videobuf_vm_open,
1105         .close    = videobuf_vm_close,
1106         .nopage   = videobuf_vm_nopage,
1107 };
1108
1109 int videobuf_mmap_setup(struct videobuf_queue *q,
1110                         unsigned int bcount, unsigned int bsize,
1111                         enum v4l2_memory memory)
1112 {
1113         unsigned int i;
1114         int err;
1115
1116         err = videobuf_mmap_free(q);
1117         if (0 != err)
1118                 return err;
1119
1120         for (i = 0; i < bcount; i++) {
1121                 q->bufs[i] = videobuf_alloc(q->msize);
1122                 q->bufs[i]->i      = i;
1123                 q->bufs[i]->input  = UNSET;
1124                 q->bufs[i]->memory = memory;
1125                 q->bufs[i]->bsize  = bsize;
1126                 switch (memory) {
1127                 case V4L2_MEMORY_MMAP:
1128                         q->bufs[i]->boff  = bsize * i;
1129                         break;
1130                 case V4L2_MEMORY_USERPTR:
1131                 case V4L2_MEMORY_OVERLAY:
1132                         /* nothing */
1133                         break;
1134                 }
1135         }
1136         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1137                 bcount,bsize);
1138         return 0;
1139 }
1140
1141 int videobuf_mmap_free(struct videobuf_queue *q)
1142 {
1143         int i;
1144
1145         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1146                 if (q->bufs[i] && q->bufs[i]->map)
1147                         return -EBUSY;
1148         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1149                 if (NULL == q->bufs[i])
1150                         continue;
1151                 q->ops->buf_release(q,q->bufs[i]);
1152                 kfree(q->bufs[i]);
1153                 q->bufs[i] = NULL;
1154         }
1155         return 0;
1156 }
1157
1158 int videobuf_mmap_mapper(struct videobuf_queue *q,
1159                          struct vm_area_struct *vma)
1160 {
1161         struct videobuf_mapping *map;
1162         unsigned int first,last,size,i;
1163         int retval;
1164
1165         down(&q->lock);
1166         retval = -EINVAL;
1167         if (!(vma->vm_flags & VM_WRITE)) {
1168                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1169                 goto done;
1170         }
1171         if (!(vma->vm_flags & VM_SHARED)) {
1172                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1173                 goto done;
1174         }
1175
1176         /* look for first buffer to map */
1177         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1178                 if (NULL == q->bufs[first])
1179                         continue;
1180                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1181                         continue;
1182                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1183                         break;
1184         }
1185         if (VIDEO_MAX_FRAME == first) {
1186                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1187                         (vma->vm_pgoff << PAGE_SHIFT));
1188                 goto done;
1189         }
1190
1191         /* look for last buffer to map */
1192         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1193                 if (NULL == q->bufs[last])
1194                         continue;
1195                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1196                         continue;
1197                 if (q->bufs[last]->map) {
1198                         retval = -EBUSY;
1199                         goto done;
1200                 }
1201                 size += q->bufs[last]->bsize;
1202                 if (size == (vma->vm_end - vma->vm_start))
1203                         break;
1204         }
1205         if (VIDEO_MAX_FRAME == last) {
1206                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1207                         (vma->vm_end - vma->vm_start));
1208                 goto done;
1209         }
1210
1211         /* create mapping + update buffer list */
1212         retval = -ENOMEM;
1213         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1214         if (NULL == map)
1215                 goto done;
1216         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1217                 q->bufs[i]->map   = map;
1218                 q->bufs[i]->baddr = vma->vm_start + size;
1219         }
1220         map->count    = 1;
1221         map->start    = vma->vm_start;
1222         map->end      = vma->vm_end;
1223         map->q        = q;
1224         vma->vm_ops   = &videobuf_vm_ops;
1225         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1226         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1227         vma->vm_private_data = map;
1228         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1229                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1230         retval = 0;
1231
1232  done:
1233         up(&q->lock);
1234         return retval;
1235 }
1236
1237 /* --------------------------------------------------------------------- */
1238
1239 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1240
1241 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1242 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1243 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1244 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1245 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1246 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1247 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1248 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1249
1250 EXPORT_SYMBOL_GPL(videobuf_alloc);
1251 EXPORT_SYMBOL_GPL(videobuf_waiton);
1252 EXPORT_SYMBOL_GPL(videobuf_iolock);
1253
1254 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1255 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1256 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1257
1258 EXPORT_SYMBOL_GPL(videobuf_next_field);
1259 EXPORT_SYMBOL_GPL(videobuf_status);
1260 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1261 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1262 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1263 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1264 EXPORT_SYMBOL_GPL(videobuf_streamon);
1265 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1266
1267 EXPORT_SYMBOL_GPL(videobuf_read_start);
1268 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1269 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1270 EXPORT_SYMBOL_GPL(videobuf_read_one);
1271 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1272
1273 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1274 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1275 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1276
1277 /*
1278  * Local variables:
1279  * c-basic-offset: 8
1280  * End:
1281  */