drivers/media/video/video-buf.c

   1 /*
   2  * $Id: video-buf.c,v 1.18 2005/02/24 13:32:30 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                 if (0 == dma->sglen) {
 224                         printk(KERN_WARNING
 225                                "%s: pci_map_sg failed\n",__FUNCTION__);
 226                         kfree(dma->sglist);
 227                         dma->sglist = NULL;
 228                         dma->sglen = 0;
 229                         return -EIO;
 230                 }
 231         }
 232         return 0;
 233 }
 234
 235 int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 236 {
 237         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 238         BUG_ON(!dma->sglen);
 239
 240         if (!dma->bus_addr)
 241                 pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
 242         return 0;
 243 }
 244
 245 int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 246 {
 247         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 248         if (!dma->sglen)
 249                 return 0;
 250
 251         if (!dma->bus_addr)
 252                 pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
 253         kfree(dma->sglist);
 254         dma->sglist = NULL;
 255         dma->sglen = 0;
 256         return 0;
 257 }
 258
 259 int videobuf_dma_free(struct videobuf_dmabuf *dma)
 260 {
 261         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
 262         BUG_ON(dma->sglen);
 263
 264         if (dma->pages) {
 265                 int i;
 266                 for (i=0; i < dma->nr_pages; i++)
 267                         page_cache_release(dma->pages[i]);
 268                 kfree(dma->pages);
 269                 dma->pages = NULL;
 270         }
 271         if (dma->vmalloc) {
 272                 vfree(dma->vmalloc);
 273                 dma->vmalloc = NULL;
 274         }
 275         if (dma->bus_addr) {
 276                 dma->bus_addr = 0;
 277         }
 278         dma->direction = PCI_DMA_NONE;
 279         return 0;
 280 }
 281
 282 /* --------------------------------------------------------------------- */
 283
 284 void* videobuf_alloc(unsigned int size)
 285 {
 286         struct videobuf_buffer *vb;
 287
 288         vb = kmalloc(size,GFP_KERNEL);
 289         if (NULL != vb) {
 290                 memset(vb,0,size);
 291                 videobuf_dma_init(&vb->dma);
 292                 init_waitqueue_head(&vb->done);
 293                 vb->magic     = MAGIC_BUFFER;
 294         }
 295         return vb;
 296 }
 297
 298 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 299 {
 300         int retval = 0;
 301         DECLARE_WAITQUEUE(wait, current);
 302
 303         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 304         add_wait_queue(&vb->done, &wait);
 305         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
 306                 if (non_blocking) {
 307                         retval = -EAGAIN;
 308                         break;
 309                 }
 310                 set_current_state(intr  ? TASK_INTERRUPTIBLE
 311                                         : TASK_UNINTERRUPTIBLE);
 312                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
 313                         schedule();
 314                 set_current_state(TASK_RUNNING);
 315                 if (intr && signal_pending(current)) {
 316                         dprintk(1,"buffer waiton: -EINTR\n");
 317                         retval = -EINTR;
 318                         break;
 319                 }
 320         }
 321         remove_wait_queue(&vb->done, &wait);
 322         return retval;
 323 }
 324
 325 int
 326 videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 327                 struct v4l2_framebuffer *fbuf)
 328 {
 329         int err,pages;
 330         dma_addr_t bus;
 331
 332         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 333         switch (vb->memory) {
 334         case V4L2_MEMORY_MMAP:
 335         case V4L2_MEMORY_USERPTR:
 336                 if (0 == vb->baddr) {
 337                         /* no userspace addr -- kernel bounce buffer */
 338                         pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 339                         err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
 340                                                        pages);
 341                         if (0 != err)
 342                                 return err;
 343                 } else {
 344                         /* dma directly to userspace */
 345                         err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
 346                                                      vb->baddr,vb->bsize);
 347                         if (0 != err)
 348                                 return err;
 349                 }
 350                 break;
 351         case V4L2_MEMORY_OVERLAY:
 352                 if (NULL == fbuf)
 353                         return -EINVAL;
 354                 /* FIXME: need sanity checks for vb->boff */
 355                 bus   = (dma_addr_t)fbuf->base + vb->boff;
 356                 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
 357                 err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
 358                                                 bus, pages);
 359                 if (0 != err)
 360                         return err;
 361                 break;
 362         default:
 363                 BUG();
 364         }
 365         err = videobuf_dma_pci_map(pci,&vb->dma);
 366         if (0 != err)
 367                 return err;
 368
 369         return 0;
 370 }
 371
 372 /* --------------------------------------------------------------------- */
 373
 374 void videobuf_queue_init(struct videobuf_queue* q,
 375                          struct videobuf_queue_ops *ops,
 376                          struct pci_dev *pci,
 377                          spinlock_t *irqlock,
 378                          enum v4l2_buf_type type,
 379                          enum v4l2_field field,
 380                          unsigned int msize,
 381                          void *priv)
 382 {
 383         memset(q,0,sizeof(*q));
 384         q->irqlock = irqlock;
 385         q->pci     = pci;
 386         q->type    = type;
 387         q->field   = field;
 388         q->msize   = msize;
 389         q->ops     = ops;
 390         q->priv_data = priv;
 391
 392         init_MUTEX(&q->lock);
 393         INIT_LIST_HEAD(&q->stream);
 394 }
 395
 396 int
 397 videobuf_queue_is_busy(struct videobuf_queue *q)
 398 {
 399         int i;
 400
 401         if (q->streaming) {
 402                 dprintk(1,"busy: streaming active\n");
 403                 return 1;
 404         }
 405         if (q->reading) {
 406                 dprintk(1,"busy: pending read #1\n");
 407                 return 1;
 408         }
 409         if (q->read_buf) {
 410                 dprintk(1,"busy: pending read #2\n");
 411                 return 1;
 412         }
 413         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 414                 if (NULL == q->bufs[i])
 415                         continue;
 416                 if (q->bufs[i]->map) {
 417                         dprintk(1,"busy: buffer #%d mapped\n",i);
 418                         return 1;
 419                 }
 420                 if (q->bufs[i]->state == STATE_QUEUED) {
 421                         dprintk(1,"busy: buffer #%d queued\n",i);
 422                         return 1;
 423                 }
 424                 if (q->bufs[i]->state == STATE_ACTIVE) {
 425                         dprintk(1,"busy: buffer #%d avtive\n",i);
 426                         return 1;
 427                 }
 428         }
 429         return 0;
 430 }
 431
 432 void
 433 videobuf_queue_cancel(struct videobuf_queue *q)
 434 {
 435         unsigned long flags;
 436         int i;
 437
 438         /* remove queued buffers from list */
 439         spin_lock_irqsave(q->irqlock,flags);
 440         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 441                 if (NULL == q->bufs[i])
 442                         continue;
 443                 if (q->bufs[i]->state == STATE_QUEUED) {
 444                         list_del(&q->bufs[i]->queue);
 445                         q->bufs[i]->state = STATE_ERROR;
 446                 }
 447         }
 448         spin_unlock_irqrestore(q->irqlock,flags);
 449
 450         /* free all buffers + clear queue */
 451         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 452                 if (NULL == q->bufs[i])
 453                         continue;
 454                 q->ops->buf_release(q,q->bufs[i]);
 455         }
 456         INIT_LIST_HEAD(&q->stream);
 457 }
 458
 459 /* --------------------------------------------------------------------- */
 460
 461 enum v4l2_field
 462 videobuf_next_field(struct videobuf_queue *q)
 463 {
 464         enum v4l2_field field = q->field;
 465
 466         BUG_ON(V4L2_FIELD_ANY == field);
 467
 468         if (V4L2_FIELD_ALTERNATE == field) {
 469                 if (V4L2_FIELD_TOP == q->last) {
 470                         field   = V4L2_FIELD_BOTTOM;
 471                         q->last = V4L2_FIELD_BOTTOM;
 472                 } else {
 473                         field   = V4L2_FIELD_TOP;
 474                         q->last = V4L2_FIELD_TOP;
 475                 }
 476         }
 477         return field;
 478 }
 479
 480 void
 481 videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
 482                 enum v4l2_buf_type type)
 483 {
 484         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 485
 486         b->index    = vb->i;
 487         b->type     = type;
 488
 489         b->memory   = vb->memory;
 490         switch (b->memory) {
 491         case V4L2_MEMORY_MMAP:
 492                 b->m.offset  = vb->boff;
 493                 b->length    = vb->bsize;
 494                 break;
 495         case V4L2_MEMORY_USERPTR:
 496                 b->m.userptr = vb->baddr;
 497                 b->length    = vb->bsize;
 498                 break;
 499         case V4L2_MEMORY_OVERLAY:
 500                 b->m.offset  = vb->boff;
 501                 break;
 502         }
 503
 504         b->flags    = 0;
 505         if (vb->map)
 506                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 507
 508         switch (vb->state) {
 509         case STATE_PREPARED:
 510         case STATE_QUEUED:
 511         case STATE_ACTIVE:
 512                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 513                 break;
 514         case STATE_DONE:
 515         case STATE_ERROR:
 516                 b->flags |= V4L2_BUF_FLAG_DONE;
 517                 break;
 518         case STATE_NEEDS_INIT:
 519         case STATE_IDLE:
 520                 /* nothing */
 521                 break;
 522         }
 523
 524         if (vb->input != UNSET) {
 525                 b->flags |= V4L2_BUF_FLAG_INPUT;
 526                 b->input  = vb->input;
 527         }
 528
 529         b->field     = vb->field;
 530         b->timestamp = vb->ts;
 531         b->bytesused = vb->size;
 532         b->sequence  = vb->field_count >> 1;
 533 }
 534
 535 int
 536 videobuf_reqbufs(struct videobuf_queue *q,
 537                  struct v4l2_requestbuffers *req)
 538 {
 539         unsigned int size,count;
 540         int retval;
 541
 542         if (req->type != q->type)
 543                 return -EINVAL;
 544         if (req->count < 1)
 545                 return -EINVAL;
 546         if (req->memory != V4L2_MEMORY_MMAP     &&
 547             req->memory != V4L2_MEMORY_USERPTR  &&
 548             req->memory != V4L2_MEMORY_OVERLAY)
 549                 return -EINVAL;
 550
 551         if (q->streaming)
 552                 return -EBUSY;
 553         if (!list_empty(&q->stream))
 554                 return -EBUSY;
 555
 556         down(&q->lock);
 557         count = req->count;
 558         if (count > VIDEO_MAX_FRAME)
 559                 count = VIDEO_MAX_FRAME;
 560         size = 0;
 561         q->ops->buf_setup(q,&count,&size);
 562         size = PAGE_ALIGN(size);
 563         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 564                 count, size, (count*size)>>PAGE_SHIFT);
 565
 566         retval = videobuf_mmap_setup(q,count,size,req->memory);
 567         if (retval < 0)
 568                 goto done;
 569
 570         req->count = count;
 571
 572  done:
 573         up(&q->lock);
 574         return retval;
 575 }
 576
 577 int
 578 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 579 {
 580         if (unlikely(b->type != q->type))
 581                 return -EINVAL;
 582         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
 583                 return -EINVAL;
 584         if (unlikely(NULL == q->bufs[b->index]))
 585                 return -EINVAL;
 586         videobuf_status(b,q->bufs[b->index],q->type);
 587         return 0;
 588 }
 589
 590 int
 591 videobuf_qbuf(struct videobuf_queue *q,
 592               struct v4l2_buffer *b)
 593 {
 594         struct videobuf_buffer *buf;
 595         enum v4l2_field field;
 596         unsigned long flags;
 597         int retval;
 598
 599         down(&q->lock);
 600         retval = -EBUSY;
 601         if (q->reading)
 602                 goto done;
 603         retval = -EINVAL;
 604         if (b->type != q->type)
 605                 goto done;
 606         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
 607                 goto done;
 608         buf = q->bufs[b->index];
 609         if (NULL == buf)
 610                 goto done;
 611         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 612         if (buf->memory != b->memory)
 613                 goto done;
 614         if (buf->state == STATE_QUEUED ||
 615             buf->state == STATE_ACTIVE)
 616                 goto done;
 617
 618         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 619                 if (b->input >= q->inputs)
 620                         goto done;
 621                 buf->input = b->input;
 622         } else {
 623                 buf->input = UNSET;
 624         }
 625
 626         switch (b->memory) {
 627         case V4L2_MEMORY_MMAP:
 628                 if (0 == buf->baddr)
 629                         goto done;
 630                 break;
 631         case V4L2_MEMORY_USERPTR:
 632                 if (b->length < buf->bsize)
 633                         goto done;
 634                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 635                         q->ops->buf_release(q,buf);
 636                 buf->baddr = b->m.userptr;
 637                 break;
 638         case V4L2_MEMORY_OVERLAY:
 639                 buf->boff = b->m.offset;
 640                 break;
 641         default:
 642                 goto done;
 643         }
 644
 645         field = videobuf_next_field(q);
 646         retval = q->ops->buf_prepare(q,buf,field);
 647         if (0 != retval)
 648                 goto done;
 649
 650         list_add_tail(&buf->stream,&q->stream);
 651         if (q->streaming) {
 652                 spin_lock_irqsave(q->irqlock,flags);
 653                 q->ops->buf_queue(q,buf);
 654                 spin_unlock_irqrestore(q->irqlock,flags);
 655         }
 656         retval = 0;
 657
 658  done:
 659         up(&q->lock);
 660         return retval;
 661 }
 662
 663 int
 664 videobuf_dqbuf(struct videobuf_queue *q,
 665                struct v4l2_buffer *b, int nonblocking)
 666 {
 667         struct videobuf_buffer *buf;
 668         int retval;
 669
 670         down(&q->lock);
 671         retval = -EBUSY;
 672         if (q->reading)
 673                 goto done;
 674         retval = -EINVAL;
 675         if (b->type != q->type)
 676                 goto done;
 677         if (list_empty(&q->stream))
 678                 goto done;
 679         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 680         retval = videobuf_waiton(buf, nonblocking, 1);
 681         if (retval < 0)
 682                 goto done;
 683         switch (buf->state) {
 684         case STATE_ERROR:
 685                 retval = -EIO;
 686                 /* fall through */
 687         case STATE_DONE:
 688                 videobuf_dma_pci_sync(q->pci,&buf->dma);
 689                 buf->state = STATE_IDLE;
 690                 break;
 691         default:
 692                 retval = -EINVAL;
 693                 goto done;
 694         }
 695         list_del(&buf->stream);
 696         memset(b,0,sizeof(*b));
 697         videobuf_status(b,buf,q->type);
 698
 699  done:
 700         up(&q->lock);
 701         return retval;
 702 }
 703
 704 int videobuf_streamon(struct videobuf_queue *q)
 705 {
 706         struct videobuf_buffer *buf;
 707         struct list_head *list;
 708         unsigned long flags;
 709         int retval;
 710
 711         down(&q->lock);
 712         retval = -EBUSY;
 713         if (q->reading)
 714                 goto done;
 715         retval = 0;
 716         if (q->streaming)
 717                 goto done;
 718         q->streaming = 1;
 719         spin_lock_irqsave(q->irqlock,flags);
 720         list_for_each(list,&q->stream) {
 721                 buf = list_entry(list, struct videobuf_buffer, stream);
 722                 if (buf->state == STATE_PREPARED)
 723                         q->ops->buf_queue(q,buf);
 724         }
 725         spin_unlock_irqrestore(q->irqlock,flags);
 726
 727  done:
 728         up(&q->lock);
 729         return retval;
 730 }
 731
 732 int videobuf_streamoff(struct videobuf_queue *q)
 733 {
 734         int retval = -EINVAL;
 735
 736         down(&q->lock);
 737         if (!q->streaming)
 738                 goto done;
 739         videobuf_queue_cancel(q);
 740         q->streaming = 0;
 741         retval = 0;
 742
 743  done:
 744         up(&q->lock);
 745         return retval;
 746 }
 747
 748 static ssize_t
 749 videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 750                        size_t count, loff_t *ppos)
 751 {
 752         enum v4l2_field field;
 753         unsigned long flags;
 754         int retval;
 755
 756         /* setup stuff */
 757         retval = -ENOMEM;
 758         q->read_buf = videobuf_alloc(q->msize);
 759         if (NULL == q->read_buf)
 760                 goto done;
 761
 762         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 763         q->read_buf->baddr  = (unsigned long)data;
 764         q->read_buf->bsize  = count;
 765         field = videobuf_next_field(q);
 766         retval = q->ops->buf_prepare(q,q->read_buf,field);
 767         if (0 != retval)
 768                 goto done;
 769
 770         /* start capture & wait */
 771         spin_lock_irqsave(q->irqlock,flags);
 772         q->ops->buf_queue(q,q->read_buf);
 773         spin_unlock_irqrestore(q->irqlock,flags);
 774         retval = videobuf_waiton(q->read_buf,0,0);
 775         if (0 == retval) {
 776                 videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 777                 if (STATE_ERROR == q->read_buf->state)
 778                         retval = -EIO;
 779                 else
 780                         retval = q->read_buf->size;
 781         }
 782
 783  done:
 784         /* cleanup */
 785         q->ops->buf_release(q,q->read_buf);
 786         kfree(q->read_buf);
 787         q->read_buf = NULL;
 788         return retval;
 789 }
 790
 791 ssize_t videobuf_read_one(struct videobuf_queue *q,
 792                           char __user *data, size_t count, loff_t *ppos,
 793                           int nonblocking)
 794 {
 795         enum v4l2_field field;
 796         unsigned long flags;
 797         unsigned size, nbufs, bytes;
 798         int retval;
 799
 800         down(&q->lock);
 801
 802         nbufs = 1; size = 0;
 803         q->ops->buf_setup(q,&nbufs,&size);
 804         if (NULL == q->read_buf  &&
 805             count >= size        &&
 806             !nonblocking) {
 807                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 808                 if (retval >= 0  ||  retval == -EIO)
 809                         /* ok, all done */
 810                         goto done;
 811                 /* fallback to kernel bounce buffer on failures */
 812         }
 813
 814         if (NULL == q->read_buf) {
 815                 /* need to capture a new frame */
 816                 retval = -ENOMEM;
 817                 q->read_buf = videobuf_alloc(q->msize);
 818                 if (NULL == q->read_buf)
 819                         goto done;
 820                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 821                 field = videobuf_next_field(q);
 822                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 823                 if (0 != retval)
 824                         goto done;
 825                 spin_lock_irqsave(q->irqlock,flags);
 826                 q->ops->buf_queue(q,q->read_buf);
 827                 spin_unlock_irqrestore(q->irqlock,flags);
 828                 q->read_off = 0;
 829         }
 830
 831         /* wait until capture is done */
 832         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 833         if (0 != retval)
 834                 goto done;
 835         videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
 836
 837         if (STATE_ERROR == q->read_buf->state) {
 838                 /* catch I/O errors */
 839                 q->ops->buf_release(q,q->read_buf);
 840                 kfree(q->read_buf);
 841                 q->read_buf = NULL;
 842                 retval = -EIO;
 843                 goto done;
 844         }
 845
 846         /* copy to userspace */
 847         bytes = count;
 848         if (bytes > q->read_buf->size - q->read_off)
 849                 bytes = q->read_buf->size - q->read_off;
 850         retval = -EFAULT;
 851         if (copy_to_user(data, q->read_buf->dma.vmalloc+q->read_off, bytes))
 852                 goto done;
 853
 854         retval = bytes;
 855         q->read_off += bytes;
 856         if (q->read_off == q->read_buf->size) {
 857                 /* all data copied, cleanup */
 858                 q->ops->buf_release(q,q->read_buf);
 859                 kfree(q->read_buf);
 860                 q->read_buf = NULL;
 861         }
 862
 863  done:
 864         up(&q->lock);
 865         return retval;
 866 }
 867
 868 int videobuf_read_start(struct videobuf_queue *q)
 869 {
 870         enum v4l2_field field;
 871         unsigned long flags;
 872         int count = 0, size = 0;
 873         int err, i;
 874
 875         q->ops->buf_setup(q,&count,&size);
 876         if (count < 2)
 877                 count = 2;
 878         if (count > VIDEO_MAX_FRAME)
 879                 count = VIDEO_MAX_FRAME;
 880         size = PAGE_ALIGN(size);
 881
 882         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 883         if (err)
 884                 return err;
 885         for (i = 0; i < count; i++) {
 886                 field = videobuf_next_field(q);
 887                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 888                 if (err)
 889                         return err;
 890                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 891         }
 892         spin_lock_irqsave(q->irqlock,flags);
 893         for (i = 0; i < count; i++)
 894                 q->ops->buf_queue(q,q->bufs[i]);
 895         spin_unlock_irqrestore(q->irqlock,flags);
 896         q->reading = 1;
 897         return 0;
 898 }
 899
 900 void videobuf_read_stop(struct videobuf_queue *q)
 901 {
 902         int i;
 903
 904         videobuf_queue_cancel(q);
 905         videobuf_mmap_free(q);
 906         INIT_LIST_HEAD(&q->stream);
 907         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 908                 if (NULL == q->bufs[i])
 909                         continue;
 910                 kfree(q->bufs[i]);
 911                 q->bufs[i] = NULL;
 912         }
 913         q->read_buf = NULL;
 914         q->reading  = 0;
 915 }
 916
 917 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 918                              char __user *data, size_t count, loff_t *ppos,
 919                              int vbihack, int nonblocking)
 920 {
 921         unsigned int *fc, bytes;
 922         int err, retval;
 923         unsigned long flags;
 924
 925         dprintk(2,"%s\n",__FUNCTION__);
 926         down(&q->lock);
 927         retval = -EBUSY;
 928         if (q->streaming)
 929                 goto done;
 930         if (!q->reading) {
 931                 retval = videobuf_read_start(q);
 932                 if (retval < 0)
 933                         goto done;
 934         }
 935
 936         retval = 0;
 937         while (count > 0) {
 938                 /* get / wait for data */
 939                 if (NULL == q->read_buf) {
 940                         q->read_buf = list_entry(q->stream.next,
 941                                                  struct videobuf_buffer,
 942                                                  stream);
 943                         list_del(&q->read_buf->stream);
 944                         q->read_off = 0;
 945                 }
 946                 err = videobuf_waiton(q->read_buf, nonblocking, 1);
 947                 if (err < 0) {
 948                         if (0 == retval)
 949                                 retval = err;
 950                         break;
 951                 }
 952
 953                 if (q->read_buf->state == STATE_DONE) {
 954                         if (vbihack) {
 955                                 /* dirty, undocumented hack -- pass the frame counter
 956                                  * within the last four bytes of each vbi data block.
 957                                  * We need that one to maintain backward compatibility
 958                                  * to all vbi decoding software out there ... */
 959                                 fc  = (unsigned int*)q->read_buf->dma.vmalloc;
 960                                 fc += (q->read_buf->size>>2) -1;
 961                                 *fc = q->read_buf->field_count >> 1;
 962                                 dprintk(1,"vbihack: %d\n",*fc);
 963                         }
 964
 965                         /* copy stuff */
 966                         bytes = count;
 967                         if (bytes > q->read_buf->size - q->read_off)
 968                                 bytes = q->read_buf->size - q->read_off;
 969                         if (copy_to_user(data + retval,
 970                                          q->read_buf->dma.vmalloc + q->read_off,
 971                                          bytes)) {
 972                                 if (0 == retval)
 973                                         retval = -EFAULT;
 974                                 break;
 975                         }
 976                         count       -= bytes;
 977                         retval      += bytes;
 978                         q->read_off += bytes;
 979                 } else {
 980                         /* some error */
 981                         q->read_off = q->read_buf->size;
 982                         if (0 == retval)
 983                                 retval = -EIO;
 984                 }
 985
 986                 /* requeue buffer when done with copying */
 987                 if (q->read_off == q->read_buf->size) {
 988                         list_add_tail(&q->read_buf->stream,
 989                                       &q->stream);
 990                         spin_lock_irqsave(q->irqlock,flags);
 991                         q->ops->buf_queue(q,q->read_buf);
 992                         spin_unlock_irqrestore(q->irqlock,flags);
 993                         q->read_buf = NULL;
 994                 }
 995                 if (retval < 0)
 996                         break;
 997         }
 998
 999  done:
1000         up(&q->lock);
1001         return retval;
1002 }
1003
1004 unsigned int videobuf_poll_stream(struct file *file,
1005                                   struct videobuf_queue *q,
1006                                   poll_table *wait)
1007 {
1008         struct videobuf_buffer *buf = NULL;
1009         unsigned int rc = 0;
1010
1011         down(&q->lock);
1012         if (q->streaming) {
1013                 if (!list_empty(&q->stream))
1014                         buf = list_entry(q->stream.next,
1015                                          struct videobuf_buffer, stream);
1016         } else {
1017                 if (!q->reading)
1018                         videobuf_read_start(q);
1019                 if (!q->reading) {
1020                         rc = POLLERR;
1021                 } else if (NULL == q->read_buf) {
1022                         q->read_buf = list_entry(q->stream.next,
1023                                                  struct videobuf_buffer,
1024                                                  stream);
1025                         list_del(&q->read_buf->stream);
1026                         q->read_off = 0;
1027                 }
1028                 buf = q->read_buf;
1029         }
1030         if (!buf)
1031                 rc = POLLERR;
1032
1033         if (0 == rc) {
1034                 poll_wait(file, &buf->done, wait);
1035                 if (buf->state == STATE_DONE ||
1036                     buf->state == STATE_ERROR)
1037                         rc = POLLIN|POLLRDNORM;
1038         }
1039         up(&q->lock);
1040         return rc;
1041 }
1042
1043 /* --------------------------------------------------------------------- */
1044
1045 static void
1046 videobuf_vm_open(struct vm_area_struct *vma)
1047 {
1048         struct videobuf_mapping *map = vma->vm_private_data;
1049
1050         dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
1051                 map->count,vma->vm_start,vma->vm_end);
1052         map->count++;
1053 }
1054
1055 static void
1056 videobuf_vm_close(struct vm_area_struct *vma)
1057 {
1058         struct videobuf_mapping *map = vma->vm_private_data;
1059         struct videobuf_queue *q = map->q;
1060         int i;
1061
1062         dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
1063                 map->count,vma->vm_start,vma->vm_end);
1064
1065         map->count--;
1066         if (0 == map->count) {
1067                 dprintk(1,"munmap %p q=%p\n",map,q);
1068                 down(&q->lock);
1069                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1070                         if (NULL == q->bufs[i])
1071                                 continue;
1072                         if (q->bufs[i])
1073                                 ;
1074                         if (q->bufs[i]->map != map)
1075                                 continue;
1076                         q->bufs[i]->map   = NULL;
1077                         q->bufs[i]->baddr = 0;
1078                         q->ops->buf_release(q,q->bufs[i]);
1079                 }
1080                 up(&q->lock);
1081                 kfree(map);
1082         }
1083         return;
1084 }
1085
1086 /*
1087  * Get a anonymous page for the mapping.  Make sure we can DMA to that
1088  * memory location with 32bit PCI devices (i.e. don't use highmem for
1089  * now ...).  Bounce buffers don't work very well for the data rates
1090  * video capture has.
1091  */
1092 static struct page*
1093 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
1094                    int *type)
1095 {
1096         struct page *page;
1097
1098         dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
1099                 vaddr,vma->vm_start,vma->vm_end);
1100         if (vaddr > vma->vm_end)
1101                 return NOPAGE_SIGBUS;
1102         page = alloc_page(GFP_USER);
1103         if (!page)
1104                 return NOPAGE_OOM;
1105         clear_user_page(page_address(page), vaddr, page);
1106         if (type)
1107                 *type = VM_FAULT_MINOR;
1108         return page;
1109 }
1110
1111 static struct vm_operations_struct videobuf_vm_ops =
1112 {
1113         .open     = videobuf_vm_open,
1114         .close    = videobuf_vm_close,
1115         .nopage   = videobuf_vm_nopage,
1116 };
1117
1118 int videobuf_mmap_setup(struct videobuf_queue *q,
1119                         unsigned int bcount, unsigned int bsize,
1120                         enum v4l2_memory memory)
1121 {
1122         unsigned int i;
1123         int err;
1124
1125         err = videobuf_mmap_free(q);
1126         if (0 != err)
1127                 return err;
1128
1129         for (i = 0; i < bcount; i++) {
1130                 q->bufs[i] = videobuf_alloc(q->msize);
1131                 q->bufs[i]->i      = i;
1132                 q->bufs[i]->input  = UNSET;
1133                 q->bufs[i]->memory = memory;
1134                 q->bufs[i]->bsize  = bsize;
1135                 switch (memory) {
1136                 case V4L2_MEMORY_MMAP:
1137                         q->bufs[i]->boff  = bsize * i;
1138                         break;
1139                 case V4L2_MEMORY_USERPTR:
1140                 case V4L2_MEMORY_OVERLAY:
1141                         /* nothing */
1142                         break;
1143                 }
1144         }
1145         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
1146                 bcount,bsize);
1147         return 0;
1148 }
1149
1150 int videobuf_mmap_free(struct videobuf_queue *q)
1151 {
1152         int i;
1153
1154         for (i = 0; i < VIDEO_MAX_FRAME; i++)
1155                 if (q->bufs[i] && q->bufs[i]->map)
1156                         return -EBUSY;
1157         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1158                 if (NULL == q->bufs[i])
1159                         continue;
1160                 q->ops->buf_release(q,q->bufs[i]);
1161                 kfree(q->bufs[i]);
1162                 q->bufs[i] = NULL;
1163         }
1164         return 0;
1165 }
1166
1167 int videobuf_mmap_mapper(struct videobuf_queue *q,
1168                          struct vm_area_struct *vma)
1169 {
1170         struct videobuf_mapping *map;
1171         unsigned int first,last,size,i;
1172         int retval;
1173
1174         down(&q->lock);
1175         retval = -EINVAL;
1176         if (!(vma->vm_flags & VM_WRITE)) {
1177                 dprintk(1,"mmap app bug: PROT_WRITE please\n");
1178                 goto done;
1179         }
1180         if (!(vma->vm_flags & VM_SHARED)) {
1181                 dprintk(1,"mmap app bug: MAP_SHARED please\n");
1182                 goto done;
1183         }
1184
1185         /* look for first buffer to map */
1186         for (first = 0; first < VIDEO_MAX_FRAME; first++) {
1187                 if (NULL == q->bufs[first])
1188                         continue;
1189                 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
1190                         continue;
1191                 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
1192                         break;
1193         }
1194         if (VIDEO_MAX_FRAME == first) {
1195                 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
1196                         (vma->vm_pgoff << PAGE_SHIFT));
1197                 goto done;
1198         }
1199
1200         /* look for last buffer to map */
1201         for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
1202                 if (NULL == q->bufs[last])
1203                         continue;
1204                 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
1205                         continue;
1206                 if (q->bufs[last]->map) {
1207                         retval = -EBUSY;
1208                         goto done;
1209                 }
1210                 size += q->bufs[last]->bsize;
1211                 if (size == (vma->vm_end - vma->vm_start))
1212                         break;
1213         }
1214         if (VIDEO_MAX_FRAME == last) {
1215                 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
1216                         (vma->vm_end - vma->vm_start));
1217                 goto done;
1218         }
1219
1220         /* create mapping + update buffer list */
1221         retval = -ENOMEM;
1222         map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
1223         if (NULL == map)
1224                 goto done;
1225         for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
1226                 q->bufs[i]->map   = map;
1227                 q->bufs[i]->baddr = vma->vm_start + size;
1228         }
1229         map->count    = 1;
1230         map->start    = vma->vm_start;
1231         map->end      = vma->vm_end;
1232         map->q        = q;
1233         vma->vm_ops   = &videobuf_vm_ops;
1234         vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
1235         vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
1236         vma->vm_private_data = map;
1237         dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
1238                 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
1239         retval = 0;
1240
1241  done:
1242         up(&q->lock);
1243         return retval;
1244 }
1245
1246 /* --------------------------------------------------------------------- */
1247
1248 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
1249
1250 EXPORT_SYMBOL_GPL(videobuf_dma_init);
1251 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
1252 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
1253 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
1254 EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
1255 EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
1256 EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
1257 EXPORT_SYMBOL_GPL(videobuf_dma_free);
1258
1259 EXPORT_SYMBOL_GPL(videobuf_alloc);
1260 EXPORT_SYMBOL_GPL(videobuf_waiton);
1261 EXPORT_SYMBOL_GPL(videobuf_iolock);
1262
1263 EXPORT_SYMBOL_GPL(videobuf_queue_init);
1264 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1265 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1266
1267 EXPORT_SYMBOL_GPL(videobuf_next_field);
1268 EXPORT_SYMBOL_GPL(videobuf_status);
1269 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1270 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1271 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1272 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1273 EXPORT_SYMBOL_GPL(videobuf_streamon);
1274 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1275
1276 EXPORT_SYMBOL_GPL(videobuf_read_start);
1277 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1278 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1279 EXPORT_SYMBOL_GPL(videobuf_read_one);
1280 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1281
1282 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1283 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1284 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1285
1286 /*
1287  * Local variables:
1288  * c-basic-offset: 8
1289  * End:
1290  */