text: /*
   * $FreeBSD: src/sys/dev/drm/drm_vm.h,v 1.6.2.1 2003/04/26 07:05:29 anholt Exp $
   */
  
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  static int DRM(dma_mmap)(dev_t kdev, vm_offset_t offset, vm_paddr_t *paddr, 
      int prot)
  #elif defined(__FreeBSD__)
  static int DRM(dma_mmap)(dev_t kdev, vm_offset_t offset, int prot)
  #elif defined(__NetBSD__)
  static paddr_t DRM(dma_mmap)(dev_t kdev, vm_offset_t offset, int prot)
  #endif
  {
  	DRM_DEVICE;
  	drm_device_dma_t *dma	 = dev->dma;
  	unsigned long	 physical;
  	unsigned long	 page;
  
  	if (!dma)		   return -1; /* Error */
  	if (!dma->pagelist)	   return -1; /* Nothing allocated */
  
  	page	 = offset >> PAGE_SHIFT;
  	physical = dma->pagelist[page];
  
  	DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", (long)offset, page, physical);
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  	*paddr = physical;
  	return 0;
  #else
  	return atop(physical);
  #endif
  }
  
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  int DRM(mmap)(dev_t kdev, vm_offset_t offset, vm_paddr_t *paddr, 
      int prot)
  #elif defined(__FreeBSD__)
  int DRM(mmap)(dev_t kdev, vm_offset_t offset, int prot)
  #elif defined(__NetBSD__)
  paddr_t DRM(mmap)(dev_t kdev, off_t offset, int prot)
  #endif
  {
  	DRM_DEVICE;
  	drm_local_map_t *map	= NULL;
  	drm_map_list_entry_t *listentry=NULL;
  	drm_file_t *priv;
  
  	priv = DRM(find_file_by_proc)(dev, DRM_CURPROC);
  	if (!priv) {
  		DRM_DEBUG("can't find authenticator\n");
  		return EINVAL;
  	}
  
  	if (!priv->authenticated)
  		return DRM_ERR(EACCES);
  
  	if (dev->dma
  	    && offset >= 0
  	    && offset < ptoa(dev->dma->page_count))
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  		return DRM(dma_mmap)(kdev, offset, paddr, prot);
  #else
  		return DRM(dma_mmap)(kdev, offset, prot);
  #endif
  
  				/* A sequential search of a linked list is
  				   fine here because: 1) there will only be
  				   about 5-10 entries in the list and, 2) a
  				   DRI client only has to do this mapping
  				   once, so it doesn't have to be optimized
  				   for performance, even if the list was a
  				   bit longer. */
  	TAILQ_FOREACH(listentry, dev->maplist, link) {
  		map = listentry->map;
  /*		DRM_DEBUG("considering 0x%x..0x%x\n", map->offset, map->offset + map->size - 1);*/
  		if (offset >= map->offset
  		    && offset < map->offset + map->size) break;
  	}
  	
  	if (!listentry) {
  		DRM_DEBUG("can't find map\n");
  		return -1;
  	}
  	if (((map->flags&_DRM_RESTRICTED) && DRM_SUSER(DRM_CURPROC))) {
  		DRM_DEBUG("restricted map\n");
  		return -1;
  	}
  
  	switch (map->type) {
  	case _DRM_FRAME_BUFFER:
  	case _DRM_REGISTERS:
  	case _DRM_AGP:
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  		*paddr = offset;
  		return 0;
  #else
  		return atop(offset);
  #endif
  	case _DRM_SCATTER_GATHER:
  	case _DRM_SHM:
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
  		*paddr = vtophys(offset);
  		return 0;
  #else
  		return atop(vtophys(offset));
  #endif
  	default:
  		return -1;	/* This should never happen. */
  	}
  	DRM_DEBUG("bailing out\n");
  	
  	return -1;
  }
  
  