drm_bufs.c

linux-2.6.15.6

	int total;
	int byte_count;
	int i;
	drm_buf_t **temp_buflist;

	if (!drm_core_check_feature(dev, DRIVER_FB_DMA))
		return -EINVAL;

	if (!dma)
		return -EINVAL;

	count = request->count;
	order = drm_order(request->size);
	size = 1 << order;

	alignment = (request->flags & _DRM_PAGE_ALIGN)
	    ? PAGE_ALIGN(size) : size;
	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
	total = PAGE_SIZE << page_order;

	byte_count = 0;
	agp_offset = request->agp_start;

	DRM_DEBUG("count:      %d\n", count);
	DRM_DEBUG("order:      %d\n", order);
	DRM_DEBUG("size:       %d\n", size);
	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
	DRM_DEBUG("alignment:  %d\n", alignment);
	DRM_DEBUG("page_order: %d\n", page_order);
	DRM_DEBUG("total:      %d\n", total);

	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
		return -EINVAL;
	if (dev->queue_count)
		return -EBUSY;	/* Not while in use */

	spin_lock(&dev->count_lock);
	if (dev->buf_use) {
		spin_unlock(&dev->count_lock);
		return -EBUSY;
	}
	atomic_inc(&dev->buf_alloc);
	spin_unlock(&dev->count_lock);

	down(&dev->struct_sem);
	entry = &dma->bufs[order];
	if (entry->buf_count) {
		up(&dev->struct_sem);
		atomic_dec(&dev->buf_alloc);
		return -ENOMEM;	/* May only call once for each order */
	}

	if (count < 0 || count > 4096) {
		up(&dev->struct_sem);
		atomic_dec(&dev->buf_alloc);
		return -EINVAL;
	}

	entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
				   DRM_MEM_BUFS);
	if (!entry->buflist) {
		up(&dev->struct_sem);
		atomic_dec(&dev->buf_alloc);
		return -ENOMEM;
	}
	memset(entry->buflist, 0, count * sizeof(*entry->buflist));

	entry->buf_size = size;
	entry->page_order = page_order;

	offset = 0;

	while (entry->buf_count < count) {
		buf = &entry->buflist[entry->buf_count];
		buf->idx = dma->buf_count + entry->buf_count;
		buf->total = alignment;
		buf->order = order;
		buf->used = 0;

		buf->offset = (dma->byte_count + offset);
		buf->bus_address = agp_offset + offset;
		buf->address = (void *)(agp_offset + offset);
		buf->next = NULL;
		buf->waiting = 0;
		buf->pending = 0;
		init_waitqueue_head(&buf->dma_wait);
		buf->filp = NULL;

		buf->dev_priv_size = dev->driver->dev_priv_size;
		buf->dev_private = drm_alloc(buf->dev_priv_size, DRM_MEM_BUFS);
		if (!buf->dev_private) {
			/* Set count correctly so we free the proper amount. */
			entry->buf_count = count;
			drm_cleanup_buf_error(dev, entry);
			up(&dev->struct_sem);
			atomic_dec(&dev->buf_alloc);
			return -ENOMEM;
		}
		memset(buf->dev_private, 0, buf->dev_priv_size);

		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);

		offset += alignment;
		entry->buf_count++;
		byte_count += PAGE_SIZE << page_order;
	}

	DRM_DEBUG("byte_count: %d\n", byte_count);

	temp_buflist = drm_realloc(dma->buflist,
				   dma->buf_count * sizeof(*dma->buflist),
				   (dma->buf_count + entry->buf_count)
				   * sizeof(*dma->buflist), DRM_MEM_BUFS);
	if (!temp_buflist) {
		/* Free the entry because it isn't valid */
		drm_cleanup_buf_error(dev, entry);
		up(&dev->struct_sem);
		atomic_dec(&dev->buf_alloc);
		return -ENOMEM;
	}
	dma->buflist = temp_buflist;

	for (i = 0; i < entry->buf_count; i++) {
		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
	}

	dma->buf_count += entry->buf_count;
	dma->byte_count += byte_count;

	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);

	up(&dev->struct_sem);

	request->count = entry->buf_count;
	request->size = size;

	dma->flags = _DRM_DMA_USE_FB;

	atomic_dec(&dev->buf_alloc);
	return 0;
}

/**
 * Add buffers for DMA transfers (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_desc_t request.
 * \return zero on success or a negative number on failure.
 *
 * According with the memory type specified in drm_buf_desc::flags and the
 * build options, it dispatches the call either to addbufs_agp(),
 * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
 * PCI memory respectively.
 */
int drm_addbufs(struct inode *inode, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
	drm_buf_desc_t request;
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	int ret;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if (copy_from_user(&request, (drm_buf_desc_t __user *) arg,
			   sizeof(request)))
		return -EFAULT;

#if __OS_HAS_AGP
	if (request.flags & _DRM_AGP_BUFFER)
		ret = drm_addbufs_agp(dev, &request);
	else
#endif
	if (request.flags & _DRM_SG_BUFFER)
		ret = drm_addbufs_sg(dev, &request);
	else if (request.flags & _DRM_FB_BUFFER)
		ret = drm_addbufs_fb(dev, &request);
	else
		ret = drm_addbufs_pci(dev, &request);

	if (ret == 0) {
		if (copy_to_user((void __user *)arg, &request, sizeof(request))) {
			ret = -EFAULT;
		}
	}
	return ret;
}

/**
 * Get information about the buffer mappings.
 *
 * This was originally mean for debugging purposes, or by a sophisticated
 * client library to determine how best to use the available buffers (e.g.,
 * large buffers can be used for image transfer).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_info structure.
 * \return zero on success or a negative number on failure.
 *
 * Increments drm_device::buf_use while holding the drm_device::count_lock
 * lock, preventing of allocating more buffers after this call. Information
 * about each requested buffer is then copied into user space.
 */
int drm_infobufs(struct inode *inode, struct file *filp,
		 unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_info_t request;
	drm_buf_info_t __user *argp = (void __user *)arg;
	int i;
	int count;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if (!dma)
		return -EINVAL;

	spin_lock(&dev->count_lock);
	if (atomic_read(&dev->buf_alloc)) {
		spin_unlock(&dev->count_lock);
		return -EBUSY;
	}
	++dev->buf_use;		/* Can't allocate more after this call */
	spin_unlock(&dev->count_lock);

	if (copy_from_user(&request, argp, sizeof(request)))
		return -EFAULT;

	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
		if (dma->bufs[i].buf_count)
			++count;
	}

	DRM_DEBUG("count = %d\n", count);

	if (request.count >= count) {
		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
			if (dma->bufs[i].buf_count) {
				drm_buf_desc_t __user *to =
				    &request.list[count];
				drm_buf_entry_t *from = &dma->bufs[i];
				drm_freelist_t *list = &dma->bufs[i].freelist;
				if (copy_to_user(&to->count,
						 &from->buf_count,
						 sizeof(from->buf_count)) ||
				    copy_to_user(&to->size,
						 &from->buf_size,
						 sizeof(from->buf_size)) ||
				    copy_to_user(&to->low_mark,
						 &list->low_mark,
						 sizeof(list->low_mark)) ||
				    copy_to_user(&to->high_mark,
						 &list->high_mark,
						 sizeof(list->high_mark)))
					return -EFAULT;

				DRM_DEBUG("%d %d %d %d %d\n",
					  i,
					  dma->bufs[i].buf_count,
					  dma->bufs[i].buf_size,
					  dma->bufs[i].freelist.low_mark,
					  dma->bufs[i].freelist.high_mark);
				++count;
			}
		}
	}
	request.count = count;

	if (copy_to_user(argp, &request, sizeof(request)))
		return -EFAULT;

	return 0;
}

/**
 * Specifies a low and high water mark for buffer allocation
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg a pointer to a drm_buf_desc structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies that the size order is bounded between the admissible orders and
 * updates the respective drm_device_dma::bufs entry low and high water mark.
 *
 * \note This ioctl is deprecated and mostly never used.
 */
int drm_markbufs(struct inode *inode, struct file *filp,
		 unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t request;
	int order;
	drm_buf_entry_t *entry;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if (!dma)
		return -EINVAL;

	if (copy_from_user(&request,
			   (drm_buf_desc_t __user *) arg, sizeof(request)))
		return -EFAULT;

	DRM_DEBUG("%d, %d, %d\n",
		  request.size, request.low_mark, request.high_mark);
	order = drm_order(request.size);
	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
		return -EINVAL;
	entry = &dma->bufs[order];

	if (request.low_mark < 0 || request.low_mark > entry->buf_count)
		return -EINVAL;
	if (request.high_mark < 0 || request.high_mark > entry->buf_count)
		return -EINVAL;

	entry->freelist.low_mark = request.low_mark;
	entry->freelist.high_mark = request.high_mark;

	return 0;
}

/**
 * Unreserve the buffers in list, previously reserved using drmDMA.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_free structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls free_buffer() for each used buffer.
 * This function is primarily used for debugging.
 */
int drm_freebufs(struct inode *inode, struct file *filp,
		 unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_free_t request;
	int i;
	int idx;
	drm_buf_t *buf;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if (!dma)
		return -EINVAL;

	if (copy_from_user(&request,
			   (drm_buf_free_t __user *) arg, sizeof(request)))
		return -EFAULT;

	DRM_DEBUG("%d\n", request.count);
	for (i = 0; i < request.count; i++) {
		if (copy_from_user(&idx, &request.list[i], sizeof(idx)))
			return -EFAULT;
		if (idx < 0 || idx >= dma->buf_count) {
			DRM_ERROR("Index %d (of %d max)\n",
				  idx, dma->buf_count - 1);
			return -EINVAL;
		}
		buf = dma->buflist[idx];
		if (buf->filp != filp) {
			DRM_ERROR("Process %d freeing buffer not owned\n",
				  current->pid);
			return -EINVAL;
		}
		drm_free_buffer(dev, buf);
	}

	return 0;
}

/**
 * Maps all of the DMA buffers into client-virtual space (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Maps the AGP or SG buffer region with do_mmap(), and copies information
 * about each buffer into user space. The PCI buffers are already mapped on the
 * addbufs_pci() call.
 */
int drm_mapbufs(struct inode *inode, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_map_t __user *argp = (void __user *)arg;
	int retcode = 0;
	const int zero = 0;
	unsigned long virtual;
	unsigned long address;
	drm_buf_map_t request;
	int i;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if (!dma)
		return -EINVAL;

	spin_lock(&dev->count_lock);
	if (atomic_read(&dev->buf_alloc)) {
		spin_unlock(&dev->count_lock);
		return -EBUSY;
	}
	dev->buf_use++;		/* Can't allocate more after this call */
	spin_unlock(&dev->count_lock);

	if (copy_from_user(&request, argp, sizeof(request)))
		return -EFAULT;

	if (request.count >= dma->buf_count) {
		if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP))
		    || (drm_core_check_feature(dev, DRIVER_SG)
			&& (dma->flags & _DRM_DMA_USE_SG))
		    || (drm_core_check_feature(dev, DRIVER_FB_DMA)
			&& (dma->flags & _DRM_DMA_USE_FB))) {
			drm_map_t *map = dev->agp_buffer_map;
			unsigned long token = dev->agp_buffer_token;

			if (!map) {
				retcode = -EINVAL;
				goto done;
			}

			down_write(&current->mm->mmap_sem);
			virtual = do_mmap(filp, 0, map->size,
					  PROT_READ | PROT_WRITE,
					  MAP_SHARED, token);
			up_write(&current->mm->mmap_sem);
		} else {
			down_write(&current->mm->mmap_sem);
			virtual = do_mmap(filp, 0, dma->byte_count,
					  PROT_READ | PROT_WRITE,
					  MAP_SHARED, 0);
			up_write(&current->mm->mmap_sem);
		}
		if (virtual > -1024UL) {
			/* Real error */
			retcode = (signed long)virtual;
			goto done;
		}
		request.virtual = (void __user *)virtual;

		for (i = 0; i < dma->buf_count; i++) {
			if (copy_to_user(&request.list[i].idx,
					 &dma->buflist[i]->idx,
					 sizeof(request.list[0].idx))) {
				retcode = -EFAULT;
				goto done;
			}
			if (copy_to_user(&request.list[i].total,
					 &dma->buflist[i]->total,
					 sizeof(request.list[0].total))) {
				retcode = -EFAULT;
				goto done;
			}
			if (copy_to_user(&request.list[i].used,
					 &zero, sizeof(zero))) {
				retcode = -EFAULT;
				goto done;
			}
			address = virtual + dma->buflist[i]->offset;	/* *** */
			if (copy_to_user(&request.list[i].address,
					 &address, sizeof(address))) {
				retcode = -EFAULT;
				goto done;
			}
		}
	}
      done:
	request.count = dma->buf_count;
	DRM_DEBUG("%d buffers, retcode = %d\n", request.count, retcode);

	if (copy_to_user(argp, &request, sizeof(request)))
		return -EFAULT;

	return retcode;
}

/**
 * Compute size order.  Returns the exponent of the smaller power of two which
 * is greater or equal to given number.
 *
 * \param size size.
 * \return order.
 *
 * \todo Can be made faster.
 */
int drm_order(unsigned long size)
{
	int order;
	unsigned long tmp;

	for (order = 0, tmp = size >> 1; tmp; tmp >>= 1, order++) ;

	if (size & (size - 1))
		++order;

	return order;
}

EXPORT_SYMBOL(drm_order);