static int rio_mport_transfer_ioctl()

in devices/rio_mport_cdev.c [961:1006]

• 37 lines of code
• 10 McCabe index (conditional complexity)

static int rio_mport_transfer_ioctl(struct file *filp, void __user *arg)
{
	struct mport_cdev_priv *priv = filp->private_data;
	struct rio_transaction transaction;
	struct rio_transfer_io *transfer;
	enum dma_data_direction dir;
	int i, ret = 0;
	size_t size;

	if (unlikely(copy_from_user(&transaction, arg, sizeof(transaction))))
		return -EFAULT;

	if (transaction.count != 1) /* only single transfer for now */
		return -EINVAL;

	if ((transaction.transfer_mode &
	     priv->md->properties.transfer_mode) == 0)
		return -ENODEV;

	size = array_size(sizeof(*transfer), transaction.count);
	transfer = vmalloc(size);
	if (!transfer)
		return -ENOMEM;

	if (unlikely(copy_from_user(transfer,
				    (void __user *)(uintptr_t)transaction.block,
				    size))) {
		ret = -EFAULT;
		goto out_free;
	}

	dir = (transaction.dir == RIO_TRANSFER_DIR_READ) ?
					DMA_FROM_DEVICE : DMA_TO_DEVICE;
	for (i = 0; i < transaction.count && ret == 0; i++)
		ret = rio_dma_transfer(filp, transaction.transfer_mode,
			transaction.sync, dir, &transfer[i]);

	if (unlikely(copy_to_user((void __user *)(uintptr_t)transaction.block,
				  transfer, size)))
		ret = -EFAULT;

out_free:
	vfree(transfer);

	return ret;
}