int register_virtio_device()

in virtio.c [392:442]

• 32 lines of code
• 4 McCabe index (conditional complexity)

int register_virtio_device(struct virtio_device *dev)
{
	int err;

	dev->dev.bus = &virtio_bus;
	device_initialize(&dev->dev);

	/* Assign a unique device index and hence name. */
	err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
	if (err < 0)
		goto out;

	dev->index = err;
	dev_set_name(&dev->dev, "virtio%u", dev->index);

	err = virtio_device_of_init(dev);
	if (err)
		goto out_ida_remove;

	spin_lock_init(&dev->config_lock);
	dev->config_enabled = false;
	dev->config_change_pending = false;

	/* We always start by resetting the device, in case a previous
	 * driver messed it up.  This also tests that code path a little. */
	dev->config->reset(dev);

	/* Acknowledge that we've seen the device. */
	virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);

	INIT_LIST_HEAD(&dev->vqs);
	spin_lock_init(&dev->vqs_list_lock);

	/*
	 * device_add() causes the bus infrastructure to look for a matching
	 * driver.
	 */
	err = device_add(&dev->dev);
	if (err)
		goto out_of_node_put;

	return 0;

out_of_node_put:
	of_node_put(dev->dev.of_node);
out_ida_remove:
	ida_simple_remove(&virtio_index_ida, dev->index);
out:
	virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
	return err;
}