static int ioctl_create_iso_context()

in core-cdev.c [971:1046]

• 62 lines of code
• 16 McCabe index (conditional complexity)

static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
{
	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
	struct fw_iso_context *context;
	union fw_iso_callback cb;
	int ret;

	BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
		     FW_CDEV_ISO_CONTEXT_RECEIVE  != FW_ISO_CONTEXT_RECEIVE  ||
		     FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL !=
					FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL);

	switch (a->type) {
	case FW_ISO_CONTEXT_TRANSMIT:
		if (a->speed > SCODE_3200 || a->channel > 63)
			return -EINVAL;

		cb.sc = iso_callback;
		break;

	case FW_ISO_CONTEXT_RECEIVE:
		if (a->header_size < 4 || (a->header_size & 3) ||
		    a->channel > 63)
			return -EINVAL;

		cb.sc = iso_callback;
		break;

	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
		cb.mc = iso_mc_callback;
		break;

	default:
		return -EINVAL;
	}

	if (a->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
		context = fw_iso_mc_context_create(client->device->card, cb.mc,
						   client);
	else
		context = fw_iso_context_create(client->device->card, a->type,
						a->channel, a->speed,
						a->header_size, cb.sc, client);
	if (IS_ERR(context))
		return PTR_ERR(context);
	if (client->version < FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW)
		context->drop_overflow_headers = true;

	/* We only support one context at this time. */
	spin_lock_irq(&client->lock);
	if (client->iso_context != NULL) {
		spin_unlock_irq(&client->lock);
		fw_iso_context_destroy(context);

		return -EBUSY;
	}
	if (!client->buffer_is_mapped) {
		ret = fw_iso_buffer_map_dma(&client->buffer,
					    client->device->card,
					    iso_dma_direction(context));
		if (ret < 0) {
			spin_unlock_irq(&client->lock);
			fw_iso_context_destroy(context);

			return ret;
		}
		client->buffer_is_mapped = true;
	}
	client->iso_closure = a->closure;
	client->iso_context = context;
	spin_unlock_irq(&client->lock);

	a->handle = 0;

	return 0;
}