static int riocm_ch_receive()

in rio_cm.c [866:927]

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

static int riocm_ch_receive(struct rio_channel *ch, void **buf, long timeout)
{
	void *rxmsg = NULL;
	int i, ret = 0;
	long wret;

	if (!riocm_cmp(ch, RIO_CM_CONNECTED)) {
		ret = -EAGAIN;
		goto out;
	}

	if (ch->rx_ring.inuse_cnt == RIOCM_RX_RING_SIZE) {
		/* If we do not have entries to track buffers given to upper
		 * layer, reject request.
		 */
		ret = -ENOMEM;
		goto out;
	}

	wret = wait_for_completion_interruptible_timeout(&ch->comp, timeout);

	riocm_debug(WAIT, "wait on %d returned %ld", ch->id, wret);

	if (!wret)
		ret = -ETIME;
	else if (wret == -ERESTARTSYS)
		ret = -EINTR;
	else
		ret = riocm_cmp(ch, RIO_CM_CONNECTED) ? 0 : -ECONNRESET;

	if (ret)
		goto out;

	spin_lock_bh(&ch->lock);

	rxmsg = ch->rx_ring.buf[ch->rx_ring.tail];
	ch->rx_ring.buf[ch->rx_ring.tail] = NULL;
	ch->rx_ring.count--;
	ch->rx_ring.tail++;
	ch->rx_ring.tail %= RIOCM_RX_RING_SIZE;
	ret = -ENOMEM;

	for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
		if (ch->rx_ring.inuse[i] == NULL) {
			ch->rx_ring.inuse[i] = rxmsg;
			ch->rx_ring.inuse_cnt++;
			ret = 0;
			break;
		}
	}

	if (ret) {
		/* We have no entry to store pending message: drop it */
		kfree(rxmsg);
		rxmsg = NULL;
	}

	spin_unlock_bh(&ch->lock);
out:
	*buf = rxmsg;
	return ret;
}