static int ntb_process_rxc()

in ntb_transport.c [1614:1684]

• 56 lines of code
• 6 McCabe index (conditional complexity)

static int ntb_process_rxc(struct ntb_transport_qp *qp)
{
	struct ntb_payload_header *hdr;
	struct ntb_queue_entry *entry;
	void *offset;

	offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
	hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);

	dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
		qp->qp_num, hdr->ver, hdr->len, hdr->flags);

	if (!(hdr->flags & DESC_DONE_FLAG)) {
		dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
		qp->rx_ring_empty++;
		return -EAGAIN;
	}

	if (hdr->flags & LINK_DOWN_FLAG) {
		dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
		ntb_qp_link_down(qp);
		hdr->flags = 0;
		return -EAGAIN;
	}

	if (hdr->ver != (u32)qp->rx_pkts) {
		dev_dbg(&qp->ndev->pdev->dev,
			"version mismatch, expected %llu - got %u\n",
			qp->rx_pkts, hdr->ver);
		qp->rx_err_ver++;
		return -EIO;
	}

	entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
	if (!entry) {
		dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
		qp->rx_err_no_buf++;
		return -EAGAIN;
	}

	entry->rx_hdr = hdr;
	entry->rx_index = qp->rx_index;

	if (hdr->len > entry->len) {
		dev_dbg(&qp->ndev->pdev->dev,
			"receive buffer overflow! Wanted %d got %d\n",
			hdr->len, entry->len);
		qp->rx_err_oflow++;

		entry->len = -EIO;
		entry->flags |= DESC_DONE_FLAG;

		ntb_complete_rxc(qp);
	} else {
		dev_dbg(&qp->ndev->pdev->dev,
			"RX OK index %u ver %u size %d into buf size %d\n",
			qp->rx_index, hdr->ver, hdr->len, entry->len);

		qp->rx_bytes += hdr->len;
		qp->rx_pkts++;

		entry->len = hdr->len;

		ntb_async_rx(entry, offset);
	}

	qp->rx_index++;
	qp->rx_index %= qp->rx_max_entry;

	return 0;
}