net/ionic: ring doorbell once at the end of each burst

This improves performance.

Signed-off-by: Andrew Boyer <aboyer@pensando.io>

diff --git a/drivers/net/ionic/ionic_rxtx.c b/drivers/net/ionic/ionic_rxtx.c
index 5236cae..bb67c49 100644 (file)
--- a/drivers/net/ionic/ionic_rxtx.c
+++ b/drivers/net/ionic/ionic_rxtx.c
@@ -47,8 +47,6 @@
 #include "ionic_lif.h"
 #include "ionic_rxtx.h"
 
-#define IONIC_RX_RING_DOORBELL_STRIDE          (32 - 1)
-
 /*********************************************************************
  *
  *  TX functions
@@ -322,9 +320,6 @@ ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
        }
 
        q->head_idx = Q_NEXT_TO_POST(q, 1);
-
-       if (done)
-               ionic_q_flush(q);
 }
 
 static struct ionic_txq_desc *
@@ -341,8 +336,7 @@ ionic_tx_tso_next(struct ionic_tx_qcq *txq, struct ionic_txq_sg_elem **elem)
 }
 
 static int
-ionic_tx_tso(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
-               bool not_xmit_more)
+ionic_tx_tso(struct ionic_tx_qcq *txq, struct rte_mbuf *txm)
 {
        struct ionic_queue *q = &txq->qcq.q;
        struct ionic_tx_stats *stats = &txq->stats;
@@ -410,7 +404,7 @@ ionic_tx_tso(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
                        hdrlen, mss,
                        encap,
                        vlan_tci, has_vlan,
-                       start, done && not_xmit_more);
+                       start, done);
                desc = ionic_tx_tso_next(txq, &elem);
                start = false;
                seglen = mss;
@@ -451,7 +445,7 @@ ionic_tx_tso(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
                                hdrlen, mss,
                                encap,
                                vlan_tci, has_vlan,
-                               start, done && not_xmit_more);
+                               start, done);
                        desc = ionic_tx_tso_next(txq, &elem);
                        start = false;
                }
@@ -465,8 +459,7 @@ ionic_tx_tso(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
 }
 
 static __rte_always_inline int
-ionic_tx(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
-               bool not_xmit_more)
+ionic_tx(struct ionic_tx_qcq *txq, struct rte_mbuf *txm)
 {
        struct ionic_queue *q = &txq->qcq.q;
        struct ionic_txq_desc *desc, *desc_base = q->base;
@@ -531,9 +524,6 @@ ionic_tx(struct ionic_tx_qcq *txq, struct rte_mbuf *txm,
 
        q->head_idx = Q_NEXT_TO_POST(q, 1);
 
-       if (not_xmit_more)
-               ionic_q_flush(q);
-
        return 0;
 }
 
@@ -548,7 +538,6 @@ ionic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
        uint32_t bytes_tx = 0;
        uint16_t nb_tx = 0;
        int err;
-       bool last;
 
        /* Cleaning old buffers */
        ionic_tx_flush(txq);
@@ -559,8 +548,6 @@ ionic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
        }
 
        while (nb_tx < nb_pkts) {
-               last = (nb_tx == (nb_pkts - 1));
-
                next_q_head_idx = Q_NEXT_TO_POST(q, 1);
                if ((next_q_head_idx & 0x3) == 0) {
                        struct ionic_txq_desc *desc_base = q->base;
@@ -569,13 +556,11 @@ ionic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                }
 
                if (tx_pkts[nb_tx]->ol_flags & PKT_TX_TCP_SEG)
-                       err = ionic_tx_tso(txq, tx_pkts[nb_tx], last);
+                       err = ionic_tx_tso(txq, tx_pkts[nb_tx]);
                else
-                       err = ionic_tx(txq, tx_pkts[nb_tx], last);
+                       err = ionic_tx(txq, tx_pkts[nb_tx]);
                if (err) {
                        stats->drop += nb_pkts - nb_tx;
-                       if (nb_tx > 0)
-                               ionic_q_flush(q);
                        break;
                }
 
@@ -583,6 +568,11 @@ ionic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                nb_tx++;
        }
 
+       if (nb_tx > 0) {
+               rte_wmb();
+               ionic_q_flush(q);
+       }
+
        stats->packets += nb_tx;
        stats->bytes += bytes_tx;
 
@@ -954,7 +944,6 @@ ionic_rx_fill(struct ionic_rx_qcq *rxq, uint32_t len)
        void **info;
        rte_iova_t dma_addr;
        uint32_t i, j, nsegs, buf_size, size;
-       bool ring_doorbell;
 
        buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
                RTE_PKTMBUF_HEADROOM);
@@ -1010,17 +999,13 @@ ionic_rx_fill(struct ionic_rx_qcq *rxq, uint32_t len)
                        IONIC_PRINT(ERR, "Rx SG size is not sufficient (%d < %d)",
                                size, len);
 
-               ring_doorbell = ((q->head_idx + 1) &
-                       IONIC_RX_RING_DOORBELL_STRIDE) == 0;
-
                info[0] = rxm;
 
                q->head_idx = Q_NEXT_TO_POST(q, 1);
-
-               if (ring_doorbell)
-                       ionic_q_flush(q);
        }
 
+       ionic_q_flush(q);
+
        return 0;
 }