net/ngbe: support Tx done cleanup

Add support for API rte_eth_tx_done_cleanup().

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>

doc/guides/nics/features/ngbe.ini

@@ -7,6 +7,7 @@
 Speed capabilities   = Y
 Link status          = Y
 Link status event    = Y
+Free Tx mbuf on demand = Y
 Queue start/stop     = Y
 Burst mode info      = Y
 MTU update           = Y

drivers/net/ngbe/ngbe_ethdev.c

@@ -3100,6 +3100,7 @@ static const struct eth_dev_ops ngbe_eth_dev_ops = {
 	.timesync_adjust_time       = ngbe_timesync_adjust_time,
 	.timesync_read_time         = ngbe_timesync_read_time,
 	.timesync_write_time        = ngbe_timesync_write_time,
+	.tx_done_cleanup            = ngbe_dev_tx_done_cleanup,
 };
 
 RTE_PMD_REGISTER_PCI(net_ngbe, rte_ngbe_pmd);

drivers/net/ngbe/ngbe_rxtx.c

@@ -1713,6 +1713,95 @@ ngbe_tx_queue_release_mbufs(struct ngbe_tx_queue *txq)
 	}
 }
 
+static int
+ngbe_tx_done_cleanup_full(struct ngbe_tx_queue *txq, uint32_t free_cnt)
+{
+	struct ngbe_tx_entry *swr_ring = txq->sw_ring;
+	uint16_t i, tx_last, tx_id;
+	uint16_t nb_tx_free_last;
+	uint16_t nb_tx_to_clean;
+	uint32_t pkt_cnt;
+
+	/* Start free mbuf from the next of tx_tail */
+	tx_last = txq->tx_tail;
+	tx_id  = swr_ring[tx_last].next_id;
+
+	if (txq->nb_tx_free == 0 && ngbe_xmit_cleanup(txq))
+		return 0;
+
+	nb_tx_to_clean = txq->nb_tx_free;
+	nb_tx_free_last = txq->nb_tx_free;
+	if (!free_cnt)
+		free_cnt = txq->nb_tx_desc;
+
+	/* Loop through swr_ring to count the amount of
+	 * freeable mubfs and packets.
+	 */
+	for (pkt_cnt = 0; pkt_cnt < free_cnt; ) {
+		for (i = 0; i < nb_tx_to_clean &&
+			pkt_cnt < free_cnt &&
+			tx_id != tx_last; i++) {
+			if (swr_ring[tx_id].mbuf != NULL) {
+				rte_pktmbuf_free_seg(swr_ring[tx_id].mbuf);
+				swr_ring[tx_id].mbuf = NULL;
+
+				/*
+				 * last segment in the packet,
+				 * increment packet count
+				 */
+				pkt_cnt += (swr_ring[tx_id].last_id == tx_id);
+			}
+
+			tx_id = swr_ring[tx_id].next_id;
+		}
+
+		if (pkt_cnt < free_cnt) {
+			if (ngbe_xmit_cleanup(txq))
+				break;
+
+			nb_tx_to_clean = txq->nb_tx_free - nb_tx_free_last;
+			nb_tx_free_last = txq->nb_tx_free;
+		}
+	}
+
+	return (int)pkt_cnt;
+}
+
+static int
+ngbe_tx_done_cleanup_simple(struct ngbe_tx_queue *txq,
+			uint32_t free_cnt)
+{
+	int i, n, cnt;
+
+	if (free_cnt == 0 || free_cnt > txq->nb_tx_desc)
+		free_cnt = txq->nb_tx_desc;
+
+	cnt = free_cnt - free_cnt % txq->tx_free_thresh;
+
+	for (i = 0; i < cnt; i += n) {
+		if (txq->nb_tx_desc - txq->nb_tx_free < txq->tx_free_thresh)
+			break;
+
+		n = ngbe_tx_free_bufs(txq);
+
+		if (n == 0)
+			break;
+	}
+
+	return i;
+}
+
+int
+ngbe_dev_tx_done_cleanup(void *tx_queue, uint32_t free_cnt)
+{
+	struct ngbe_tx_queue *txq = (struct ngbe_tx_queue *)tx_queue;
+	if (txq->offloads == 0 &&
+		txq->tx_free_thresh >= RTE_PMD_NGBE_TX_MAX_BURST)
+		return ngbe_tx_done_cleanup_simple(txq, free_cnt);
+
+	return ngbe_tx_done_cleanup_full(txq, free_cnt);
+}
+
 static void
 ngbe_tx_free_swring(struct ngbe_tx_queue *txq)
 {

drivers/net/ngbe/ngbe_rxtx.h

@@ -368,6 +368,7 @@ struct ngbe_txq_ops {
 void ngbe_set_tx_function(struct rte_eth_dev *dev, struct ngbe_tx_queue *txq);
 
 void ngbe_set_rx_function(struct rte_eth_dev *dev);
+int ngbe_dev_tx_done_cleanup(void *tx_queue, uint32_t free_cnt);
 
 uint64_t ngbe_get_tx_port_offloads(struct rte_eth_dev *dev);
 uint64_t ngbe_get_rx_queue_offloads(struct rte_eth_dev *dev);