net/sfc: support deferred start of transmit queues

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andrew Lee <alee@solarflare.com>
Reviewed-by: Robert Stonehouse <rstonehouse@solarflare.com>

doc/guides/nics/features/sfc_efx.ini

@@ -7,7 +7,7 @@
 Speed capabilities   = Y
 Link status          = Y
 Link status event    = Y
-Queue start/stop     = P
+Queue start/stop     = Y
 MTU update           = Y
 Jumbo frame          = Y
 Scattered Rx         = Y

doc/guides/nics/sfc_efx.rst

@@ -71,7 +71,7 @@ SFC EFX PMD has support for:
 
 - Scattered Rx DMA for packet that are larger that a single Rx descriptor
 
-- Deferred receive queue start
+- Deferred receive and transmit queue start
 
 
 Non-supported Features

drivers/net/sfc/sfc_ethdev.c

@@ -864,6 +864,7 @@ sfc_tx_queue_info_get(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 
 	qinfo->conf.txq_flags = txq_info->txq->flags;
 	qinfo->conf.tx_free_thresh = txq_info->txq->free_thresh;
+	qinfo->conf.tx_deferred_start = txq_info->deferred_start;
 	qinfo->nb_desc = txq_info->entries;
 
 	sfc_adapter_unlock(sa);
@@ -935,6 +936,54 @@ sfc_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	return 0;
 }
 
+static int
+sfc_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+	int rc;
+
+	sfc_log_init(sa, "TxQ = %u", tx_queue_id);
+
+	sfc_adapter_lock(sa);
+
+	rc = EINVAL;
+	if (sa->state != SFC_ADAPTER_STARTED)
+		goto fail_not_started;
+
+	rc = sfc_tx_qstart(sa, tx_queue_id);
+	if (rc != 0)
+		goto fail_tx_qstart;
+
+	sa->txq_info[tx_queue_id].deferred_started = B_TRUE;
+
+	sfc_adapter_unlock(sa);
+	return 0;
+
+fail_tx_qstart:
+
+fail_not_started:
+	sfc_adapter_unlock(sa);
+	SFC_ASSERT(rc > 0);
+	return -rc;
+}
+
+static int
+sfc_tx_queue_stop(struct rte_eth_dev *dev, uint16_t tx_queue_id)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+
+	sfc_log_init(sa, "TxQ = %u", tx_queue_id);
+
+	sfc_adapter_lock(sa);
+
+	sfc_tx_qstop(sa, tx_queue_id);
+
+	sa->txq_info[tx_queue_id].deferred_started = B_FALSE;
+
+	sfc_adapter_unlock(sa);
+	return 0;
+}
+
 static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.dev_configure			= sfc_dev_configure,
 	.dev_start			= sfc_dev_start,
@@ -955,6 +1004,8 @@ static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.mtu_set			= sfc_dev_set_mtu,
 	.rx_queue_start			= sfc_rx_queue_start,
 	.rx_queue_stop			= sfc_rx_queue_stop,
+	.tx_queue_start			= sfc_tx_queue_start,
+	.tx_queue_stop			= sfc_tx_queue_stop,
 	.rx_queue_setup			= sfc_rx_queue_setup,
 	.rx_queue_release		= sfc_rx_queue_release,
 	.rx_queue_count			= sfc_rx_queue_count,

drivers/net/sfc/sfc_tx.c

@@ -72,11 +72,6 @@ sfc_tx_qcheck_conf(struct sfc_adapter *sa, uint16_t nb_tx_desc,
 		rc = EINVAL;
 	}
 
-	if (tx_conf->tx_deferred_start != 0) {
-		sfc_err(sa, "TX queue deferred start is not supported (yet)");
-		rc = EINVAL;
-	}
-
 	if (tx_conf->tx_thresh.pthresh != 0 ||
 	    tx_conf->tx_thresh.hthresh != 0 ||
 	    tx_conf->tx_thresh.wthresh != 0) {
@@ -198,6 +193,7 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 	evq->txq = txq;
 
 	txq_info->txq = txq;
+	txq_info->deferred_start = (tx_conf->tx_deferred_start != 0);
 
 	return 0;
 
@@ -425,6 +421,9 @@ sfc_tx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 
 	txq = txq_info->txq;
 
+	if (txq->state == SFC_TXQ_INITIALIZED)
+		return;
+
 	SFC_ASSERT(txq->state & SFC_TXQ_STARTED);
 
 	txq->state &= ~SFC_TXQ_RUNNING;
@@ -497,10 +496,13 @@ sfc_tx_start(struct sfc_adapter *sa)
 		goto fail_efx_tx_init;
 
 	for (sw_index = 0; sw_index < sa->txq_count; ++sw_index) {
+		if (!(sa->txq_info[sw_index].deferred_start) ||
+		    sa->txq_info[sw_index].deferred_started) {
 			rc = sfc_tx_qstart(sa, sw_index);
 			if (rc != 0)
 				goto fail_tx_qstart;
 		}
+	}
 
 	return 0;
 

drivers/net/sfc/sfc_tx.h

@@ -91,6 +91,8 @@ sfc_txq_sw_index(const struct sfc_txq *txq)
 struct sfc_txq_info {
 	unsigned int		entries;
 	struct sfc_txq		*txq;
+	boolean_t		deferred_start;
+	boolean_t		deferred_started;
 };
 
 int sfc_tx_init(struct sfc_adapter *sa);