net/sfc: support flow control settings

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

@@ -5,6 +5,7 @@
 ;
 [Features]
 Link status          = Y
+Flow control         = Y
 L3 checksum offload  = P
 L4 checksum offload  = P
 Basic stats          = Y

doc/guides/nics/sfc_efx.rst

@@ -53,6 +53,8 @@ SFC EFX PMD has support for:
 - Extended statistics (see Solarflare Server Adapter User's Guide for
   the statistics description)
 
+- Basic flow control
+
 
 Non-supported Features
 ----------------------

drivers/net/sfc/sfc_ethdev.c

@@ -452,6 +452,102 @@ sfc_xstats_get_names(struct rte_eth_dev *dev,
 	return nstats;
 }
 
+static int
+sfc_flow_ctrl_get(struct rte_eth_dev *dev, struct rte_eth_fc_conf *fc_conf)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+	unsigned int wanted_fc, link_fc;
+
+	memset(fc_conf, 0, sizeof(*fc_conf));
+
+	sfc_adapter_lock(sa);
+
+	if (sa->state == SFC_ADAPTER_STARTED)
+		efx_mac_fcntl_get(sa->nic, &wanted_fc, &link_fc);
+	else
+		link_fc = sa->port.flow_ctrl;
+
+	switch (link_fc) {
+	case 0:
+		fc_conf->mode = RTE_FC_NONE;
+		break;
+	case EFX_FCNTL_RESPOND:
+		fc_conf->mode = RTE_FC_RX_PAUSE;
+		break;
+	case EFX_FCNTL_GENERATE:
+		fc_conf->mode = RTE_FC_TX_PAUSE;
+		break;
+	case (EFX_FCNTL_RESPOND | EFX_FCNTL_GENERATE):
+		fc_conf->mode = RTE_FC_FULL;
+		break;
+	default:
+		sfc_err(sa, "%s: unexpected flow control value %#x",
+			__func__, link_fc);
+	}
+
+	fc_conf->autoneg = sa->port.flow_ctrl_autoneg;
+
+	sfc_adapter_unlock(sa);
+
+	return 0;
+}
+
+static int
+sfc_flow_ctrl_set(struct rte_eth_dev *dev, struct rte_eth_fc_conf *fc_conf)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+	struct sfc_port *port = &sa->port;
+	unsigned int fcntl;
+	int rc;
+
+	if (fc_conf->high_water != 0 || fc_conf->low_water != 0 ||
+	    fc_conf->pause_time != 0 || fc_conf->send_xon != 0 ||
+	    fc_conf->mac_ctrl_frame_fwd != 0) {
+		sfc_err(sa, "unsupported flow control settings specified");
+		rc = EINVAL;
+		goto fail_inval;
+	}
+
+	switch (fc_conf->mode) {
+	case RTE_FC_NONE:
+		fcntl = 0;
+		break;
+	case RTE_FC_RX_PAUSE:
+		fcntl = EFX_FCNTL_RESPOND;
+		break;
+	case RTE_FC_TX_PAUSE:
+		fcntl = EFX_FCNTL_GENERATE;
+		break;
+	case RTE_FC_FULL:
+		fcntl = EFX_FCNTL_RESPOND | EFX_FCNTL_GENERATE;
+		break;
+	default:
+		rc = EINVAL;
+		goto fail_inval;
+	}
+
+	sfc_adapter_lock(sa);
+
+	if (sa->state == SFC_ADAPTER_STARTED) {
+		rc = efx_mac_fcntl_set(sa->nic, fcntl, fc_conf->autoneg);
+		if (rc != 0)
+			goto fail_mac_fcntl_set;
+	}
+
+	port->flow_ctrl = fcntl;
+	port->flow_ctrl_autoneg = fc_conf->autoneg;
+
+	sfc_adapter_unlock(sa);
+
+	return 0;
+
+fail_mac_fcntl_set:
+	sfc_adapter_unlock(sa);
+fail_inval:
+	SFC_ASSERT(rc > 0);
+	return -rc;
+}
+
 static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.dev_configure			= sfc_dev_configure,
 	.dev_start			= sfc_dev_start,
@@ -466,6 +562,8 @@ static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.rx_queue_release		= sfc_rx_queue_release,
 	.tx_queue_setup			= sfc_tx_queue_setup,
 	.tx_queue_release		= sfc_tx_queue_release,
+	.flow_ctrl_get			= sfc_flow_ctrl_get,
+	.flow_ctrl_set			= sfc_flow_ctrl_set,
 };
 
 static int

drivers/net/sfc/sfc_port.c

@@ -79,6 +79,13 @@ sfc_port_start(struct sfc_adapter *sa)
 	if (rc != 0)
 		goto fail_port_init;
 
+	sfc_log_init(sa, "set flow control to %#x autoneg=%u",
+		     port->flow_ctrl, port->flow_ctrl_autoneg);
+	rc = efx_mac_fcntl_set(sa->nic, port->flow_ctrl,
+			       port->flow_ctrl_autoneg);
+	if (rc != 0)
+		goto fail_mac_fcntl_set;
+
 	sfc_log_init(sa, "set MAC PDU %u", (unsigned int)port->pdu);
 	rc = efx_mac_pdu_set(sa->nic, port->pdu);
 	if (rc != 0)
@@ -124,6 +131,7 @@ fail_mac_stats_periodic:
 fail_mac_filter_set:
 fail_mac_addr_set:
 fail_mac_pdu_set:
+fail_mac_fcntl_set:
 	efx_port_fini(sa->nic);
 
 fail_port_init: