nfp: add support for .get_pauseparam()

Show correct pause frame parameters for nfp. These parameters cannot
be configured, so .set_pauseparam() is not implemented. With this
change:

 #ethtool --show-pause enp1s0np0
 Pause parameters for enp1s0np0:
 Autonegotiate:  off
 RX:             on
 TX:             on
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220616133358.135305-1-simon.horman@corigine.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c

@@ -1460,6 +1460,23 @@ static int nfp_net_set_channels(struct net_device *netdev,
 	return nfp_net_set_num_rings(nn, total_rx, total_tx);
 }
 
+static void nfp_port_get_pauseparam(struct net_device *netdev,
+				    struct ethtool_pauseparam *pause)
+{
+	struct nfp_eth_table_port *eth_port;
+	struct nfp_port *port;
+
+	port = nfp_port_from_netdev(netdev);
+	eth_port = nfp_port_get_eth_port(port);
+	if (!eth_port)
+		return;
+
+	/* Currently pause frame support is fixed */
+	pause->autoneg = AUTONEG_DISABLE;
+	pause->rx_pause = 1;
+	pause->tx_pause = 1;
+}
+
 static const struct ethtool_ops nfp_net_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
 				     ETHTOOL_COALESCE_MAX_FRAMES |
@@ -1492,6 +1509,7 @@ static const struct ethtool_ops nfp_net_ethtool_ops = {
 	.set_link_ksettings	= nfp_net_set_link_ksettings,
 	.get_fecparam		= nfp_port_get_fecparam,
 	.set_fecparam		= nfp_port_set_fecparam,
+	.get_pauseparam		= nfp_port_get_pauseparam,
 };
 
 const struct ethtool_ops nfp_port_ethtool_ops = {
@@ -1509,6 +1527,7 @@ const struct ethtool_ops nfp_port_ethtool_ops = {
 	.set_link_ksettings	= nfp_net_set_link_ksettings,
 	.get_fecparam		= nfp_port_get_fecparam,
 	.set_fecparam		= nfp_port_set_fecparam,
+	.get_pauseparam		= nfp_port_get_pauseparam,
 };
 
 void nfp_net_set_ethtool_ops(struct net_device *netdev)