enic: add ethtool get_channel support

Add .get_channel to enic_ethtool_ops to enable basic ethtool -l
support to get the current channel configuration.

Note that the driver does not support dynamically changing queue
configuration, so .set_channel is intentionally unused. Instead, users
should use Cisco's hardware management tools (UCSM/IMC) to modify
virtual interface card configuration out of band.

Signed-off-by: Jon Kohler <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/cisco/enic/enic_ethtool.c

···
 	return 0;
 }
 
+static void enic_get_channels(struct net_device *netdev,
+			      struct ethtool_channels *channels)
+{
+	struct enic *enic = netdev_priv(netdev);
+
+	switch (vnic_dev_get_intr_mode(enic->vdev)) {
+	case VNIC_DEV_INTR_MODE_MSIX:
+		channels->max_rx = ENIC_RQ_MAX;
+		channels->max_tx = ENIC_WQ_MAX;
+		channels->rx_count = enic->rq_count;
+		channels->tx_count = enic->wq_count;
+		break;
+	case VNIC_DEV_INTR_MODE_MSI:
+	case VNIC_DEV_INTR_MODE_INTX:
+		channels->max_combined = 1;
+		channels->combined_count = 1;
+		break;
+	default:
+		break;
+	}
+}
+
 static const struct ethtool_ops enic_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
 				     ETHTOOL_COALESCE_USE_ADAPTIVE_RX |
···
 	.set_rxfh = enic_set_rxfh,
 	.get_link_ksettings = enic_get_ksettings,
 	.get_ts_info = enic_get_ts_info,
+	.get_channels = enic_get_channels,
 };
 
 void enic_set_ethtool_ops(struct net_device *netdev)