[PATCH net-next] net: enetc: add ethtool::get_channels support

[Wei Fang]

Since ETHTOOL_MSG_RSS_GET netlink message [1] has been applied to
ethtool tree, there is a netlink error when using "ethtool -x eno0"
command to get RSS information from fsl-enetc driver, and the user
cannot get the information, the error logs are as follows:

root@ls1028ardb:~# ./ethtool -x eno0
netlink error: Operation not supported

The rationale is that ethtool will issue a ETHTOOL_MSG_CHANNELS_GET
netlink message to get the number of Rx ring. However, the fsl-enetc
driver doesn't support ethtool::get_channels, so it directly returns
-EOPNOTSUPP error.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/ethtool.git/commit/?id=ffab99c1f3820e21d65686e030dcf2c4fd0a8bd0

Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
 .../net/ethernet/freescale/enetc/enetc_ethtool.c    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index e993ed04ab57..5fa1000b9b83 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -740,6 +740,17 @@ static int enetc_set_rxfh(struct net_device *ndev, const u32 *indir,
 	return err;
 }
 
+static void enetc_get_channels(struct net_device *ndev,
+			       struct ethtool_channels *ch)
+{
+	struct enetc_ndev_priv *priv = netdev_priv(ndev);
+
+	ch->max_rx = priv->num_rx_rings;
+	ch->max_tx = priv->num_tx_rings;
+	ch->rx_count = priv->num_rx_rings;
+	ch->tx_count = priv->num_tx_rings;
+}
+
 static void enetc_get_ringparam(struct net_device *ndev,
 				struct ethtool_ringparam *ring,
 				struct kernel_ethtool_ringparam *kernel_ring,
@@ -1196,6 +1207,7 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
 	.get_rxfh_indir_size = enetc_get_rxfh_indir_size,
 	.get_rxfh = enetc_get_rxfh,
 	.set_rxfh = enetc_set_rxfh,
+	.get_channels = enetc_get_channels,
 	.get_ringparam = enetc_get_ringparam,
 	.get_coalesce = enetc_get_coalesce,
 	.set_coalesce = enetc_set_coalesce,
@@ -1226,6 +1238,7 @@ static const struct ethtool_ops enetc_vf_ethtool_ops = {
 	.get_rxfh_indir_size = enetc_get_rxfh_indir_size,
 	.get_rxfh = enetc_get_rxfh,
 	.set_rxfh = enetc_set_rxfh,
+	.get_channels = enetc_get_channels,
 	.get_ringparam = enetc_get_ringparam,
 	.get_coalesce = enetc_get_coalesce,
 	.set_coalesce = enetc_set_coalesce,
-- 
2.25.1