Implement igc_ethtool_get_rxfh_key_size() and extend
igc_ethtool_get_rxfh() to return the RSS key to userspace.

This can be tested using `ethtool -x <dev>`.

Signed-off-by: Kohei Enju <kohei@enjuk.jp>
Tested-by: Avigail Dahan <avigailx.dahan@intel.com>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 1b4075e7e8e6..661b044073ca 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1502,6 +1502,11 @@ void igc_write_rss_indir_tbl(struct igc_adapter *adapter)
 	}
 }
 
+static u32 igc_ethtool_get_rxfh_key_size(struct net_device *netdev)
+{
+	return IGC_RSS_KEY_SIZE;
+}
+
 static u32 igc_ethtool_get_rxfh_indir_size(struct net_device *netdev)
 {
 	return IGC_RETA_SIZE;
@@ -1514,10 +1519,13 @@ static int igc_ethtool_get_rxfh(struct net_device *netdev,
 	int i;
 
 	rxfh->hfunc = ETH_RSS_HASH_TOP;
-	if (!rxfh->indir)
-		return 0;
-	for (i = 0; i < IGC_RETA_SIZE; i++)
-		rxfh->indir[i] = adapter->rss_indir_tbl[i];
+
+	if (rxfh->indir)
+		for (i = 0; i < IGC_RETA_SIZE; i++)
+			rxfh->indir[i] = adapter->rss_indir_tbl[i];
+
+	if (rxfh->key)
+		memcpy(rxfh->key, adapter->rss_key, sizeof(adapter->rss_key));
 
 	return 0;
 }
@@ -2195,6 +2203,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.get_rxnfc		= igc_ethtool_get_rxnfc,
 	.set_rxnfc		= igc_ethtool_set_rxnfc,
 	.get_rx_ring_count	= igc_ethtool_get_rx_ring_count,
+	.get_rxfh_key_size	= igc_ethtool_get_rxfh_key_size,
 	.get_rxfh_indir_size	= igc_ethtool_get_rxfh_indir_size,
 	.get_rxfh		= igc_ethtool_get_rxfh,
 	.set_rxfh		= igc_ethtool_set_rxfh,
-- 
2.51.0