netdev: ethtool RXHASH flag

This adds ethtool and device feature flag to allow control
of receive hashing offload.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index f4cb6b6..73c81ed 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -121,7 +121,7 @@
  * NETIF_F_xxx values in include/linux/netdevice.h
  */
 static const u32 flags_dup_features =
-	(ETH_FLAG_LRO | ETH_FLAG_NTUPLE);
+	(ETH_FLAG_LRO | ETH_FLAG_NTUPLE | ETH_FLAG_RXHASH);
 
 u32 ethtool_op_get_flags(struct net_device *dev)
 {
@@ -152,6 +152,11 @@
 		features &= ~NETIF_F_NTUPLE;
 	}
 
+	if (data & ETH_FLAG_RXHASH)
+		features |= NETIF_F_RXHASH;
+	else
+		features &= ~NETIF_F_RXHASH;
+
 	dev->features = features;
 	return 0;
 }