From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu, 4 Jan 2018 16:10:19 +0100
Subject: nfp: add basic multicast filtering
Patch-mainline: v4.16-rc1
Git-commit: d0adb51edb73c94a595bfa9d9bd8b35977e74fbf
References: bsc#1109837

We currently always pass all multicast traffic through.
Only set L2MC when actually needed.  Since the driver
was not making use of the capability to filter out mcast
frames, some FW projects don't implement it any more.
Don't warn users if capability is not present (like we
do for promisc flag).  The lack of L2MC capability is
assumed to mean all multicast traffic goes through.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -2852,6 +2852,11 @@ static void nfp_net_set_rx_mode(struct n
 
 	new_ctrl = nn->dp.ctrl;
 
+	if (!netdev_mc_empty(netdev) || netdev->flags & IFF_ALLMULTI)
+		new_ctrl |= nn->cap & NFP_NET_CFG_CTRL_L2MC;
+	else
+		new_ctrl &= ~NFP_NET_CFG_CTRL_L2MC;
+
 	if (netdev->flags & IFF_PROMISC) {
 		if (nn->cap & NFP_NET_CFG_CTRL_PROMISC)
 			new_ctrl |= NFP_NET_CFG_CTRL_PROMISC;
@@ -3790,8 +3795,6 @@ int nfp_net_init(struct nfp_net *nn)
 	/* Allow L2 Broadcast and Multicast through by default, if supported */
 	if (nn->cap & NFP_NET_CFG_CTRL_L2BC)
 		nn->dp.ctrl |= NFP_NET_CFG_CTRL_L2BC;
-	if (nn->cap & NFP_NET_CFG_CTRL_L2MC)
-		nn->dp.ctrl |= NFP_NET_CFG_CTRL_L2MC;
 
 	/* Allow IRQ moderation, if supported */
 	if (nn->cap & NFP_NET_CFG_CTRL_IRQMOD) {