[PATCH 4.9 031/241] drivers: net: xgene: Fix Rx checksum validation logic

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Iyappan Subramanian <isubramanian@xxxxxxx>


[ Upstream commit 0a0400c3094b5d5cedd479ddbf1329de74c09c4b ]

This patch fixes Rx checksum validation logic and
adds NETIF_F_RXCSUM flag.

Signed-off-by: Iyappan Subramanian <isubramanian@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.c |   27 ++++++++++++++---------
 1 file changed, 17 insertions(+), 10 deletions(-)

--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
@@ -505,14 +505,24 @@ static netdev_tx_t xgene_enet_start_xmit
 	return NETDEV_TX_OK;
 }
 
-static void xgene_enet_skip_csum(struct sk_buff *skb)
+static void xgene_enet_rx_csum(struct sk_buff *skb)
 {
+	struct net_device *ndev = skb->dev;
 	struct iphdr *iph = ip_hdr(skb);
 
-	if (!ip_is_fragment(iph) ||
-	    (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)) {
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	}
+	if (!(ndev->features & NETIF_F_RXCSUM))
+		return;
+
+	if (skb->protocol != htons(ETH_P_IP))
+		return;
+
+	if (ip_is_fragment(iph))
+		return;
+
+	if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
+		return;
+
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
 }
 
 static int xgene_enet_rx_frame(struct xgene_enet_desc_ring *rx_ring,
@@ -555,10 +565,7 @@ static int xgene_enet_rx_frame(struct xg
 
 	skb_checksum_none_assert(skb);
 	skb->protocol = eth_type_trans(skb, ndev);
-	if (likely((ndev->features & NETIF_F_IP_CSUM) &&
-		   skb->protocol == htons(ETH_P_IP))) {
-		xgene_enet_skip_csum(skb);
-	}
+	xgene_enet_rx_csum(skb);
 
 	rx_ring->rx_packets++;
 	rx_ring->rx_bytes += datalen;
@@ -1725,7 +1732,7 @@ static int xgene_enet_probe(struct platf
 	xgene_enet_setup_ops(pdata);
 
 	if (pdata->phy_mode == PHY_INTERFACE_MODE_XGMII) {
-		ndev->features |= NETIF_F_TSO;
+		ndev->features |= NETIF_F_TSO | NETIF_F_RXCSUM;
 		spin_lock_init(&pdata->mss_lock);
 	}
 	ndev->hw_features = ndev->features;