net: convert xen-netfront to hw_features

Not tested in any way. The original code for offload setting seems broken
as it resets the features on every netback reconnect.

This will set GSO_ROBUST at device creation time (earlier than connect time).

RX checksum offload is forced on - so advertise as it is.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/xen-netfront.c

@@ -1148,6 +1148,8 @@ static const struct net_device_ops xennet_netdev_ops = {
 	.ndo_change_mtu	     = xennet_change_mtu,
 	.ndo_set_mac_address = eth_mac_addr,
 	.ndo_validate_addr   = eth_validate_addr,
+	.ndo_fix_features    = xennet_fix_features,
+	.ndo_set_features    = xennet_set_features,
 };
 
 static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
@@ -1209,7 +1211,9 @@ static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev
 	netdev->netdev_ops	= &xennet_netdev_ops;
 
 	netif_napi_add(netdev, &np->napi, xennet_poll, 64);
-	netdev->features        = NETIF_F_IP_CSUM;
+	netdev->features        = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
+				  NETIF_F_GSO_ROBUST;
+	netdev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
 
 	SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
 	SET_NETDEV_DEV(netdev, &dev->dev);
@@ -1509,52 +1513,40 @@ static int talk_to_netback(struct xenbus_device *dev,
 	return err;
 }
 
-static int xennet_set_sg(struct net_device *dev, u32 data)
+static u32 xennet_fix_features(struct net_device *dev, u32 features)
 {
-	if (data) {
-		struct netfront_info *np = netdev_priv(dev);
-		int val;
+	struct netfront_info *np = netdev_priv(dev);
+	int val;
 
+	if (features & NETIF_F_SG) {
 		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
 				 "%d", &val) < 0)
 			val = 0;
-		if (!val)
-			return -ENOSYS;
-	} else if (dev->mtu > ETH_DATA_LEN)
-		dev->mtu = ETH_DATA_LEN;
 
-	return ethtool_op_set_sg(dev, data);
-}
-
-static int xennet_set_tso(struct net_device *dev, u32 data)
-{
-	if (data) {
-		struct netfront_info *np = netdev_priv(dev);
-		int val;
+		if (!val)
+			features &= ~NETIF_F_SG;
+	}
 
+	if (features & NETIF_F_TSO) {
 		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
 				 "feature-gso-tcpv4", "%d", &val) < 0)
 			val = 0;
+
 		if (!val)
-			return -ENOSYS;
+			features &= ~NETIF_F_TSO;
 	}
 
-	return ethtool_op_set_tso(dev, data);
+	return features;
 }
 
-static void xennet_set_features(struct net_device *dev)
+static int xennet_set_features(struct net_device *dev, u32 features)
 {
-	/* Turn off all GSO bits except ROBUST. */
-	dev->features &= ~NETIF_F_GSO_MASK;
-	dev->features |= NETIF_F_GSO_ROBUST;
-	xennet_set_sg(dev, 0);
-
-	/* We need checksum offload to enable scatter/gather and TSO. */
-	if (!(dev->features & NETIF_F_IP_CSUM))
-		return;
+	if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
+		netdev_info(dev, "Reducing MTU because no SG offload");
+		dev->mtu = ETH_DATA_LEN;
+	}
 
-	if (!xennet_set_sg(dev, 1))
-		xennet_set_tso(dev, 1);
+	return 0;
 }
 
 static int xennet_connect(struct net_device *dev)
@@ -1581,7 +1573,7 @@ static int xennet_connect(struct net_device *dev)
 	if (err)
 		return err;
 
-	xennet_set_features(dev);
+	netdev_update_features(dev);
 
 	spin_lock_bh(&np->rx_lock);
 	spin_lock_irq(&np->tx_lock);
@@ -1709,9 +1701,6 @@ static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
 
 static const struct ethtool_ops xennet_ethtool_ops =
 {
-	.set_tx_csum = ethtool_op_set_tx_csum,
-	.set_sg = xennet_set_sg,
-	.set_tso = xennet_set_tso,
 	.get_link = ethtool_op_get_link,
 
 	.get_sset_count = xennet_get_sset_count,