ibmveth: Add support for TSO

Add support for TSO.  TSO is turned off by default and
must be enabled and configured by the user.  The driver
version number is increased so that users can be sure
that they are using ibmveth with TSO support.

Cc: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmveth.c

@@ -58,7 +58,7 @@ static struct kobj_type ktype_veth_pool;
 
 static const char ibmveth_driver_name[] = "ibmveth";
 static const char ibmveth_driver_string[] = "IBM Power Virtual Ethernet Driver";
-#define ibmveth_driver_version "1.04"
+#define ibmveth_driver_version "1.05"
 
 MODULE_AUTHOR("Santiago Leon <santil@linux.vnet.ibm.com>");
 MODULE_DESCRIPTION("IBM Power Virtual Ethernet Driver");
@@ -100,6 +100,7 @@ struct ibmveth_stat ibmveth_stats[] = {
 	{ "tx_send_failed", IBMVETH_STAT_OFF(tx_send_failed) },
 	{ "fw_enabled_ipv4_csum", IBMVETH_STAT_OFF(fw_ipv4_csum_support) },
 	{ "fw_enabled_ipv6_csum", IBMVETH_STAT_OFF(fw_ipv6_csum_support) },
+	{ "tx_large_packets", IBMVETH_STAT_OFF(tx_large_packets) },
 };
 
 /* simple methods of getting data from the current rxq entry */
@@ -852,6 +853,10 @@ static int ibmveth_set_features(struct net_device *dev,
 	struct ibmveth_adapter *adapter = netdev_priv(dev);
 	int rx_csum = !!(features & NETIF_F_RXCSUM);
 	int rc;
+	netdev_features_t changed = features ^ dev->features;
+
+	if (features & NETIF_F_TSO & changed)
+		netdev_info(dev, "TSO feature requires all partitions to have updated driver");
 
 	if (rx_csum == adapter->rx_csum)
 		return 0;
@@ -1035,6 +1040,15 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
 		descs[i+1].fields.address = dma_addr;
 	}
 
+	if (skb_is_gso(skb) && !skb_is_gso_v6(skb)) {
+		/* Put -1 in the IP checksum to tell phyp it
+		 *  is a largesend packet and put the mss in the TCP checksum.
+		 */
+		ip_hdr(skb)->check = 0xffff;
+		tcp_hdr(skb)->check = cpu_to_be16(skb_shinfo(skb)->gso_size);
+		adapter->tx_large_packets++;
+	}
+
 	if (ibmveth_send(adapter, descs)) {
 		adapter->tx_send_failed++;
 		netdev->stats.tx_dropped++;
@@ -1422,6 +1436,9 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
 	netdev->features |= netdev->hw_features;
 
+	/* TSO is disabled by default */
+	netdev->hw_features |= NETIF_F_TSO;
+
 	memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);
 
 	if (firmware_has_feature(FW_FEATURE_CMO))

drivers/net/ethernet/ibm/ibmveth.h

@@ -161,6 +161,7 @@ struct ibmveth_adapter {
     u64 rx_no_buffer;
     u64 tx_map_failed;
     u64 tx_send_failed;
+    u64 tx_large_packets;
 };
 
 /*