ibmveth: Add support for Large Receive Offload

Enables receiving large packets from other LPARs. These packets
have a -1 IP header checksum, so we must recalculate to have
a valid checksum.

Signed-off-by: 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>

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 33ffd349fb054f3b930a76115419a9e09a2f1ca0..29bbb628d712b38e8b17529626b85c3532d7942f 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -101,6 +101,7 @@ struct ibmveth_stat ibmveth_stats[] = {
        { "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) },
+       { "rx_large_packets", IBMVETH_STAT_OFF(rx_large_packets) }
 };
 
 /* simple methods of getting data from the current rxq entry */
@@ -1094,6 +1095,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
        struct net_device *netdev = adapter->netdev;
        int frames_processed = 0;
        unsigned long lpar_rc;
+       struct iphdr *iph;
 
 restart_poll:
        while (frames_processed < budget) {
@@ -1136,8 +1138,21 @@ restart_poll:
                        skb_put(skb, length);
                        skb->protocol = eth_type_trans(skb, netdev);
 
-                       if (csum_good)
+                       if (csum_good) {
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
+                               if (be16_to_cpu(skb->protocol) == ETH_P_IP) {
+                                       iph = (struct iphdr *)skb->data;
+
+                                       /* If the IP checksum is not offloaded and if the packet
+                                        *  is large send, the checksum must be rebuilt.
+                                        */
+                                       if (iph->check == 0xffff) {
+                                               iph->check = 0;
+                                               iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+                                               adapter->rx_large_packets++;
+                                       }
+                               }
+                       }
 
                        napi_gro_receive(napi, skb);    /* send it up */
 

diff --git a/drivers/net/ethernet/ibm/ibmveth.h b/drivers/net/ethernet/ibm/ibmveth.h
index 56d1e22bd1d3299cd6b967beb11cf476322f315f..41dedb1fb2ae7403d89f3feed38b4f87197de067 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmveth.h
+++ b/drivers/net/ethernet/ibm/ibmveth.h
@@ -162,6 +162,7 @@ struct ibmveth_adapter {
     u64 tx_map_failed;
     u64 tx_send_failed;
     u64 tx_large_packets;
+    u64 rx_large_packets;
 };
 
 /*