Drivers: net: hyperv: Enable send side checksum offload

Enable send side checksum offload.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 77 insertions, 2 deletions

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index faeb74623fbd..4cf238234321 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1035,6 +1035,16 @@ struct rndis_message {
 #define NDIS_PACKET_TYPE_FUNCTIONAL     0x00000400
 #define NDIS_PACKET_TYPE_MAC_FRAME      0x00000800
 
+#define INFO_IPV4       2
+#define INFO_IPV6       4
+#define INFO_TCP        2
+#define INFO_UDP        4
+
+#define TRANSPORT_INFO_NOT_IP   0
+#define TRANSPORT_INFO_IPV4_TCP ((INFO_IPV4 << 16) | INFO_TCP)
+#define TRANSPORT_INFO_IPV4_UDP ((INFO_IPV4 << 16) | INFO_UDP)
+#define TRANSPORT_INFO_IPV6_TCP ((INFO_IPV6 << 16) | INFO_TCP)
+#define TRANSPORT_INFO_IPV6_UDP ((INFO_IPV6 << 16) | INFO_UDP)
 
 
 #endif /* _HYPERV_NET_H */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 9bee0650c7ca..697837537ccb 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -257,6 +257,35 @@ static int netvsc_get_slots(struct sk_buff *skb)
         return slots + frag_slots;
 }
 
+static u32 get_net_transport_info(struct sk_buff *skb, u32 *trans_off)
+{
+        u32 ret_val = TRANSPORT_INFO_NOT_IP;
+
+        if ((eth_hdr(skb)->h_proto != htons(ETH_P_IP)) &&
+                (eth_hdr(skb)->h_proto != htons(ETH_P_IPV6))) {
+                goto not_ip;
+        }
+
+        *trans_off = skb_transport_offset(skb);
+
+        if ((eth_hdr(skb)->h_proto == htons(ETH_P_IP))) {
+                struct iphdr *iphdr = ip_hdr(skb);
+
+                if (iphdr->protocol == IPPROTO_TCP)
+                        ret_val = TRANSPORT_INFO_IPV4_TCP;
+                else if (iphdr->protocol == IPPROTO_UDP)
+                        ret_val = TRANSPORT_INFO_IPV4_UDP;
+        } else {
+                if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
+                        ret_val = TRANSPORT_INFO_IPV6_TCP;
+                else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
+                        ret_val = TRANSPORT_INFO_IPV6_UDP;
+        }
+
+not_ip:
+        return ret_val;
+}
+
 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 {
         struct net_device_context *net_device_ctx = netdev_priv(net);
@@ -268,6 +297,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
         u32 rndis_msg_size;
         bool isvlan;
         struct rndis_per_packet_info *ppi;
+        struct ndis_tcp_ip_checksum_info *csum_info;
+        int  hdr_offset;
+        u32 net_trans_info;
+
 
         /* We will atmost need two pages to describe the rndis
          * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
@@ -335,6 +368,37 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
                                 VLAN_PRIO_SHIFT;
         }
 
+        net_trans_info = get_net_transport_info(skb, &hdr_offset);
+        if (net_trans_info == TRANSPORT_INFO_NOT_IP)
+                goto do_send;
+
+        /*
+         * Setup the sendside checksum offload only if this is not a
+         * GSO packet.
+         */
+        if (skb_is_gso(skb))
+                goto do_send;
+
+        rndis_msg_size += NDIS_CSUM_PPI_SIZE;
+        ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
+                            TCPIP_CHKSUM_PKTINFO);
+
+        csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
+                        ppi->ppi_offset);
+
+        if (net_trans_info & (INFO_IPV4 << 16))
+                csum_info->transmit.is_ipv4 = 1;
+        else
+                csum_info->transmit.is_ipv6 = 1;
+
+        if (net_trans_info & INFO_TCP) {
+                csum_info->transmit.tcp_checksum = 1;
+                csum_info->transmit.tcp_header_offset = hdr_offset;
+        } else if (net_trans_info & INFO_UDP) {
+                csum_info->transmit.udp_checksum = 1;
+        }
+
+do_send:
         /* Start filling in the page buffers with the rndis hdr */
         rndis_msg->msg_len += rndis_msg_size;
         packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
@@ -589,8 +653,9 @@ static int netvsc_probe(struct hv_device *dev,
         net->netdev_ops = &device_ops;
 
         /* TODO: Add GSO and Checksum offload */
-        net->hw_features = NETIF_F_RXCSUM | NETIF_F_SG;
-        net->features = NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_RXCSUM;
+        net->hw_features = NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_IP_CSUM;
+        net->features = NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_RXCSUM |
+                        NETIF_F_IP_CSUM;
 
         SET_ETHTOOL_OPS(net, &ethtool_ops);
         SET_NETDEV_DEV(net, &dev->device);