ixgbe: Add support for UDP-encapsulated tx checksum offload

Orabug: 21918732

By using GSO for UDP-encapsulated packets, all ixgbe devices can
be directed to generate checksums for the inner headers because
the outer UDP checksum can be zero. So point the machinery at the
inner headers and have the hardware generate the checksum.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit f467bc06022d4d37de459f9498ff4fbc7e9b0fca)
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 4a485ec173f062e6de980ff4ab9ab5f2ee4349d9..9abfce6570b9c599b18da3ed8eb54db10969c852 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6906,31 +6906,55 @@ static void ixgbe_tx_csum(struct ixgbe_ring *tx_ring,
                if (!(first->tx_flags & IXGBE_TX_FLAGS_HW_VLAN) &&
                    !(first->tx_flags & IXGBE_TX_FLAGS_CC))
                        return;
+               vlan_macip_lens = skb_network_offset(skb) <<
+                                 IXGBE_ADVTXD_MACLEN_SHIFT;
        } else {
                u8 l4_hdr = 0;
-               switch (first->protocol) {
-               case htons(ETH_P_IP):
-                       vlan_macip_lens |= skb_network_header_len(skb);
+               union {
+                       struct iphdr *ipv4;
+                       struct ipv6hdr *ipv6;
+                       u8 *raw;
+               } network_hdr;
+               union {
+                       struct tcphdr *tcphdr;
+                       u8 *raw;
+               } transport_hdr;
+
+               if (skb->encapsulation) {
+                       network_hdr.raw = skb_inner_network_header(skb);
+                       transport_hdr.raw = skb_inner_transport_header(skb);
+                       vlan_macip_lens = skb_inner_network_offset(skb) <<
+                                         IXGBE_ADVTXD_MACLEN_SHIFT;
+               } else {
+                       network_hdr.raw = skb_network_header(skb);
+                       transport_hdr.raw = skb_transport_header(skb);
+                       vlan_macip_lens = skb_network_offset(skb) <<
+                                         IXGBE_ADVTXD_MACLEN_SHIFT;
+               }
+
+               /* use first 4 bits to determine IP version */
+               switch (network_hdr.ipv4->version) {
+               case IPVERSION:
+                       vlan_macip_lens |= transport_hdr.raw - network_hdr.raw;
                        type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
-                       l4_hdr = ip_hdr(skb)->protocol;
+                       l4_hdr = network_hdr.ipv4->protocol;
                        break;
-               case htons(ETH_P_IPV6):
-                       vlan_macip_lens |= skb_network_header_len(skb);
-                       l4_hdr = ipv6_hdr(skb)->nexthdr;
+               case 6:
+                       vlan_macip_lens |= transport_hdr.raw - network_hdr.raw;
+                       l4_hdr = network_hdr.ipv6->nexthdr;
                        break;
                default:
                        if (unlikely(net_ratelimit())) {
                                dev_warn(tx_ring->dev,
-                                "partial checksum but proto=%x!\n",
-                                first->protocol);
+                                        "partial checksum but version=%d\n",
+                                        network_hdr.ipv4->version);
                        }
-                       break;
                }
 
                switch (l4_hdr) {
                case IPPROTO_TCP:
                        type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
-                       mss_l4len_idx = tcp_hdrlen(skb) <<
+                       mss_l4len_idx = (transport_hdr.tcphdr->doff * 4) <<
                                        IXGBE_ADVTXD_L4LEN_SHIFT;
                        break;
                case IPPROTO_SCTP:
@@ -6956,7 +6980,6 @@ static void ixgbe_tx_csum(struct ixgbe_ring *tx_ring,
        }
 
        /* vlan_macip_lens: MACLEN, VLAN tag */
-       vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
        vlan_macip_lens |= first->tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
 
        ixgbe_tx_ctxtdesc(tx_ring, vlan_macip_lens, 0,
@@ -8200,6 +8223,21 @@ static void ixgbe_fwd_del(struct net_device *pdev, void *priv)
        kfree(fwd_adapter);
 }
 
+#define IXGBE_MAX_TUNNEL_HDR_LEN 80
+static netdev_features_t
+ixgbe_features_check(struct sk_buff *skb, struct net_device *dev,
+                    netdev_features_t features)
+{
+       if (!skb->encapsulation)
+               return features;
+
+       if (unlikely(skb_inner_mac_header(skb) - skb_transport_header(skb) >
+                    IXGBE_MAX_TUNNEL_HDR_LEN))
+               return features & ~NETIF_F_ALL_CSUM;
+
+       return features;
+}
+
 static const struct net_device_ops ixgbe_netdev_ops = {
        .ndo_open               = ixgbe_open,
        .ndo_stop               = ixgbe_close,
@@ -8247,6 +8285,7 @@ static const struct net_device_ops ixgbe_netdev_ops = {
        .ndo_dfwd_del_station   = ixgbe_fwd_del,
        .ndo_add_vxlan_port     = ixgbe_add_vxlan_port,
        .ndo_del_vxlan_port     = ixgbe_del_vxlan_port,
+       .ndo_features_check     = ixgbe_features_check,
 };
 
 /**
@@ -8606,6 +8645,9 @@ skip_sriov:
        netdev->vlan_features |= NETIF_F_IPV6_CSUM;
        netdev->vlan_features |= NETIF_F_SG;
 
+       netdev->hw_enc_features |= NETIF_F_SG | NETIF_F_IP_CSUM |
+                                  NETIF_F_IPV6_CSUM;
+
        netdev->priv_flags |= IFF_UNICAST_FLT;
        netdev->priv_flags |= IFF_SUPP_NOFCS;