IB/rxe: Replace av->network_type with skb->protocol

In the function rxe_init_packet, based on av->network_type, skb->protocol
is set to ipv4 or ipv6. The functions rxe_prepare and rxe_send are called
after the functin rxe_init_packet.  So in these functions,
av->network_type can be replaced with skb->protocol.

The functions are in the xmit fast path. So with skb->protocol, the
performance will be better.
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/rxe/rxe_net.c

@@ -338,13 +338,13 @@ static void prepare_ipv6_hdr(struct dst_entry *dst, struct sk_buff *skb,
 	ip6h->payload_len = htons(skb->len - sizeof(*ip6h));
 }
 
-static int prepare4(struct rxe_pkt_info *pkt, struct sk_buff *skb,
-		    struct rxe_av *av)
+static int prepare4(struct rxe_pkt_info *pkt, struct sk_buff *skb)
 {
 	struct rxe_qp *qp = pkt->qp;
 	struct dst_entry *dst;
 	bool xnet = false;
 	__be16 df = htons(IP_DF);
+	struct rxe_av *av = rxe_get_av(pkt);
 	struct in_addr *saddr = &av->sgid_addr._sockaddr_in.sin_addr;
 	struct in_addr *daddr = &av->dgid_addr._sockaddr_in.sin_addr;
 
@@ -364,11 +364,11 @@ static int prepare4(struct rxe_pkt_info *pkt, struct sk_buff *skb,
 	return 0;
 }
 
-static int prepare6(struct rxe_pkt_info *pkt, struct sk_buff *skb,
-		    struct rxe_av *av)
+static int prepare6(struct rxe_pkt_info *pkt, struct sk_buff *skb)
 {
 	struct rxe_qp *qp = pkt->qp;
 	struct dst_entry *dst;
+	struct rxe_av *av = rxe_get_av(pkt);
 	struct in6_addr *saddr = &av->sgid_addr._sockaddr_in6.sin6_addr;
 	struct in6_addr *daddr = &av->dgid_addr._sockaddr_in6.sin6_addr;
 
@@ -392,16 +392,15 @@ static int prepare6(struct rxe_pkt_info *pkt, struct sk_buff *skb,
 int rxe_prepare(struct rxe_pkt_info *pkt, struct sk_buff *skb, u32 *crc)
 {
 	int err = 0;
-	struct rxe_av *av = rxe_get_av(pkt);
 
-	if (av->network_type == RDMA_NETWORK_IPV4)
-		err = prepare4(pkt, skb, av);
-	else if (av->network_type == RDMA_NETWORK_IPV6)
-		err = prepare6(pkt, skb, av);
+	if (skb->protocol == htons(ETH_P_IP))
+		err = prepare4(pkt, skb);
+	else if (skb->protocol == htons(ETH_P_IPV6))
+		err = prepare6(pkt, skb);
 
 	*crc = rxe_icrc_hdr(pkt, skb);
 
-	if (ether_addr_equal(skb->dev->dev_addr, av->dmac))
+	if (ether_addr_equal(skb->dev->dev_addr, rxe_get_av(pkt)->dmac))
 		pkt->mask |= RXE_LOOPBACK_MASK;
 
 	return err;
@@ -422,23 +421,20 @@ static void rxe_skb_tx_dtor(struct sk_buff *skb)
 
 int rxe_send(struct rxe_pkt_info *pkt, struct sk_buff *skb)
 {
-	struct rxe_av *av;
 	int err;
 
-	av = rxe_get_av(pkt);
-
 	skb->destructor = rxe_skb_tx_dtor;
 	skb->sk = pkt->qp->sk->sk;
 
 	rxe_add_ref(pkt->qp);
 	atomic_inc(&pkt->qp->skb_out);
 
-	if (av->network_type == RDMA_NETWORK_IPV4) {
+	if (skb->protocol == htons(ETH_P_IP)) {
 		err = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
-	} else if (av->network_type == RDMA_NETWORK_IPV6) {
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
 		err = ip6_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
 	} else {
-		pr_err("Unknown layer 3 protocol: %d\n", av->network_type);
+		pr_err("Unknown layer 3 protocol: %d\n", skb->protocol);
 		atomic_dec(&pkt->qp->skb_out);
 		rxe_drop_ref(pkt->qp);
 		kfree_skb(skb);