net/mlx5e: Maximize ip tunnel key usage on the TC offloading path

Use more fields out of the tunnel key (e.g the tunnel source IP address)
provided by upper layers for the route lookup done on the encap offload path.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -684,7 +684,6 @@ static int mlx5e_route_lookup_ipv4(struct mlx5e_priv *priv,
 				   struct net_device **out_dev,
 				   struct flowi4 *fl4,
 				   struct neighbour **out_n,
-				   __be32 *saddr,
 				   int *out_ttl)
 {
 	struct rtable *rt;
@@ -714,7 +713,6 @@ static int mlx5e_route_lookup_ipv4(struct mlx5e_priv *priv,
 		return -ENOMEM;
 
 	*out_n = n;
-	*saddr = fl4->saddr;
 	*out_dev = rt->dst.dev;
 
 	return 0;
@@ -763,13 +761,10 @@ static int mlx5e_create_encap_header_ipv4(struct mlx5e_priv *priv,
 {
 	int max_encap_size = MLX5_CAP_ESW(priv->mdev, max_encap_header_size);
 	struct ip_tunnel_key *tun_key = &e->tun_info.key;
+	int encap_size, ttl, err;
 	struct neighbour *n = NULL;
 	struct flowi4 fl4 = {};
 	char *encap_header;
-	int encap_size;
-	__be32 saddr;
-	int ttl;
-	int err;
 
 	encap_header = kzalloc(max_encap_size, GFP_KERNEL);
 	if (!encap_header)
@@ -784,10 +779,12 @@ static int mlx5e_create_encap_header_ipv4(struct mlx5e_priv *priv,
 		err = -EOPNOTSUPP;
 		goto out;
 	}
+	fl4.flowi4_tos = tun_key->tos;
 	fl4.daddr = tun_key->u.ipv4.dst;
+	fl4.saddr = tun_key->u.ipv4.src;
 
 	err = mlx5e_route_lookup_ipv4(priv, mirred_dev, out_dev,
-				      &fl4, &n, &saddr, &ttl);
+				      &fl4, &n, &ttl);
 	if (err)
 		goto out;
 
@@ -806,8 +803,8 @@ static int mlx5e_create_encap_header_ipv4(struct mlx5e_priv *priv,
 	case MLX5_HEADER_TYPE_VXLAN:
 		encap_size = gen_vxlan_header_ipv4(*out_dev, encap_header,
 						   e->h_dest, ttl,
-						   tun_key->u.ipv4.dst,
-						   saddr, tun_key->tp_dst,
+						   fl4.daddr,
+						   fl4.saddr, tun_key->tp_dst,
 						   tunnel_id_to_key32(tun_key->tun_id));
 		break;
 	default: