net/mlx5e: Add 802.1ad VLAN insertion support

Report VLAN insertion support for S-tagged packets and add support by
choosing the correct VLAN type in the WQE.
Signed-off-by: NGal Pressman <galp@mellanox.com>
Reviewed-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

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

@@ -4194,6 +4194,7 @@ static void mlx5e_build_nic_netdev(struct net_device *netdev)
 	netdev->hw_features      |= NETIF_F_HW_VLAN_CTAG_TX;
 	netdev->hw_features      |= NETIF_F_HW_VLAN_CTAG_RX;
 	netdev->hw_features      |= NETIF_F_HW_VLAN_CTAG_FILTER;
+	netdev->hw_features      |= NETIF_F_HW_VLAN_STAG_TX;
 
 	if (mlx5e_vxlan_allowed(mdev) || MLX5_CAP_ETH(mdev, tunnel_stateless_gre)) {
 		netdev->hw_features     |= NETIF_F_GSO_PARTIAL;

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

@@ -369,6 +369,8 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 		ds_cnt += DIV_ROUND_UP(ihs - sizeof(eseg->inline_hdr.start), MLX5_SEND_WQE_DS);
 	} else if (skb_vlan_tag_present(skb)) {
 		eseg->insert.type = cpu_to_be16(MLX5_ETH_WQE_INSERT_VLAN);
+		if (skb->vlan_proto == cpu_to_be16(ETH_P_8021AD))
+			eseg->insert.type |= cpu_to_be16(MLX5_ETH_WQE_SVLAN);
 		eseg->insert.vlan_tci = cpu_to_be16(skb_vlan_tag_get(skb));
 	}
 

include/linux/mlx5/qp.h

@@ -221,6 +221,7 @@ enum {
 };
 
 enum {
+	MLX5_ETH_WQE_SVLAN              = 1 << 0,
 	MLX5_ETH_WQE_INSERT_VLAN        = 1 << 15,
 };