net/mlx5: VLAN push on RX, pop on TX

Some older NIC hardware isn't capable of doing VLAN push on RX and pop
on TX.

A workaround has been added in software to support it, but it has a
performance penalty since it requires a hairpin + loopback.

There's no such limitation with the newer NICs, so no need to pay the
price of the w/a. With this change the software w/a is disabled for
certain HW versions and steering modes that support it.
Signed-off-by: Dima Chumak <dchumak@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -224,7 +224,9 @@ mlx5_eswitch_termtbl_required(struct mlx5_eswitch *esw,
 		return false;
 
 	/* push vlan on RX */
-	if (flow_act->action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH)
+	if (flow_act->action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH &&
+	    !(mlx5_fs_get_capabilities(esw->dev, MLX5_FLOW_NAMESPACE_FDB) &
+	      MLX5_FLOW_STEERING_CAP_VLAN_PUSH_ON_RX))
 		return true;
 
 	/* hairpin */