net/mlx5: Don't use termination tables in slow path

Don't use termination tables for packets that are steered to the slow path,
as a pre-step for supporting packet encap (packet reformat) action on
termination tables. Packet encap (reformat action) actions steer the packet
to the slow path until outer arp entries are resolved.

Signed-off-by: Eli Cohen <[email protected]>
Reviewed-by: Oz Shlomo <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>

Author: Eli Cohen

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

@@ -332,6 +332,7 @@ struct mlx5_termtbl_handle;
 
 bool
 mlx5_eswitch_termtbl_required(struct mlx5_eswitch *esw,
+			      struct mlx5_esw_flow_attr *attr,
 			      struct mlx5_flow_act *flow_act,
 			      struct mlx5_flow_spec *spec);
 
@@ -393,6 +394,7 @@ enum {
 	MLX5_ESW_ATTR_FLAG_VLAN_HANDLED  = BIT(0),
 	MLX5_ESW_ATTR_FLAG_SLOW_PATH     = BIT(1),
 	MLX5_ESW_ATTR_FLAG_NO_IN_PORT    = BIT(2),
+	MLX5_ESW_ATTR_FLAG_HAIRPIN	 = BIT(3),
 };
 
 struct mlx5_esw_flow_attr {

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

@@ -300,6 +300,7 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw,
 	bool split = !!(attr->split_count);
 	struct mlx5_flow_handle *rule;
 	struct mlx5_flow_table *fdb;
+	bool hairpin = false;
 	int j, i = 0;
 
 	if (esw->mode != MLX5_ESWITCH_OFFLOADS)
@@ -397,16 +398,21 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw,
 		goto err_esw_get;
 	}
 
-	if (mlx5_eswitch_termtbl_required(esw, &flow_act, spec))
+	if (mlx5_eswitch_termtbl_required(esw, attr, &flow_act, spec)) {
 		rule = mlx5_eswitch_add_termtbl_rule(esw, fdb, spec, attr,
 						     &flow_act, dest, i);
-	else
+		hairpin = true;
+	} else {
 		rule = mlx5_add_flow_rules(fdb, spec, &flow_act, dest, i);
+	}
 	if (IS_ERR(rule))
 		goto err_add_rule;
 	else
 		atomic64_inc(&esw->offloads.num_flows);
 
+	if (hairpin)
+		attr->flags |= MLX5_ESW_ATTR_FLAG_HAIRPIN;
+
 	return rule;
 
 err_add_rule:
@@ -495,10 +501,12 @@ __mlx5_eswitch_del_rule(struct mlx5_eswitch *esw,
 
 	mlx5_del_flow_rules(rule);
 
-	/* unref the term table */
-	for (i = 0; i < MLX5_MAX_FLOW_FWD_VPORTS; i++) {
-		if (attr->dests[i].termtbl)
-			mlx5_eswitch_termtbl_put(esw, attr->dests[i].termtbl);
+	if (attr->flags & MLX5_ESW_ATTR_FLAG_HAIRPIN) {
+		/* unref the term table */
+		for (i = 0; i < MLX5_MAX_FLOW_FWD_VPORTS; i++) {
+			if (attr->dests[i].termtbl)
+				mlx5_eswitch_termtbl_put(esw, attr->dests[i].termtbl);
+		}
 	}
 
 	atomic64_dec(&esw->offloads.num_flows);

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

@@ -195,10 +195,12 @@ static bool mlx5_eswitch_offload_is_uplink_port(const struct mlx5_eswitch *esw,
 
 bool
 mlx5_eswitch_termtbl_required(struct mlx5_eswitch *esw,
+			      struct mlx5_esw_flow_attr *attr,
 			      struct mlx5_flow_act *flow_act,
 			      struct mlx5_flow_spec *spec)
 {
-	if (!MLX5_CAP_ESW_FLOWTABLE_FDB(esw->dev, termination_table))
+	if (!MLX5_CAP_ESW_FLOWTABLE_FDB(esw->dev, termination_table) ||
+	    attr->flags & MLX5_ESW_ATTR_FLAG_SLOW_PATH)
 		return false;
 
 	/* push vlan on RX */