net/mlx5: Lag, offload active-backup drops to hardware

In active-backup mode the backup interface's packets are dropped by the
bond device. In switchdev where TC rules are offloaded to the FDB
this can lead to packets being hit in the FDB where without offload
they would have been dropped before reaching TC rules in the kernel.

Create a drop rule to make sure packets on inactive ports are dropped
before reaching the FDB.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -38,6 +38,7 @@
 #include "lib/devcom.h"
 #include "mlx5_core.h"
 #include "eswitch.h"
+#include "esw/acl/ofld.h"
 #include "lag.h"
 #include "mp.h"
 
@@ -210,6 +211,62 @@ static void mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker,
 		*port1 = MLX5_LAG_EGRESS_PORT_2;
 }
 
+static bool mlx5_lag_has_drop_rule(struct mlx5_lag *ldev)
+{
+	return ldev->pf[MLX5_LAG_P1].has_drop || ldev->pf[MLX5_LAG_P2].has_drop;
+}
+
+static void mlx5_lag_drop_rule_cleanup(struct mlx5_lag *ldev)
+{
+	int i;
+
+	for (i = 0; i < MLX5_MAX_PORTS; i++) {
+		if (!ldev->pf[i].has_drop)
+			continue;
+
+		mlx5_esw_acl_ingress_vport_drop_rule_destroy(ldev->pf[i].dev->priv.eswitch,
+							     MLX5_VPORT_UPLINK);
+		ldev->pf[i].has_drop = false;
+	}
+}
+
+static void mlx5_lag_drop_rule_setup(struct mlx5_lag *ldev,
+				     struct lag_tracker *tracker)
+{
+	struct mlx5_core_dev *dev0 = ldev->pf[MLX5_LAG_P1].dev;
+	struct mlx5_core_dev *dev1 = ldev->pf[MLX5_LAG_P2].dev;
+	struct mlx5_core_dev *inactive;
+	u8 v2p_port1, v2p_port2;
+	int inactive_idx;
+	int err;
+
+	/* First delete the current drop rule so there won't be any dropped
+	 * packets
+	 */
+	mlx5_lag_drop_rule_cleanup(ldev);
+
+	if (!ldev->tracker.has_inactive)
+		return;
+
+	mlx5_infer_tx_affinity_mapping(tracker, &v2p_port1, &v2p_port2);
+
+	if (v2p_port1 == MLX5_LAG_EGRESS_PORT_1) {
+		inactive = dev1;
+		inactive_idx = MLX5_LAG_P2;
+	} else {
+		inactive = dev0;
+		inactive_idx = MLX5_LAG_P1;
+	}
+
+	err = mlx5_esw_acl_ingress_vport_drop_rule_create(inactive->priv.eswitch,
+							  MLX5_VPORT_UPLINK);
+	if (!err)
+		ldev->pf[inactive_idx].has_drop = true;
+	else
+		mlx5_core_err(inactive,
+			      "Failed to create lag drop rule, error: %d", err);
+}
+
 static int _mlx5_modify_lag(struct mlx5_lag *ldev, u8 v2p_port1, u8 v2p_port2)
 {
 	struct mlx5_core_dev *dev0 = ldev->pf[MLX5_LAG_P1].dev;
@@ -244,6 +301,10 @@ void mlx5_modify_lag(struct mlx5_lag *ldev,
 			       ldev->v2p_map[MLX5_LAG_P1],
 			       ldev->v2p_map[MLX5_LAG_P2]);
 	}
+
+	if (tracker->tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP &&
+	    !(ldev->flags & MLX5_LAG_FLAG_ROCE))
+		mlx5_lag_drop_rule_setup(ldev, tracker);
 }
 
 static void mlx5_lag_set_port_sel_mode(struct mlx5_lag *ldev,
@@ -345,6 +406,10 @@ int mlx5_activate_lag(struct mlx5_lag *ldev,
 		return err;
 	}
 
+	if (tracker->tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP &&
+	    !roce_lag)
+		mlx5_lag_drop_rule_setup(ldev, tracker);
+
 	ldev->flags |= flags;
 	ldev->shared_fdb = shared_fdb;
 	return 0;
@@ -379,11 +444,15 @@ static int mlx5_deactivate_lag(struct mlx5_lag *ldev)
 				      "Failed to deactivate VF LAG; driver restart required\n"
 				      "Make sure all VFs are unbound prior to VF LAG activation or deactivation\n");
 		}
-	} else if (flags & MLX5_LAG_FLAG_HASH_BASED) {
-		mlx5_lag_port_sel_destroy(ldev);
+		return err;
 	}
 
-	return err;
+	if (flags & MLX5_LAG_FLAG_HASH_BASED)
+		mlx5_lag_port_sel_destroy(ldev);
+	if (mlx5_lag_has_drop_rule(ldev))
+		mlx5_lag_drop_rule_cleanup(ldev);
+
+	return 0;
 }
 
 static bool mlx5_lag_check_prereq(struct mlx5_lag *ldev)

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

@@ -28,6 +28,7 @@ enum {
 struct lag_func {
 	struct mlx5_core_dev *dev;
 	struct net_device    *netdev;
+	bool has_drop;
 };
 
 /* Used for collection of netdev event info. */