net/mlx5: Lag, use port selection tables when available

JIRA: https://issues.redhat.com/browse/RHEL-72227
JIRA: https://issues.redhat.com/browse/RHEL-73520
Upstream-status: v6.15-rc1

commit 16ad839
Author: Mark Bloch <mbloch@nvidia.com>
Date:   Wed Mar 19 16:02:59 2025 +0200

    net/mlx5: Lag, use port selection tables when available

    As queue affinity is being deprecated and will no longer be supported
    in the future, Always check for the presence of the port selection
    namespace. When available, leverage it to distribute traffic
    across the physical ports via steering, ensuring compatibility with
    future NICs.

    Signed-off-by: Mark Bloch <mbloch@nvidia.com>
    Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
    Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
    Link: https://patch.msgid.link/1742392983-153050-2-git-send-email-tariqt@nvidia.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Benjamin Poirier <bpoirier@redhat.com>

Author: Benjamin Poirier

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

@@ -583,16 +583,22 @@ void mlx5_modify_lag(struct mlx5_lag *ldev,
 	}
 }
 
-static int mlx5_lag_set_port_sel_mode_roce(struct mlx5_lag *ldev,
-					   unsigned long *flags)
+static int mlx5_lag_set_port_sel_mode(struct mlx5_lag *ldev,
+				      enum mlx5_lag_mode mode,
+				      unsigned long *flags)
 {
 	int first_idx = mlx5_lag_get_dev_index_by_seq(ldev, MLX5_LAG_P1);
 	struct mlx5_core_dev *dev0;
 
 	if (first_idx < 0)
 		return -EINVAL;
 
+	if (mode == MLX5_LAG_MODE_MPESW ||
+	    mode == MLX5_LAG_MODE_MULTIPATH)
+		return 0;
+
 	dev0 = ldev->pf[first_idx].dev;
+
 	if (!MLX5_CAP_PORT_SELECTION(dev0, port_select_flow_table)) {
 		if (ldev->ports > 2)
 			return -EINVAL;
@@ -607,32 +613,10 @@ static int mlx5_lag_set_port_sel_mode_roce(struct mlx5_lag *ldev,
 	return 0;
 }
 
-static void mlx5_lag_set_port_sel_mode_offloads(struct mlx5_lag *ldev,
-						struct lag_tracker *tracker,
-						enum mlx5_lag_mode mode,
-						unsigned long *flags)
-{
-	int first_idx = mlx5_lag_get_dev_index_by_seq(ldev, MLX5_LAG_P1);
-	struct lag_func *dev0;
-
-	if (first_idx < 0 || mode == MLX5_LAG_MODE_MPESW)
-		return;
-
-	dev0 = &ldev->pf[first_idx];
-	if (MLX5_CAP_PORT_SELECTION(dev0->dev, port_select_flow_table) &&
-	    tracker->tx_type == NETDEV_LAG_TX_TYPE_HASH) {
-		if (ldev->ports > 2)
-			ldev->buckets = MLX5_LAG_MAX_HASH_BUCKETS;
-		set_bit(MLX5_LAG_MODE_FLAG_HASH_BASED, flags);
-	}
-}
-
 static int mlx5_lag_set_flags(struct mlx5_lag *ldev, enum mlx5_lag_mode mode,
 			      struct lag_tracker *tracker, bool shared_fdb,
 			      unsigned long *flags)
 {
-	bool roce_lag = mode == MLX5_LAG_MODE_ROCE;
-
 	*flags = 0;
 	if (shared_fdb) {
 		set_bit(MLX5_LAG_MODE_FLAG_SHARED_FDB, flags);
@@ -642,11 +626,7 @@ static int mlx5_lag_set_flags(struct mlx5_lag *ldev, enum mlx5_lag_mode mode,
 	if (mode == MLX5_LAG_MODE_MPESW)
 		set_bit(MLX5_LAG_MODE_FLAG_FDB_SEL_MODE_NATIVE, flags);
 
-	if (roce_lag)
-		return mlx5_lag_set_port_sel_mode_roce(ldev, flags);
-
-	mlx5_lag_set_port_sel_mode_offloads(ldev, tracker, mode, flags);
-	return 0;
+	return mlx5_lag_set_port_sel_mode(ldev, mode, flags);
 }
 
 char *mlx5_get_str_port_sel_mode(enum mlx5_lag_mode mode, unsigned long flags)