net/mlx5: Get RoCE netdev

Used by IB driver for determining the IB bond
device's netdev, when LAG is active.

Returns PF0's netdev if mode is not active-backup,
or the PF netdev of the active slave when mode is
active-backup.
Signed-off-by: Aviv Heller <avivh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

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

@@ -528,3 +528,30 @@ bool mlx5_lag_is_active(struct mlx5_core_dev *dev)
 }
 EXPORT_SYMBOL(mlx5_lag_is_active);
 
+struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev)
+{
+	struct net_device *ndev = NULL;
+	struct mlx5_lag *ldev;
+
+	mutex_lock(&lag_mutex);
+	ldev = mlx5_lag_dev_get(dev);
+
+	if (!(ldev && mlx5_lag_is_bonded(ldev)))
+		goto unlock;
+
+	if (ldev->tracker.tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP) {
+		ndev = ldev->tracker.netdev_state[0].tx_enabled ?
+		       ldev->pf[0].netdev : ldev->pf[1].netdev;
+	} else {
+		ndev = ldev->pf[0].netdev;
+	}
+	if (ndev)
+		dev_hold(ndev);
+
+unlock:
+	mutex_unlock(&lag_mutex);
+
+	return ndev;
+}
+EXPORT_SYMBOL(mlx5_lag_get_roce_netdev);
+

include/linux/mlx5/driver.h

@@ -945,6 +945,7 @@ void mlx5_unregister_interface(struct mlx5_interface *intf);
 int mlx5_core_query_vendor_id(struct mlx5_core_dev *mdev, u32 *vendor_id);
 
 bool mlx5_lag_is_active(struct mlx5_core_dev *dev);
+struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev);
 
 struct mlx5_profile {
 	u64	mask;