net/mlx5: Lag, add initial logic for shared FDB

As shared FDB requires changes in two subsystems first expose the needed
core functions so the RDMA side can be changed.

mlx5_lag_is_master(): return true if a given mlx5 device is the lag master.
mlx5_lag_is_shared_fdb(): Returns true if the lag mode is shared FDB.
mlx5_lag_get_peer_mdev(): Return the peer mdev in lag.

The mentioned functions will be used by downstream patches in order
to add support for shared FDB for the RDMA side.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -746,6 +746,21 @@ bool mlx5_lag_is_active(struct mlx5_core_dev *dev)
 }
 EXPORT_SYMBOL(mlx5_lag_is_active);
 
+bool mlx5_lag_is_master(struct mlx5_core_dev *dev)
+{
+	struct mlx5_lag *ldev;
+	bool res;
+
+	spin_lock(&lag_lock);
+	ldev = mlx5_lag_dev(dev);
+	res = ldev && __mlx5_lag_is_active(ldev) &&
+		dev == ldev->pf[MLX5_LAG_P1].dev;
+	spin_unlock(&lag_lock);
+
+	return res;
+}
+EXPORT_SYMBOL(mlx5_lag_is_master);
+
 bool mlx5_lag_is_sriov(struct mlx5_core_dev *dev)
 {
 	struct mlx5_lag *ldev;
@@ -760,6 +775,20 @@ bool mlx5_lag_is_sriov(struct mlx5_core_dev *dev)
 }
 EXPORT_SYMBOL(mlx5_lag_is_sriov);
 
+bool mlx5_lag_is_shared_fdb(struct mlx5_core_dev *dev)
+{
+	struct mlx5_lag *ldev;
+	bool res;
+
+	spin_lock(&lag_lock);
+	ldev = mlx5_lag_dev(dev);
+	res = ldev && __mlx5_lag_is_sriov(ldev) && ldev->shared_fdb;
+	spin_unlock(&lag_lock);
+
+	return res;
+}
+EXPORT_SYMBOL(mlx5_lag_is_shared_fdb);
+
 void mlx5_lag_update(struct mlx5_core_dev *dev)
 {
 	struct mlx5_lag *ldev;
@@ -827,6 +856,26 @@ u8 mlx5_lag_get_slave_port(struct mlx5_core_dev *dev,
 }
 EXPORT_SYMBOL(mlx5_lag_get_slave_port);
 
+struct mlx5_core_dev *mlx5_lag_get_peer_mdev(struct mlx5_core_dev *dev)
+{
+	struct mlx5_core_dev *peer_dev = NULL;
+	struct mlx5_lag *ldev;
+
+	spin_lock(&lag_lock);
+	ldev = mlx5_lag_dev(dev);
+	if (!ldev)
+		goto unlock;
+
+	peer_dev = ldev->pf[MLX5_LAG_P1].dev == dev ?
+			   ldev->pf[MLX5_LAG_P2].dev :
+			   ldev->pf[MLX5_LAG_P1].dev;
+
+unlock:
+	spin_unlock(&lag_lock);
+	return peer_dev;
+}
+EXPORT_SYMBOL(mlx5_lag_get_peer_mdev);
+
 int mlx5_lag_query_cong_counters(struct mlx5_core_dev *dev,
 				 u64 *values,
 				 int num_counters,

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

@@ -39,6 +39,7 @@ struct lag_tracker {
  */
 struct mlx5_lag {
 	u8                        flags;
+	bool			  shared_fdb;
 	u8                        v2p_map[MLX5_MAX_PORTS];
 	struct kref               ref;
 	struct lag_func           pf[MLX5_MAX_PORTS];

include/linux/mlx5/driver.h

@@ -1138,6 +1138,8 @@ bool mlx5_lag_is_roce(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_sriov(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_multipath(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_active(struct mlx5_core_dev *dev);
+bool mlx5_lag_is_master(struct mlx5_core_dev *dev);
+bool mlx5_lag_is_shared_fdb(struct mlx5_core_dev *dev);
 struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev);
 u8 mlx5_lag_get_slave_port(struct mlx5_core_dev *dev,
 			   struct net_device *slave);
@@ -1145,6 +1147,7 @@ int mlx5_lag_query_cong_counters(struct mlx5_core_dev *dev,
 				 u64 *values,
 				 int num_counters,
 				 size_t *offsets);
+struct mlx5_core_dev *mlx5_lag_get_peer_mdev(struct mlx5_core_dev *dev);
 struct mlx5_uars_page *mlx5_get_uars_page(struct mlx5_core_dev *mdev);
 void mlx5_put_uars_page(struct mlx5_core_dev *mdev, struct mlx5_uars_page *up);
 int mlx5_dm_sw_icm_alloc(struct mlx5_core_dev *dev, enum mlx5_sw_icm_type type,