RDMA/mlx5: Refactor transport domain bookkeeping logic

In preparation to enable loopback on a single user context move the logic
that enables/disables loopback to separate functions and group variables
under a single struct.

Signed-off-by: Mark Bloch <markb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -858,6 +858,12 @@ to_mcounters(struct ib_counters *ibcntrs)
 	return container_of(ibcntrs, struct mlx5_ib_mcounters, ibcntrs);
 }
 
+struct mlx5_ib_lb_state {
+	/* protect the user_td */
+	struct mutex		mutex;
+	u32			user_td;
+};
+
 struct mlx5_ib_dev {
 	struct ib_device		ib_dev;
 	const struct uverbs_object_tree_def *driver_trees[6];
@@ -899,9 +905,7 @@ struct mlx5_ib_dev {
 	const struct mlx5_ib_profile	*profile;
 	struct mlx5_eswitch_rep		*rep;
 
-	/* protect the user_td */
-	struct mutex		lb_mutex;
-	u32			user_td;
+	struct mlx5_ib_lb_state		lb;
 	u8			umr_fence;
 	struct list_head	ib_dev_list;
 	u64			sys_image_guid;