RDMA/mlx5: Use IB set_netdev and get_netdev functions

The IB layer provides a common interface to store and get net
devices associated to an IB device port (ib_device_set_netdev()
and ib_device_get_netdev()).
Previously, mlx5_ib stored and managed the associated net devices
internally.

Replace internal net device management in mlx5_ib with
ib_device_set_netdev() when attaching/detaching  a net device and
ib_device_get_netdev() when retrieving the net device.

Export ib_device_get_netdev().

For mlx5 representors/PFs/VFs and lag creation we replace the netdev
assignments with the IB set/get netdev functions.

In active-backup mode lag the active slave net device is stored in the
lag itself. To assure the net device stored in a lag bond IB device is
the active slave we implement the following:
- mlx5_core: when modifying the slave of a bond we send the internal driver event
  MLX5_DRIVER_EVENT_ACTIVE_BACKUP_LAG_CHANGE_LOWERSTATE.
- mlx5_ib: when catching the event call ib_device_set_netdev()

This patch also ensures the correct IB events are sent in switchdev lag.

While at it, when in multiport eswitch mode, only a single IB device is
created for all ports. The said IB device will receive all netdev events
of its VFs once loaded, thus to avoid overwriting the mapping of PF IB
device to PF netdev, ignore NETDEV_REGISTER events if the ib device has
already been mapped to a netdev.

Signed-off-by: Chiara Meiohas <cmeiohas@nvidia.com>
Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://patch.msgid.link/20240909173025.30422-6-michaelgur@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

3 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index 57c9b18c3adb..dac33cfe9c0c 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -371,6 +371,7 @@ enum mlx5_driver_event {
 	MLX5_DRIVER_EVENT_SF_PEER_DEVLINK,
 	MLX5_DRIVER_EVENT_AFFILIATION_DONE,
 	MLX5_DRIVER_EVENT_AFFILIATION_REMOVED,
+	MLX5_DRIVER_EVENT_ACTIVE_BACKUP_LAG_CHANGE_LOWERSTATE,
 };
 
 enum {
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index a96438ded15f..46a7a3d11048 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -643,6 +643,7 @@ struct mlx5_priv {
 	struct mlx5_sf_hw_table *sf_hw_table;
 	struct mlx5_sf_table *sf_table;
 #endif
+	struct blocking_notifier_head lag_nh;
 };
 
 enum mlx5_device_state {
@@ -1181,7 +1182,6 @@ bool mlx5_lag_mode_is_hash(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);
 bool mlx5_lag_is_mpesw(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);
 int mlx5_lag_query_cong_counters(struct mlx5_core_dev *dev,
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a1dcf812d787..aa8ede439905 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -4453,6 +4453,8 @@ struct net_device *ib_get_net_dev_by_params(struct ib_device *dev, u32 port,
 					    const struct sockaddr *addr);
 int ib_device_set_netdev(struct ib_device *ib_dev, struct net_device *ndev,
 			 unsigned int port);
+struct net_device *ib_device_get_netdev(struct ib_device *ib_dev,
+					u32 port);
 struct ib_wq *ib_create_wq(struct ib_pd *pd,
 			   struct ib_wq_init_attr *init_attr);
 int ib_destroy_wq_user(struct ib_wq *wq, struct ib_udata *udata);