net/mlx5: Support enable_rdma devlink dev param

Enable user to disable RDMA auxiliary device so that when it is not
required, user can disable it.

For example,

$ devlink dev param set pci/0000:06:00.0 \
              name enable_rdma value false cmode driverinit
$ devlink dev reload pci/0000:06:00.0

At this point devlink instance do not create auxiliary device
mlx5_core.rdma.2 for the RDMA functionality.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -181,7 +181,7 @@ static bool is_mp_supported(struct mlx5_core_dev *dev)
 	return true;
 }
 
-static bool is_ib_supported(struct mlx5_core_dev *dev)
+bool mlx5_rdma_supported(struct mlx5_core_dev *dev)
 {
 	if (!IS_ENABLED(CONFIG_MLX5_INFINIBAND))
 		return false;
@@ -198,6 +198,17 @@ static bool is_ib_supported(struct mlx5_core_dev *dev)
 	return true;
 }
 
+static bool is_ib_enabled(struct mlx5_core_dev *dev)
+{
+	union devlink_param_value val;
+	int err;
+
+	err = devlink_param_driverinit_value_get(priv_to_devlink(dev),
+						 DEVLINK_PARAM_GENERIC_ID_ENABLE_RDMA,
+						 &val);
+	return err ? false : val.vbool;
+}
+
 enum {
 	MLX5_INTERFACE_PROTOCOL_ETH,
 	MLX5_INTERFACE_PROTOCOL_ETH_REP,
@@ -217,7 +228,8 @@ static const struct mlx5_adev_device {
 	[MLX5_INTERFACE_PROTOCOL_VNET] = { .suffix = "vnet",
 					   .is_supported = &is_vnet_supported },
 	[MLX5_INTERFACE_PROTOCOL_IB] = { .suffix = "rdma",
-					 .is_supported = &is_ib_supported },
+					 .is_supported = &mlx5_rdma_supported,
+					 .is_enabled = &is_ib_enabled },
 	[MLX5_INTERFACE_PROTOCOL_ETH] = { .suffix = "eth",
 					  .is_supported = &mlx5_eth_supported,
 					  .is_enabled = &is_eth_enabled },

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

@@ -632,13 +632,76 @@ static void mlx5_devlink_eth_param_unregister(struct devlink *devlink)
 	devlink_param_unregister(devlink, &enable_eth_param);
 }
 
+static int mlx5_devlink_enable_rdma_validate(struct devlink *devlink, u32 id,
+					     union devlink_param_value val,
+					     struct netlink_ext_ack *extack)
+{
+	struct mlx5_core_dev *dev = devlink_priv(devlink);
+	bool new_state = val.vbool;
+
+	if (new_state && !mlx5_rdma_supported(dev))
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+static const struct devlink_param enable_rdma_param =
+	DEVLINK_PARAM_GENERIC(ENABLE_RDMA, BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
+			      NULL, NULL, mlx5_devlink_enable_rdma_validate);
+
+static int mlx5_devlink_rdma_param_register(struct devlink *devlink)
+{
+	struct mlx5_core_dev *dev = devlink_priv(devlink);
+	union devlink_param_value value;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_MLX5_INFINIBAND) || MLX5_ESWITCH_MANAGER(dev))
+		return 0;
+
+	err = devlink_param_register(devlink, &enable_rdma_param);
+	if (err)
+		return err;
+
+	value.vbool = true;
+	devlink_param_driverinit_value_set(devlink,
+					   DEVLINK_PARAM_GENERIC_ID_ENABLE_RDMA,
+					   value);
+	devlink_param_publish(devlink, &enable_rdma_param);
+	return 0;
+}
+
+static void mlx5_devlink_rdma_param_unregister(struct devlink *devlink)
+{
+	struct mlx5_core_dev *dev = devlink_priv(devlink);
+
+	if (!IS_ENABLED(CONFIG_MLX5_INFINIBAND) || MLX5_ESWITCH_MANAGER(dev))
+		return;
+
+	devlink_param_unpublish(devlink, &enable_rdma_param);
+	devlink_param_unregister(devlink, &enable_rdma_param);
+}
+
 static int mlx5_devlink_auxdev_params_register(struct devlink *devlink)
 {
-	return mlx5_devlink_eth_param_register(devlink);
+	int err;
+
+	err = mlx5_devlink_eth_param_register(devlink);
+	if (err)
+		return err;
+
+	err = mlx5_devlink_rdma_param_register(devlink);
+	if (err)
+		goto rdma_err;
+
+	return 0;
+
+rdma_err:
+	mlx5_devlink_eth_param_unregister(devlink);
+	return err;
 }
 
 static void mlx5_devlink_auxdev_params_unregister(struct devlink *devlink)
 {
+	mlx5_devlink_rdma_param_unregister(devlink);
 	mlx5_devlink_eth_param_unregister(devlink);
 }
 

drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h

@@ -274,5 +274,6 @@ static inline u32 mlx5_sriov_get_vf_total_msix(struct pci_dev *pdev)
 }
 
 bool mlx5_eth_supported(struct mlx5_core_dev *dev);
+bool mlx5_rdma_supported(struct mlx5_core_dev *dev);
 
 #endif /* __MLX5_CORE_H__ */