Commit 7b19119f authored by Moshe Shemesh's avatar Moshe Shemesh Committed by Paolo Abeni
Browse files

net/mlx5: Use devl_ API in mlx5e_devlink_port_register 



As part of the flows invoked by mlx5_devlink_eswitch_mode_set() get to
mlx5_rescan_drivers_locked() which can call mlx5e_probe()/mlx5e_remove
and register/unregister mlx5e driver ports accordingly. This can lead to
deadlock once mlx5_devlink_eswitch_mode_set() will use devlink lock.
Use devl_port_register/unregister() instead of
devlink_port_register/unregister() and add devlink instance locks in the
driver paths to this function to have it locked while calling devl_ API
function.

If remove or probe were called by module init or module cleanup flows,
need to lock devlink just before calling devl_port_register(), otherwise
it is called by attach/detach or register/unregister flow and we can
have the flow locked. Added flag to distinguish between these cases.

This will be used by the downstream patch to invoke
mlx5_devlink_eswitch_mode_set() with devlink locked.

Signed-off-by: default avatarMoshe Shemesh <moshe@nvidia.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent df539fc6

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

+27 −2
Original line number Diff line number Diff line
@@ -335,13 +335,16 @@ static void del_adev(struct auxiliary_device *adev) 


int mlx5_attach_device(struct mlx5_core_dev *dev)

{

	struct devlink *devlink = priv_to_devlink(dev);

	struct mlx5_priv *priv = &dev->priv;

	struct auxiliary_device *adev;

	struct auxiliary_driver *adrv;

	int ret = 0, i;



	devl_lock(devlink);

	mutex_lock(&mlx5_intf_mutex);

	priv->flags &= ~MLX5_PRIV_FLAGS_DETACH;

	priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	for (i = 0; i < ARRAY_SIZE(mlx5_adev_devices); i++) {

		if (!priv->adev[i]) {

			bool is_supported = false;
@@ -389,19 +392,24 @@ int mlx5_attach_device(struct mlx5_core_dev *dev) 
			break;

		}

	}

	priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	mutex_unlock(&mlx5_intf_mutex);

	devl_unlock(devlink);

	return ret;

}



void mlx5_detach_device(struct mlx5_core_dev *dev)

{

	struct devlink *devlink = priv_to_devlink(dev);

	struct mlx5_priv *priv = &dev->priv;

	struct auxiliary_device *adev;

	struct auxiliary_driver *adrv;

	pm_message_t pm = {};

	int i;



	devl_lock(devlink);

	mutex_lock(&mlx5_intf_mutex);

	priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	for (i = ARRAY_SIZE(mlx5_adev_devices) - 1; i >= 0; i--) {

		if (!priv->adev[i])

			continue;
@@ -430,18 +438,24 @@ void mlx5_detach_device(struct mlx5_core_dev *dev) 
		del_adev(&priv->adev[i]->adev);

		priv->adev[i] = NULL;

	}

	priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	priv->flags |= MLX5_PRIV_FLAGS_DETACH;

	mutex_unlock(&mlx5_intf_mutex);

	devl_unlock(devlink);

}



int mlx5_register_device(struct mlx5_core_dev *dev)

{

	struct devlink *devlink;

	int ret;



	devlink = priv_to_devlink(dev);

	devl_lock(devlink);

	mutex_lock(&mlx5_intf_mutex);

	dev->priv.flags &= ~MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV;

	ret = mlx5_rescan_drivers_locked(dev);

	mutex_unlock(&mlx5_intf_mutex);

	devl_unlock(devlink);

	if (ret)

		mlx5_unregister_device(dev);
@@ -450,10 +464,15 @@ int mlx5_register_device(struct mlx5_core_dev *dev) 


void mlx5_unregister_device(struct mlx5_core_dev *dev)

{

	struct devlink *devlink;



	devlink = priv_to_devlink(dev);

	devl_lock(devlink);

	mutex_lock(&mlx5_intf_mutex);

	dev->priv.flags = MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV;

	mlx5_rescan_drivers_locked(dev);

	mutex_unlock(&mlx5_intf_mutex);

	devl_unlock(devlink);

}



static int add_drivers(struct mlx5_core_dev *dev)
@@ -526,16 +545,22 @@ static void delete_drivers(struct mlx5_core_dev *dev) 
int mlx5_rescan_drivers_locked(struct mlx5_core_dev *dev)

{

	struct mlx5_priv *priv = &dev->priv;

	int err = 0;



	lockdep_assert_held(&mlx5_intf_mutex);

	if (priv->flags & MLX5_PRIV_FLAGS_DETACH)

		return 0;



	priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	delete_drivers(dev);

	if (priv->flags & MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV)

		return 0;

		goto out;



	err = add_drivers(dev);



	return add_drivers(dev);

out:

	priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW;

	return err;

}



bool mlx5_same_hw_devs(struct mlx5_core_dev *dev, struct mlx5_core_dev *peer_dev)

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

+14 −2
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ int mlx5e_devlink_port_register(struct mlx5e_priv *priv) 
	struct netdev_phys_item_id ppid = {};

	struct devlink_port *dl_port;

	unsigned int dl_port_index;

	int ret;



	if (mlx5_core_is_pf(priv->mdev)) {

		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
@@ -41,7 +42,13 @@ int mlx5e_devlink_port_register(struct mlx5e_priv *priv) 
	memset(dl_port, 0, sizeof(*dl_port));

	devlink_port_attrs_set(dl_port, &attrs);



	return devlink_port_register(devlink, dl_port, dl_port_index);

	if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW))

		devl_lock(devlink);

	ret = devl_port_register(devlink, dl_port, dl_port_index);

	if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW))

		devl_unlock(devlink);



	return ret;

}



void mlx5e_devlink_port_type_eth_set(struct mlx5e_priv *priv)
@@ -54,8 +61,13 @@ void mlx5e_devlink_port_type_eth_set(struct mlx5e_priv *priv) 
void mlx5e_devlink_port_unregister(struct mlx5e_priv *priv)

{

	struct devlink_port *dl_port = mlx5e_devlink_get_dl_port(priv);

	struct devlink *devlink = priv_to_devlink(priv->mdev);



	devlink_port_unregister(dl_port);

	if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW))

		devl_lock(devlink);

	devl_port_unregister(dl_port);

	if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW))

		devl_unlock(devlink);

}



struct devlink_port *mlx5e_get_devlink_port(struct net_device *dev)

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

+2 −0
Original line number Diff line number Diff line
@@ -3400,7 +3400,9 @@ int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode, 
		err = esw_offloads_start(esw, extack);

	} else if (mode == DEVLINK_ESWITCH_MODE_LEGACY) {

		err = esw_offloads_stop(esw, extack);

		devl_lock(devlink);

		mlx5_rescan_drivers(esw->dev);

		devl_unlock(devlink);

	} else {

		err = -EINVAL;

	}

include/linux/mlx5/driver.h

+4 −0
Original line number Diff line number Diff line
@@ -551,6 +551,10 @@ enum { 
	 * creation/deletion on drivers rescan. Unset during device attach.

	 */

	MLX5_PRIV_FLAGS_DETACH = 1 << 2,

	/* Distinguish between mlx5e_probe/remove called by module init/cleanup

	 * and called by other flows which can already hold devlink lock

	 */

	MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW = 1 << 3,

};



struct mlx5_adev {