Merge tag 'mlx5-next-netdev-deadlock' of git://git.kernel.org/pub/scm…

…/linux/kernel/git/mellanox/linux

Saeed Mahameed says:

====================
mlx5-next-netdev-deadlock

This series from Jiri solves a deadlock when removing a network namespace
with mlx5 devlink instance being in it.
The deadlock is between:
1) mlx5_ib->unregister_netdevice_notifier()
AND
2) mlx5_core->devlink_reload->cleanup_net()

To slove this introduced mlx5 netdev added/removed events to track uplink
netdev to be used for register_netdevice_notifier_dev_net() purposes.

* tag 'mlx5-next-netdev-deadlock' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux:
  RDMA/mlx5: Track netdev to avoid deadlock during netdev notifier unregister
  net/mlx5e: Propagate an internal event in case uplink netdev changes
  net/mlx5e: Fix trap event handling
  net/mlx5: Introduce CQE error syndrome
====================

Link: https://lore.kernel.org/r/20230208005626.72930-1-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/infiniband/hw/mlx5/main.c

@@ -3012,26 +3012,63 @@ static void mlx5_eth_lag_cleanup(struct mlx5_ib_dev *dev)
 	}
 }
 
-static int mlx5_add_netdev_notifier(struct mlx5_ib_dev *dev, u32 port_num)
+static void mlx5_netdev_notifier_register(struct mlx5_roce *roce,
+					  struct net_device *netdev)
 {
 	int err;
 
-	dev->port[port_num].roce.nb.notifier_call = mlx5_netdev_event;
-	err = register_netdevice_notifier(&dev->port[port_num].roce.nb);
-	if (err) {
-		dev->port[port_num].roce.nb.notifier_call = NULL;
-		return err;
-	}
+	if (roce->tracking_netdev)
+		return;
+	roce->tracking_netdev = netdev;
+	roce->nb.notifier_call = mlx5_netdev_event;
+	err = register_netdevice_notifier_dev_net(netdev, &roce->nb, &roce->nn);
+	WARN_ON(err);
+}
 
-	return 0;
+static void mlx5_netdev_notifier_unregister(struct mlx5_roce *roce)
+{
+	if (!roce->tracking_netdev)
+		return;
+	unregister_netdevice_notifier_dev_net(roce->tracking_netdev, &roce->nb,
+					      &roce->nn);
+	roce->tracking_netdev = NULL;
 }
 
-static void mlx5_remove_netdev_notifier(struct mlx5_ib_dev *dev, u32 port_num)
+static int mlx5e_mdev_notifier_event(struct notifier_block *nb,
+				     unsigned long event, void *data)
 {
-	if (dev->port[port_num].roce.nb.notifier_call) {
-		unregister_netdevice_notifier(&dev->port[port_num].roce.nb);
-		dev->port[port_num].roce.nb.notifier_call = NULL;
+	struct mlx5_roce *roce = container_of(nb, struct mlx5_roce, mdev_nb);
+	struct net_device *netdev = data;
+
+	switch (event) {
+	case MLX5_DRIVER_EVENT_UPLINK_NETDEV:
+		if (netdev)
+			mlx5_netdev_notifier_register(roce, netdev);
+		else
+			mlx5_netdev_notifier_unregister(roce);
+		break;
+	default:
+		return NOTIFY_DONE;
 	}
+
+	return NOTIFY_OK;
+}
+
+static void mlx5_mdev_netdev_track(struct mlx5_ib_dev *dev, u32 port_num)
+{
+	struct mlx5_roce *roce = &dev->port[port_num].roce;
+
+	roce->mdev_nb.notifier_call = mlx5e_mdev_notifier_event;
+	mlx5_blocking_notifier_register(dev->mdev, &roce->mdev_nb);
+	mlx5_core_uplink_netdev_event_replay(dev->mdev);
+}
+
+static void mlx5_mdev_netdev_untrack(struct mlx5_ib_dev *dev, u32 port_num)
+{
+	struct mlx5_roce *roce = &dev->port[port_num].roce;
+
+	mlx5_blocking_notifier_unregister(dev->mdev, &roce->mdev_nb);
+	mlx5_netdev_notifier_unregister(roce);
 }
 
 static int mlx5_enable_eth(struct mlx5_ib_dev *dev)
@@ -3138,7 +3175,7 @@ static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev,
 	if (mpi->mdev_events.notifier_call)
 		mlx5_notifier_unregister(mpi->mdev, &mpi->mdev_events);
 	mpi->mdev_events.notifier_call = NULL;
-	mlx5_remove_netdev_notifier(ibdev, port_num);
+	mlx5_mdev_netdev_untrack(ibdev, port_num);
 	spin_lock(&port->mp.mpi_lock);
 
 	comps = mpi->mdev_refcnt;
@@ -3196,12 +3233,7 @@ static bool mlx5_ib_bind_slave_port(struct mlx5_ib_dev *ibdev,
 	if (err)
 		goto unbind;
 
-	err = mlx5_add_netdev_notifier(ibdev, port_num);
-	if (err) {
-		mlx5_ib_err(ibdev, "failed adding netdev notifier for port %u\n",
-			    port_num + 1);
-		goto unbind;
-	}
+	mlx5_mdev_netdev_track(ibdev, port_num);
 
 	mpi->mdev_events.notifier_call = mlx5_ib_event_slave_port;
 	mlx5_notifier_register(mpi->mdev, &mpi->mdev_events);
@@ -3909,9 +3941,7 @@ static int mlx5_ib_roce_init(struct mlx5_ib_dev *dev)
 		port_num = mlx5_core_native_port_num(dev->mdev) - 1;
 
 		/* Register only for native ports */
-		err = mlx5_add_netdev_notifier(dev, port_num);
-		if (err)
-			return err;
+		mlx5_mdev_netdev_track(dev, port_num);
 
 		err = mlx5_enable_eth(dev);
 		if (err)
@@ -3920,7 +3950,7 @@ static int mlx5_ib_roce_init(struct mlx5_ib_dev *dev)
 
 	return 0;
 cleanup:
-	mlx5_remove_netdev_notifier(dev, port_num);
+	mlx5_mdev_netdev_untrack(dev, port_num);
 	return err;
 }
 
@@ -3938,7 +3968,7 @@ static void mlx5_ib_roce_cleanup(struct mlx5_ib_dev *dev)
 		mlx5_disable_eth(dev);
 
 		port_num = mlx5_core_native_port_num(dev->mdev) - 1;
-		mlx5_remove_netdev_notifier(dev, port_num);
+		mlx5_mdev_netdev_untrack(dev, port_num);
 	}
 }
 

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -832,6 +832,9 @@ struct mlx5_roce {
 	rwlock_t		netdev_lock;
 	struct net_device	*netdev;
 	struct notifier_block	nb;
+	struct netdev_net_notifier nn;
+	struct notifier_block	mdev_nb;
+	struct net_device	*tracking_netdev;
 	atomic_t		tx_port_affinity;
 	enum ib_port_state last_port_state;
 	struct mlx5_ib_dev	*dev;

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

@@ -268,9 +268,10 @@ static int mlx5_devlink_trap_action_set(struct devlink *devlink,
 					struct netlink_ext_ack *extack)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
+	struct mlx5_devlink_trap_event_ctx trap_event_ctx;
 	enum devlink_trap_action action_orig;
 	struct mlx5_devlink_trap *dl_trap;
-	int err = 0;
+	int err;
 
 	if (is_mdev_switchdev_mode(dev)) {
 		NL_SET_ERR_MSG_MOD(extack, "Devlink traps can't be set in switchdev mode");
@@ -280,26 +281,25 @@ static int mlx5_devlink_trap_action_set(struct devlink *devlink,
 	dl_trap = mlx5_find_trap_by_id(dev, trap->id);
 	if (!dl_trap) {
 		mlx5_core_err(dev, "Devlink trap: Set action on invalid trap id 0x%x", trap->id);
-		err = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
-	if (action != DEVLINK_TRAP_ACTION_DROP && action != DEVLINK_TRAP_ACTION_TRAP) {
-		err = -EOPNOTSUPP;
-		goto out;
-	}
+	if (action != DEVLINK_TRAP_ACTION_DROP && action != DEVLINK_TRAP_ACTION_TRAP)
+		return -EOPNOTSUPP;
 
 	if (action == dl_trap->trap.action)
-		goto out;
+		return 0;
 
 	action_orig = dl_trap->trap.action;
 	dl_trap->trap.action = action;
+	trap_event_ctx.trap = &dl_trap->trap;
+	trap_event_ctx.err = 0;
 	err = mlx5_blocking_notifier_call_chain(dev, MLX5_DRIVER_EVENT_TYPE_TRAP,
-						&dl_trap->trap);
-	if (err)
+						&trap_event_ctx);
+	if (err == NOTIFY_BAD)
 		dl_trap->trap.action = action_orig;
-out:
-	return err;
+
+	return trap_event_ctx.err;
 }
 
 static const struct devlink_ops mlx5_devlink_ops = {

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

@@ -24,6 +24,11 @@ struct mlx5_devlink_trap {
 	struct list_head list;
 };
 
+struct mlx5_devlink_trap_event_ctx {
+	struct mlx5_trap_ctx *trap;
+	int err;
+};
+
 struct mlx5_core_dev;
 void mlx5_devlink_trap_report(struct mlx5_core_dev *dev, int trap_id, struct sk_buff *skb,
 			      struct devlink_port *dl_port);

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

@@ -181,17 +181,21 @@ static void mlx5e_disable_async_events(struct mlx5e_priv *priv)
 static int blocking_event(struct notifier_block *nb, unsigned long event, void *data)
 {
 	struct mlx5e_priv *priv = container_of(nb, struct mlx5e_priv, blocking_events_nb);
+	struct mlx5_devlink_trap_event_ctx *trap_event_ctx = data;
 	int err;
 
 	switch (event) {
 	case MLX5_DRIVER_EVENT_TYPE_TRAP:
-		err = mlx5e_handle_trap_event(priv, data);
+		err = mlx5e_handle_trap_event(priv, trap_event_ctx->trap);
+		if (err) {
+			trap_event_ctx->err = err;
+			return NOTIFY_BAD;
+		}
 		break;
 	default:
-		netdev_warn(priv->netdev, "Sync event: Unknown event %ld\n", event);
-		err = -EINVAL;
+		return NOTIFY_DONE;
 	}
-	return err;
+	return NOTIFY_OK;
 }
 
 static void mlx5e_enable_blocking_events(struct mlx5e_priv *priv)
@@ -5984,7 +5988,7 @@ static int mlx5e_probe(struct auxiliary_device *adev,
 	}
 
 	mlx5e_dcbnl_init_app(priv);
-	mlx5_uplink_netdev_set(mdev, netdev);
+	mlx5_core_uplink_netdev_set(mdev, netdev);
 	mlx5e_params_print_info(mdev, &priv->channels.params);
 	return 0;
 
@@ -6008,6 +6012,7 @@ static void mlx5e_remove(struct auxiliary_device *adev)
 	struct mlx5e_priv *priv = mlx5e_dev->priv;
 	pm_message_t state = {};
 
+	mlx5_core_uplink_netdev_set(priv->mdev, NULL);
 	mlx5e_dcbnl_delete_app(priv);
 	unregister_netdev(priv->netdev);
 	mlx5e_suspend(adev, state);

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

@@ -424,13 +424,15 @@ int mlx5_blocking_notifier_register(struct mlx5_core_dev *dev, struct notifier_b
 
 	return blocking_notifier_chain_register(&events->sw_nh, nb);
 }
+EXPORT_SYMBOL(mlx5_blocking_notifier_register);
 
 int mlx5_blocking_notifier_unregister(struct mlx5_core_dev *dev, struct notifier_block *nb)
 {
 	struct mlx5_events *events = dev->priv.events;
 
 	return blocking_notifier_chain_unregister(&events->sw_nh, nb);
 }
+EXPORT_SYMBOL(mlx5_blocking_notifier_unregister);
 
 int mlx5_blocking_notifier_call_chain(struct mlx5_core_dev *dev, unsigned int event,
 				      void *data)

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

@@ -84,11 +84,6 @@ static inline struct net *mlx5_core_net(struct mlx5_core_dev *dev)
 	return devlink_net(priv_to_devlink(dev));
 }
 
-static inline void mlx5_uplink_netdev_set(struct mlx5_core_dev *mdev, struct net_device *netdev)
-{
-	mdev->mlx5e_res.uplink_netdev = netdev;
-}
-
 static inline struct net_device *mlx5_uplink_netdev_get(struct mlx5_core_dev *mdev)
 {
 	return mdev->mlx5e_res.uplink_netdev;

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

@@ -336,6 +336,24 @@ static u16 to_fw_pkey_sz(struct mlx5_core_dev *dev, u32 size)
 	}
 }
 
+void mlx5_core_uplink_netdev_set(struct mlx5_core_dev *dev, struct net_device *netdev)
+{
+	mutex_lock(&dev->mlx5e_res.uplink_netdev_lock);
+	dev->mlx5e_res.uplink_netdev = netdev;
+	mlx5_blocking_notifier_call_chain(dev, MLX5_DRIVER_EVENT_UPLINK_NETDEV,
+					  netdev);
+	mutex_unlock(&dev->mlx5e_res.uplink_netdev_lock);
+}
+
+void mlx5_core_uplink_netdev_event_replay(struct mlx5_core_dev *dev)
+{
+	mutex_lock(&dev->mlx5e_res.uplink_netdev_lock);
+	mlx5_blocking_notifier_call_chain(dev, MLX5_DRIVER_EVENT_UPLINK_NETDEV,
+					  dev->mlx5e_res.uplink_netdev);
+	mutex_unlock(&dev->mlx5e_res.uplink_netdev_lock);
+}
+EXPORT_SYMBOL(mlx5_core_uplink_netdev_event_replay);
+
 static int mlx5_core_get_caps_mode(struct mlx5_core_dev *dev,
 				   enum mlx5_cap_type cap_type,
 				   enum mlx5_cap_mode cap_mode)
@@ -1609,6 +1627,7 @@ int mlx5_mdev_init(struct mlx5_core_dev *dev, int profile_idx)
 	lockdep_register_key(&dev->lock_key);
 	mutex_init(&dev->intf_state_mutex);
 	lockdep_set_class(&dev->intf_state_mutex, &dev->lock_key);
+	mutex_init(&dev->mlx5e_res.uplink_netdev_lock);
 
 	mutex_init(&priv->bfregs.reg_head.lock);
 	mutex_init(&priv->bfregs.wc_head.lock);
@@ -1697,6 +1716,7 @@ void mlx5_mdev_uninit(struct mlx5_core_dev *dev)
 	mutex_destroy(&priv->alloc_mutex);
 	mutex_destroy(&priv->bfregs.wc_head.lock);
 	mutex_destroy(&priv->bfregs.reg_head.lock);
+	mutex_destroy(&dev->mlx5e_res.uplink_netdev_lock);
 	mutex_destroy(&dev->intf_state_mutex);
 	lockdep_unregister_key(&dev->lock_key);
 }

include/linux/mlx5/device.h

@@ -362,6 +362,7 @@ enum mlx5_event {
 
 enum mlx5_driver_event {
 	MLX5_DRIVER_EVENT_TYPE_TRAP = 0,
+	MLX5_DRIVER_EVENT_UPLINK_NETDEV,
 };
 
 enum {

include/linux/mlx5/driver.h

@@ -49,6 +49,7 @@
 #include <linux/notifier.h>
 #include <linux/refcount.h>
 #include <linux/auxiliary_bus.h>
+#include <linux/mutex.h>
 
 #include <linux/mlx5/device.h>
 #include <linux/mlx5/doorbell.h>
@@ -672,6 +673,7 @@ struct mlx5e_resources {
 	} hw_objs;
 	struct devlink_port dl_port;
 	struct net_device *uplink_netdev;
+	struct mutex uplink_netdev_lock;
 	struct mlx5_crypto_dek_priv *dek_priv;
 };
 
@@ -1010,6 +1012,9 @@ int mlx5_cmd_exec_polling(struct mlx5_core_dev *dev, void *in, int in_size,
 			  void *out, int out_size);
 bool mlx5_cmd_is_down(struct mlx5_core_dev *dev);
 
+void mlx5_core_uplink_netdev_set(struct mlx5_core_dev *mdev, struct net_device *netdev);
+void mlx5_core_uplink_netdev_event_replay(struct mlx5_core_dev *mdev);
+
 int mlx5_core_get_caps(struct mlx5_core_dev *dev, enum mlx5_cap_type cap_type);
 void mlx5_health_cleanup(struct mlx5_core_dev *dev);
 int mlx5_health_init(struct mlx5_core_dev *dev);