net: dsa: remove the DSA specific notifiers

This effectively reverts commit 60724d4 ("net: dsa: Add support for
DSA specific notifiers"). The reason is that since commit 2f1e8ea
("net: dsa: link interfaces with the DSA master to get rid of lockdep
warnings"), it appears that there is a generic way to achieve the same
purpose. The only user thus far, the Broadcom SYSTEMPORT driver, was
converted to use the generic notifiers.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/dsa.h

@@ -833,51 +833,9 @@ static inline int dsa_switch_resume(struct dsa_switch *ds)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-enum dsa_notifier_type {
-	DSA_PORT_REGISTER,
-	DSA_PORT_UNREGISTER,
-};
-
-struct dsa_notifier_info {
-	struct net_device *dev;
-};
-
-struct dsa_notifier_register_info {
-	struct dsa_notifier_info info;	/* must be first */
-	struct net_device *master;
-	unsigned int port_number;
-	unsigned int switch_number;
-};
-
-static inline struct net_device *
-dsa_notifier_info_to_dev(const struct dsa_notifier_info *info)
-{
-	return info->dev;
-}
-
 #if IS_ENABLED(CONFIG_NET_DSA)
-int register_dsa_notifier(struct notifier_block *nb);
-int unregister_dsa_notifier(struct notifier_block *nb);
-int call_dsa_notifiers(unsigned long val, struct net_device *dev,
-		       struct dsa_notifier_info *info);
 bool dsa_slave_dev_check(const struct net_device *dev);
 #else
-static inline int register_dsa_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline int unregister_dsa_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline int call_dsa_notifiers(unsigned long val, struct net_device *dev,
-				     struct dsa_notifier_info *info)
-{
-	return NOTIFY_DONE;
-}
-
 static inline bool dsa_slave_dev_check(const struct net_device *dev)
 {
 	return false;

net/dsa/dsa.c

@@ -309,28 +309,6 @@ bool dsa_schedule_work(struct work_struct *work)
 	return queue_work(dsa_owq, work);
 }
 
-static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
-
-int register_dsa_notifier(struct notifier_block *nb)
-{
-	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
-}
-EXPORT_SYMBOL_GPL(register_dsa_notifier);
-
-int unregister_dsa_notifier(struct notifier_block *nb)
-{
-	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
-}
-EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
-
-int call_dsa_notifiers(unsigned long val, struct net_device *dev,
-		       struct dsa_notifier_info *info)
-{
-	info->dev = dev;
-	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
-}
-EXPORT_SYMBOL_GPL(call_dsa_notifiers);
-
 int dsa_devlink_param_get(struct devlink *dl, u32 id,
 			  struct devlink_param_gset_ctx *ctx)
 {

net/dsa/slave.c

@@ -1764,20 +1764,6 @@ int dsa_slave_resume(struct net_device *slave_dev)
 	return 0;
 }
 
-static void dsa_slave_notify(struct net_device *dev, unsigned long val)
-{
-	struct net_device *master = dsa_slave_to_master(dev);
-	struct dsa_port *dp = dsa_slave_to_port(dev);
-	struct dsa_notifier_register_info rinfo = {
-		.switch_number = dp->ds->index,
-		.port_number = dp->index,
-		.master = master,
-		.info.dev = dev,
-	};
-
-	call_dsa_notifiers(val, dev, &rinfo.info);
-}
-
 int dsa_slave_create(struct dsa_port *port)
 {
 	const struct dsa_port *cpu_dp = port->cpu_dp;
@@ -1863,8 +1849,6 @@ int dsa_slave_create(struct dsa_port *port)
 		goto out_gcells;
 	}
 
-	dsa_slave_notify(slave_dev, DSA_PORT_REGISTER);
-
 	rtnl_lock();
 
 	ret = register_netdevice(slave_dev);
@@ -1913,7 +1897,6 @@ void dsa_slave_destroy(struct net_device *slave_dev)
 	phylink_disconnect_phy(dp->pl);
 	rtnl_unlock();
 
-	dsa_slave_notify(slave_dev, DSA_PORT_UNREGISTER);
 	phylink_destroy(dp->pl);
 	gro_cells_destroy(&p->gcells);
 	free_percpu(slave_dev->tstats);