driver core: bus: move bus notifier logic into bus.c

The logic to touch the bus notifier was open-coded in numberous places
in the driver core.  Clean that up by creating a local bus_notify()
function and have everyone call this function instead, making the
reading of the caller code simpler and easier to maintain over time.
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/base.h

@@ -130,6 +130,7 @@ struct kobject *virtual_device_parent(struct device *dev);
 extern int bus_add_device(struct device *dev);
 extern void bus_probe_device(struct device *dev);
 extern void bus_remove_device(struct device *dev);
+void bus_notify(struct device *dev, enum bus_notifier_event value);
 
 extern int bus_add_driver(struct device_driver *drv);
 extern void bus_remove_driver(struct device_driver *drv);

drivers/base/bus.c

@@ -850,6 +850,14 @@ int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(bus_unregister_notifier);
 
+void bus_notify(struct device *dev, enum bus_notifier_event value)
+{
+	struct bus_type *bus = dev->bus;
+
+	if (bus)
+		blocking_notifier_call_chain(&bus->p->bus_notifier, value, dev);
+}
+
 struct kset *bus_get_kset(struct bus_type *bus)
 {
 	return &bus->p->subsys;

drivers/base/core.c

@@ -3453,10 +3453,7 @@ int device_add(struct device *dev)
 	/* Notify clients of device addition.  This call must come
 	 * after dpm_sysfs_add() and before kobject_uevent().
 	 */
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_ADD_DEVICE, dev);
-
+	bus_notify(dev, BUS_NOTIFY_ADD_DEVICE);
 	kobject_uevent(&dev->kobj, KOBJ_ADD);
 
 	/*
@@ -3637,9 +3634,7 @@ void device_del(struct device *dev)
 	 * before dpm_sysfs_remove().
 	 */
 	noio_flag = memalloc_noio_save();
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_DEL_DEVICE, dev);
+	bus_notify(dev, BUS_NOTIFY_DEL_DEVICE);
 
 	dpm_sysfs_remove(dev);
 	if (parent)
@@ -3670,9 +3665,7 @@ void device_del(struct device *dev)
 	device_platform_notify_remove(dev);
 	device_links_purge(dev);
 
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_REMOVED_DEVICE, dev);
+	bus_notify(dev, BUS_NOTIFY_REMOVED_DEVICE);
 	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 	glue_dir = get_glue_dir(dev);
 	kobject_del(&dev->kobj);

drivers/base/dd.c

@@ -411,10 +411,7 @@ static void driver_bound(struct device *dev)
 	driver_deferred_probe_del(dev);
 	driver_deferred_probe_trigger();
 
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_BOUND_DRIVER, dev);
-
+	bus_notify(dev, BUS_NOTIFY_BOUND_DRIVER);
 	kobject_uevent(&dev->kobj, KOBJ_BIND);
 }
 
@@ -433,9 +430,7 @@ static int driver_sysfs_add(struct device *dev)
 {
 	int ret;
 
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_BIND_DRIVER, dev);
+	bus_notify(dev, BUS_NOTIFY_BIND_DRIVER);
 
 	ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
 				kobject_name(&dev->kobj));
@@ -500,9 +495,8 @@ int device_bind_driver(struct device *dev)
 		device_links_force_bind(dev);
 		driver_bound(dev);
 	}
-	else if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+	else
+		bus_notify(dev, BUS_NOTIFY_DRIVER_NOT_BOUND);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(device_bind_driver);
@@ -693,9 +687,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 probe_failed:
 	driver_sysfs_remove(dev);
 sysfs_failed:
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+	bus_notify(dev, BUS_NOTIFY_DRIVER_NOT_BOUND);
 	if (dev->bus && dev->bus->dma_cleanup)
 		dev->bus->dma_cleanup(dev);
 pinctrl_bind_failed:
@@ -1241,10 +1233,7 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 
 		driver_sysfs_remove(dev);
 
-		if (dev->bus)
-			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-						     BUS_NOTIFY_UNBIND_DRIVER,
-						     dev);
+		bus_notify(dev, BUS_NOTIFY_UNBIND_DRIVER);
 
 		pm_runtime_put_sync(dev);
 
@@ -1258,11 +1247,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 
 		klist_remove(&dev->p->knode_driver);
 		device_pm_check_callbacks(dev);
-		if (dev->bus)
-			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-						     BUS_NOTIFY_UNBOUND_DRIVER,
-						     dev);
 
+		bus_notify(dev, BUS_NOTIFY_UNBOUND_DRIVER);
 		kobject_uevent(&dev->kobj, KOBJ_UNBIND);
 	}
 }