Re: [PATCH 2/2] driver core: bus: move bus notifier logic into bus.c

From: Rafael J. Wysocki
Date: Tue Jan 10 2023 - 07:56:13 EST

On Tue, Jan 10, 2023 at 1:43 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> 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.
>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/base/base.h | 1 +
> drivers/base/bus.c | 8 ++++++++
> drivers/base/core.c | 13 +++----------
> drivers/base/dd.c | 28 +++++++---------------------
> 4 files changed, 19 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/base/base.h b/drivers/base/base.h
> index 7d4803c03d3e..2e08258ce82e 100644
> --- a/drivers/base/base.h
> +++ b/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);
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index 428c26c6b615..cf1b8f00b4c0 100644
> --- a/drivers/base/bus.c
> +++ b/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);

I'm not sure if the local var is really helpful. Personally, I
wouldn't use it, but anyway

Reviewed-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

> +}
> +
> struct kset *bus_get_kset(struct bus_type *bus)
> {
> return &bus->p->subsys;
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index a3e14143ec0c..af6a2761b31d 100644
> --- a/drivers/base/core.c
> +++ b/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);
>
> /*
> @@ -3636,9 +3633,7 @@ 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)
> @@ -3669,9 +3664,7 @@ 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);
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index e9b2f9c25efe..a519eaf1990c 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -413,10 +413,7 @@ 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);
> }
>
> @@ -435,9 +432,7 @@ 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));
> @@ -502,9 +497,8 @@ 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);
> @@ -695,9 +689,7 @@ 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:
> @@ -1243,10 +1235,7 @@ 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);
>
> @@ -1260,11 +1249,8 @@ 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);
> }
> }
> --
> 2.39.0
>