Commit 5221b82d authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

driver core: bus: bus_add/probe/remove_device() cleanups 

Convert the bus_add_device(), bus_probe_device(), and
bus_remove_device() functions to use bus_to_subsys() and not use the
back-pointer to the private structure.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-7-gregkh@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a00fdb98

drivers/base/bus.c

+54 −33
Original line number Diff line number Diff line
@@ -466,32 +466,46 @@ EXPORT_SYMBOL_GPL(bus_for_each_drv); 
 */

int bus_add_device(struct device *dev)

{

	struct bus_type *bus = bus_get(dev->bus);

	int error = 0;

	struct subsys_private *sp = bus_to_subsys(dev->bus);

	int error;



	if (!sp) {

		/*

		 * This is a normal operation for many devices that do not

		 * have a bus assigned to them, just say that all went

		 * well.

		 */

		return 0;

	}



	if (bus) {

		pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));

		error = device_add_groups(dev, bus->dev_groups);

	/*

	 * Reference in sp is now incremented and will be dropped when

	 * the device is removed from the bus

	 */



	pr_debug("bus: '%s': add device %s\n", sp->bus->name, dev_name(dev));



	error = device_add_groups(dev, sp->bus->dev_groups);

	if (error)

		goto out_put;

		error = sysfs_create_link(&bus->p->devices_kset->kobj,

						&dev->kobj, dev_name(dev));



	error = sysfs_create_link(&sp->devices_kset->kobj, &dev->kobj, dev_name(dev));

	if (error)

		goto out_groups;

		error = sysfs_create_link(&dev->kobj,

				&dev->bus->p->subsys.kobj, "subsystem");



	error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem");

	if (error)

		goto out_subsys;

		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);

	}



	klist_add_tail(&dev->p->knode_bus, &sp->klist_devices);

	return 0;



out_subsys:

	sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));

	sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev));

out_groups:

	device_remove_groups(dev, bus->dev_groups);

	device_remove_groups(dev, sp->bus->dev_groups);

out_put:

	bus_put(dev->bus);

	subsys_put(sp);

	return error;

}
@@ -503,20 +517,21 @@ int bus_add_device(struct device *dev) 
 */

void bus_probe_device(struct device *dev)

{

	struct bus_type *bus = dev->bus;

	struct subsys_private *sp = bus_to_subsys(dev->bus);

	struct subsys_interface *sif;



	if (!bus)

	if (!sp)

		return;



	if (bus->p->drivers_autoprobe)

	if (sp->drivers_autoprobe)

		device_initial_probe(dev);



	mutex_lock(&bus->p->mutex);

	list_for_each_entry(sif, &bus->p->interfaces, node)

	mutex_lock(&sp->mutex);

	list_for_each_entry(sif, &sp->interfaces, node)

		if (sif->add_dev)

			sif->add_dev(dev, sif);

	mutex_unlock(&bus->p->mutex);

	mutex_unlock(&sp->mutex);

	subsys_put(sp);

}



/**
@@ -531,21 +546,20 @@ void bus_probe_device(struct device *dev) 
 */

void bus_remove_device(struct device *dev)

{

	struct bus_type *bus = dev->bus;

	struct subsys_private *sp = bus_to_subsys(dev->bus);

	struct subsys_interface *sif;



	if (!bus)

	if (!sp)

		return;



	mutex_lock(&bus->p->mutex);

	list_for_each_entry(sif, &bus->p->interfaces, node)

	mutex_lock(&sp->mutex);

	list_for_each_entry(sif, &sp->interfaces, node)

		if (sif->remove_dev)

			sif->remove_dev(dev, sif);

	mutex_unlock(&bus->p->mutex);

	mutex_unlock(&sp->mutex);



	sysfs_remove_link(&dev->kobj, "subsystem");

	sysfs_remove_link(&dev->bus->p->devices_kset->kobj,

			  dev_name(dev));

	sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev));

	device_remove_groups(dev, dev->bus->dev_groups);

	if (klist_node_attached(&dev->p->knode_bus))

		klist_del(&dev->p->knode_bus);
@@ -553,7 +567,14 @@ void bus_remove_device(struct device *dev) 
	pr_debug("bus: '%s': remove device %s\n",

		 dev->bus->name, dev_name(dev));

	device_release_driver(dev);

	bus_put(dev->bus);



	/*

	 * Decrement the reference count twice, once for the bus_to_subsys()

	 * call in the start of this function, and the second one from the

	 * reference increment in bus_add_device()

	 */

	subsys_put(sp);

	subsys_put(sp);

}



static int __must_check add_bind_files(struct device_driver *drv)