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Commit 465c7a3a authored by Patrick Mochel's avatar Patrick Mochel Committed by Greg Kroah-Hartman
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[PATCH] Add a klist to struct bus_type for its devices. 



- Use it for bus_for_each_dev().
- Use the klist spinlock instead of the bus rwsem.

Signed-off-by: default avatarPatrick Mochel <mochel@digitalimplant.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 9a19fea4

drivers/base/bus.c

+24 −30
Original line number Diff line number Diff line
@@ -134,28 +134,6 @@ static struct kobj_type ktype_bus = { 


decl_subsys(bus, &ktype_bus, NULL);



static int __bus_for_each_dev(struct bus_type *bus, struct device *start,

			      void *data, int (*fn)(struct device *, void *))

{

	struct list_head *head;

	struct device *dev;

	int error = 0;



	if (!(bus = get_bus(bus)))

		return -EINVAL;



	head = &bus->devices.list;

	dev = list_prepare_entry(start, head, bus_list);

	list_for_each_entry_continue(dev, head, bus_list) {

		get_device(dev);

		error = fn(dev, data);

		put_device(dev);

		if (error)

			break;

	}

	put_bus(bus);

	return error;

}



static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,

			      void * data, int (*fn)(struct device_driver *, void *))
@@ -180,6 +158,13 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, 
	return error;

}





static struct device * next_device(struct klist_iter * i)

{

	struct klist_node * n = klist_next(i);

	return n ? container_of(n, struct device, knode_bus) : NULL;

}



/**

 *	bus_for_each_dev - device iterator.

 *	@bus:	bus type.
@@ -203,12 +188,19 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, 
int bus_for_each_dev(struct bus_type * bus, struct device * start,

		     void * data, int (*fn)(struct device *, void *))

{

	int ret;

	struct klist_iter i;

	struct device * dev;

	int error = 0;



	down_read(&bus->subsys.rwsem);

	ret = __bus_for_each_dev(bus, start, data, fn);

	up_read(&bus->subsys.rwsem);

	return ret;

	if (!bus)

		return -EINVAL;



	klist_iter_init_node(&bus->klist_devices, &i,

			     (start ? &start->knode_bus : NULL));

	while ((dev = next_device(&i)) && !error)

		error = fn(dev, data);

	klist_iter_exit(&i);

	return error;

}



/**
@@ -293,6 +285,7 @@ int bus_add_device(struct device * dev) 
		list_add_tail(&dev->bus_list, &dev->bus->devices.list);

		device_attach(dev);

		up_write(&dev->bus->subsys.rwsem);

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

		device_add_attrs(bus, dev);

		sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);

		sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
@@ -315,6 +308,7 @@ void bus_remove_device(struct device * dev) 
		sysfs_remove_link(&dev->kobj, "bus");

		sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);

		device_remove_attrs(dev->bus, dev);

		klist_remove(&dev->knode_bus);

		down_write(&dev->bus->subsys.rwsem);

		pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);

		device_release_driver(dev);
@@ -439,9 +433,7 @@ int bus_rescan_devices(struct bus_type * bus) 
{

	int count = 0;



	down_write(&bus->subsys.rwsem);

	__bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);

	up_write(&bus->subsys.rwsem);

	bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);



	return count;

}
@@ -542,6 +534,8 @@ int bus_register(struct bus_type * bus) 
	retval = kset_register(&bus->drivers);

	if (retval)

		goto bus_drivers_fail;



	klist_init(&bus->klist_devices);

	bus_add_attrs(bus);



	pr_debug("bus type '%s' registered\n", bus->name);

include/linux/device.h

+3 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/config.h>

#include <linux/ioport.h>

#include <linux/kobject.h>

#include <linux/klist.h>

#include <linux/list.h>

#include <linux/types.h>

#include <linux/module.h>
@@ -51,6 +52,7 @@ struct bus_type { 
	struct subsystem	subsys;

	struct kset		drivers;

	struct kset		devices;

	struct klist		klist_devices;



	struct bus_attribute	* bus_attrs;

	struct device_attribute	* dev_attrs;
@@ -262,6 +264,7 @@ struct device { 
	struct list_head bus_list;	/* node in bus's list */

	struct list_head driver_list;

	struct list_head children;

	struct klist_node	knode_bus;

	struct device 	* parent;



	struct kobject kobj;