Greg KH
2005-06-20T23:51:13Z

[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: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit 465c7a3a3a5aabcedd2e43612cac5a12f23da19a
tree 392dabbfe84d1de3e84b1eb238bfd09d0ade6c4c
parent 9a19fea43616066561e221359596ce532e631395
author mochel@digitalimplant.org <mochel@digitalimplant.org> Mon, 21 Mar 2005 11:49:14 -0800
committer Greg Kroah-Hartman <gregkh@suse.de> Mon, 20 Jun 2005 15:15:14 -0700

drivers/base/bus.c | 54 +++++++++++++++++++++---------------------------
include/linux/device.h | 3 +++
2 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -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
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
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 * d
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 *
{
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);
diff --git a/include/linux/device.h b/include/linux/device.h
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -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;