Greg KH
2005-06-21T00:46:29Z

[PATCH] Add a klist to struct bus_type for its drivers.

- Use it in bus_for_each_drv().
- 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 38fdac3cdce276554b4484a41f8ec2daf81cb2ff
tree 1bdd0b8b69bd8e13de53036c8ef8b968a0dacc1d
parent 465c7a3a3a5aabcedd2e43612cac5a12f23da19a
author mochel@digitalimplant.org <mochel@digitalimplant.org> Mon, 21 Mar 2005 12:00:18 -0800
committer Greg Kroah-Hartman <gregkh@suse.de> Mon, 20 Jun 2005 15:15:14 -0700

drivers/base/bus.c | 52 +++++++++++++++++++++---------------------------
include/linux/device.h | 2 ++
2 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -135,30 +135,6 @@ static struct kobj_type ktype_bus = {
decl_subsys(bus, &ktype_bus, NULL);

-static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
- void * data, int (*fn)(struct device_driver *, void *))
-{
- struct list_head *head;
- struct device_driver *drv;
- int error = 0;
-
- if (!(bus = get_bus(bus)))
- return -EINVAL;
-
- head = &bus->drivers.list;
- drv = list_prepare_entry(start, head, kobj.entry);
- list_for_each_entry_continue(drv, head, kobj.entry) {
- get_driver(drv);
- error = fn(drv, data);
- put_driver(drv);
- if (error)
- break;
- }
- put_bus(bus);
- return error;
-}
-
-
static struct device * next_device(struct klist_iter * i)
{
struct klist_node * n = klist_next(i);
@@ -203,6 +179,14 @@ int bus_for_each_dev(struct bus_type * b
return error;
}

+
+
+static struct device_driver * next_driver(struct klist_iter * i)
+{
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device_driver, knode_bus) : NULL;
+}
+
/**
* bus_for_each_drv - driver iterator
* @bus: bus we're dealing with.
@@ -226,12 +210,19 @@ int bus_for_each_dev(struct bus_type * b
int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
void * data, int (*fn)(struct device_driver *, void *))
{
- int ret;
+ struct klist_iter i;
+ struct device_driver * drv;
+ int error = 0;

- down_read(&bus->subsys.rwsem);
- ret = __bus_for_each_drv(bus, start, data, fn);
- up_read(&bus->subsys.rwsem);
- return ret;
+ if (!bus)
+ return -EINVAL;
+
+ klist_iter_init_node(&bus->klist_drivers, &i,
+ start ? &start->knode_bus : NULL);
+ while ((drv = next_driver(&i)) && !error)
+ error = fn(drv, data);
+ klist_iter_exit(&i);
+ return error;
}

static int device_add_attrs(struct bus_type * bus, struct device * dev)
@@ -376,6 +367,7 @@ int bus_add_driver(struct device_driver
down_write(&bus->subsys.rwsem);
driver_attach(drv);
up_write(&bus->subsys.rwsem);
+ klist_add_tail(&bus->klist_drivers, &drv->knode_bus);
module_add_driver(drv->owner, drv);

driver_add_attrs(bus, drv);
@@ -397,6 +389,7 @@ void bus_remove_driver(struct device_dri
{
if (drv->bus) {
driver_remove_attrs(drv->bus, drv);
+ klist_remove(&drv->knode_bus);
down_write(&drv->bus->subsys.rwsem);
pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
driver_detach(drv);
@@ -536,6 +529,7 @@ int bus_register(struct bus_type * bus)
goto bus_drivers_fail;

klist_init(&bus->klist_devices);
+ klist_init(&bus->klist_drivers);
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
@@ -53,6 +53,7 @@ struct bus_type {
struct kset drivers;
struct kset devices;
struct klist klist_devices;
+ struct klist klist_drivers;

struct bus_attribute * bus_attrs;
struct device_attribute * dev_attrs;
@@ -105,6 +106,7 @@ struct device_driver {
struct completion unloaded;
struct kobject kobj;
struct list_head devices;
+ struct klist_node knode_bus;

struct module * owner;