[PATCH 140/196] driver core: remove fields from struct bus_type

Greg Kroah-Hartman
2008-01-25T08:12:34Z

struct bus_type is static everywhere in the kernel. This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure. This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/base/base.h | 30 ++++++++++++-
drivers/base/bus.c | 116 ++++++++++++++++++++++++++---------------------
drivers/base/core.c | 6 +-
drivers/base/dd.c | 4 +-
drivers/base/driver.c | 2 +-
drivers/base/platform.c | 4 +-
include/linux/device.h | 12 +----
7 files changed, 104 insertions(+), 70 deletions(-)

diff --git a/drivers/base/base.h b/drivers/base/base.h
index 7e309a4..ca6d273 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -1,6 +1,34 @@

-/* initialisation functions */
+/**
+ * struct bus_type_private - structure to hold the private to the driver core portions of the bus_type structure.
+ *
+ * @subsys - the struct kset that defines this bus. This is the main kobject
+ * @drivers_kset - the list of drivers associated with this bus
+ * @devices_kset - the list of devices associated with this bus
+ * @klist_devices - the klist to iterate over the @devices_kset
+ * @klist_drivers - the klist to iterate over the @drivers_kset
+ * @bus_notifier - the bus notifier list for anything that cares about things
+ * on this bus.
+ * @bus - pointer back to the struct bus_type that this structure is associated
+ * with.
+ *
+ * This structure is the one that is the actual kobject allowing struct
+ * bus_type to be statically allocated safely. Nothing outside of the driver
+ * core should ever touch these fields.
+ */
+struct bus_type_private {
+ struct kset subsys;
+ struct kset *drivers_kset;
+ struct kset *devices_kset;
+ struct klist klist_devices;
+ struct klist klist_drivers;
+ struct blocking_notifier_head bus_notifier;
+ unsigned int drivers_autoprobe:1;
+ struct bus_type *bus;
+};
+

+/* initialisation functions */
extern int devices_init(void);
extern int buses_init(void);
extern int classes_init(void);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 9c9027b..04d3850 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -17,7 +17,7 @@
#include "power/power.h"

#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
-#define to_bus(obj) container_of(obj, struct bus_type, subsys.kobj)
+#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)

/*
* sysfs bindings for drivers
@@ -32,13 +32,17 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,

static struct bus_type *bus_get(struct bus_type *bus)
{
- return bus ? container_of(kset_get(&bus->subsys),
- struct bus_type, subsys) : NULL;
+ if (bus) {
+ kset_get(&bus->p->subsys);
+ return bus;
+ }
+ return NULL;
}

static void bus_put(struct bus_type *bus)
{
- kset_put(&bus->subsys);
+ if (bus)
+ kset_put(&bus->p->subsys);
}

static ssize_t
@@ -104,11 +108,11 @@ static ssize_t
bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct bus_attribute * bus_attr = to_bus_attr(attr);
- struct bus_type * bus = to_bus(kobj);
+ struct bus_type_private *bus_priv = to_bus(kobj);
ssize_t ret = 0;

if (bus_attr->show)
- ret = bus_attr->show(bus, buf);
+ ret = bus_attr->show(bus_priv->bus, buf);
return ret;
}

@@ -117,11 +121,11 @@ bus_attr_store(struct kobject * kobj, struct attribute * attr,
const char * buf, size_t count)
{
struct bus_attribute * bus_attr = to_bus_attr(attr);
- struct bus_type * bus = to_bus(kobj);
+ struct bus_type_private *bus_priv = to_bus(kobj);
ssize_t ret = 0;

if (bus_attr->store)
- ret = bus_attr->store(bus, buf, count);
+ ret = bus_attr->store(bus_priv->bus, buf, count);
return ret;
}

@@ -134,7 +138,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
{
int error;
if (bus_get(bus)) {
- error = sysfs_create_file(&bus->subsys.kobj, &attr->attr);
+ error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
bus_put(bus);
} else
error = -EINVAL;
@@ -144,7 +148,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr)
{
if (bus_get(bus)) {
- sysfs_remove_file(&bus->subsys.kobj, &attr->attr);
+ sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
bus_put(bus);
}
}
@@ -237,16 +241,16 @@ static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);

static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
{
- return sprintf(buf, "%d\n", bus->drivers_autoprobe);
+ return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
}

static ssize_t store_drivers_autoprobe(struct bus_type *bus,
const char *buf, size_t count)
{
if (buf[0] == '0')
- bus->drivers_autoprobe = 0;
+ bus->p->drivers_autoprobe = 0;
else
- bus->drivers_autoprobe = 1;
+ bus->p->drivers_autoprobe = 1;
return count;
}

@@ -300,7 +304,7 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
if (!bus)
return -EINVAL;

- klist_iter_init_node(&bus->klist_devices, &i,
+ klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->knode_bus : NULL));
while ((dev = next_device(&i)) && !error)
error = fn(dev, data);
@@ -333,7 +337,7 @@ struct device * bus_find_device(struct bus_type *bus,
if (!bus)
return NULL;

- klist_iter_init_node(&bus->klist_devices, &i,
+ klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->knode_bus : NULL));
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
@@ -379,7 +383,7 @@ int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
if (!bus)
return -EINVAL;

- klist_iter_init_node(&bus->klist_drivers, &i,
+ klist_iter_init_node(&bus->p->klist_drivers, &i,
start ? &start->knode_bus : NULL);
while ((drv = next_driver(&i)) && !error)
error = fn(drv, data);
@@ -420,7 +424,7 @@ static void device_remove_attrs(struct bus_type * bus, struct device * dev)
static int make_deprecated_bus_links(struct device *dev)
{
return sysfs_create_link(&dev->kobj,
- &dev->bus->subsys.kobj, "bus");
+ &dev->bus->p->subsys.kobj, "bus");
}

static void remove_deprecated_bus_links(struct device *dev)
@@ -449,12 +453,12 @@ int bus_add_device(struct device * dev)
error = device_add_attrs(bus, dev);
if (error)
goto out_put;
- error = sysfs_create_link(&bus->devices_kset->kobj,
+ error = sysfs_create_link(&bus->p->devices_kset->kobj,
&dev->kobj, dev->bus_id);
if (error)
goto out_id;
error = sysfs_create_link(&dev->kobj,
- &dev->bus->subsys.kobj, "subsystem");
+ &dev->bus->p->subsys.kobj, "subsystem");
if (error)
goto out_subsys;
error = make_deprecated_bus_links(dev);
@@ -466,7 +470,7 @@ int bus_add_device(struct device * dev)
out_deprecated:
sysfs_remove_link(&dev->kobj, "subsystem");
out_subsys:
- sysfs_remove_link(&bus->devices_kset->kobj, dev->bus_id);
+ sysfs_remove_link(&bus->p->devices_kset->kobj, dev->bus_id);
out_id:
device_remove_attrs(bus, dev);
out_put:
@@ -488,11 +492,11 @@ void bus_attach_device(struct device * dev)

if (bus) {
dev->is_registered = 1;
- if (bus->drivers_autoprobe)
+ if (bus->p->drivers_autoprobe)
ret = device_attach(dev);
WARN_ON(ret < 0);
if (ret >= 0)
- klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ klist_add_tail(&dev->knode_bus, &bus->p->klist_devices);
else
dev->is_registered = 0;
}
@@ -512,7 +516,7 @@ void bus_remove_device(struct device * dev)
if (dev->bus) {
sysfs_remove_link(&dev->kobj, "subsystem");
remove_deprecated_bus_links(dev);
- sysfs_remove_link(&dev->bus->devices_kset->kobj, dev->bus_id);
+ sysfs_remove_link(&dev->bus->p->devices_kset->kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
if (dev->is_registered) {
dev->is_registered = 0;
@@ -638,18 +642,18 @@ int bus_add_driver(struct device_driver *drv)
error = kobject_set_name(&drv->kobj, "%s", drv->name);
if (error)
goto out_put_bus;
- drv->kobj.kset = bus->drivers_kset;
+ drv->kobj.kset = bus->p->drivers_kset;
drv->kobj.ktype = &driver_ktype;
error = kobject_register(&drv->kobj);
if (error)
goto out_put_bus;

- if (drv->bus->drivers_autoprobe) {
+ if (drv->bus->p->drivers_autoprobe) {
error = driver_attach(drv);
if (error)
goto out_unregister;
}
- klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
+ klist_add_tail(&drv->knode_bus, &bus->p->klist_drivers);
module_add_driver(drv->owner, drv);

error = driver_create_file(drv, &driver_attr_uevent);
@@ -828,7 +832,7 @@ static ssize_t bus_uevent_store(struct bus_type *bus,
enum kobject_action action;

if (kobject_action_type(buf, count, &action) == 0)
- kobject_uevent(&bus->subsys.kobj, action);
+ kobject_uevent(&bus->p->subsys.kobj, action);
return count;
}
static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
@@ -844,17 +848,26 @@ static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
int bus_register(struct bus_type * bus)
{
int retval;
+ struct bus_type_private *priv;
+
+ priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->bus = bus;
+ bus->p = priv;

- BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier);
+ BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);

- retval = kobject_set_name(&bus->subsys.kobj, "%s", bus->name);
+ retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
if (retval)
goto out;

- bus->subsys.kobj.kset = bus_kset;
- bus->subsys.kobj.ktype = &bus_ktype;
+ priv->subsys.kobj.kset = bus_kset;
+ priv->subsys.kobj.ktype = &bus_ktype;
+ priv->drivers_autoprobe = 1;

- retval = kset_register(&bus->subsys);
+ retval = kset_register(&priv->subsys);
if (retval)
goto out;

@@ -862,24 +875,23 @@ int bus_register(struct bus_type * bus)
if (retval)
goto bus_uevent_fail;

- bus->devices_kset = kset_create_and_add("devices", NULL,
- &bus->subsys.kobj);
- if (!bus->devices_kset) {
+ priv->devices_kset = kset_create_and_add("devices", NULL,
+ &priv->subsys.kobj);
+ if (!priv->devices_kset) {
retval = -ENOMEM;
goto bus_devices_fail;
}

- bus->drivers_kset = kset_create_and_add("drivers", NULL,
- &bus->subsys.kobj);
- if (!bus->drivers_kset) {
+ priv->drivers_kset = kset_create_and_add("drivers", NULL,
+ &priv->subsys.kobj);
+ if (!priv->drivers_kset) {
retval = -ENOMEM;
goto bus_drivers_fail;
}

- klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
- klist_init(&bus->klist_drivers, NULL, NULL);
+ klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
+ klist_init(&priv->klist_drivers, NULL, NULL);

- bus->drivers_autoprobe = 1;
retval = add_probe_files(bus);
if (retval)
goto bus_probe_files_fail;
@@ -894,13 +906,14 @@ int bus_register(struct bus_type * bus)
bus_attrs_fail:
remove_probe_files(bus);
bus_probe_files_fail:
- kset_unregister(bus->drivers_kset);
+ kset_unregister(bus->p->drivers_kset);
bus_drivers_fail:
- kset_unregister(bus->devices_kset);
+ kset_unregister(bus->p->devices_kset);
bus_devices_fail:
bus_remove_file(bus, &bus_attr_uevent);
bus_uevent_fail:
- kset_unregister(&bus->subsys);
+ kset_unregister(&bus->p->subsys);
+ kfree(bus->p);
out:
return retval;
}
@@ -917,33 +930,34 @@ void bus_unregister(struct bus_type * bus)
pr_debug("bus %s: unregistering\n", bus->name);
bus_remove_attrs(bus);
remove_probe_files(bus);
- kset_unregister(bus->drivers_kset);
- kset_unregister(bus->devices_kset);
+ kset_unregister(bus->p->drivers_kset);
+ kset_unregister(bus->p->devices_kset);
bus_remove_file(bus, &bus_attr_uevent);
- kset_unregister(&bus->subsys);
+ kset_unregister(&bus->p->subsys);
+ kfree(bus->p);
}

int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
{
- return blocking_notifier_chain_register(&bus->bus_notifier, nb);
+ return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
}
EXPORT_SYMBOL_GPL(bus_register_notifier);

int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
{
- return blocking_notifier_chain_unregister(&bus->bus_notifier, nb);
+ return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
}
EXPORT_SYMBOL_GPL(bus_unregister_notifier);

struct kset *bus_get_kset(struct bus_type *bus)
{
- return &bus->subsys;
+ return &bus->p->subsys;
}
EXPORT_SYMBOL_GPL(bus_get_kset);

struct klist *bus_get_device_klist(struct bus_type *bus)
{
- return &bus->klist_devices;
+ return &bus->p->klist_devices;
}
EXPORT_SYMBOL_GPL(bus_get_device_klist);

diff --git a/drivers/base/core.c b/drivers/base/core.c
index beb3516..414a480 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -769,7 +769,7 @@ int device_add(struct device *dev)

/* notify clients of device entry (new way) */
if (dev->bus)
- blocking_notifier_call_chain(&dev->bus->bus_notifier,
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_ADD_DEVICE, dev);

error = device_create_file(dev, &uevent_attr);
@@ -820,7 +820,7 @@ int device_add(struct device *dev)
dpm_sysfs_remove(dev);
PMError:
if (dev->bus)
- blocking_notifier_call_chain(&dev->bus->bus_notifier,
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
device_remove_attrs(dev);
AttrsError:
@@ -999,7 +999,7 @@ void device_del(struct device * dev)
if (platform_notify_remove)
platform_notify_remove(dev);
if (dev->bus)
- blocking_notifier_call_chain(&dev->bus->bus_notifier,
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
kobject_del(&dev->kobj);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 7ac474d..7bf0e67 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -38,7 +38,7 @@ static void driver_bound(struct device *dev)
dev->bus_id, dev->driver->name);

if (dev->bus)
- blocking_notifier_call_chain(&dev->bus->bus_notifier,
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_BOUND_DRIVER, dev);

klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
@@ -296,7 +296,7 @@ static void __device_release_driver(struct device * dev)
klist_remove(&dev->knode_driver);

if (dev->bus)
- blocking_notifier_call_chain(&dev->bus->bus_notifier,
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_UNBIND_DRIVER,
dev);

diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 1c9770d..f94be40 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -185,7 +185,7 @@ void driver_unregister(struct device_driver * drv)
*/
struct device_driver *driver_find(const char *name, struct bus_type *bus)
{
- struct kobject *k = kset_find_obj(bus->drivers_kset, name);
+ struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
if (k)
return to_drv(k);
return NULL;
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index fb56092..d56a05f 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -497,12 +497,12 @@ int __init_or_module platform_driver_probe(struct platform_driver *drv,
* if the probe was successful, and make sure any forced probes of
* new devices fail.
*/
- spin_lock(&platform_bus_type.klist_drivers.k_lock);
+ spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
drv->probe = NULL;
if (code == 0 && list_empty(&drv->driver.klist_devices.k_list))
retval = -ENODEV;
drv->driver.probe = platform_drv_probe_fail;
- spin_unlock(&platform_bus_type.klist_drivers.k_lock);
+ spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);

if (code != retval)
platform_driver_unregister(drv);
diff --git a/include/linux/device.h b/include/linux/device.h
index 62e695b..3f24bf4 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -35,6 +35,7 @@ struct device_driver;
struct class;
struct class_device;
struct bus_type;
+struct bus_type_private;

struct bus_attribute {
struct attribute attr;
@@ -51,15 +52,6 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);

struct bus_type {
const char * name;
-
- struct kset subsys;
- struct kset *drivers_kset;
- struct kset *devices_kset;
- struct klist klist_devices;
- struct klist klist_drivers;
-
- struct blocking_notifier_head bus_notifier;
-
struct bus_attribute * bus_attrs;
struct device_attribute * dev_attrs;
struct driver_attribute * drv_attrs;
@@ -75,7 +67,7 @@ struct bus_type {
int (*resume_early)(struct device * dev);
int (*resume)(struct device * dev);

- unsigned int drivers_autoprobe:1;
+ struct bus_type_private *p;
};

extern int __must_check bus_register(struct bus_type * bus);
--
1.5.3.8