Driver core: move the static kobject out of struct driver

This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only.  Now drivers can be
safely create on the stack or statically (like they currently are.)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

7 files changed, 99 insertions, 74 deletions

diff --git a/drivers/base/base.h b/drivers/base/base.h
index 0547236..3b0f395 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -27,6 +27,14 @@ struct bus_type_private {
 	struct bus_type *bus;
 };
 
+struct driver_private {
+	struct kobject kobj;
+	struct klist klist_devices;
+	struct klist_node knode_bus;
+	struct module_kobject *mkobj;
+	struct device_driver *driver;
+};
+#define to_driver(obj) container_of(obj, struct driver_private, kobj)
 
 /* initialisation functions */
 extern int devices_init(void);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 04d3850..aa0c986 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2002-3 Patrick Mochel
  * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007 Novell Inc.
  *
  * This file is released under the GPLv2
  *
@@ -24,7 +26,6 @@
  */
 
 #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
-#define to_driver(obj) container_of(obj, struct device_driver, kobj)
 
 
 static int __must_check bus_rescan_devices_helper(struct device *dev,
@@ -49,11 +50,11 @@ static ssize_t
 drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
-	struct device_driver * drv = to_driver(kobj);
+	struct driver_private *drv_priv = to_driver(kobj);
 	ssize_t ret = -EIO;
 
 	if (drv_attr->show)
-		ret = drv_attr->show(drv, buf);
+		ret = drv_attr->show(drv_priv->driver, buf);
 	return ret;
 }
 
@@ -62,11 +63,11 @@ drv_attr_store(struct kobject * kobj, struct attribute * attr,
 	       const char * buf, size_t count)
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
-	struct device_driver * drv = to_driver(kobj);
+	struct driver_private *drv_priv = to_driver(kobj);
 	ssize_t ret = -EIO;
 
 	if (drv_attr->store)
-		ret = drv_attr->store(drv, buf, count);
+		ret = drv_attr->store(drv_priv->driver, buf, count);
 	return ret;
 }
 
@@ -75,22 +76,12 @@ static struct sysfs_ops driver_sysfs_ops = {
 	.store	= drv_attr_store,
 };
 
-
-static void driver_release(struct kobject * kobj)
+static void driver_release(struct kobject *kobj)
 {
-	/*
-	 * Yes this is an empty release function, it is this way because struct
-	 * device is always a static object, not a dynamic one.  Yes, this is
-	 * not nice and bad, but remember, drivers are code, reference counted
-	 * by the module count, not a device, which is really data.  And yes,
-	 * in the future I do want to have all drivers be created dynamically,
-	 * and am working toward that goal, but it will take a bit longer...
-	 *
-	 * But do not let this example give _anyone_ the idea that they can
-	 * create a release function without any code in it at all, to do that
-	 * is almost always wrong.  If you have any questions about this,
-	 * please send an email to <greg@kroah.com>
-	 */
+	struct driver_private *drv_priv = to_driver(kobj);
+
+	pr_debug("%s: freeing %s\n", __FUNCTION__, kobject_name(kobj));
+	kfree(drv_priv);
 }
 
 static struct kobj_type driver_ktype = {
@@ -350,7 +341,13 @@ struct device * bus_find_device(struct bus_type *bus,
 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;
+	struct driver_private *drv_priv;
+
+	if (n) {
+		drv_priv = container_of(n, struct driver_private, knode_bus);
+		return drv_priv->driver;
+	}
+	return NULL;
 }
 
 /**
@@ -384,7 +381,7 @@ int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
 		return -EINVAL;
 
 	klist_iter_init_node(&bus->p->klist_drivers, &i,
-			     start ? &start->knode_bus : NULL);
+			     start ? &start->p->knode_bus : NULL);
 	while ((drv = next_driver(&i)) && !error)
 		error = fn(drv, data);
 	klist_iter_exit(&i);
@@ -620,7 +617,7 @@ static ssize_t driver_uevent_store(struct device_driver *drv,
 	enum kobject_action action;
 
 	if (kobject_action_type(buf, count, &action) == 0)
-		kobject_uevent(&drv->kobj, action);
+		kobject_uevent(&drv->p->kobj, action);
 	return count;
 }
 static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
@@ -632,19 +629,29 @@ static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
  */
 int bus_add_driver(struct device_driver *drv)
 {
-	struct bus_type * bus = bus_get(drv->bus);
+	struct bus_type *bus;
+	struct driver_private *priv;
 	int error = 0;
 
+	bus = bus_get(drv->bus);
 	if (!bus)
 		return -EINVAL;
 
 	pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
-	error = kobject_set_name(&drv->kobj, "%s", drv->name);
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	error = kobject_set_name(&priv->kobj, "%s", drv->name);
 	if (error)
 		goto out_put_bus;
-	drv->kobj.kset = bus->p->drivers_kset;
-	drv->kobj.ktype = &driver_ktype;
-	error = kobject_register(&drv->kobj);
+	priv->kobj.kset = bus->p->drivers_kset;
+	priv->kobj.ktype = &driver_ktype;
+	klist_init(&priv->klist_devices, NULL, NULL);
+	priv->driver = drv;
+	drv->p = priv;
+	error = kobject_register(&priv->kobj);
 	if (error)
 		goto out_put_bus;
 
@@ -653,7 +660,7 @@ int bus_add_driver(struct device_driver *drv)
 		if (error)
 			goto out_unregister;
 	}
-	klist_add_tail(&drv->knode_bus, &bus->p->klist_drivers);
+	klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
 	module_add_driver(drv->owner, drv);
 
 	error = driver_create_file(drv, &driver_attr_uevent);
@@ -676,7 +683,7 @@ int bus_add_driver(struct device_driver *drv)
 
 	return error;
 out_unregister:
-	kobject_unregister(&drv->kobj);
+	kobject_unregister(&priv->kobj);
 out_put_bus:
 	bus_put(bus);
 	return error;
@@ -699,11 +706,11 @@ void bus_remove_driver(struct device_driver * drv)
 	remove_bind_files(drv);
 	driver_remove_attrs(drv->bus, drv);
 	driver_remove_file(drv, &driver_attr_uevent);
-	klist_remove(&drv->knode_bus);
+	klist_remove(&drv->p->knode_bus);
 	pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
 	driver_detach(drv);
 	module_remove_driver(drv);
-	kobject_unregister(&drv->kobj);
+	kobject_unregister(&drv->p->kobj);
 	bus_put(drv->bus);
 }
 
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 7bf0e67..87a348c 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -11,6 +11,8 @@
  *
  *	Copyright (c) 2002-5 Patrick Mochel
  *	Copyright (c) 2002-3 Open Source Development Labs
+ *	Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
+ *	Copyright (c) 2007 Novell Inc.
  *
  *	This file is released under the GPLv2
  */
@@ -23,8 +25,6 @@
 #include "base.h"
 #include "power/power.h"
 
-#define to_drv(node) container_of(node, struct device_driver, kobj.entry)
-
 
 static void driver_bound(struct device *dev)
 {
@@ -41,20 +41,20 @@ static void driver_bound(struct device *dev)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_BOUND_DRIVER, dev);
 
-	klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
+	klist_add_tail(&dev->knode_driver, &dev->driver->p->klist_devices);
 }
 
 static int driver_sysfs_add(struct device *dev)
 {
 	int ret;
 
-	ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+	ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
 			  kobject_name(&dev->kobj));
 	if (ret == 0) {
-		ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
+		ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
 					"driver");
 		if (ret)
-			sysfs_remove_link(&dev->driver->kobj,
+			sysfs_remove_link(&dev->driver->p->kobj,
 					kobject_name(&dev->kobj));
 	}
 	return ret;
@@ -65,7 +65,7 @@ static void driver_sysfs_remove(struct device *dev)
 	struct device_driver *drv = dev->driver;
 
 	if (drv) {
-		sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
+		sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
 		sysfs_remove_link(&dev->kobj, "driver");
 	}
 }
@@ -339,15 +339,15 @@ void driver_detach(struct device_driver * drv)
 	struct device * dev;
 
 	for (;;) {
-		spin_lock(&drv->klist_devices.k_lock);
-		if (list_empty(&drv->klist_devices.k_list)) {
-			spin_unlock(&drv->klist_devices.k_lock);
+		spin_lock(&drv->p->klist_devices.k_lock);
+		if (list_empty(&drv->p->klist_devices.k_list)) {
+			spin_unlock(&drv->p->klist_devices.k_lock);
 			break;
 		}
-		dev = list_entry(drv->klist_devices.k_list.prev,
+		dev = list_entry(drv->p->klist_devices.k_list.prev,
 				struct device, knode_driver.n_node);
 		get_device(dev);
-		spin_unlock(&drv->klist_devices.k_lock);
+		spin_unlock(&drv->p->klist_devices.k_lock);
 
 		if (dev->parent)	/* Needed for USB */
 			down(&dev->parent->sem);
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 633ae1d..5aacff2 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2002-3 Patrick Mochel
  * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007 Novell Inc.
  *
  * This file is released under the GPLv2
  *
@@ -15,7 +17,6 @@
 #include "base.h"
 
 #define to_dev(node) container_of(node, struct device, driver_list)
-#define to_drv(obj) container_of(obj, struct device_driver, kobj)
 
 
 static struct device * next_device(struct klist_iter * i)
@@ -44,7 +45,7 @@ int driver_for_each_device(struct device_driver * drv, struct device * start,
 	if (!drv)
 		return -EINVAL;
 
-	klist_iter_init_node(&drv->klist_devices, &i,
+	klist_iter_init_node(&drv->p->klist_devices, &i,
 			     start ? &start->knode_driver : NULL);
 	while ((dev = next_device(&i)) && !error)
 		error = fn(dev, data);
@@ -80,7 +81,7 @@ struct device * driver_find_device(struct device_driver *drv,
 	if (!drv)
 		return NULL;
 
-	klist_iter_init_node(&drv->klist_devices, &i,
+	klist_iter_init_node(&drv->p->klist_devices, &i,
 			     (start ? &start->knode_driver : NULL));
 	while ((dev = next_device(&i)))
 		if (match(dev, data) && get_device(dev))
@@ -100,7 +101,7 @@ int driver_create_file(struct device_driver * drv, struct driver_attribute * att
 {
 	int error;
 	if (get_driver(drv)) {
-		error = sysfs_create_file(&drv->kobj, &attr->attr);
+		error = sysfs_create_file(&drv->p->kobj, &attr->attr);
 		put_driver(drv);
 	} else
 		error = -EINVAL;
@@ -117,7 +118,7 @@ int driver_create_file(struct device_driver * drv, struct driver_attribute * att
 void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
 {
 	if (get_driver(drv)) {
-		sysfs_remove_file(&drv->kobj, &attr->attr);
+		sysfs_remove_file(&drv->p->kobj, &attr->attr);
 		put_driver(drv);
 	}
 }
@@ -143,7 +144,7 @@ int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
 	if (!name)
 		return -ENOMEM;
 
-	return kobject_add_ng(kobj, &drv->kobj, "%s", name);
+	return kobject_add_ng(kobj, &drv->p->kobj, "%s", name);
 }
 EXPORT_SYMBOL_GPL(driver_add_kobj);
 
@@ -153,7 +154,15 @@ EXPORT_SYMBOL_GPL(driver_add_kobj);
  */
 struct device_driver * get_driver(struct device_driver * drv)
 {
-	return drv ? to_drv(kobject_get(&drv->kobj)) : NULL;
+	if (drv) {
+		struct driver_private *priv;
+		struct kobject *kobj;
+
+		kobj = kobject_get(&drv->p->kobj);
+		priv = to_driver(kobj);
+		return priv->driver;
+	}
+	return NULL;
 }
 
 
@@ -163,7 +172,7 @@ struct device_driver * get_driver(struct device_driver * drv)
  */
 void put_driver(struct device_driver * drv)
 {
-	kobject_put(&drv->kobj);
+	kobject_put(&drv->p->kobj);
 }
 
 static int driver_add_groups(struct device_driver *drv,
@@ -174,10 +183,10 @@ static int driver_add_groups(struct device_driver *drv,
 
 	if (groups) {
 		for (i = 0; groups[i]; i++) {
-			error = sysfs_create_group(&drv->kobj, groups[i]);
+			error = sysfs_create_group(&drv->p->kobj, groups[i]);
 			if (error) {
 				while (--i >= 0)
-					sysfs_remove_group(&drv->kobj,
+					sysfs_remove_group(&drv->p->kobj,
 							   groups[i]);
 				break;
 			}
@@ -193,7 +202,7 @@ static void driver_remove_groups(struct device_driver *drv,
 
 	if (groups)
 		for (i = 0; groups[i]; i++)
-			sysfs_remove_group(&drv->kobj, groups[i]);
+			sysfs_remove_group(&drv->p->kobj, groups[i]);
 }
 
 
@@ -214,7 +223,6 @@ int driver_register(struct device_driver * drv)
 	    (drv->bus->shutdown && drv->shutdown)) {
 		printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
 	}
-	klist_init(&drv->klist_devices, NULL, NULL);
 	ret = bus_add_driver(drv);
 	if (ret)
 		return ret;
@@ -250,8 +258,12 @@ 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->p->drivers_kset, name);
-	if (k)
-		return to_drv(k);
+	struct driver_private *priv;
+
+	if (k) {
+		priv = to_driver(k);
+		return priv->driver;
+	}
 	return NULL;
 }
 
diff --git a/drivers/base/module.c b/drivers/base/module.c
index cad07be..103be9c 100644
--- a/drivers/base/module.c
+++ b/drivers/base/module.c
@@ -50,7 +50,7 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
 		if (mkobj) {
 			mk = container_of(mkobj, struct module_kobject, kobj);
 			/* remember our module structure */
-			drv->mkobj = mk;
+			drv->p->mkobj = mk;
 			/* kset_find_obj took a reference */
 			kobject_put(mkobj);
 		}
@@ -60,11 +60,11 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
 		return;
 
 	/* Don't check return codes; these calls are idempotent */
-	no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
+	no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
 	driver_name = make_driver_name(drv);
 	if (driver_name) {
 		module_create_drivers_dir(mk);
-		no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
+		no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
 					    driver_name);
 		kfree(driver_name);
 	}
@@ -78,12 +78,12 @@ void module_remove_driver(struct device_driver *drv)
 	if (!drv)
 		return;
 
-	sysfs_remove_link(&drv->kobj, "module");
+	sysfs_remove_link(&drv->p->kobj, "module");
 
 	if (drv->owner)
 		mk = &drv->owner->mkobj;
-	else if (drv->mkobj)
-		mk = drv->mkobj;
+	else if (drv->p->mkobj)
+		mk = drv->p->mkobj;
 	if (mk && mk->drivers_dir) {
 		driver_name = make_driver_name(drv);
 		if (driver_name) {
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index d56a05f..bdd59e8 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -499,7 +499,7 @@ int __init_or_module platform_driver_probe(struct platform_driver *drv,
 	 */
 	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
 	drv->probe = NULL;
-	if (code == 0 && list_empty(&drv->driver.klist_devices.k_list))
+	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
 		retval = -ENODEV;
 	drv->driver.probe = platform_drv_probe_fail;
 	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
diff --git a/include/linux/device.h b/include/linux/device.h
index 721ee31..92ba3a8 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -32,6 +32,7 @@
 
 struct device;
 struct device_driver;
+struct driver_private;
 struct class;
 struct class_device;
 struct bus_type;
@@ -113,16 +114,11 @@ extern struct kset *bus_get_kset(struct bus_type *bus);
 extern struct klist *bus_get_device_klist(struct bus_type *bus);
 
 struct device_driver {
-	const char		* name;
-	struct bus_type		* bus;
-
-	struct kobject		kobj;
-	struct klist		klist_devices;
-	struct klist_node	knode_bus;
+	const char		*name;
+	struct bus_type		*bus;
 
-	struct module		* owner;
-	const char 		* mod_name;	/* used for built-in modules */
-	struct module_kobject	* mkobj;
+	struct module		*owner;
+	const char 		*mod_name;	/* used for built-in modules */
 
 	int	(*probe)	(struct device * dev);
 	int	(*remove)	(struct device * dev);
@@ -130,6 +126,8 @@ struct device_driver {
 	int	(*suspend)	(struct device * dev, pm_message_t state);
 	int	(*resume)	(struct device * dev);
 	struct attribute_group **groups;
+
+	struct driver_private *p;
 };