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 05472360f6a2..3b0f395552db 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 04d3850ff4b7..aa0c986c323a 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 7bf0e674c975..87a348ce818c 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 633ae1d70e14..5aacff208f21 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 cad07be5de1a..103be9cacb05 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 d56a05f94f67..bdd59e8358f0 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 721ee318d57b..92ba3a874627 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;
 };