driver core: create a private portion of struct device

[linux-2.6-omap-h63xx.git] / drivers / base / core.c

diff --git a/drivers/base/core.c b/drivers/base/core.c
index b98cb1416a2d7a8a74dd5f64e4d1f1abcc35fbf2..6657787e64f8064453bcac84e19ff743caae07f9 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -109,6 +109,7 @@ static struct sysfs_ops dev_sysfs_ops = {
 static void device_release(struct kobject *kobj)
 {
        struct device *dev = to_dev(kobj);
+       struct device_private *p = dev->p;
 
        if (dev->release)
                dev->release(dev);
@@ -119,7 +120,8 @@ static void device_release(struct kobject *kobj)
        else
                WARN(1, KERN_ERR "Device '%s' does not have a release() "
                        "function, it is broken and must be fixed.\n",
-                       dev->bus_id);
+                       dev_name(dev));
+       kfree(p);
 }
 
 static struct kobj_type device_ktype = {
@@ -209,7 +211,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->bus->uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
-                                dev->bus_id, __func__, retval);
+                                dev_name(dev), __func__, retval);
        }
 
        /* have the class specific function add its stuff */
@@ -217,7 +219,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->class->dev_uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: class uevent() "
-                                "returned %d\n", dev->bus_id,
+                                "returned %d\n", dev_name(dev),
                                 __func__, retval);
        }
 
@@ -226,7 +228,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->type->uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: dev_type uevent() "
-                                "returned %d\n", dev->bus_id,
+                                "returned %d\n", dev_name(dev),
                                 __func__, retval);
        }
 
@@ -523,14 +525,25 @@ static void klist_children_put(struct klist_node *n)
  * device_initialize - init device structure.
  * @dev: device.
  *
- * This prepares the device for use by other layers,
- * including adding it to the device hierarchy.
+ * This prepares the device for use by other layers by initializing
+ * its fields.
  * It is the first half of device_register(), if called by
- * that, though it can also be called separately, so one
- * may use @dev's fields (e.g. the refcount).
+ * that function, though it can also be called separately, so one
+ * may use @dev's fields. In particular, get_device()/put_device()
+ * may be used for reference counting of @dev after calling this
+ * function.
+ *
+ * NOTE: Use put_device() to give up your reference instead of freeing
+ * @dev directly once you have called this function.
  */
 void device_initialize(struct device *dev)
 {
+       dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
+       if (!dev->p) {
+               WARN_ON(1);
+               return;
+       }
+       dev->p->device = dev;
        dev->kobj.kset = devices_kset;
        kobject_init(&dev->kobj, &device_ktype);
        klist_init(&dev->klist_children, klist_children_get,
@@ -667,7 +680,7 @@ static int device_add_class_symlinks(struct device *dev)
        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev)) {
                error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-                                         &dev->kobj, dev->bus_id);
+                                         &dev->kobj, dev_name(dev));
                if (error)
                        goto out_subsys;
        }
@@ -707,11 +720,11 @@ out_busid:
        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev))
                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
-                                 dev->bus_id);
+                                 dev_name(dev));
 #else
        /* link in the class directory pointing to the device */
        error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-                                 &dev->kobj, dev->bus_id);
+                                 &dev->kobj, dev_name(dev));
        if (error)
                goto out_subsys;
 
@@ -724,7 +737,7 @@ out_busid:
        return 0;
 
 out_busid:
-       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
+       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
 #endif
 
 out_subsys:
@@ -753,12 +766,12 @@ static void device_remove_class_symlinks(struct device *dev)
        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev))
                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
-                                 dev->bus_id);
+                                 dev_name(dev));
 #else
        if (dev->parent && device_is_not_partition(dev))
                sysfs_remove_link(&dev->kobj, "device");
 
-       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
+       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
 #endif
 
        sysfs_remove_link(&dev->kobj, "subsystem");
@@ -835,9 +848,13 @@ static void device_remove_sys_dev_entry(struct device *dev)
  * This is part 2 of device_register(), though may be called
  * separately _iff_ device_initialize() has been called separately.
  *
- * This adds it to the kobject hierarchy via kobject_add(), adds it
+ * This adds @dev to the kobject hierarchy via kobject_add(), adds it
  * to the global and sibling lists for the device, then
  * adds it to the other relevant subsystems of the driver model.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up your
+ * reference instead.
  */
 int device_add(struct device *dev)
 {
@@ -857,7 +874,7 @@ int device_add(struct device *dev)
        if (!strlen(dev->bus_id))
                goto done;
 
-       pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 
        parent = get_device(dev->parent);
        setup_parent(dev, parent);
@@ -867,7 +884,7 @@ int device_add(struct device *dev)
                set_dev_node(dev, dev_to_node(parent));
 
        /* first, register with generic layer. */
-       error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
+       error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev));
        if (error)
                goto Error;
 
@@ -965,6 +982,10 @@ done:
  * I.e. you should only call the two helpers separately if
  * have a clearly defined need to use and refcount the device
  * before it is added to the hierarchy.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up the
+ * reference initialized in this function instead.
  */
 int device_register(struct device *dev)
 {
@@ -1073,7 +1094,7 @@ void device_del(struct device *dev)
  */
 void device_unregister(struct device *dev)
 {
-       pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        device_del(dev);
        put_device(dev);
 }
@@ -1186,7 +1207,7 @@ EXPORT_SYMBOL_GPL(device_remove_file);
 
 static void device_create_release(struct device *dev)
 {
-       pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        kfree(dev);
 }
 
@@ -1243,7 +1264,7 @@ struct device *device_create_vargs(struct class *class, struct device *parent,
        return dev;
 
 error:
-       kfree(dev);
+       put_device(dev);
        return ERR_PTR(retval);
 }
 EXPORT_SYMBOL_GPL(device_create_vargs);
@@ -1314,6 +1335,11 @@ EXPORT_SYMBOL_GPL(device_destroy);
  * device_rename - renames a device
  * @dev: the pointer to the struct device to be renamed
  * @new_name: the new name of the device
+ *
+ * It is the responsibility of the caller to provide mutual
+ * exclusion between two different calls of device_rename
+ * on the same device to ensure that new_name is valid and
+ * won't conflict with other devices.
  */
 int device_rename(struct device *dev, char *new_name)
 {
@@ -1326,7 +1352,7 @@ int device_rename(struct device *dev, char *new_name)
        if (!dev)
                return -EINVAL;
 
-       pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
+       pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
                 __func__, new_name);
 
 #ifdef CONFIG_SYSFS_DEPRECATED
@@ -1363,7 +1389,7 @@ int device_rename(struct device *dev, char *new_name)
 #else
        if (dev->class) {
                error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
-                                                &dev->kobj, dev->bus_id);
+                                                &dev->kobj, dev_name(dev));
                if (error)
                        goto out;
                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
@@ -1441,8 +1467,8 @@ int device_move(struct device *dev, struct device *new_parent)
        new_parent = get_device(new_parent);
        new_parent_kobj = get_device_parent(dev, new_parent);
 
-       pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
-                __func__, new_parent ? new_parent->bus_id : "<NULL>");
+       pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
+                __func__, new_parent ? dev_name(new_parent) : "<NULL>");
        error = kobject_move(&dev->kobj, new_parent_kobj);
        if (error) {
                cleanup_glue_dir(dev, new_parent_kobj);