driver core: class: use lock_class_key already present in struct subsys_private

In commit 37e98d9bedb5 ("driver core: bus: move lock_class_key into
dynamic structure"), we moved the lock_class_key into the internal
structure shared by busses and classes, but only used it for buses.

Move the class code to use this structure as it is already present and
being allocated, instead of the statically allocated on-the-stack
variable that class_create() was using as part of a macro wrapper around
the core function call.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230324100132.1633647-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 3d65221b0dcb..dbaeb79ae917 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -154,9 +154,10 @@ static void class_remove_groups(struct class *cls,
 	return sysfs_remove_groups(&cls->p->subsys.kobj, groups);
 }
 
-int __class_register(struct class *cls, struct lock_class_key *key)
+int class_register(struct class *cls)
 {
 	struct subsys_private *cp;
+	struct lock_class_key *key;
 	int error;
 
 	pr_debug("device class '%s': registering\n", cls->name);
@@ -167,6 +168,8 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 	klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put);
 	INIT_LIST_HEAD(&cp->interfaces);
 	kset_init(&cp->glue_dirs);
+	key = &cp->lock_key;
+	lockdep_register_key(key);
 	__mutex_init(&cp->mutex, "subsys mutex", key);
 	error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name);
 	if (error) {
@@ -201,7 +204,7 @@ err_out:
 	cls->p = NULL;
 	return error;
 }
-EXPORT_SYMBOL_GPL(__class_register);
+EXPORT_SYMBOL_GPL(class_register);
 
 void class_unregister(struct class *cls)
 {
@@ -218,7 +221,7 @@ static void class_create_release(struct class *cls)
 }
 
 /**
- * __class_create - create a struct class structure
+ * class_create - create a struct class structure
  * @name: pointer to a string for the name of this class.
  * @key: the lock_class_key for this class; used by mutex lock debugging
  *
@@ -230,7 +233,7 @@ static void class_create_release(struct class *cls)
  * Note, the pointer created here is to be destroyed when finished by
  * making a call to class_destroy().
  */
-struct class *__class_create(const char *name, struct lock_class_key *key)
+struct class *class_create(const char *name)
 {
 	struct class *cls;
 	int retval;
@@ -244,7 +247,7 @@ struct class *__class_create(const char *name, struct lock_class_key *key)
 	cls->name = name;
 	cls->class_release = class_create_release;
 
-	retval = __class_register(cls, key);
+	retval = class_register(cls);
 	if (retval)
 		goto error;
 
@@ -254,7 +257,7 @@ error:
 	kfree(cls);
 	return ERR_PTR(retval);
 }
-EXPORT_SYMBOL_GPL(__class_create);
+EXPORT_SYMBOL_GPL(class_create);
 
 /**
  * class_destroy - destroys a struct class structure