driver core: class: remove struct module owner out of struct class

The module owner field for a struct class was never actually used, so
remove it as it is not doing anything at all.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-3-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/class.c

@@ -154,7 +154,7 @@ static void class_remove_groups(struct class *cls,
 	return sysfs_remove_groups(&cls->p->subsys.kobj, groups);
 }
 
-int __class_register(struct class *cls, struct module *owner, struct lock_class_key *key)
+int __class_register(struct class *cls, struct lock_class_key *key)
 {
 	struct subsys_private *cp;
 	int error;
@@ -187,7 +187,6 @@ int __class_register(struct class *cls, struct module *owner, struct lock_class_
 	if (error)
 		goto err_out;
 
-	cls->owner = owner;
 	error = class_add_groups(class_get(cls), cls->class_groups);
 	class_put(cls);
 	if (error) {
@@ -220,7 +219,6 @@ static void class_create_release(struct class *cls)
 
 /**
  * __class_create - create a struct class structure
- * @owner: pointer to the module that is to "own" this struct class
  * @name: pointer to a string for the name of this class.
  * @key: the lock_class_key for this class; used by mutex lock debugging
  *
@@ -232,8 +230,7 @@ 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(struct module *owner, const char *name,
-			     struct lock_class_key *key)
+struct class *__class_create(const char *name, struct lock_class_key *key)
 {
 	struct class *cls;
 	int retval;
@@ -247,7 +244,7 @@ struct class *__class_create(struct module *owner, const char *name,
 	cls->name = name;
 	cls->class_release = class_create_release;
 
-	retval = __class_register(cls, owner, key);
+	retval = __class_register(cls, key);
 	if (retval)
 		goto error;
 

include/linux/device/class.h

@@ -25,7 +25,6 @@ struct fwnode_handle;
 /**
  * struct class - device classes
  * @name:	Name of the class.
- * @owner:	The module owner.
  * @class_groups: Default attributes of this class.
  * @dev_groups:	Default attributes of the devices that belong to the class.
  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
@@ -53,7 +52,6 @@ struct fwnode_handle;
  */
 struct class {
 	const char		*name;
-	struct module		*owner;
 
 	const struct attribute_group	**class_groups;
 	const struct attribute_group	**dev_groups;
@@ -85,16 +83,15 @@ struct class_dev_iter {
 extern struct kobject *sysfs_dev_block_kobj;
 extern struct kobject *sysfs_dev_char_kobj;
 extern int __must_check __class_register(struct class *class,
-					 struct module *owner,
 					 struct lock_class_key *key);
 extern void class_unregister(struct class *class);
 
 /* This is a #define to keep the compiler from merging different
  * instances of the __key variable */
-#define class_register(class)				\
-({							\
-	static struct lock_class_key __key;		\
-	__class_register(class, THIS_MODULE, &__key);	\
+#define class_register(class)			\
+({						\
+	static struct lock_class_key __key;	\
+	__class_register(class, &__key);	\
 })
 
 struct class_compat;
@@ -250,8 +247,7 @@ struct class_interface {
 extern int __must_check class_interface_register(struct class_interface *);
 extern void class_interface_unregister(struct class_interface *);
 
-extern struct class * __must_check __class_create(struct module *owner,
-						  const char *name,
+extern struct class * __must_check __class_create(const char *name,
 						  struct lock_class_key *key);
 extern void class_destroy(struct class *cls);
 
@@ -260,7 +256,7 @@ extern void class_destroy(struct class *cls);
 
 /**
  * class_create - create a struct class structure
- * @owner: pointer to the module that is to "own" this struct class
+ * @owner: dummy pointer, does nothing, will be removed soon.
  * @name: pointer to a string for the name of this class.
  *
  * This is used to create a struct class pointer that can then be used
@@ -274,7 +270,7 @@ extern void class_destroy(struct class *cls);
 #define class_create(owner, name)		\
 ({						\
 	static struct lock_class_key __key;	\
-	__class_create(owner, name, &__key);	\
+	__class_create(name, &__key);		\
 })