2 * kobject.h - generic kernel object infrastructure.
4 * Copyright (c) 2002-2003 Patrick Mochel
5 * Copyright (c) 2002-2003 Open Source Development Labs
7 * This file is released under the GPLv2.
10 * Please read Documentation/kobject.txt before using the kobject
11 * interface, ESPECIALLY the parts about reference counts and object
20 #include <linux/types.h>
21 #include <linux/list.h>
22 #include <linux/sysfs.h>
23 #include <linux/spinlock.h>
24 #include <linux/rwsem.h>
25 #include <linux/kref.h>
26 #include <linux/kernel.h>
27 #include <asm/atomic.h>
29 #define KOBJ_NAME_LEN 20
31 #define HOTPLUG_PATH_LEN 256
33 /* path to the userspace helper executed on an event */
34 extern char hotplug_path[];
36 /* counter to tag the hotplug event, read only except for the kobject core */
37 extern u64 hotplug_seqnum;
39 /* the actions here must match the proper string in lib/kobject_uevent.c */
40 typedef int __bitwise kobject_action_t;
42 KOBJ_ADD = (__force kobject_action_t) 0x01, /* add event, for hotplug */
43 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* remove event, for hotplug */
44 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* a sysfs attribute file has changed */
45 KOBJ_OFFLINE = (__force kobject_action_t) 0x04, /* offline event for hotplug devices */
46 KOBJ_ONLINE = (__force kobject_action_t) 0x05, /* online event for hotplug devices */
51 char name[KOBJ_NAME_LEN];
53 struct list_head entry;
54 struct kobject * parent;
56 struct kobj_type * ktype;
57 struct dentry * dentry;
60 extern int kobject_set_name(struct kobject *, const char *, ...)
61 __attribute__((format(printf,2,3)));
63 static inline const char * kobject_name(const struct kobject * kobj)
68 extern void kobject_init(struct kobject *);
69 extern void kobject_cleanup(struct kobject *);
71 extern int kobject_add(struct kobject *);
72 extern void kobject_del(struct kobject *);
74 extern int kobject_rename(struct kobject *, const char *new_name);
76 extern int kobject_register(struct kobject *);
77 extern void kobject_unregister(struct kobject *);
79 extern struct kobject * kobject_get(struct kobject *);
80 extern void kobject_put(struct kobject *);
82 extern char * kobject_get_path(struct kobject *, gfp_t);
85 void (*release)(struct kobject *);
86 struct sysfs_ops * sysfs_ops;
87 struct attribute ** default_attrs;
92 * kset - a set of kobjects of a specific type, belonging
93 * to a specific subsystem.
95 * All kobjects of a kset should be embedded in an identical
96 * type. This type may have a descriptor, which the kset points
97 * to. This allows there to exist sets of objects of the same
98 * type in different subsystems.
100 * A subsystem does not have to be a list of only one type
101 * of object; multiple ksets can belong to one subsystem. All
102 * ksets of a subsystem share the subsystem's lock.
104 * Each kset can support hotplugging; if it does, it will be given
105 * the opportunity to filter out specific kobjects from being
106 * reported, as well as to add its own "data" elements to the
107 * environment being passed to the hotplug helper.
109 struct kset_hotplug_ops {
110 int (*filter)(struct kset *kset, struct kobject *kobj);
111 const char *(*name)(struct kset *kset, struct kobject *kobj);
112 int (*hotplug)(struct kset *kset, struct kobject *kobj, char **envp,
113 int num_envp, char *buffer, int buffer_size);
117 struct subsystem * subsys;
118 struct kobj_type * ktype;
119 struct list_head list;
120 spinlock_t list_lock;
122 struct kset_hotplug_ops * hotplug_ops;
126 extern void kset_init(struct kset * k);
127 extern int kset_add(struct kset * k);
128 extern int kset_register(struct kset * k);
129 extern void kset_unregister(struct kset * k);
131 static inline struct kset * to_kset(struct kobject * kobj)
133 return kobj ? container_of(kobj,struct kset,kobj) : NULL;
136 static inline struct kset * kset_get(struct kset * k)
138 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
141 static inline void kset_put(struct kset * k)
143 kobject_put(&k->kobj);
146 static inline struct kobj_type * get_ktype(struct kobject * k)
148 if (k->kset && k->kset->ktype)
149 return k->kset->ktype;
154 extern struct kobject * kset_find_obj(struct kset *, const char *);
158 * Use this when initializing an embedded kset with no other
159 * fields to initialize.
161 #define set_kset_name(str) .kset = { .kobj = { .name = str } }
167 struct rw_semaphore rwsem;
170 #define decl_subsys(_name,_type,_hotplug_ops) \
171 struct subsystem _name##_subsys = { \
173 .kobj = { .name = __stringify(_name) }, \
175 .hotplug_ops =_hotplug_ops, \
178 #define decl_subsys_name(_varname,_name,_type,_hotplug_ops) \
179 struct subsystem _varname##_subsys = { \
181 .kobj = { .name = __stringify(_name) }, \
183 .hotplug_ops =_hotplug_ops, \
187 /* The global /sys/kernel/ subsystem for people to chain off of */
188 extern struct subsystem kernel_subsys;
191 * Helpers for setting the kset of registered objects.
192 * Often, a registered object belongs to a kset embedded in a
193 * subsystem. These do no magic, just make the resulting code
198 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
199 * @obj: ptr to some object type.
200 * @subsys: a subsystem object (not a ptr).
202 * Can be used for any object type with an embedded ->kobj.
205 #define kobj_set_kset_s(obj,subsys) \
206 (obj)->kobj.kset = &(subsys).kset
209 * kset_set_kset_s(obj,subsys) - set kset for embedded kset.
210 * @obj: ptr to some object type.
211 * @subsys: a subsystem object (not a ptr).
213 * Can be used for any object type with an embedded ->kset.
214 * Sets the kset of @obj's embedded kobject (via its embedded
215 * kset) to @subsys.kset. This makes @obj a member of that
219 #define kset_set_kset_s(obj,subsys) \
220 (obj)->kset.kobj.kset = &(subsys).kset
223 * subsys_set_kset(obj,subsys) - set kset for subsystem
224 * @obj: ptr to some object type.
225 * @subsys: a subsystem object (not a ptr).
227 * Can be used for any object type with an embedded ->subsys.
228 * Sets the kset of @obj's kobject to @subsys.kset. This makes
229 * the object a member of that kset.
232 #define subsys_set_kset(obj,_subsys) \
233 (obj)->subsys.kset.kobj.kset = &(_subsys).kset
235 extern void subsystem_init(struct subsystem *);
236 extern int subsystem_register(struct subsystem *);
237 extern void subsystem_unregister(struct subsystem *);
239 static inline struct subsystem * subsys_get(struct subsystem * s)
241 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL;
244 static inline void subsys_put(struct subsystem * s)
249 struct subsys_attribute {
250 struct attribute attr;
251 ssize_t (*show)(struct subsystem *, char *);
252 ssize_t (*store)(struct subsystem *, const char *, size_t);
255 extern int subsys_create_file(struct subsystem * , struct subsys_attribute *);
256 extern void subsys_remove_file(struct subsystem * , struct subsys_attribute *);
258 #ifdef CONFIG_HOTPLUG
259 void kobject_hotplug(struct kobject *kobj, enum kobject_action action);
261 int add_hotplug_env_var(char **envp, int num_envp, int *cur_index,
262 char *buffer, int buffer_size, int *cur_len,
263 const char *format, ...)
264 __attribute__((format (printf, 7, 8)));
266 int kobject_uevent(struct kobject *kobj,
267 enum kobject_action action,
268 struct attribute *attr);
269 int kobject_uevent_atomic(struct kobject *kobj,
270 enum kobject_action action,
271 struct attribute *attr);
274 static inline void kobject_hotplug(struct kobject *kobj, enum kobject_action action) { }
275 static inline int add_hotplug_env_var(char **envp, int num_envp, int *cur_index,
276 char *buffer, int buffer_size, int *cur_len,
277 const char *format, ...)
279 int kobject_uevent(struct kobject *kobj,
280 enum kobject_action action,
281 struct attribute *attr)
283 int kobject_uevent_atomic(struct kobject *kobj,
284 enum kobject_action action,
285 struct attribute *attr)
289 #endif /* __KERNEL__ */
290 #endif /* _KOBJECT_H_ */