2 * kobject.h - generic kernel object infrastructure.
4 * Copyright (c) 2002-2003 Patrick Mochel
5 * Copyright (c) 2002-2003 Open Source Development Labs
6 * Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
7 * Copyright (c) 2006-2008 Novell Inc.
9 * This file is released under the GPLv2.
11 * Please read Documentation/kobject.txt before using the kobject
12 * interface, ESPECIALLY the parts about reference counts and object
19 #include <linux/types.h>
20 #include <linux/list.h>
21 #include <linux/sysfs.h>
22 #include <linux/compiler.h>
23 #include <linux/spinlock.h>
24 #include <linux/kref.h>
25 #include <linux/kobject_ns.h>
26 #include <linux/kernel.h>
27 #include <linux/wait.h>
28 #include <linux/atomic.h>
29 #include <linux/workqueue.h>
31 #define UEVENT_HELPER_PATH_LEN 256
32 #define UEVENT_NUM_ENVP 32 /* number of env pointers */
33 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
35 #ifdef CONFIG_UEVENT_HELPER
36 /* path to the userspace helper executed on an event */
37 extern char uevent_helper[];
40 /* counter to tag the uevent, read only except for the kobject core */
41 extern u64 uevent_seqnum;
44 * The actions here must match the index to the string array
45 * in lib/kobject_uevent.c
47 * Do not add new actions here without checking with the driver-core
48 * maintainers. Action strings are not meant to express subsystem
49 * or device specific properties. In most cases you want to send a
50 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
51 * specific variables added to the event environment.
65 struct list_head entry;
66 struct kobject *parent;
68 struct kobj_type *ktype;
69 struct kernfs_node *sd; /* sysfs directory entry */
71 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
72 struct delayed_work release;
74 unsigned int state_initialized:1;
75 unsigned int state_in_sysfs:1;
76 unsigned int state_add_uevent_sent:1;
77 unsigned int state_remove_uevent_sent:1;
78 unsigned int uevent_suppress:1;
82 int kobject_set_name(struct kobject *kobj, const char *name, ...);
84 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
87 static inline const char *kobject_name(const struct kobject *kobj)
92 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
93 extern __printf(3, 4) __must_check
94 int kobject_add(struct kobject *kobj, struct kobject *parent,
95 const char *fmt, ...);
96 extern __printf(4, 5) __must_check
97 int kobject_init_and_add(struct kobject *kobj,
98 struct kobj_type *ktype, struct kobject *parent,
99 const char *fmt, ...);
101 extern void kobject_del(struct kobject *kobj);
103 extern struct kobject * __must_check kobject_create(void);
104 extern struct kobject * __must_check kobject_create_and_add(const char *name,
105 struct kobject *parent);
107 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
108 extern int __must_check kobject_move(struct kobject *, struct kobject *);
110 extern struct kobject *kobject_get(struct kobject *kobj);
111 extern struct kobject * __must_check kobject_get_unless_zero(
112 struct kobject *kobj);
113 extern void kobject_put(struct kobject *kobj);
115 extern const void *kobject_namespace(struct kobject *kobj);
116 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
119 * kobject_has_children - Returns whether a kobject has children.
120 * @kobj: the object to test
122 * This will return whether a kobject has other kobjects as children.
124 * It does NOT account for the presence of attribute files, only sub
125 * directories. It also assumes there is no concurrent addition or
126 * removal of such children, and thus relies on external locking.
128 static inline bool kobject_has_children(struct kobject *kobj)
130 WARN_ON_ONCE(atomic_read(&kobj->kref.refcount) == 0);
132 return kobj->sd && kobj->sd->dir.subdirs;
136 void (*release)(struct kobject *kobj);
137 const struct sysfs_ops *sysfs_ops;
138 struct attribute **default_attrs;
139 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
140 const void *(*namespace)(struct kobject *kobj);
143 struct kobj_uevent_env {
145 char *envp[UEVENT_NUM_ENVP];
147 char buf[UEVENT_BUFFER_SIZE];
151 struct kset_uevent_ops {
152 int (* const filter)(struct kset *kset, struct kobject *kobj);
153 const char *(* const name)(struct kset *kset, struct kobject *kobj);
154 int (* const uevent)(struct kset *kset, struct kobject *kobj,
155 struct kobj_uevent_env *env);
158 struct kobj_attribute {
159 struct attribute attr;
160 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
162 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
163 const char *buf, size_t count);
166 extern const struct sysfs_ops kobj_sysfs_ops;
171 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
173 * A kset defines a group of kobjects. They can be individually
174 * different "types" but overall these kobjects all want to be grouped
175 * together and operated on in the same manner. ksets are used to
176 * define the attribute callbacks and other common events that happen to
179 * @list: the list of all kobjects for this kset
180 * @list_lock: a lock for iterating over the kobjects
181 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
182 * @uevent_ops: the set of uevent operations for this kset. These are
183 * called whenever a kobject has something happen to it so that the kset
184 * can add new environment variables, or filter out the uevents if so
188 struct list_head list;
189 spinlock_t list_lock;
191 const struct kset_uevent_ops *uevent_ops;
194 extern void kset_init(struct kset *kset);
195 extern int __must_check kset_register(struct kset *kset);
196 extern void kset_unregister(struct kset *kset);
197 extern struct kset * __must_check kset_create_and_add(const char *name,
198 const struct kset_uevent_ops *u,
199 struct kobject *parent_kobj);
201 static inline struct kset *to_kset(struct kobject *kobj)
203 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
206 static inline struct kset *kset_get(struct kset *k)
208 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
211 static inline void kset_put(struct kset *k)
213 kobject_put(&k->kobj);
216 static inline struct kobj_type *get_ktype(struct kobject *kobj)
221 extern struct kobject *kset_find_obj(struct kset *, const char *);
223 /* The global /sys/kernel/ kobject for people to chain off of */
224 extern struct kobject *kernel_kobj;
225 /* The global /sys/kernel/mm/ kobject for people to chain off of */
226 extern struct kobject *mm_kobj;
227 /* The global /sys/hypervisor/ kobject for people to chain off of */
228 extern struct kobject *hypervisor_kobj;
229 /* The global /sys/power/ kobject for people to chain off of */
230 extern struct kobject *power_kobj;
231 /* The global /sys/firmware/ kobject for people to chain off of */
232 extern struct kobject *firmware_kobj;
234 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
235 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
239 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
241 int kobject_action_type(const char *buf, size_t count,
242 enum kobject_action *type);
244 #endif /* _KOBJECT_H_ */