1/*
2 * kobject.h - generic kernel object infrastructure.
3 *
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.
8 *
9 * This file is released under the GPLv2.
10 *
11 * Please read Documentation/kobject.txt before using the kobject
12 * interface, ESPECIALLY the parts about reference counts and object
13 * destructors.
14 */
15
16#ifndef _KOBJECT_H_
17#define _KOBJECT_H_
18
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>
30
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 */
34
35#ifdef CONFIG_UEVENT_HELPER
36/* path to the userspace helper executed on an event */
37extern char uevent_helper[];
38#endif
39
40/* counter to tag the uevent, read only except for the kobject core */
41extern u64 uevent_seqnum;
42
43/*
44 * The actions here must match the index to the string array
45 * in lib/kobject_uevent.c
46 *
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.
52 */
53enum kobject_action {
54	KOBJ_ADD,
55	KOBJ_REMOVE,
56	KOBJ_CHANGE,
57	KOBJ_MOVE,
58	KOBJ_ONLINE,
59	KOBJ_OFFLINE,
60	KOBJ_MAX
61};
62
63struct kobject {
64	const char		*name;
65	struct list_head	entry;
66	struct kobject		*parent;
67	struct kset		*kset;
68	struct kobj_type	*ktype;
69	struct kernfs_node	*sd;
70	struct kref		kref;
71#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
72	struct delayed_work	release;
73#endif
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;
79};
80
81extern __printf(2, 3)
82int kobject_set_name(struct kobject *kobj, const char *name, ...);
83extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
84				  va_list vargs);
85
86static inline const char *kobject_name(const struct kobject *kobj)
87{
88	return kobj->name;
89}
90
91extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
92extern __printf(3, 4) __must_check
93int kobject_add(struct kobject *kobj, struct kobject *parent,
94		const char *fmt, ...);
95extern __printf(4, 5) __must_check
96int kobject_init_and_add(struct kobject *kobj,
97			 struct kobj_type *ktype, struct kobject *parent,
98			 const char *fmt, ...);
99
100extern void kobject_del(struct kobject *kobj);
101
102extern struct kobject * __must_check kobject_create(void);
103extern struct kobject * __must_check kobject_create_and_add(const char *name,
104						struct kobject *parent);
105
106extern int __must_check kobject_rename(struct kobject *, const char *new_name);
107extern int __must_check kobject_move(struct kobject *, struct kobject *);
108
109extern struct kobject *kobject_get(struct kobject *kobj);
110extern void kobject_put(struct kobject *kobj);
111
112extern const void *kobject_namespace(struct kobject *kobj);
113extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
114
115struct kobj_type {
116	void (*release)(struct kobject *kobj);
117	const struct sysfs_ops *sysfs_ops;
118	struct attribute **default_attrs;
119	const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
120	const void *(*namespace)(struct kobject *kobj);
121};
122
123struct kobj_uevent_env {
124	char *argv[3];
125	char *envp[UEVENT_NUM_ENVP];
126	int envp_idx;
127	char buf[UEVENT_BUFFER_SIZE];
128	int buflen;
129};
130
131struct kset_uevent_ops {
132	int (* const filter)(struct kset *kset, struct kobject *kobj);
133	const char *(* const name)(struct kset *kset, struct kobject *kobj);
134	int (* const uevent)(struct kset *kset, struct kobject *kobj,
135		      struct kobj_uevent_env *env);
136};
137
138struct kobj_attribute {
139	struct attribute attr;
140	ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
141			char *buf);
142	ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
143			 const char *buf, size_t count);
144};
145
146extern const struct sysfs_ops kobj_sysfs_ops;
147
148struct sock;
149
150/**
151 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
152 *
153 * A kset defines a group of kobjects.  They can be individually
154 * different "types" but overall these kobjects all want to be grouped
155 * together and operated on in the same manner.  ksets are used to
156 * define the attribute callbacks and other common events that happen to
157 * a kobject.
158 *
159 * @list: the list of all kobjects for this kset
160 * @list_lock: a lock for iterating over the kobjects
161 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
162 * @uevent_ops: the set of uevent operations for this kset.  These are
163 * called whenever a kobject has something happen to it so that the kset
164 * can add new environment variables, or filter out the uevents if so
165 * desired.
166 */
167struct kset {
168	struct list_head list;
169	spinlock_t list_lock;
170	struct kobject kobj;
171	const struct kset_uevent_ops *uevent_ops;
172};
173
174extern void kset_init(struct kset *kset);
175extern int __must_check kset_register(struct kset *kset);
176extern void kset_unregister(struct kset *kset);
177extern struct kset * __must_check kset_create_and_add(const char *name,
178						const struct kset_uevent_ops *u,
179						struct kobject *parent_kobj);
180
181static inline struct kset *to_kset(struct kobject *kobj)
182{
183	return kobj ? container_of(kobj, struct kset, kobj) : NULL;
184}
185
186static inline struct kset *kset_get(struct kset *k)
187{
188	return k ? to_kset(kobject_get(&k->kobj)) : NULL;
189}
190
191static inline void kset_put(struct kset *k)
192{
193	kobject_put(&k->kobj);
194}
195
196static inline struct kobj_type *get_ktype(struct kobject *kobj)
197{
198	return kobj->ktype;
199}
200
201extern struct kobject *kset_find_obj(struct kset *, const char *);
202
203/* The global /sys/kernel/ kobject for people to chain off of */
204extern struct kobject *kernel_kobj;
205/* The global /sys/kernel/mm/ kobject for people to chain off of */
206extern struct kobject *mm_kobj;
207/* The global /sys/hypervisor/ kobject for people to chain off of */
208extern struct kobject *hypervisor_kobj;
209/* The global /sys/power/ kobject for people to chain off of */
210extern struct kobject *power_kobj;
211/* The global /sys/firmware/ kobject for people to chain off of */
212extern struct kobject *firmware_kobj;
213
214int kobject_uevent(struct kobject *kobj, enum kobject_action action);
215int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
216			char *envp[]);
217
218__printf(2, 3)
219int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
220
221int kobject_action_type(const char *buf, size_t count,
222			enum kobject_action *type);
223
224#endif /* _KOBJECT_H_ */
225