aboutsummaryrefslogtreecommitdiff
path: root/include/linux/kobject.h
blob: 949706c33622dfca669418f4fa3e0551bc79c529 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * kobject.h - generic kernel object infrastructure.
 *
 * Copyright (c) 2002-2003	Patrick Mochel
 * Copyright (c) 2002-2003	Open Source Development Labs
 *
 * This file is released under the GPLv2.
 *
 * 
 * Please read Documentation/kobject.txt before using the kobject
 * interface, ESPECIALLY the parts about reference counts and object
 * destructors. 
 */

#ifndef _KOBJECT_H_
#define _KOBJECT_H_

#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/list.h>
#include <linux/sysfs.h>
#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/kref.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <asm/atomic.h>

#define KOBJ_NAME_LEN			20
#define UEVENT_HELPER_PATH_LEN		256

/* path to the userspace helper executed on an event */
extern char uevent_helper[];

/* counter to tag the uevent, read only except for the kobject core */
extern u64 uevent_seqnum;

/*
 * The actions here must match the index to the string array
 * in lib/kobject_uevent.c
 *
 * Do not add new actions here without checking with the driver-core
 * maintainers. Action strings are not meant to express subsystem
 * or device specific properties. In most cases you want to send a
 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
 * specific variables added to the event environment.
 */
enum kobject_action {
	KOBJ_ADD,
	KOBJ_REMOVE,
	KOBJ_CHANGE,
	KOBJ_MOVE,
	KOBJ_ONLINE,
	KOBJ_OFFLINE,
	KOBJ_MAX
};

/* The list of strings defining the valid kobject actions as specified above */
extern const char *kobject_actions[];

struct kobject {
	const char		* k_name;
	char			name[KOBJ_NAME_LEN];
	struct kref		kref;
	struct list_head	entry;
	struct kobject		* parent;
	struct kset		* kset;
	struct kobj_type	* ktype;
	struct sysfs_dirent	* sd;
	wait_queue_head_t	poll;
};

extern int kobject_set_name(struct kobject *, const char *, ...)
	__attribute__((format(printf,2,3)));

static inline const char * kobject_name(const struct kobject * kobj)
{
	return kobj->k_name;
}

extern void kobject_init(struct kobject *);
extern void kobject_cleanup(struct kobject *);

extern int __must_check kobject_add(struct kobject *);
extern int __must_check kobject_shadow_add(struct kobject *kobj,
					   struct sysfs_dirent *shadow_parent);
extern void kobject_del(struct kobject *);

extern int __must_check kobject_rename(struct kobject *, const char *new_name);
extern int __must_check kobject_shadow_rename(struct kobject *kobj,
					      struct sysfs_dirent *new_parent,
					      const char *new_name);
extern int __must_check kobject_move(struct kobject *, struct kobject *);

extern int __must_check kobject_register(struct kobject *);
extern void kobject_unregister(struct kobject *);

extern struct kobject * kobject_get(struct kobject *);
extern void kobject_put(struct kobject *);

extern struct kobject *kobject_kset_add_dir(struct kset *kset,
					    struct kobject *, const char *);
extern struct kobject *kobject_add_dir(struct kobject *, const char *);

extern char * kobject_get_path(struct kobject *, gfp_t);

struct kobj_type {
	void (*release)(struct kobject *);
	struct sysfs_ops	* sysfs_ops;
	struct attribute	** default_attrs;
};

struct kset_uevent_ops {
	int (*filter)(struct kset *kset, struct kobject *kobj);
	const char *(*name)(struct kset *kset, struct kobject *kobj);
	int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp,
			int num_envp, char *buffer, int buffer_size);
};

/*
 *	struct kset - a set of kobjects of a specific type, belonging
 *	to a specific subsystem.
 *
 *	All kobjects of a kset should be embedded in an identical 
 *	type. This type may have a descriptor, which the kset points
 *	to. This allows there to exist sets of objects of the same
 *	type in different subsystems.
 *
 *	A subsystem does not have to be a list of only one type 
 *	of object; multiple ksets can belong to one subsystem. All 
 *	ksets of a subsystem share the subsystem's lock.
 *
 *	Each kset can support specific event variables; it can
 *	supress the event generation or add subsystem specific
 *	variables carried with the event.
 */
struct kset {
	struct kobj_type	* ktype;
	struct list_head	list;
	spinlock_t		list_lock;
	struct kobject		kobj;
	struct kset_uevent_ops	* uevent_ops;
};


extern void kset_init(struct kset * k);
extern int __must_check kset_add(struct kset * k);
extern int __must_check kset_register(struct kset * k);
extern void kset_unregister(struct kset * k);

static inline struct kset * to_kset(struct kobject * kobj)
{
	return kobj ? container_of(kobj,struct kset,kobj) : NULL;
}

static inline struct kset * kset_get(struct kset * k)
{
	return k ? to_kset(kobject_get(&k->kobj)) : NULL;
}

static inline void kset_put(struct kset * k)
{
	kobject_put(&k->kobj);
}

static inline struct kobj_type * get_ktype(struct kobject * k)
{
	if (k->kset && k->kset->ktype)
		return k->kset->ktype;
	else 
		return k->ktype;
}

extern struct kobject * kset_find_obj(struct kset *, const char *);


/*
 * Use this when initializing an embedded kset with no other 
 * fields to initialize.
 */
#define set_kset_name(str)	.kset = { .kobj = { .name = str } }


#define decl_subsys(_name,_type,_uevent_ops) \
struct kset _name##_subsys = { \
	.kobj = { .name = __stringify(_name) }, \
	.ktype = _type, \
	.uevent_ops =_uevent_ops, \
}
#define decl_subsys_name(_varname,_name,_type,_uevent_ops) \
struct kset _varname##_subsys = { \
	.kobj = { .name = __stringify(_name) }, \
	.ktype = _type, \
	.uevent_ops =_uevent_ops, \
}

/* The global /sys/kernel/ subsystem for people to chain off of */
extern struct kset kernel_subsys;
/* The global /sys/hypervisor/ subsystem  */
extern struct kset hypervisor_subsys;

/*
 * Helpers for setting the kset of registered objects.
 * Often, a registered object belongs to a kset embedded in a 
 * subsystem. These do no magic, just make the resulting code
 * easier to follow. 
 */

/**
 *	kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
 *	@obj:		ptr to some object type.
 *	@subsys:	a subsystem object (not a ptr).
 *
 *	Can be used for any object type with an embedded ->kobj.
 */

#define kobj_set_kset_s(obj,subsys) \
	(obj)->kobj.kset = &(subsys)

/**
 *	kset_set_kset_s(obj,subsys) - set kset for embedded kset.
 *	@obj:		ptr to some object type.
 *	@subsys:	a subsystem object (not a ptr).
 *
 *	Can be used for any object type with an embedded ->kset.
 *	Sets the kset of @obj's  embedded kobject (via its embedded
 *	kset) to @subsys.kset. This makes @obj a member of that 
 *	kset.
 */

#define kset_set_kset_s(obj,subsys) \
	(obj)->kset.kobj.kset = &(subsys)

/**
 *	subsys_set_kset(obj,subsys) - set kset for subsystem
 *	@obj:		ptr to some object type.
 *	@_subsys:	a subsystem object (not a ptr).
 *
 *	Can be used for any object type with an embedded ->subsys.
 *	Sets the kset of @obj's kobject to @subsys.kset. This makes
 *	the object a member of that kset.
 */

#define subsys_set_kset(obj,_subsys) \
	(obj)->subsys.kobj.kset = &(_subsys)

extern void subsystem_init(struct kset *);
extern int __must_check subsystem_register(struct kset *);
extern void subsystem_unregister(struct kset *);

static inline struct kset *subsys_get(struct kset *s)
{
	if (s)
		return kset_get(s);
	return NULL;
}

static inline void subsys_put(struct kset *s)
{
	kset_put(s);
}

struct subsys_attribute {
	struct attribute attr;
	ssize_t (*show)(struct kset *, char *);
	ssize_t (*store)(struct kset *, const char *, size_t);
};

extern int __must_check subsys_create_file(struct kset *,
					struct subsys_attribute *);

#if defined(CONFIG_HOTPLUG)
int kobject_uevent(struct kobject *kobj, enum kobject_action action);
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
			char *envp[]);

int add_uevent_var(char **envp, int num_envp, int *cur_index,
			char *buffer, int buffer_size, int *cur_len,
			const char *format, ...)
	__attribute__((format (printf, 7, 8)));
#else
static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action)
{ return 0; }
static inline int kobject_uevent_env(struct kobject *kobj,
				      enum kobject_action action,
				      char *envp[])
{ return 0; }

static inline int add_uevent_var(char **envp, int num_envp, int *cur_index,
				      char *buffer, int buffer_size, int *cur_len, 
				      const char *format, ...)
{ return 0; }
#endif

#endif /* __KERNEL__ */
#endif /* _KOBJECT_H_ */