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 *
7 * This file is released under the GPLv2.
8 *
9 *
10 * Please read Documentation/kobject.txt before using the kobject
11 * interface, ESPECIALLY the parts about reference counts and object
12 * destructors.
13 */
14
15 #ifndef _KOBJECT_H_
16 #define _KOBJECT_H_
17
18 #ifdef __KERNEL__
19
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 <linux/wait.h>
28 #include <asm/atomic.h>
29
30 #define KOBJ_NAME_LEN 20
31 #define UEVENT_HELPER_PATH_LEN 256
32
33 /* path to the userspace helper executed on an event */
34 extern char uevent_helper[];
35
36 /* counter to tag the uevent, read only except for the kobject core */
37 extern u64 uevent_seqnum;
38
39 /* the actions here must match the proper string in lib/kobject_uevent.c */
40 typedef int __bitwise kobject_action_t;
41 enum kobject_action {
42 KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */
43 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */
44 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */
45 KOBJ_MOUNT = (__force kobject_action_t) 0x04, /* mount event for block devices (broken) */
46 KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */
47 KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */
48 KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */
49 };
50
51 struct kobject {
52 const char * k_name;
53 char name[KOBJ_NAME_LEN];
54 struct kref kref;
55 struct list_head entry;
56 struct kobject * parent;
57 struct kset * kset;
58 struct kobj_type * ktype;
59 struct dentry * dentry;
60 wait_queue_head_t poll;
61 };
62
63 extern int kobject_set_name(struct kobject *, const char *, ...)
64 __attribute__((format(printf,2,3)));
65
kobject_name(const struct kobject * kobj)66 static inline const char * kobject_name(const struct kobject * kobj)
67 {
68 return kobj->k_name;
69 }
70
71 extern void kobject_init(struct kobject *);
72 extern void kobject_cleanup(struct kobject *);
73
74 extern int kobject_add(struct kobject *);
75 extern void kobject_del(struct kobject *);
76
77 extern int kobject_rename(struct kobject *, const char *new_name);
78
79 extern int kobject_register(struct kobject *);
80 extern void kobject_unregister(struct kobject *);
81
82 extern struct kobject * kobject_get(struct kobject *);
83 extern void kobject_put(struct kobject *);
84
85 extern struct kobject *kobject_add_dir(struct kobject *, const char *);
86
87 extern char * kobject_get_path(struct kobject *, gfp_t);
88
89 struct kobj_type {
90 void (*release)(struct kobject *);
91 struct sysfs_ops * sysfs_ops;
92 struct attribute ** default_attrs;
93 };
94
95
96 /**
97 * kset - a set of kobjects of a specific type, belonging
98 * to a specific subsystem.
99 *
100 * All kobjects of a kset should be embedded in an identical
101 * type. This type may have a descriptor, which the kset points
102 * to. This allows there to exist sets of objects of the same
103 * type in different subsystems.
104 *
105 * A subsystem does not have to be a list of only one type
106 * of object; multiple ksets can belong to one subsystem. All
107 * ksets of a subsystem share the subsystem's lock.
108 *
109 * Each kset can support specific event variables; it can
110 * supress the event generation or add subsystem specific
111 * variables carried with the event.
112 */
113 struct kset_uevent_ops {
114 int (*filter)(struct kset *kset, struct kobject *kobj);
115 const char *(*name)(struct kset *kset, struct kobject *kobj);
116 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp,
117 int num_envp, char *buffer, int buffer_size);
118 };
119
120 struct kset {
121 struct subsystem * subsys;
122 struct kobj_type * ktype;
123 struct list_head list;
124 spinlock_t list_lock;
125 struct kobject kobj;
126 struct kset_uevent_ops * uevent_ops;
127 };
128
129
130 extern void kset_init(struct kset * k);
131 extern int kset_add(struct kset * k);
132 extern int kset_register(struct kset * k);
133 extern void kset_unregister(struct kset * k);
134
to_kset(struct kobject * kobj)135 static inline struct kset * to_kset(struct kobject * kobj)
136 {
137 return kobj ? container_of(kobj,struct kset,kobj) : NULL;
138 }
139
kset_get(struct kset * k)140 static inline struct kset * kset_get(struct kset * k)
141 {
142 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
143 }
144
kset_put(struct kset * k)145 static inline void kset_put(struct kset * k)
146 {
147 kobject_put(&k->kobj);
148 }
149
get_ktype(struct kobject * k)150 static inline struct kobj_type * get_ktype(struct kobject * k)
151 {
152 if (k->kset && k->kset->ktype)
153 return k->kset->ktype;
154 else
155 return k->ktype;
156 }
157
158 extern struct kobject * kset_find_obj(struct kset *, const char *);
159
160
161 /**
162 * Use this when initializing an embedded kset with no other
163 * fields to initialize.
164 */
165 #define set_kset_name(str) .kset = { .kobj = { .name = str } }
166
167
168
169 struct subsystem {
170 struct kset kset;
171 struct rw_semaphore rwsem;
172 };
173
174 #define decl_subsys(_name,_type,_uevent_ops) \
175 struct subsystem _name##_subsys = { \
176 .kset = { \
177 .kobj = { .name = __stringify(_name) }, \
178 .ktype = _type, \
179 .uevent_ops =_uevent_ops, \
180 } \
181 }
182 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \
183 struct subsystem _varname##_subsys = { \
184 .kset = { \
185 .kobj = { .name = __stringify(_name) }, \
186 .ktype = _type, \
187 .uevent_ops =_uevent_ops, \
188 } \
189 }
190
191 /* The global /sys/kernel/ subsystem for people to chain off of */
192 extern struct subsystem kernel_subsys;
193 /* The global /sys/hypervisor/ subsystem */
194 extern struct subsystem hypervisor_subsys;
195
196 /**
197 * Helpers for setting the kset of registered objects.
198 * Often, a registered object belongs to a kset embedded in a
199 * subsystem. These do no magic, just make the resulting code
200 * easier to follow.
201 */
202
203 /**
204 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
205 * @obj: ptr to some object type.
206 * @subsys: a subsystem object (not a ptr).
207 *
208 * Can be used for any object type with an embedded ->kobj.
209 */
210
211 #define kobj_set_kset_s(obj,subsys) \
212 (obj)->kobj.kset = &(subsys).kset
213
214 /**
215 * kset_set_kset_s(obj,subsys) - set kset for embedded kset.
216 * @obj: ptr to some object type.
217 * @subsys: a subsystem object (not a ptr).
218 *
219 * Can be used for any object type with an embedded ->kset.
220 * Sets the kset of @obj's embedded kobject (via its embedded
221 * kset) to @subsys.kset. This makes @obj a member of that
222 * kset.
223 */
224
225 #define kset_set_kset_s(obj,subsys) \
226 (obj)->kset.kobj.kset = &(subsys).kset
227
228 /**
229 * subsys_set_kset(obj,subsys) - set kset for subsystem
230 * @obj: ptr to some object type.
231 * @subsys: a subsystem object (not a ptr).
232 *
233 * Can be used for any object type with an embedded ->subsys.
234 * Sets the kset of @obj's kobject to @subsys.kset. This makes
235 * the object a member of that kset.
236 */
237
238 #define subsys_set_kset(obj,_subsys) \
239 (obj)->subsys.kset.kobj.kset = &(_subsys).kset
240
241 extern void subsystem_init(struct subsystem *);
242 extern int subsystem_register(struct subsystem *);
243 extern void subsystem_unregister(struct subsystem *);
244
subsys_get(struct subsystem * s)245 static inline struct subsystem * subsys_get(struct subsystem * s)
246 {
247 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL;
248 }
249
subsys_put(struct subsystem * s)250 static inline void subsys_put(struct subsystem * s)
251 {
252 kset_put(&s->kset);
253 }
254
255 struct subsys_attribute {
256 struct attribute attr;
257 ssize_t (*show)(struct subsystem *, char *);
258 ssize_t (*store)(struct subsystem *, const char *, size_t);
259 };
260
261 extern int subsys_create_file(struct subsystem * , struct subsys_attribute *);
262
263 #if defined(CONFIG_HOTPLUG)
264 void kobject_uevent(struct kobject *kobj, enum kobject_action action);
265
266 int add_uevent_var(char **envp, int num_envp, int *cur_index,
267 char *buffer, int buffer_size, int *cur_len,
268 const char *format, ...)
269 __attribute__((format (printf, 7, 8)));
270 #else
kobject_uevent(struct kobject * kobj,enum kobject_action action)271 static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { }
272
add_uevent_var(char ** envp,int num_envp,int * cur_index,char * buffer,int buffer_size,int * cur_len,const char * format,...)273 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index,
274 char *buffer, int buffer_size, int *cur_len,
275 const char *format, ...)
276 { return 0; }
277 #endif
278
279 #endif /* __KERNEL__ */
280 #endif /* _KOBJECT_H_ */
281