projects/linux·blob v3.7-rc3 · refs

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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 <[email protected]>
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
30#define UEVENT_HELPER_PATH_LEN 256
31#define UEVENT_NUM_ENVP 32 /* number of env pointers */
32#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
33
34/* path to the userspace helper executed on an event */
35extern char uevent_helper[];
36
37/* counter to tag the uevent, read only except for the kobject core */
38extern u64 uevent_seqnum;
39
40/*
41 * The actions here must match the index to the string array
42 * in lib/kobject_uevent.c
43 *
44 * Do not add new actions here without checking with the driver-core
45 * maintainers. Action strings are not meant to express subsystem
46 * or device specific properties. In most cases you want to send a
47 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
48 * specific variables added to the event environment.
49 */
50enum kobject_action {
51 KOBJ_ADD,
52 KOBJ_REMOVE,
53 KOBJ_CHANGE,
54 KOBJ_MOVE,
55 KOBJ_ONLINE,
56 KOBJ_OFFLINE,
57 KOBJ_MAX
58};
59
60struct kobject {
61 const char *name;
62 struct list_head entry;
63 struct kobject *parent;
64 struct kset *kset;
65 struct kobj_type *ktype;
66 struct sysfs_dirent *sd;
67 struct kref kref;
68 unsigned int state_initialized:1;
69 unsigned int state_in_sysfs:1;
70 unsigned int state_add_uevent_sent:1;
71 unsigned int state_remove_uevent_sent:1;
72 unsigned int uevent_suppress:1;
73};
74
75extern __printf(2, 3)
76int kobject_set_name(struct kobject *kobj, const char *name, ...);
77extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
78 va_list vargs);
79
80static inline const char *kobject_name(const struct kobject *kobj)
81{
82 return kobj->name;
83}
84
85extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
86extern __printf(3, 4) __must_check
87int kobject_add(struct kobject *kobj, struct kobject *parent,
88 const char *fmt, ...);
89extern __printf(4, 5) __must_check
90int kobject_init_and_add(struct kobject *kobj,
91 struct kobj_type *ktype, struct kobject *parent,
92 const char *fmt, ...);
93
94extern void kobject_del(struct kobject *kobj);
95
96extern struct kobject * __must_check kobject_create(void);
97extern struct kobject * __must_check kobject_create_and_add(const char *name,
98 struct kobject *parent);
99
100extern int __must_check kobject_rename(struct kobject *, const char *new_name);
101extern int __must_check kobject_move(struct kobject *, struct kobject *);
102
103extern struct kobject *kobject_get(struct kobject *kobj);
104extern void kobject_put(struct kobject *kobj);
105
106extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
107
108struct kobj_type {
109 void (*release)(struct kobject *kobj);
110 const struct sysfs_ops *sysfs_ops;
111 struct attribute **default_attrs;
112 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
113 const void *(*namespace)(struct kobject *kobj);
114};
115
116struct kobj_uevent_env {
117 char *envp[UEVENT_NUM_ENVP];
118 int envp_idx;
119 char buf[UEVENT_BUFFER_SIZE];
120 int buflen;
121};
122
123struct kset_uevent_ops {
124 int (* const filter)(struct kset *kset, struct kobject *kobj);
125 const char *(* const name)(struct kset *kset, struct kobject *kobj);
126 int (* const uevent)(struct kset *kset, struct kobject *kobj,
127 struct kobj_uevent_env *env);
128};
129
130struct kobj_attribute {
131 struct attribute attr;
132 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
133 char *buf);
134 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
135 const char *buf, size_t count);
136};
137
138extern const struct sysfs_ops kobj_sysfs_ops;
139
140struct sock;
141
142/**
143 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
144 *
145 * A kset defines a group of kobjects. They can be individually
146 * different "types" but overall these kobjects all want to be grouped
147 * together and operated on in the same manner. ksets are used to
148 * define the attribute callbacks and other common events that happen to
149 * a kobject.
150 *
151 * @list: the list of all kobjects for this kset
152 * @list_lock: a lock for iterating over the kobjects
153 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
154 * @uevent_ops: the set of uevent operations for this kset. These are
155 * called whenever a kobject has something happen to it so that the kset
156 * can add new environment variables, or filter out the uevents if so
157 * desired.
158 */
159struct kset {
160 struct list_head list;
161 spinlock_t list_lock;
162 struct kobject kobj;
163 const struct kset_uevent_ops *uevent_ops;
164};
165
166extern void kset_init(struct kset *kset);
167extern int __must_check kset_register(struct kset *kset);
168extern void kset_unregister(struct kset *kset);
169extern struct kset * __must_check kset_create_and_add(const char *name,
170 const struct kset_uevent_ops *u,
171 struct kobject *parent_kobj);
172
173static inline struct kset *to_kset(struct kobject *kobj)
174{
175 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
176}
177
178static inline struct kset *kset_get(struct kset *k)
179{
180 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
181}
182
183static inline void kset_put(struct kset *k)
184{
185 kobject_put(&k->kobj);
186}
187
188static inline struct kobj_type *get_ktype(struct kobject *kobj)
189{
190 return kobj->ktype;
191}
192
193extern struct kobject *kset_find_obj(struct kset *, const char *);
194
195/* The global /sys/kernel/ kobject for people to chain off of */
196extern struct kobject *kernel_kobj;
197/* The global /sys/kernel/mm/ kobject for people to chain off of */
198extern struct kobject *mm_kobj;
199/* The global /sys/hypervisor/ kobject for people to chain off of */
200extern struct kobject *hypervisor_kobj;
201/* The global /sys/power/ kobject for people to chain off of */
202extern struct kobject *power_kobj;
203/* The global /sys/firmware/ kobject for people to chain off of */
204extern struct kobject *firmware_kobj;
205
206#if defined(CONFIG_HOTPLUG)
207int kobject_uevent(struct kobject *kobj, enum kobject_action action);
208int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
209 char *envp[]);
210
211__printf(2, 3)
212int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
213
214int kobject_action_type(const char *buf, size_t count,
215 enum kobject_action *type);
216#else
217static inline int kobject_uevent(struct kobject *kobj,
218 enum kobject_action action)
219{ return 0; }
220static inline int kobject_uevent_env(struct kobject *kobj,
221 enum kobject_action action,
222 char *envp[])
223{ return 0; }
224
225static inline __printf(2, 3)
226int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
227{ return -ENOMEM; }
228
229static inline int kobject_action_type(const char *buf, size_t count,
230 enum kobject_action *type)
231{ return -EINVAL; }
232#endif
233
234#endif /* _KOBJECT_H_ */