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
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 */
35 extern char uevent_helper[];
36
37 /* counter to tag the uevent, read only except for the kobject core */
38 extern 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 */
50 enum 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
60 struct 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
75 extern __printf(2, 3)
76 int kobject_set_name(struct kobject *kobj, const char *name, ...);
77 extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
78 va_list vargs);
79
kobject_name(const struct kobject * kobj)80 static inline const char *kobject_name(const struct kobject *kobj)
81 {
82 return kobj->name;
83 }
84
85 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
86 extern __printf(3, 4) __must_check
87 int kobject_add(struct kobject *kobj, struct kobject *parent,
88 const char *fmt, ...);
89 extern __printf(4, 5) __must_check
90 int kobject_init_and_add(struct kobject *kobj,
91 struct kobj_type *ktype, struct kobject *parent,
92 const char *fmt, ...);
93
94 extern void kobject_del(struct kobject *kobj);
95
96 extern struct kobject * __must_check kobject_create(void);
97 extern struct kobject * __must_check kobject_create_and_add(const char *name,
98 struct kobject *parent);
99
100 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
101 extern int __must_check kobject_move(struct kobject *, struct kobject *);
102
103 extern struct kobject *kobject_get(struct kobject *kobj);
104 extern void kobject_put(struct kobject *kobj);
105
106 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
107
108 struct 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
116 struct kobj_uevent_env {
117 char *envp[UEVENT_NUM_ENVP];
118 int envp_idx;
119 char buf[UEVENT_BUFFER_SIZE];
120 int buflen;
121 };
122
123 struct 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
130 struct 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
138 extern const struct sysfs_ops kobj_sysfs_ops;
139
140 struct 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 */
159 struct 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
166 extern void kset_init(struct kset *kset);
167 extern int __must_check kset_register(struct kset *kset);
168 extern void kset_unregister(struct kset *kset);
169 extern struct kset * __must_check kset_create_and_add(const char *name,
170 const struct kset_uevent_ops *u,
171 struct kobject *parent_kobj);
172
to_kset(struct kobject * kobj)173 static inline struct kset *to_kset(struct kobject *kobj)
174 {
175 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
176 }
177
kset_get(struct kset * k)178 static inline struct kset *kset_get(struct kset *k)
179 {
180 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
181 }
182
kset_put(struct kset * k)183 static inline void kset_put(struct kset *k)
184 {
185 kobject_put(&k->kobj);
186 }
187
get_ktype(struct kobject * kobj)188 static inline struct kobj_type *get_ktype(struct kobject *kobj)
189 {
190 return kobj->ktype;
191 }
192
193 extern struct kobject *kset_find_obj(struct kset *, const char *);
194
195 /* The global /sys/kernel/ kobject for people to chain off of */
196 extern struct kobject *kernel_kobj;
197 /* The global /sys/kernel/mm/ kobject for people to chain off of */
198 extern struct kobject *mm_kobj;
199 /* The global /sys/hypervisor/ kobject for people to chain off of */
200 extern struct kobject *hypervisor_kobj;
201 /* The global /sys/power/ kobject for people to chain off of */
202 extern struct kobject *power_kobj;
203 /* The global /sys/firmware/ kobject for people to chain off of */
204 extern struct kobject *firmware_kobj;
205
206 #if defined(CONFIG_HOTPLUG)
207 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
208 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
209 char *envp[]);
210
211 __printf(2, 3)
212 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
213
214 int kobject_action_type(const char *buf, size_t count,
215 enum kobject_action *type);
216 #else
kobject_uevent(struct kobject * kobj,enum kobject_action action)217 static inline int kobject_uevent(struct kobject *kobj,
218 enum kobject_action action)
219 { return 0; }
kobject_uevent_env(struct kobject * kobj,enum kobject_action action,char * envp[])220 static inline int kobject_uevent_env(struct kobject *kobj,
221 enum kobject_action action,
222 char *envp[])
223 { return 0; }
224
225 static inline __printf(2, 3)
add_uevent_var(struct kobj_uevent_env * env,const char * format,...)226 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
227 { return -ENOMEM; }
228
kobject_action_type(const char * buf,size_t count,enum kobject_action * type)229 static 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_ */
235