kobject.h 8.1 KB

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