kobject.h 7.6 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/spinlock.h>
  21. #include <linux/rwsem.h>
  22. #include <linux/kref.h>
  23. #include <linux/kernel.h>
  24. #include <asm/atomic.h>
  25. #define KOBJ_NAME_LEN 20
  26. #define UEVENT_HELPER_PATH_LEN 256
  27. /* path to the userspace helper executed on an event */
  28. extern char uevent_helper[];
  29. /* counter to tag the uevent, read only except for the kobject core */
  30. extern u64 uevent_seqnum;
  31. /* the actions here must match the proper string in lib/kobject_uevent.c */
  32. typedef int __bitwise kobject_action_t;
  33. enum kobject_action {
  34. KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */
  35. KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */
  36. KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */
  37. KOBJ_MOUNT = (__force kobject_action_t) 0x04, /* mount event for block devices (broken) */
  38. KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */
  39. KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */
  40. KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */
  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 dentry * dentry;
  51. };
  52. extern int kobject_set_name(struct kobject *, const char *, ...)
  53. __attribute__((format(printf,2,3)));
  54. static inline const char * kobject_name(const struct kobject * kobj)
  55. {
  56. return kobj->k_name;
  57. }
  58. extern void kobject_init(struct kobject *);
  59. extern void kobject_cleanup(struct kobject *);
  60. extern int kobject_add(struct kobject *);
  61. extern void kobject_del(struct kobject *);
  62. extern int kobject_rename(struct kobject *, const char *new_name);
  63. extern int kobject_register(struct kobject *);
  64. extern void kobject_unregister(struct kobject *);
  65. extern struct kobject * kobject_get(struct kobject *);
  66. extern void kobject_put(struct kobject *);
  67. extern char * kobject_get_path(struct kobject *, gfp_t);
  68. struct kobj_type {
  69. void (*release)(struct kobject *);
  70. struct sysfs_ops * sysfs_ops;
  71. struct attribute ** default_attrs;
  72. };
  73. /**
  74. * kset - a set of kobjects of a specific type, belonging
  75. * to a specific subsystem.
  76. *
  77. * All kobjects of a kset should be embedded in an identical
  78. * type. This type may have a descriptor, which the kset points
  79. * to. This allows there to exist sets of objects of the same
  80. * type in different subsystems.
  81. *
  82. * A subsystem does not have to be a list of only one type
  83. * of object; multiple ksets can belong to one subsystem. All
  84. * ksets of a subsystem share the subsystem's lock.
  85. *
  86. * Each kset can support specific event variables; it can
  87. * supress the event generation or add subsystem specific
  88. * variables carried with the event.
  89. */
  90. struct kset_uevent_ops {
  91. int (*filter)(struct kset *kset, struct kobject *kobj);
  92. const char *(*name)(struct kset *kset, struct kobject *kobj);
  93. int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp,
  94. int num_envp, char *buffer, int buffer_size);
  95. };
  96. struct kset {
  97. struct subsystem * subsys;
  98. struct kobj_type * ktype;
  99. struct list_head list;
  100. spinlock_t list_lock;
  101. struct kobject kobj;
  102. struct kset_uevent_ops * uevent_ops;
  103. };
  104. extern void kset_init(struct kset * k);
  105. extern int kset_add(struct kset * k);
  106. extern int kset_register(struct kset * k);
  107. extern void kset_unregister(struct kset * k);
  108. static inline struct kset * to_kset(struct kobject * kobj)
  109. {
  110. return kobj ? container_of(kobj,struct kset,kobj) : NULL;
  111. }
  112. static inline struct kset * kset_get(struct kset * k)
  113. {
  114. return k ? to_kset(kobject_get(&k->kobj)) : NULL;
  115. }
  116. static inline void kset_put(struct kset * k)
  117. {
  118. kobject_put(&k->kobj);
  119. }
  120. static inline struct kobj_type * get_ktype(struct kobject * k)
  121. {
  122. if (k->kset && k->kset->ktype)
  123. return k->kset->ktype;
  124. else
  125. return k->ktype;
  126. }
  127. extern struct kobject * kset_find_obj(struct kset *, const char *);
  128. /**
  129. * Use this when initializing an embedded kset with no other
  130. * fields to initialize.
  131. */
  132. #define set_kset_name(str) .kset = { .kobj = { .name = str } }
  133. struct subsystem {
  134. struct kset kset;
  135. struct rw_semaphore rwsem;
  136. };
  137. #define decl_subsys(_name,_type,_uevent_ops) \
  138. struct subsystem _name##_subsys = { \
  139. .kset = { \
  140. .kobj = { .name = __stringify(_name) }, \
  141. .ktype = _type, \
  142. .uevent_ops =_uevent_ops, \
  143. } \
  144. }
  145. #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \
  146. struct subsystem _varname##_subsys = { \
  147. .kset = { \
  148. .kobj = { .name = __stringify(_name) }, \
  149. .ktype = _type, \
  150. .uevent_ops =_uevent_ops, \
  151. } \
  152. }
  153. /* The global /sys/kernel/ subsystem for people to chain off of */
  154. extern struct subsystem kernel_subsys;
  155. /**
  156. * Helpers for setting the kset of registered objects.
  157. * Often, a registered object belongs to a kset embedded in a
  158. * subsystem. These do no magic, just make the resulting code
  159. * easier to follow.
  160. */
  161. /**
  162. * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
  163. * @obj: ptr to some object type.
  164. * @subsys: a subsystem object (not a ptr).
  165. *
  166. * Can be used for any object type with an embedded ->kobj.
  167. */
  168. #define kobj_set_kset_s(obj,subsys) \
  169. (obj)->kobj.kset = &(subsys).kset
  170. /**
  171. * kset_set_kset_s(obj,subsys) - set kset for embedded kset.
  172. * @obj: ptr to some object type.
  173. * @subsys: a subsystem object (not a ptr).
  174. *
  175. * Can be used for any object type with an embedded ->kset.
  176. * Sets the kset of @obj's embedded kobject (via its embedded
  177. * kset) to @subsys.kset. This makes @obj a member of that
  178. * kset.
  179. */
  180. #define kset_set_kset_s(obj,subsys) \
  181. (obj)->kset.kobj.kset = &(subsys).kset
  182. /**
  183. * subsys_set_kset(obj,subsys) - set kset for subsystem
  184. * @obj: ptr to some object type.
  185. * @subsys: a subsystem object (not a ptr).
  186. *
  187. * Can be used for any object type with an embedded ->subsys.
  188. * Sets the kset of @obj's kobject to @subsys.kset. This makes
  189. * the object a member of that kset.
  190. */
  191. #define subsys_set_kset(obj,_subsys) \
  192. (obj)->subsys.kset.kobj.kset = &(_subsys).kset
  193. extern void subsystem_init(struct subsystem *);
  194. extern int subsystem_register(struct subsystem *);
  195. extern void subsystem_unregister(struct subsystem *);
  196. static inline struct subsystem * subsys_get(struct subsystem * s)
  197. {
  198. return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL;
  199. }
  200. static inline void subsys_put(struct subsystem * s)
  201. {
  202. kset_put(&s->kset);
  203. }
  204. struct subsys_attribute {
  205. struct attribute attr;
  206. ssize_t (*show)(struct subsystem *, char *);
  207. ssize_t (*store)(struct subsystem *, const char *, size_t);
  208. };
  209. extern int subsys_create_file(struct subsystem * , struct subsys_attribute *);
  210. extern void subsys_remove_file(struct subsystem * , struct subsys_attribute *);
  211. #if defined(CONFIG_HOTPLUG) & defined(CONFIG_NET)
  212. void kobject_uevent(struct kobject *kobj, enum kobject_action action);
  213. int add_uevent_var(char **envp, int num_envp, int *cur_index,
  214. char *buffer, int buffer_size, int *cur_len,
  215. const char *format, ...)
  216. __attribute__((format (printf, 7, 8)));
  217. #else
  218. static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { }
  219. static inline int add_uevent_var(char **envp, int num_envp, int *cur_index,
  220. char *buffer, int buffer_size, int *cur_len,
  221. const char *format, ...)
  222. { return 0; }
  223. #endif
  224. #endif /* __KERNEL__ */
  225. #endif /* _KOBJECT_H_ */