kobject.h revision 864062457a2e444227bd368ca5f2a2b740de604f
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/compiler.h> 24#include <linux/spinlock.h> 25#include <linux/rwsem.h> 26#include <linux/kref.h> 27#include <linux/kernel.h> 28#include <linux/wait.h> 29#include <asm/atomic.h> 30 31#define KOBJ_NAME_LEN 20 32#define UEVENT_HELPER_PATH_LEN 256 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/* the actions here must match the proper string in lib/kobject_uevent.c */ 41typedef int __bitwise kobject_action_t; 42enum kobject_action { 43 KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */ 44 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */ 45 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */ 46 KOBJ_MOUNT = (__force kobject_action_t) 0x04, /* mount event for block devices (broken) */ 47 KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */ 48 KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */ 49 KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */ 50 KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move */ 51}; 52 53struct kobject { 54 const char * k_name; 55 char name[KOBJ_NAME_LEN]; 56 struct kref kref; 57 struct list_head entry; 58 struct kobject * parent; 59 struct kset * kset; 60 struct kobj_type * ktype; 61 struct dentry * dentry; 62 wait_queue_head_t poll; 63}; 64 65extern int kobject_set_name(struct kobject *, const char *, ...) 66 __attribute__((format(printf,2,3))); 67 68static inline const char * kobject_name(const struct kobject * kobj) 69{ 70 return kobj->k_name; 71} 72 73extern void kobject_init(struct kobject *); 74extern void kobject_cleanup(struct kobject *); 75 76extern int __must_check kobject_add(struct kobject *); 77extern int __must_check kobject_shadow_add(struct kobject *, struct dentry *); 78extern void kobject_del(struct kobject *); 79 80extern int __must_check kobject_rename(struct kobject *, const char *new_name); 81extern int __must_check kobject_shadow_rename(struct kobject *kobj, 82 struct dentry *new_parent, 83 const char *new_name); 84extern int __must_check kobject_move(struct kobject *, struct kobject *); 85 86extern int __must_check kobject_register(struct kobject *); 87extern void kobject_unregister(struct kobject *); 88 89extern struct kobject * kobject_get(struct kobject *); 90extern void kobject_put(struct kobject *); 91 92extern struct kobject *kobject_kset_add_dir(struct kset *kset, 93 struct kobject *, const char *); 94extern struct kobject *kobject_add_dir(struct kobject *, const char *); 95 96extern char * kobject_get_path(struct kobject *, gfp_t); 97 98struct kobj_type { 99 void (*release)(struct kobject *); 100 struct sysfs_ops * sysfs_ops; 101 struct attribute ** default_attrs; 102}; 103 104 105/** 106 * kset - a set of kobjects of a specific type, belonging 107 * to a specific subsystem. 108 * 109 * All kobjects of a kset should be embedded in an identical 110 * type. This type may have a descriptor, which the kset points 111 * to. This allows there to exist sets of objects of the same 112 * type in different subsystems. 113 * 114 * A subsystem does not have to be a list of only one type 115 * of object; multiple ksets can belong to one subsystem. All 116 * ksets of a subsystem share the subsystem's lock. 117 * 118 * Each kset can support specific event variables; it can 119 * supress the event generation or add subsystem specific 120 * variables carried with the event. 121 */ 122struct kset_uevent_ops { 123 int (*filter)(struct kset *kset, struct kobject *kobj); 124 const char *(*name)(struct kset *kset, struct kobject *kobj); 125 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 126 int num_envp, char *buffer, int buffer_size); 127}; 128 129struct kset { 130 struct subsystem * subsys; 131 struct kobj_type * ktype; 132 struct list_head list; 133 spinlock_t list_lock; 134 struct kobject kobj; 135 struct kset_uevent_ops * uevent_ops; 136}; 137 138 139extern void kset_init(struct kset * k); 140extern int __must_check kset_add(struct kset * k); 141extern int __must_check kset_register(struct kset * k); 142extern void kset_unregister(struct kset * k); 143 144static inline struct kset * to_kset(struct kobject * kobj) 145{ 146 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 147} 148 149static inline struct kset * kset_get(struct kset * k) 150{ 151 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 152} 153 154static inline void kset_put(struct kset * k) 155{ 156 kobject_put(&k->kobj); 157} 158 159static inline struct kobj_type * get_ktype(struct kobject * k) 160{ 161 if (k->kset && k->kset->ktype) 162 return k->kset->ktype; 163 else 164 return k->ktype; 165} 166 167extern struct kobject * kset_find_obj(struct kset *, const char *); 168 169 170/** 171 * Use this when initializing an embedded kset with no other 172 * fields to initialize. 173 */ 174#define set_kset_name(str) .kset = { .kobj = { .name = str } } 175 176 177 178struct subsystem { 179 struct kset kset; 180 struct rw_semaphore rwsem; 181}; 182 183#define decl_subsys(_name,_type,_uevent_ops) \ 184struct subsystem _name##_subsys = { \ 185 .kset = { \ 186 .kobj = { .name = __stringify(_name) }, \ 187 .ktype = _type, \ 188 .uevent_ops =_uevent_ops, \ 189 } \ 190} 191#define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 192struct subsystem _varname##_subsys = { \ 193 .kset = { \ 194 .kobj = { .name = __stringify(_name) }, \ 195 .ktype = _type, \ 196 .uevent_ops =_uevent_ops, \ 197 } \ 198} 199 200/* The global /sys/kernel/ subsystem for people to chain off of */ 201extern struct subsystem kernel_subsys; 202/* The global /sys/hypervisor/ subsystem */ 203extern struct subsystem hypervisor_subsys; 204 205/** 206 * Helpers for setting the kset of registered objects. 207 * Often, a registered object belongs to a kset embedded in a 208 * subsystem. These do no magic, just make the resulting code 209 * easier to follow. 210 */ 211 212/** 213 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 214 * @obj: ptr to some object type. 215 * @subsys: a subsystem object (not a ptr). 216 * 217 * Can be used for any object type with an embedded ->kobj. 218 */ 219 220#define kobj_set_kset_s(obj,subsys) \ 221 (obj)->kobj.kset = &(subsys).kset 222 223/** 224 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 225 * @obj: ptr to some object type. 226 * @subsys: a subsystem object (not a ptr). 227 * 228 * Can be used for any object type with an embedded ->kset. 229 * Sets the kset of @obj's embedded kobject (via its embedded 230 * kset) to @subsys.kset. This makes @obj a member of that 231 * kset. 232 */ 233 234#define kset_set_kset_s(obj,subsys) \ 235 (obj)->kset.kobj.kset = &(subsys).kset 236 237/** 238 * subsys_set_kset(obj,subsys) - set kset for subsystem 239 * @obj: ptr to some object type. 240 * @subsys: a subsystem object (not a ptr). 241 * 242 * Can be used for any object type with an embedded ->subsys. 243 * Sets the kset of @obj's kobject to @subsys.kset. This makes 244 * the object a member of that kset. 245 */ 246 247#define subsys_set_kset(obj,_subsys) \ 248 (obj)->subsys.kset.kobj.kset = &(_subsys).kset 249 250extern void subsystem_init(struct subsystem *); 251extern int __must_check subsystem_register(struct subsystem *); 252extern void subsystem_unregister(struct subsystem *); 253 254static inline struct subsystem * subsys_get(struct subsystem * s) 255{ 256 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 257} 258 259static inline void subsys_put(struct subsystem * s) 260{ 261 kset_put(&s->kset); 262} 263 264struct subsys_attribute { 265 struct attribute attr; 266 ssize_t (*show)(struct subsystem *, char *); 267 ssize_t (*store)(struct subsystem *, const char *, size_t); 268}; 269 270extern int __must_check subsys_create_file(struct subsystem * , 271 struct subsys_attribute *); 272 273#if defined(CONFIG_HOTPLUG) 274int kobject_uevent(struct kobject *kobj, enum kobject_action action); 275int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 276 char *envp[]); 277 278int add_uevent_var(char **envp, int num_envp, int *cur_index, 279 char *buffer, int buffer_size, int *cur_len, 280 const char *format, ...) 281 __attribute__((format (printf, 7, 8))); 282#else 283static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 284{ return 0; } 285static inline int kobject_uevent_env(struct kobject *kobj, 286 enum kobject_action action, 287 char *envp[]) 288{ return 0; } 289 290static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 291 char *buffer, int buffer_size, int *cur_len, 292 const char *format, ...) 293{ return 0; } 294#endif 295 296#endif /* __KERNEL__ */ 297#endif /* _KOBJECT_H_ */ 298