kobject.h revision 823bccfc4002296ba88c3ad0f049e1abd8108d30
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/kref.h> 26#include <linux/kernel.h> 27#include <linux/wait.h> 28#include <asm/atomic.h> 29 30#define KOBJ_NAME_LEN 20 31#define UEVENT_HELPER_PATH_LEN 256 32 33/* path to the userspace helper executed on an event */ 34extern char uevent_helper[]; 35 36/* counter to tag the uevent, read only except for the kobject core */ 37extern u64 uevent_seqnum; 38 39/* the actions here must match the proper string in lib/kobject_uevent.c */ 40typedef int __bitwise kobject_action_t; 41enum kobject_action { 42 KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */ 43 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */ 44 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */ 45 KOBJ_OFFLINE = (__force kobject_action_t) 0x04, /* device offline */ 46 KOBJ_ONLINE = (__force kobject_action_t) 0x05, /* device online */ 47 KOBJ_MOVE = (__force kobject_action_t) 0x06, /* device move */ 48}; 49 50struct kobject { 51 const char * k_name; 52 char name[KOBJ_NAME_LEN]; 53 struct kref kref; 54 struct list_head entry; 55 struct kobject * parent; 56 struct kset * kset; 57 struct kobj_type * ktype; 58 struct dentry * dentry; 59 wait_queue_head_t poll; 60}; 61 62extern int kobject_set_name(struct kobject *, const char *, ...) 63 __attribute__((format(printf,2,3))); 64 65static inline const char * kobject_name(const struct kobject * kobj) 66{ 67 return kobj->k_name; 68} 69 70extern void kobject_init(struct kobject *); 71extern void kobject_cleanup(struct kobject *); 72 73extern int __must_check kobject_add(struct kobject *); 74extern int __must_check kobject_shadow_add(struct kobject *, struct dentry *); 75extern void kobject_del(struct kobject *); 76 77extern int __must_check kobject_rename(struct kobject *, const char *new_name); 78extern int __must_check kobject_shadow_rename(struct kobject *kobj, 79 struct dentry *new_parent, 80 const char *new_name); 81extern int __must_check kobject_move(struct kobject *, struct kobject *); 82 83extern int __must_check kobject_register(struct kobject *); 84extern void kobject_unregister(struct kobject *); 85 86extern struct kobject * kobject_get(struct kobject *); 87extern void kobject_put(struct kobject *); 88 89extern struct kobject *kobject_kset_add_dir(struct kset *kset, 90 struct kobject *, const char *); 91extern struct kobject *kobject_add_dir(struct kobject *, const char *); 92 93extern char * kobject_get_path(struct kobject *, gfp_t); 94 95struct kobj_type { 96 void (*release)(struct kobject *); 97 struct sysfs_ops * sysfs_ops; 98 struct attribute ** default_attrs; 99}; 100 101 102/** 103 * kset - a set of kobjects of a specific type, belonging 104 * to a specific subsystem. 105 * 106 * All kobjects of a kset should be embedded in an identical 107 * type. This type may have a descriptor, which the kset points 108 * to. This allows there to exist sets of objects of the same 109 * type in different subsystems. 110 * 111 * A subsystem does not have to be a list of only one type 112 * of object; multiple ksets can belong to one subsystem. All 113 * ksets of a subsystem share the subsystem's lock. 114 * 115 * Each kset can support specific event variables; it can 116 * supress the event generation or add subsystem specific 117 * variables carried with the event. 118 */ 119struct kset_uevent_ops { 120 int (*filter)(struct kset *kset, struct kobject *kobj); 121 const char *(*name)(struct kset *kset, struct kobject *kobj); 122 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 123 int num_envp, char *buffer, int buffer_size); 124}; 125 126struct kset { 127 struct kobj_type * ktype; 128 struct list_head list; 129 spinlock_t list_lock; 130 struct kobject kobj; 131 struct kset_uevent_ops * uevent_ops; 132}; 133 134 135extern void kset_init(struct kset * k); 136extern int __must_check kset_add(struct kset * k); 137extern int __must_check kset_register(struct kset * k); 138extern void kset_unregister(struct kset * k); 139 140static inline struct kset * to_kset(struct kobject * kobj) 141{ 142 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 143} 144 145static inline struct kset * kset_get(struct kset * k) 146{ 147 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 148} 149 150static inline void kset_put(struct kset * k) 151{ 152 kobject_put(&k->kobj); 153} 154 155static inline struct kobj_type * get_ktype(struct kobject * k) 156{ 157 if (k->kset && k->kset->ktype) 158 return k->kset->ktype; 159 else 160 return k->ktype; 161} 162 163extern struct kobject * kset_find_obj(struct kset *, const char *); 164 165 166/** 167 * Use this when initializing an embedded kset with no other 168 * fields to initialize. 169 */ 170#define set_kset_name(str) .kset = { .kobj = { .name = str } } 171 172 173#define decl_subsys(_name,_type,_uevent_ops) \ 174struct kset _name##_subsys = { \ 175 .kobj = { .name = __stringify(_name) }, \ 176 .ktype = _type, \ 177 .uevent_ops =_uevent_ops, \ 178} 179#define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 180struct kset _varname##_subsys = { \ 181 .kobj = { .name = __stringify(_name) }, \ 182 .ktype = _type, \ 183 .uevent_ops =_uevent_ops, \ 184} 185 186/* The global /sys/kernel/ subsystem for people to chain off of */ 187extern struct kset kernel_subsys; 188/* The global /sys/hypervisor/ subsystem */ 189extern struct kset hypervisor_subsys; 190 191/** 192 * Helpers for setting the kset of registered objects. 193 * Often, a registered object belongs to a kset embedded in a 194 * subsystem. These do no magic, just make the resulting code 195 * easier to follow. 196 */ 197 198/** 199 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 200 * @obj: ptr to some object type. 201 * @subsys: a subsystem object (not a ptr). 202 * 203 * Can be used for any object type with an embedded ->kobj. 204 */ 205 206#define kobj_set_kset_s(obj,subsys) \ 207 (obj)->kobj.kset = &(subsys) 208 209/** 210 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 211 * @obj: ptr to some object type. 212 * @subsys: a subsystem object (not a ptr). 213 * 214 * Can be used for any object type with an embedded ->kset. 215 * Sets the kset of @obj's embedded kobject (via its embedded 216 * kset) to @subsys.kset. This makes @obj a member of that 217 * kset. 218 */ 219 220#define kset_set_kset_s(obj,subsys) \ 221 (obj)->kset.kobj.kset = &(subsys) 222 223/** 224 * subsys_set_kset(obj,subsys) - set kset for subsystem 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 ->subsys. 229 * Sets the kset of @obj's kobject to @subsys.kset. This makes 230 * the object a member of that kset. 231 */ 232 233#define subsys_set_kset(obj,_subsys) \ 234 (obj)->subsys.kobj.kset = &(_subsys) 235 236extern void subsystem_init(struct kset *); 237extern int __must_check subsystem_register(struct kset *); 238extern void subsystem_unregister(struct kset *); 239 240static inline struct kset *subsys_get(struct kset *s) 241{ 242 if (s) 243 return kset_get(s); 244 return NULL; 245} 246 247static inline void subsys_put(struct kset *s) 248{ 249 kset_put(s); 250} 251 252struct subsys_attribute { 253 struct attribute attr; 254 ssize_t (*show)(struct kset *, char *); 255 ssize_t (*store)(struct kset *, const char *, size_t); 256}; 257 258extern int __must_check subsys_create_file(struct kset *, 259 struct subsys_attribute *); 260 261#if defined(CONFIG_HOTPLUG) 262int kobject_uevent(struct kobject *kobj, enum kobject_action action); 263int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 264 char *envp[]); 265 266int add_uevent_var(char **envp, int num_envp, int *cur_index, 267 char *buffer, int buffer_size, int *cur_len, 268 const char *format, ...) 269 __attribute__((format (printf, 7, 8))); 270#else 271static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 272{ return 0; } 273static inline int kobject_uevent_env(struct kobject *kobj, 274 enum kobject_action action, 275 char *envp[]) 276{ return 0; } 277 278static inline int 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{ return 0; } 282#endif 283 284#endif /* __KERNEL__ */ 285#endif /* _KOBJECT_H_ */ 286