kobject.h revision e4bc16621d82ee1fd3685dcbf889a7c49891847b
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#define UEVENT_NUM_ENVP 32 /* number of env pointers */ 33#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 34 35/* path to the userspace helper executed on an event */ 36extern char uevent_helper[]; 37 38/* counter to tag the uevent, read only except for the kobject core */ 39extern u64 uevent_seqnum; 40 41/* 42 * The actions here must match the index to the string array 43 * in lib/kobject_uevent.c 44 * 45 * Do not add new actions here without checking with the driver-core 46 * maintainers. Action strings are not meant to express subsystem 47 * or device specific properties. In most cases you want to send a 48 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 49 * specific variables added to the event environment. 50 */ 51enum kobject_action { 52 KOBJ_ADD, 53 KOBJ_REMOVE, 54 KOBJ_CHANGE, 55 KOBJ_MOVE, 56 KOBJ_ONLINE, 57 KOBJ_OFFLINE, 58 KOBJ_MAX 59}; 60 61struct kobject { 62 const char * k_name; 63 struct kref kref; 64 struct list_head entry; 65 struct kobject * parent; 66 struct kset * kset; 67 struct kobj_type * ktype; 68 struct sysfs_dirent * sd; 69}; 70 71extern int kobject_set_name(struct kobject *, const char *, ...) 72 __attribute__((format(printf,2,3))); 73 74static inline const char * kobject_name(const struct kobject * kobj) 75{ 76 return kobj->k_name; 77} 78 79extern void kobject_init(struct kobject *); 80extern void kobject_cleanup(struct kobject *); 81 82extern int __must_check kobject_add(struct kobject *); 83extern void kobject_del(struct kobject *); 84 85extern int __must_check kobject_rename(struct kobject *, const char *new_name); 86extern int __must_check kobject_move(struct kobject *, struct kobject *); 87 88extern int __must_check kobject_register(struct kobject *); 89extern void kobject_unregister(struct kobject *); 90 91extern struct kobject * kobject_get(struct kobject *); 92extern void kobject_put(struct kobject *); 93 94extern struct kobject *kobject_kset_add_dir(struct kset *kset, 95 struct kobject *, const char *); 96extern struct kobject *kobject_add_dir(struct kobject *, const char *); 97 98extern char * kobject_get_path(struct kobject *, gfp_t); 99 100struct kobj_type { 101 void (*release)(struct kobject *); 102 struct sysfs_ops * sysfs_ops; 103 struct attribute ** default_attrs; 104}; 105 106struct kobj_uevent_env { 107 char *envp[UEVENT_NUM_ENVP]; 108 int envp_idx; 109 char buf[UEVENT_BUFFER_SIZE]; 110 int buflen; 111}; 112 113struct kset_uevent_ops { 114 int (*filter)(struct kset *kset, struct kobject *kobj); 115 const char *(*name)(struct kset *kset, struct kobject *kobj); 116 int (*uevent)(struct kset *kset, struct kobject *kobj, 117 struct kobj_uevent_env *env); 118}; 119 120/* 121 * struct kset - a set of kobjects of a specific type, belonging 122 * to a specific subsystem. 123 * 124 * All kobjects of a kset should be embedded in an identical 125 * type. This type may have a descriptor, which the kset points 126 * to. This allows there to exist sets of objects of the same 127 * type in different subsystems. 128 * 129 * A subsystem does not have to be a list of only one type 130 * of object; multiple ksets can belong to one subsystem. All 131 * ksets of a subsystem share the subsystem's lock. 132 * 133 * Each kset can support specific event variables; it can 134 * supress the event generation or add subsystem specific 135 * variables carried with the event. 136 */ 137struct kset { 138 struct kobj_type * ktype; 139 struct list_head list; 140 spinlock_t list_lock; 141 struct kobject kobj; 142 struct kset_uevent_ops * uevent_ops; 143}; 144 145 146extern void kset_init(struct kset * k); 147extern int __must_check kset_add(struct kset * k); 148extern int __must_check kset_register(struct kset * k); 149extern void kset_unregister(struct kset * k); 150 151static inline struct kset * to_kset(struct kobject * kobj) 152{ 153 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 154} 155 156static inline struct kset * kset_get(struct kset * k) 157{ 158 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 159} 160 161static inline void kset_put(struct kset * k) 162{ 163 kobject_put(&k->kobj); 164} 165 166static inline struct kobj_type * get_ktype(struct kobject * k) 167{ 168 if (k->kset && k->kset->ktype) 169 return k->kset->ktype; 170 else 171 return k->ktype; 172} 173 174extern struct kobject * kset_find_obj(struct kset *, const char *); 175 176 177/* 178 * Use this when initializing an embedded kset with no other 179 * fields to initialize. 180 */ 181#define set_kset_name(str) .kset = { .kobj = { .k_name = str } } 182 183 184#define decl_subsys(_name,_type,_uevent_ops) \ 185struct kset _name##_subsys = { \ 186 .kobj = { .k_name = __stringify(_name) }, \ 187 .ktype = _type, \ 188 .uevent_ops =_uevent_ops, \ 189} 190#define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 191struct kset _varname##_subsys = { \ 192 .kobj = { .k_name = __stringify(_name) }, \ 193 .ktype = _type, \ 194 .uevent_ops =_uevent_ops, \ 195} 196 197/* The global /sys/kernel/ subsystem for people to chain off of */ 198extern struct kset kernel_subsys; 199/* The global /sys/hypervisor/ subsystem */ 200extern struct kset hypervisor_subsys; 201 202/* 203 * Helpers for setting the kset of registered objects. 204 * Often, a registered object belongs to a kset embedded in a 205 * subsystem. These do no magic, just make the resulting code 206 * easier to follow. 207 */ 208 209/** 210 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 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 ->kobj. 215 */ 216 217#define kobj_set_kset_s(obj,subsys) \ 218 (obj)->kobj.kset = &(subsys) 219 220extern int __must_check subsystem_register(struct kset *); 221extern void subsystem_unregister(struct kset *); 222 223struct subsys_attribute { 224 struct attribute attr; 225 ssize_t (*show)(struct kset *, char *); 226 ssize_t (*store)(struct kset *, const char *, size_t); 227}; 228 229extern int __must_check subsys_create_file(struct kset *, 230 struct subsys_attribute *); 231 232#if defined(CONFIG_HOTPLUG) 233int kobject_uevent(struct kobject *kobj, enum kobject_action action); 234int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 235 char *envp[]); 236 237int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 238 __attribute__((format (printf, 2, 3))); 239 240int kobject_action_type(const char *buf, size_t count, 241 enum kobject_action *type); 242#else 243static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 244{ return 0; } 245static inline int kobject_uevent_env(struct kobject *kobj, 246 enum kobject_action action, 247 char *envp[]) 248{ return 0; } 249 250static inline int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 251{ return 0; } 252 253static inline int kobject_action_type(const char *buf, size_t count, 254 enum kobject_action *type) 255{ return -EINVAL; } 256#endif 257 258#endif /* __KERNEL__ */ 259#endif /* _KOBJECT_H_ */ 260