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 */ 34 extern char uevent_helper[]; 35 36 /* counter to tag the uevent, read only except for the kobject core */ 37 extern u64 uevent_seqnum; 38 39 /* the actions here must match the proper string in lib/kobject_uevent.c */ 40 typedef int __bitwise kobject_action_t; 41 enum 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 50 struct 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 sysfs_dirent * sd; 59 wait_queue_head_t poll; 60 }; 61 62 extern int kobject_set_name(struct kobject *, const char *, ...) 63 __attribute__((format(printf,2,3))); 64 65 static inline const char * kobject_name(const struct kobject * kobj) 66 { 67 return kobj->k_name; 68 } 69 70 extern void kobject_init(struct kobject *); 71 extern void kobject_cleanup(struct kobject *); 72 73 extern int __must_check kobject_add(struct kobject *); 74 extern int __must_check kobject_shadow_add(struct kobject *kobj, 75 struct sysfs_dirent *shadow_parent); 76 extern void kobject_del(struct kobject *); 77 78 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 79 extern int __must_check kobject_shadow_rename(struct kobject *kobj, 80 struct sysfs_dirent *new_parent, 81 const char *new_name); 82 extern int __must_check kobject_move(struct kobject *, struct kobject *); 83 84 extern int __must_check kobject_register(struct kobject *); 85 extern void kobject_unregister(struct kobject *); 86 87 extern struct kobject * kobject_get(struct kobject *); 88 extern void kobject_put(struct kobject *); 89 90 extern struct kobject *kobject_kset_add_dir(struct kset *kset, 91 struct kobject *, const char *); 92 extern struct kobject *kobject_add_dir(struct kobject *, const char *); 93 94 extern char * kobject_get_path(struct kobject *, gfp_t); 95 96 struct kobj_type { 97 void (*release)(struct kobject *); 98 struct sysfs_ops * sysfs_ops; 99 struct attribute ** default_attrs; 100 }; 101 102 103 /** 104 * kset - a set of kobjects of a specific type, belonging 105 * to a specific subsystem. 106 * 107 * All kobjects of a kset should be embedded in an identical 108 * type. This type may have a descriptor, which the kset points 109 * to. This allows there to exist sets of objects of the same 110 * type in different subsystems. 111 * 112 * A subsystem does not have to be a list of only one type 113 * of object; multiple ksets can belong to one subsystem. All 114 * ksets of a subsystem share the subsystem's lock. 115 * 116 * Each kset can support specific event variables; it can 117 * supress the event generation or add subsystem specific 118 * variables carried with the event. 119 */ 120 struct kset_uevent_ops { 121 int (*filter)(struct kset *kset, struct kobject *kobj); 122 const char *(*name)(struct kset *kset, struct kobject *kobj); 123 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 124 int num_envp, char *buffer, int buffer_size); 125 }; 126 127 struct kset { 128 struct kobj_type * ktype; 129 struct list_head list; 130 spinlock_t list_lock; 131 struct kobject kobj; 132 struct kset_uevent_ops * uevent_ops; 133 }; 134 135 136 extern void kset_init(struct kset * k); 137 extern int __must_check kset_add(struct kset * k); 138 extern int __must_check kset_register(struct kset * k); 139 extern void kset_unregister(struct kset * k); 140 141 static inline struct kset * to_kset(struct kobject * kobj) 142 { 143 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 144 } 145 146 static inline struct kset * kset_get(struct kset * k) 147 { 148 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 149 } 150 151 static inline void kset_put(struct kset * k) 152 { 153 kobject_put(&k->kobj); 154 } 155 156 static inline struct kobj_type * get_ktype(struct kobject * k) 157 { 158 if (k->kset && k->kset->ktype) 159 return k->kset->ktype; 160 else 161 return k->ktype; 162 } 163 164 extern struct kobject * kset_find_obj(struct kset *, const char *); 165 166 167 /** 168 * Use this when initializing an embedded kset with no other 169 * fields to initialize. 170 */ 171 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 172 173 174 #define decl_subsys(_name,_type,_uevent_ops) \ 175 struct kset _name##_subsys = { \ 176 .kobj = { .name = __stringify(_name) }, \ 177 .ktype = _type, \ 178 .uevent_ops =_uevent_ops, \ 179 } 180 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 181 struct kset _varname##_subsys = { \ 182 .kobj = { .name = __stringify(_name) }, \ 183 .ktype = _type, \ 184 .uevent_ops =_uevent_ops, \ 185 } 186 187 /* The global /sys/kernel/ subsystem for people to chain off of */ 188 extern struct kset kernel_subsys; 189 /* The global /sys/hypervisor/ subsystem */ 190 extern struct kset hypervisor_subsys; 191 192 /** 193 * Helpers for setting the kset of registered objects. 194 * Often, a registered object belongs to a kset embedded in a 195 * subsystem. These do no magic, just make the resulting code 196 * easier to follow. 197 */ 198 199 /** 200 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 201 * @obj: ptr to some object type. 202 * @subsys: a subsystem object (not a ptr). 203 * 204 * Can be used for any object type with an embedded ->kobj. 205 */ 206 207 #define kobj_set_kset_s(obj,subsys) \ 208 (obj)->kobj.kset = &(subsys) 209 210 /** 211 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 212 * @obj: ptr to some object type. 213 * @subsys: a subsystem object (not a ptr). 214 * 215 * Can be used for any object type with an embedded ->kset. 216 * Sets the kset of @obj's embedded kobject (via its embedded 217 * kset) to @subsys.kset. This makes @obj a member of that 218 * kset. 219 */ 220 221 #define kset_set_kset_s(obj,subsys) \ 222 (obj)->kset.kobj.kset = &(subsys) 223 224 /** 225 * subsys_set_kset(obj,subsys) - set kset for subsystem 226 * @obj: ptr to some object type. 227 * @subsys: a subsystem object (not a ptr). 228 * 229 * Can be used for any object type with an embedded ->subsys. 230 * Sets the kset of @obj's kobject to @subsys.kset. This makes 231 * the object a member of that kset. 232 */ 233 234 #define subsys_set_kset(obj,_subsys) \ 235 (obj)->subsys.kobj.kset = &(_subsys) 236 237 extern void subsystem_init(struct kset *); 238 extern int __must_check subsystem_register(struct kset *); 239 extern void subsystem_unregister(struct kset *); 240 241 static inline struct kset *subsys_get(struct kset *s) 242 { 243 if (s) 244 return kset_get(s); 245 return NULL; 246 } 247 248 static inline void subsys_put(struct kset *s) 249 { 250 kset_put(s); 251 } 252 253 struct subsys_attribute { 254 struct attribute attr; 255 ssize_t (*show)(struct kset *, char *); 256 ssize_t (*store)(struct kset *, const char *, size_t); 257 }; 258 259 extern int __must_check subsys_create_file(struct kset *, 260 struct subsys_attribute *); 261 262 #if defined(CONFIG_HOTPLUG) 263 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 264 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 265 char *envp[]); 266 267 int add_uevent_var(char **envp, int num_envp, int *cur_index, 268 char *buffer, int buffer_size, int *cur_len, 269 const char *format, ...) 270 __attribute__((format (printf, 7, 8))); 271 #else 272 static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 273 { return 0; } 274 static inline int kobject_uevent_env(struct kobject *kobj, 275 enum kobject_action action, 276 char *envp[]) 277 { return 0; } 278 279 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 280 char *buffer, int buffer_size, int *cur_len, 281 const char *format, ...) 282 { return 0; } 283 #endif 284 285 #endif /* __KERNEL__ */ 286 #endif /* _KOBJECT_H_ */ 287