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 */ 35 extern char uevent_helper[]; 36 37 /* counter to tag the uevent, read only except for the kobject core */ 38 extern u64 uevent_seqnum; 39 40 /* the actions here must match the proper string in lib/kobject_uevent.c */ 41 typedef int __bitwise kobject_action_t; 42 enum 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 53 struct 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 65 extern int kobject_set_name(struct kobject *, const char *, ...) 66 __attribute__((format(printf,2,3))); 67 68 static inline const char * kobject_name(const struct kobject * kobj) 69 { 70 return kobj->k_name; 71 } 72 73 extern void kobject_init(struct kobject *); 74 extern void kobject_cleanup(struct kobject *); 75 76 extern int __must_check kobject_add(struct kobject *); 77 extern void kobject_del(struct kobject *); 78 79 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 80 extern int __must_check kobject_move(struct kobject *, struct kobject *); 81 82 extern int __must_check kobject_register(struct kobject *); 83 extern void kobject_unregister(struct kobject *); 84 85 extern struct kobject * kobject_get(struct kobject *); 86 extern void kobject_put(struct kobject *); 87 88 extern struct kobject *kobject_add_dir(struct kobject *, const char *); 89 90 extern char * kobject_get_path(struct kobject *, gfp_t); 91 92 struct kobj_type { 93 void (*release)(struct kobject *); 94 struct sysfs_ops * sysfs_ops; 95 struct attribute ** default_attrs; 96 }; 97 98 99 /** 100 * kset - a set of kobjects of a specific type, belonging 101 * to a specific subsystem. 102 * 103 * All kobjects of a kset should be embedded in an identical 104 * type. This type may have a descriptor, which the kset points 105 * to. This allows there to exist sets of objects of the same 106 * type in different subsystems. 107 * 108 * A subsystem does not have to be a list of only one type 109 * of object; multiple ksets can belong to one subsystem. All 110 * ksets of a subsystem share the subsystem's lock. 111 * 112 * Each kset can support specific event variables; it can 113 * supress the event generation or add subsystem specific 114 * variables carried with the event. 115 */ 116 struct kset_uevent_ops { 117 int (*filter)(struct kset *kset, struct kobject *kobj); 118 const char *(*name)(struct kset *kset, struct kobject *kobj); 119 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 120 int num_envp, char *buffer, int buffer_size); 121 }; 122 123 struct kset { 124 struct subsystem * subsys; 125 struct kobj_type * ktype; 126 struct list_head list; 127 spinlock_t list_lock; 128 struct kobject kobj; 129 struct kset_uevent_ops * uevent_ops; 130 }; 131 132 133 extern void kset_init(struct kset * k); 134 extern int __must_check kset_add(struct kset * k); 135 extern int __must_check kset_register(struct kset * k); 136 extern void kset_unregister(struct kset * k); 137 138 static inline struct kset * to_kset(struct kobject * kobj) 139 { 140 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 141 } 142 143 static inline struct kset * kset_get(struct kset * k) 144 { 145 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 146 } 147 148 static inline void kset_put(struct kset * k) 149 { 150 kobject_put(&k->kobj); 151 } 152 153 static inline struct kobj_type * get_ktype(struct kobject * k) 154 { 155 if (k->kset && k->kset->ktype) 156 return k->kset->ktype; 157 else 158 return k->ktype; 159 } 160 161 extern struct kobject * kset_find_obj(struct kset *, const char *); 162 163 164 /** 165 * Use this when initializing an embedded kset with no other 166 * fields to initialize. 167 */ 168 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 169 170 171 172 struct subsystem { 173 struct kset kset; 174 struct rw_semaphore rwsem; 175 }; 176 177 #define decl_subsys(_name,_type,_uevent_ops) \ 178 struct subsystem _name##_subsys = { \ 179 .kset = { \ 180 .kobj = { .name = __stringify(_name) }, \ 181 .ktype = _type, \ 182 .uevent_ops =_uevent_ops, \ 183 } \ 184 } 185 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 186 struct subsystem _varname##_subsys = { \ 187 .kset = { \ 188 .kobj = { .name = __stringify(_name) }, \ 189 .ktype = _type, \ 190 .uevent_ops =_uevent_ops, \ 191 } \ 192 } 193 194 /* The global /sys/kernel/ subsystem for people to chain off of */ 195 extern struct subsystem kernel_subsys; 196 /* The global /sys/hypervisor/ subsystem */ 197 extern struct subsystem hypervisor_subsys; 198 199 /** 200 * Helpers for setting the kset of registered objects. 201 * Often, a registered object belongs to a kset embedded in a 202 * subsystem. These do no magic, just make the resulting code 203 * easier to follow. 204 */ 205 206 /** 207 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 208 * @obj: ptr to some object type. 209 * @subsys: a subsystem object (not a ptr). 210 * 211 * Can be used for any object type with an embedded ->kobj. 212 */ 213 214 #define kobj_set_kset_s(obj,subsys) \ 215 (obj)->kobj.kset = &(subsys).kset 216 217 /** 218 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 219 * @obj: ptr to some object type. 220 * @subsys: a subsystem object (not a ptr). 221 * 222 * Can be used for any object type with an embedded ->kset. 223 * Sets the kset of @obj's embedded kobject (via its embedded 224 * kset) to @subsys.kset. This makes @obj a member of that 225 * kset. 226 */ 227 228 #define kset_set_kset_s(obj,subsys) \ 229 (obj)->kset.kobj.kset = &(subsys).kset 230 231 /** 232 * subsys_set_kset(obj,subsys) - set kset for subsystem 233 * @obj: ptr to some object type. 234 * @subsys: a subsystem object (not a ptr). 235 * 236 * Can be used for any object type with an embedded ->subsys. 237 * Sets the kset of @obj's kobject to @subsys.kset. This makes 238 * the object a member of that kset. 239 */ 240 241 #define subsys_set_kset(obj,_subsys) \ 242 (obj)->subsys.kset.kobj.kset = &(_subsys).kset 243 244 extern void subsystem_init(struct subsystem *); 245 extern int __must_check subsystem_register(struct subsystem *); 246 extern void subsystem_unregister(struct subsystem *); 247 248 static inline struct subsystem * subsys_get(struct subsystem * s) 249 { 250 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 251 } 252 253 static inline void subsys_put(struct subsystem * s) 254 { 255 kset_put(&s->kset); 256 } 257 258 struct subsys_attribute { 259 struct attribute attr; 260 ssize_t (*show)(struct subsystem *, char *); 261 ssize_t (*store)(struct subsystem *, const char *, size_t); 262 }; 263 264 extern int __must_check subsys_create_file(struct subsystem * , 265 struct subsys_attribute *); 266 267 #if defined(CONFIG_HOTPLUG) 268 void kobject_uevent(struct kobject *kobj, enum kobject_action action); 269 void kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 270 char *envp[]); 271 272 int add_uevent_var(char **envp, int num_envp, int *cur_index, 273 char *buffer, int buffer_size, int *cur_len, 274 const char *format, ...) 275 __attribute__((format (printf, 7, 8))); 276 #else 277 static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { } 278 static inline void kobject_uevent_env(struct kobject *kobj, 279 enum kobject_action action, 280 char *envp[]) 281 { } 282 283 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 284 char *buffer, int buffer_size, int *cur_len, 285 const char *format, ...) 286 { return 0; } 287 #endif 288 289 #endif /* __KERNEL__ */ 290 #endif /* _KOBJECT_H_ */ 291