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 int __must_check kobject_shadow_add(struct kobject *, struct dentry *); 78 extern void kobject_del(struct kobject *); 79 80 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 81 extern int __must_check kobject_shadow_rename(struct kobject *kobj, 82 struct dentry *new_parent, 83 const char *new_name); 84 extern int __must_check kobject_move(struct kobject *, struct kobject *); 85 86 extern int __must_check kobject_register(struct kobject *); 87 extern void kobject_unregister(struct kobject *); 88 89 extern struct kobject * kobject_get(struct kobject *); 90 extern void kobject_put(struct kobject *); 91 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 subsystem * subsys; 129 struct kobj_type * ktype; 130 struct list_head list; 131 spinlock_t list_lock; 132 struct kobject kobj; 133 struct kset_uevent_ops * uevent_ops; 134 }; 135 136 137 extern void kset_init(struct kset * k); 138 extern int __must_check kset_add(struct kset * k); 139 extern int __must_check kset_register(struct kset * k); 140 extern void kset_unregister(struct kset * k); 141 142 static inline struct kset * to_kset(struct kobject * kobj) 143 { 144 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 145 } 146 147 static inline struct kset * kset_get(struct kset * k) 148 { 149 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 150 } 151 152 static inline void kset_put(struct kset * k) 153 { 154 kobject_put(&k->kobj); 155 } 156 157 static inline struct kobj_type * get_ktype(struct kobject * k) 158 { 159 if (k->kset && k->kset->ktype) 160 return k->kset->ktype; 161 else 162 return k->ktype; 163 } 164 165 extern struct kobject * kset_find_obj(struct kset *, const char *); 166 167 168 /** 169 * Use this when initializing an embedded kset with no other 170 * fields to initialize. 171 */ 172 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 173 174 175 176 struct subsystem { 177 struct kset kset; 178 struct rw_semaphore rwsem; 179 }; 180 181 #define decl_subsys(_name,_type,_uevent_ops) \ 182 struct subsystem _name##_subsys = { \ 183 .kset = { \ 184 .kobj = { .name = __stringify(_name) }, \ 185 .ktype = _type, \ 186 .uevent_ops =_uevent_ops, \ 187 } \ 188 } 189 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 190 struct subsystem _varname##_subsys = { \ 191 .kset = { \ 192 .kobj = { .name = __stringify(_name) }, \ 193 .ktype = _type, \ 194 .uevent_ops =_uevent_ops, \ 195 } \ 196 } 197 198 /* The global /sys/kernel/ subsystem for people to chain off of */ 199 extern struct subsystem kernel_subsys; 200 /* The global /sys/hypervisor/ subsystem */ 201 extern struct subsystem hypervisor_subsys; 202 203 /** 204 * Helpers for setting the kset of registered objects. 205 * Often, a registered object belongs to a kset embedded in a 206 * subsystem. These do no magic, just make the resulting code 207 * easier to follow. 208 */ 209 210 /** 211 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 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 ->kobj. 216 */ 217 218 #define kobj_set_kset_s(obj,subsys) \ 219 (obj)->kobj.kset = &(subsys).kset 220 221 /** 222 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 223 * @obj: ptr to some object type. 224 * @subsys: a subsystem object (not a ptr). 225 * 226 * Can be used for any object type with an embedded ->kset. 227 * Sets the kset of @obj's embedded kobject (via its embedded 228 * kset) to @subsys.kset. This makes @obj a member of that 229 * kset. 230 */ 231 232 #define kset_set_kset_s(obj,subsys) \ 233 (obj)->kset.kobj.kset = &(subsys).kset 234 235 /** 236 * subsys_set_kset(obj,subsys) - set kset for subsystem 237 * @obj: ptr to some object type. 238 * @subsys: a subsystem object (not a ptr). 239 * 240 * Can be used for any object type with an embedded ->subsys. 241 * Sets the kset of @obj's kobject to @subsys.kset. This makes 242 * the object a member of that kset. 243 */ 244 245 #define subsys_set_kset(obj,_subsys) \ 246 (obj)->subsys.kset.kobj.kset = &(_subsys).kset 247 248 extern void subsystem_init(struct subsystem *); 249 extern int __must_check subsystem_register(struct subsystem *); 250 extern void subsystem_unregister(struct subsystem *); 251 252 static inline struct subsystem * subsys_get(struct subsystem * s) 253 { 254 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 255 } 256 257 static inline void subsys_put(struct subsystem * s) 258 { 259 kset_put(&s->kset); 260 } 261 262 struct subsys_attribute { 263 struct attribute attr; 264 ssize_t (*show)(struct subsystem *, char *); 265 ssize_t (*store)(struct subsystem *, const char *, size_t); 266 }; 267 268 extern int __must_check subsys_create_file(struct subsystem * , 269 struct subsys_attribute *); 270 271 #if defined(CONFIG_HOTPLUG) 272 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 273 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 274 char *envp[]); 275 276 int add_uevent_var(char **envp, int num_envp, int *cur_index, 277 char *buffer, int buffer_size, int *cur_len, 278 const char *format, ...) 279 __attribute__((format (printf, 7, 8))); 280 #else 281 static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 282 { return 0; } 283 static inline int kobject_uevent_env(struct kobject *kobj, 284 enum kobject_action action, 285 char *envp[]) 286 { return 0; } 287 288 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 289 char *buffer, int buffer_size, int *cur_len, 290 const char *format, ...) 291 { return 0; } 292 #endif 293 294 #endif /* __KERNEL__ */ 295 #endif /* _KOBJECT_H_ */ 296