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/spinlock.h> 24 #include <linux/rwsem.h> 25 #include <linux/kref.h> 26 #include <linux/kernel.h> 27 #include <asm/atomic.h> 28 29 #define KOBJ_NAME_LEN 20 30 #define UEVENT_HELPER_PATH_LEN 256 31 32 /* path to the userspace helper executed on an event */ 33 extern char uevent_helper[]; 34 35 /* counter to tag the uevent, read only except for the kobject core */ 36 extern u64 uevent_seqnum; 37 38 /* the actions here must match the proper string in lib/kobject_uevent.c */ 39 typedef int __bitwise kobject_action_t; 40 enum kobject_action { 41 KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */ 42 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */ 43 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */ 44 KOBJ_MOUNT = (__force kobject_action_t) 0x04, /* mount event for block devices (broken) */ 45 KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */ 46 KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */ 47 KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */ 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 dentry * dentry; 59 }; 60 61 extern int kobject_set_name(struct kobject *, const char *, ...) 62 __attribute__((format(printf,2,3))); 63 64 static inline const char * kobject_name(const struct kobject * kobj) 65 { 66 return kobj->k_name; 67 } 68 69 extern void kobject_init(struct kobject *); 70 extern void kobject_cleanup(struct kobject *); 71 72 extern int kobject_add(struct kobject *); 73 extern void kobject_del(struct kobject *); 74 75 extern int kobject_rename(struct kobject *, const char *new_name); 76 77 extern int kobject_register(struct kobject *); 78 extern void kobject_unregister(struct kobject *); 79 80 extern struct kobject * kobject_get(struct kobject *); 81 extern void kobject_put(struct kobject *); 82 83 extern struct kobject *kobject_add_dir(struct kobject *, const char *); 84 85 extern char * kobject_get_path(struct kobject *, gfp_t); 86 87 struct kobj_type { 88 void (*release)(struct kobject *); 89 struct sysfs_ops * sysfs_ops; 90 struct attribute ** default_attrs; 91 }; 92 93 94 /** 95 * kset - a set of kobjects of a specific type, belonging 96 * to a specific subsystem. 97 * 98 * All kobjects of a kset should be embedded in an identical 99 * type. This type may have a descriptor, which the kset points 100 * to. This allows there to exist sets of objects of the same 101 * type in different subsystems. 102 * 103 * A subsystem does not have to be a list of only one type 104 * of object; multiple ksets can belong to one subsystem. All 105 * ksets of a subsystem share the subsystem's lock. 106 * 107 * Each kset can support specific event variables; it can 108 * supress the event generation or add subsystem specific 109 * variables carried with the event. 110 */ 111 struct kset_uevent_ops { 112 int (*filter)(struct kset *kset, struct kobject *kobj); 113 const char *(*name)(struct kset *kset, struct kobject *kobj); 114 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 115 int num_envp, char *buffer, int buffer_size); 116 }; 117 118 struct kset { 119 struct subsystem * subsys; 120 struct kobj_type * ktype; 121 struct list_head list; 122 spinlock_t list_lock; 123 struct kobject kobj; 124 struct kset_uevent_ops * uevent_ops; 125 }; 126 127 128 extern void kset_init(struct kset * k); 129 extern int kset_add(struct kset * k); 130 extern int kset_register(struct kset * k); 131 extern void kset_unregister(struct kset * k); 132 133 static inline struct kset * to_kset(struct kobject * kobj) 134 { 135 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 136 } 137 138 static inline struct kset * kset_get(struct kset * k) 139 { 140 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 141 } 142 143 static inline void kset_put(struct kset * k) 144 { 145 kobject_put(&k->kobj); 146 } 147 148 static inline struct kobj_type * get_ktype(struct kobject * k) 149 { 150 if (k->kset && k->kset->ktype) 151 return k->kset->ktype; 152 else 153 return k->ktype; 154 } 155 156 extern struct kobject * kset_find_obj(struct kset *, const char *); 157 158 159 /** 160 * Use this when initializing an embedded kset with no other 161 * fields to initialize. 162 */ 163 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 164 165 166 167 struct subsystem { 168 struct kset kset; 169 struct rw_semaphore rwsem; 170 }; 171 172 #define decl_subsys(_name,_type,_uevent_ops) \ 173 struct subsystem _name##_subsys = { \ 174 .kset = { \ 175 .kobj = { .name = __stringify(_name) }, \ 176 .ktype = _type, \ 177 .uevent_ops =_uevent_ops, \ 178 } \ 179 } 180 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 181 struct subsystem _varname##_subsys = { \ 182 .kset = { \ 183 .kobj = { .name = __stringify(_name) }, \ 184 .ktype = _type, \ 185 .uevent_ops =_uevent_ops, \ 186 } \ 187 } 188 189 /* The global /sys/kernel/ subsystem for people to chain off of */ 190 extern struct subsystem kernel_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).kset 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).kset 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.kset.kobj.kset = &(_subsys).kset 236 237 extern void subsystem_init(struct subsystem *); 238 extern int subsystem_register(struct subsystem *); 239 extern void subsystem_unregister(struct subsystem *); 240 241 static inline struct subsystem * subsys_get(struct subsystem * s) 242 { 243 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 244 } 245 246 static inline void subsys_put(struct subsystem * s) 247 { 248 kset_put(&s->kset); 249 } 250 251 struct subsys_attribute { 252 struct attribute attr; 253 ssize_t (*show)(struct subsystem *, char *); 254 ssize_t (*store)(struct subsystem *, const char *, size_t); 255 }; 256 257 extern int subsys_create_file(struct subsystem * , struct subsys_attribute *); 258 extern void subsys_remove_file(struct subsystem * , struct subsys_attribute *); 259 260 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) 261 void kobject_uevent(struct kobject *kobj, enum kobject_action action); 262 263 int add_uevent_var(char **envp, int num_envp, int *cur_index, 264 char *buffer, int buffer_size, int *cur_len, 265 const char *format, ...) 266 __attribute__((format (printf, 7, 8))); 267 #else 268 static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { } 269 270 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 271 char *buffer, int buffer_size, int *cur_len, 272 const char *format, ...) 273 { return 0; } 274 #endif 275 276 #endif /* __KERNEL__ */ 277 #endif /* _KOBJECT_H_ */ 278