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_OFFLINE = (__force kobject_action_t) 0x04, /* device offline */ 45 KOBJ_ONLINE = (__force kobject_action_t) 0x05, /* device online */ 46 }; 47 48 struct kobject { 49 const char * k_name; 50 char name[KOBJ_NAME_LEN]; 51 struct kref kref; 52 struct list_head entry; 53 struct kobject * parent; 54 struct kset * kset; 55 struct kobj_type * ktype; 56 struct dentry * dentry; 57 }; 58 59 extern int kobject_set_name(struct kobject *, const char *, ...) 60 __attribute__((format(printf,2,3))); 61 62 static inline const char * kobject_name(const struct kobject * kobj) 63 { 64 return kobj->k_name; 65 } 66 67 extern void kobject_init(struct kobject *); 68 extern void kobject_cleanup(struct kobject *); 69 70 extern int kobject_add(struct kobject *); 71 extern void kobject_del(struct kobject *); 72 73 extern int kobject_rename(struct kobject *, const char *new_name); 74 75 extern int kobject_register(struct kobject *); 76 extern void kobject_unregister(struct kobject *); 77 78 extern struct kobject * kobject_get(struct kobject *); 79 extern void kobject_put(struct kobject *); 80 81 extern char * kobject_get_path(struct kobject *, gfp_t); 82 83 struct kobj_type { 84 void (*release)(struct kobject *); 85 struct sysfs_ops * sysfs_ops; 86 struct attribute ** default_attrs; 87 }; 88 89 90 /** 91 * kset - a set of kobjects of a specific type, belonging 92 * to a specific subsystem. 93 * 94 * All kobjects of a kset should be embedded in an identical 95 * type. This type may have a descriptor, which the kset points 96 * to. This allows there to exist sets of objects of the same 97 * type in different subsystems. 98 * 99 * A subsystem does not have to be a list of only one type 100 * of object; multiple ksets can belong to one subsystem. All 101 * ksets of a subsystem share the subsystem's lock. 102 * 103 * Each kset can support specific event variables; it can 104 * supress the event generation or add subsystem specific 105 * variables carried with the event. 106 */ 107 struct kset_uevent_ops { 108 int (*filter)(struct kset *kset, struct kobject *kobj); 109 const char *(*name)(struct kset *kset, struct kobject *kobj); 110 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 111 int num_envp, char *buffer, int buffer_size); 112 }; 113 114 struct kset { 115 struct subsystem * subsys; 116 struct kobj_type * ktype; 117 struct list_head list; 118 spinlock_t list_lock; 119 struct kobject kobj; 120 struct kset_uevent_ops * uevent_ops; 121 }; 122 123 124 extern void kset_init(struct kset * k); 125 extern int kset_add(struct kset * k); 126 extern int kset_register(struct kset * k); 127 extern void kset_unregister(struct kset * k); 128 129 static inline struct kset * to_kset(struct kobject * kobj) 130 { 131 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 132 } 133 134 static inline struct kset * kset_get(struct kset * k) 135 { 136 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 137 } 138 139 static inline void kset_put(struct kset * k) 140 { 141 kobject_put(&k->kobj); 142 } 143 144 static inline struct kobj_type * get_ktype(struct kobject * k) 145 { 146 if (k->kset && k->kset->ktype) 147 return k->kset->ktype; 148 else 149 return k->ktype; 150 } 151 152 extern struct kobject * kset_find_obj(struct kset *, const char *); 153 154 155 /** 156 * Use this when initializing an embedded kset with no other 157 * fields to initialize. 158 */ 159 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 160 161 162 163 struct subsystem { 164 struct kset kset; 165 struct rw_semaphore rwsem; 166 }; 167 168 #define decl_subsys(_name,_type,_uevent_ops) \ 169 struct subsystem _name##_subsys = { \ 170 .kset = { \ 171 .kobj = { .name = __stringify(_name) }, \ 172 .ktype = _type, \ 173 .uevent_ops =_uevent_ops, \ 174 } \ 175 } 176 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 177 struct subsystem _varname##_subsys = { \ 178 .kset = { \ 179 .kobj = { .name = __stringify(_name) }, \ 180 .ktype = _type, \ 181 .uevent_ops =_uevent_ops, \ 182 } \ 183 } 184 185 /* The global /sys/kernel/ subsystem for people to chain off of */ 186 extern struct subsystem kernel_subsys; 187 188 /** 189 * Helpers for setting the kset of registered objects. 190 * Often, a registered object belongs to a kset embedded in a 191 * subsystem. These do no magic, just make the resulting code 192 * easier to follow. 193 */ 194 195 /** 196 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 197 * @obj: ptr to some object type. 198 * @subsys: a subsystem object (not a ptr). 199 * 200 * Can be used for any object type with an embedded ->kobj. 201 */ 202 203 #define kobj_set_kset_s(obj,subsys) \ 204 (obj)->kobj.kset = &(subsys).kset 205 206 /** 207 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 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 ->kset. 212 * Sets the kset of @obj's embedded kobject (via its embedded 213 * kset) to @subsys.kset. This makes @obj a member of that 214 * kset. 215 */ 216 217 #define kset_set_kset_s(obj,subsys) \ 218 (obj)->kset.kobj.kset = &(subsys).kset 219 220 /** 221 * subsys_set_kset(obj,subsys) - set kset for subsystem 222 * @obj: ptr to some object type. 223 * @subsys: a subsystem object (not a ptr). 224 * 225 * Can be used for any object type with an embedded ->subsys. 226 * Sets the kset of @obj's kobject to @subsys.kset. This makes 227 * the object a member of that kset. 228 */ 229 230 #define subsys_set_kset(obj,_subsys) \ 231 (obj)->subsys.kset.kobj.kset = &(_subsys).kset 232 233 extern void subsystem_init(struct subsystem *); 234 extern int subsystem_register(struct subsystem *); 235 extern void subsystem_unregister(struct subsystem *); 236 237 static inline struct subsystem * subsys_get(struct subsystem * s) 238 { 239 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 240 } 241 242 static inline void subsys_put(struct subsystem * s) 243 { 244 kset_put(&s->kset); 245 } 246 247 struct subsys_attribute { 248 struct attribute attr; 249 ssize_t (*show)(struct subsystem *, char *); 250 ssize_t (*store)(struct subsystem *, const char *, size_t); 251 }; 252 253 extern int subsys_create_file(struct subsystem * , struct subsys_attribute *); 254 extern void subsys_remove_file(struct subsystem * , struct subsys_attribute *); 255 256 #if defined(CONFIG_HOTPLUG) & defined(CONFIG_NET) 257 void kobject_uevent(struct kobject *kobj, enum kobject_action action); 258 259 int add_uevent_var(char **envp, int num_envp, int *cur_index, 260 char *buffer, int buffer_size, int *cur_len, 261 const char *format, ...) 262 __attribute__((format (printf, 7, 8))); 263 #else 264 static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { } 265 266 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 267 char *buffer, int buffer_size, int *cur_len, 268 const char *format, ...) 269 { return 0; } 270 #endif 271 272 #endif /* __KERNEL__ */ 273 #endif /* _KOBJECT_H_ */ 274