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 /* 40 * The actions here must match the index to the string array 41 * in lib/kobject_uevent.c 42 * 43 * Do not add new actions here without checking with the driver-core 44 * maintainers. Action strings are not meant to express subsystem 45 * or device specific properties. In most cases you want to send a 46 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 47 * specific variables added to the event environment. 48 */ 49 enum kobject_action { 50 KOBJ_ADD, 51 KOBJ_REMOVE, 52 KOBJ_CHANGE, 53 KOBJ_MOVE, 54 KOBJ_ONLINE, 55 KOBJ_OFFLINE, 56 KOBJ_MAX 57 }; 58 59 /* The list of strings defining the valid kobject actions as specified above */ 60 extern const char *kobject_actions[]; 61 62 struct kobject { 63 const char * k_name; 64 char name[KOBJ_NAME_LEN]; 65 struct kref kref; 66 struct list_head entry; 67 struct kobject * parent; 68 struct kset * kset; 69 struct kobj_type * ktype; 70 struct sysfs_dirent * sd; 71 wait_queue_head_t poll; 72 }; 73 74 extern int kobject_set_name(struct kobject *, const char *, ...) 75 __attribute__((format(printf,2,3))); 76 77 static inline const char * kobject_name(const struct kobject * kobj) 78 { 79 return kobj->k_name; 80 } 81 82 extern void kobject_init(struct kobject *); 83 extern void kobject_cleanup(struct kobject *); 84 85 extern int __must_check kobject_add(struct kobject *); 86 extern int __must_check kobject_shadow_add(struct kobject *kobj, 87 struct sysfs_dirent *shadow_parent); 88 extern void kobject_del(struct kobject *); 89 90 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 91 extern int __must_check kobject_shadow_rename(struct kobject *kobj, 92 struct sysfs_dirent *new_parent, 93 const char *new_name); 94 extern int __must_check kobject_move(struct kobject *, struct kobject *); 95 96 extern int __must_check kobject_register(struct kobject *); 97 extern void kobject_unregister(struct kobject *); 98 99 extern struct kobject * kobject_get(struct kobject *); 100 extern void kobject_put(struct kobject *); 101 102 extern struct kobject *kobject_kset_add_dir(struct kset *kset, 103 struct kobject *, const char *); 104 extern struct kobject *kobject_add_dir(struct kobject *, const char *); 105 106 extern char * kobject_get_path(struct kobject *, gfp_t); 107 108 struct kobj_type { 109 void (*release)(struct kobject *); 110 struct sysfs_ops * sysfs_ops; 111 struct attribute ** default_attrs; 112 }; 113 114 struct kset_uevent_ops { 115 int (*filter)(struct kset *kset, struct kobject *kobj); 116 const char *(*name)(struct kset *kset, struct kobject *kobj); 117 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 118 int num_envp, char *buffer, int buffer_size); 119 }; 120 121 /* 122 * struct kset - a set of kobjects of a specific type, belonging 123 * to a specific subsystem. 124 * 125 * All kobjects of a kset should be embedded in an identical 126 * type. This type may have a descriptor, which the kset points 127 * to. This allows there to exist sets of objects of the same 128 * type in different subsystems. 129 * 130 * A subsystem does not have to be a list of only one type 131 * of object; multiple ksets can belong to one subsystem. All 132 * ksets of a subsystem share the subsystem's lock. 133 * 134 * Each kset can support specific event variables; it can 135 * supress the event generation or add subsystem specific 136 * variables carried with the event. 137 */ 138 struct kset { 139 struct kobj_type * ktype; 140 struct list_head list; 141 spinlock_t list_lock; 142 struct kobject kobj; 143 struct kset_uevent_ops * uevent_ops; 144 }; 145 146 147 extern void kset_init(struct kset * k); 148 extern int __must_check kset_add(struct kset * k); 149 extern int __must_check kset_register(struct kset * k); 150 extern void kset_unregister(struct kset * k); 151 152 static inline struct kset * to_kset(struct kobject * kobj) 153 { 154 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 155 } 156 157 static inline struct kset * kset_get(struct kset * k) 158 { 159 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 160 } 161 162 static inline void kset_put(struct kset * k) 163 { 164 kobject_put(&k->kobj); 165 } 166 167 static inline struct kobj_type * get_ktype(struct kobject * k) 168 { 169 if (k->kset && k->kset->ktype) 170 return k->kset->ktype; 171 else 172 return k->ktype; 173 } 174 175 extern struct kobject * kset_find_obj(struct kset *, const char *); 176 177 178 /* 179 * Use this when initializing an embedded kset with no other 180 * fields to initialize. 181 */ 182 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 183 184 185 #define decl_subsys(_name,_type,_uevent_ops) \ 186 struct kset _name##_subsys = { \ 187 .kobj = { .name = __stringify(_name) }, \ 188 .ktype = _type, \ 189 .uevent_ops =_uevent_ops, \ 190 } 191 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 192 struct kset _varname##_subsys = { \ 193 .kobj = { .name = __stringify(_name) }, \ 194 .ktype = _type, \ 195 .uevent_ops =_uevent_ops, \ 196 } 197 198 /* The global /sys/kernel/ subsystem for people to chain off of */ 199 extern struct kset kernel_subsys; 200 /* The global /sys/hypervisor/ subsystem */ 201 extern struct kset 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) 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) 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.kobj.kset = &(_subsys) 247 248 extern void subsystem_init(struct kset *); 249 extern int __must_check subsystem_register(struct kset *); 250 extern void subsystem_unregister(struct kset *); 251 252 static inline struct kset *subsys_get(struct kset *s) 253 { 254 if (s) 255 return kset_get(s); 256 return NULL; 257 } 258 259 static inline void subsys_put(struct kset *s) 260 { 261 kset_put(s); 262 } 263 264 struct subsys_attribute { 265 struct attribute attr; 266 ssize_t (*show)(struct kset *, char *); 267 ssize_t (*store)(struct kset *, const char *, size_t); 268 }; 269 270 extern int __must_check subsys_create_file(struct kset *, 271 struct subsys_attribute *); 272 273 #if defined(CONFIG_HOTPLUG) 274 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 275 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 276 char *envp[]); 277 278 int add_uevent_var(char **envp, int num_envp, int *cur_index, 279 char *buffer, int buffer_size, int *cur_len, 280 const char *format, ...) 281 __attribute__((format (printf, 7, 8))); 282 #else 283 static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action) 284 { return 0; } 285 static inline int kobject_uevent_env(struct kobject *kobj, 286 enum kobject_action action, 287 char *envp[]) 288 { return 0; } 289 290 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 291 char *buffer, int buffer_size, int *cur_len, 292 const char *format, ...) 293 { return 0; } 294 #endif 295 296 #endif /* __KERNEL__ */ 297 #endif /* _KOBJECT_H_ */ 298