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 <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 /* the actions here must match the proper string in lib/kobject_uevent.c */ 40 typedef int __bitwise kobject_action_t; 41 enum kobject_action { 42 KOBJ_ADD = (__force kobject_action_t) 0x01, /* exclusive to core */ 43 KOBJ_REMOVE = (__force kobject_action_t) 0x02, /* exclusive to core */ 44 KOBJ_CHANGE = (__force kobject_action_t) 0x03, /* device state change */ 45 KOBJ_MOUNT = (__force kobject_action_t) 0x04, /* mount event for block devices (broken) */ 46 KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */ 47 KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */ 48 KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */ 49 }; 50 51 struct kobject { 52 const char * k_name; 53 char name[KOBJ_NAME_LEN]; 54 struct kref kref; 55 struct list_head entry; 56 struct kobject * parent; 57 struct kset * kset; 58 struct kobj_type * ktype; 59 struct dentry * dentry; 60 wait_queue_head_t poll; 61 }; 62 63 extern int kobject_set_name(struct kobject *, const char *, ...) 64 __attribute__((format(printf,2,3))); 65 66 static inline const char * kobject_name(const struct kobject * kobj) 67 { 68 return kobj->k_name; 69 } 70 71 extern void kobject_init(struct kobject *); 72 extern void kobject_cleanup(struct kobject *); 73 74 extern int kobject_add(struct kobject *); 75 extern void kobject_del(struct kobject *); 76 77 extern int kobject_rename(struct kobject *, const char *new_name); 78 79 extern int kobject_register(struct kobject *); 80 extern void kobject_unregister(struct kobject *); 81 82 extern struct kobject * kobject_get(struct kobject *); 83 extern void kobject_put(struct kobject *); 84 85 extern struct kobject *kobject_add_dir(struct kobject *, const char *); 86 87 extern char * kobject_get_path(struct kobject *, gfp_t); 88 89 struct kobj_type { 90 void (*release)(struct kobject *); 91 struct sysfs_ops * sysfs_ops; 92 struct attribute ** default_attrs; 93 }; 94 95 96 /** 97 * kset - a set of kobjects of a specific type, belonging 98 * to a specific subsystem. 99 * 100 * All kobjects of a kset should be embedded in an identical 101 * type. This type may have a descriptor, which the kset points 102 * to. This allows there to exist sets of objects of the same 103 * type in different subsystems. 104 * 105 * A subsystem does not have to be a list of only one type 106 * of object; multiple ksets can belong to one subsystem. All 107 * ksets of a subsystem share the subsystem's lock. 108 * 109 * Each kset can support specific event variables; it can 110 * supress the event generation or add subsystem specific 111 * variables carried with the event. 112 */ 113 struct kset_uevent_ops { 114 int (*filter)(struct kset *kset, struct kobject *kobj); 115 const char *(*name)(struct kset *kset, struct kobject *kobj); 116 int (*uevent)(struct kset *kset, struct kobject *kobj, char **envp, 117 int num_envp, char *buffer, int buffer_size); 118 }; 119 120 struct kset { 121 struct subsystem * subsys; 122 struct kobj_type * ktype; 123 struct list_head list; 124 spinlock_t list_lock; 125 struct kobject kobj; 126 struct kset_uevent_ops * uevent_ops; 127 }; 128 129 130 extern void kset_init(struct kset * k); 131 extern int kset_add(struct kset * k); 132 extern int kset_register(struct kset * k); 133 extern void kset_unregister(struct kset * k); 134 135 static inline struct kset * to_kset(struct kobject * kobj) 136 { 137 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 138 } 139 140 static inline struct kset * kset_get(struct kset * k) 141 { 142 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 143 } 144 145 static inline void kset_put(struct kset * k) 146 { 147 kobject_put(&k->kobj); 148 } 149 150 static inline struct kobj_type * get_ktype(struct kobject * k) 151 { 152 if (k->kset && k->kset->ktype) 153 return k->kset->ktype; 154 else 155 return k->ktype; 156 } 157 158 extern struct kobject * kset_find_obj(struct kset *, const char *); 159 160 161 /** 162 * Use this when initializing an embedded kset with no other 163 * fields to initialize. 164 */ 165 #define set_kset_name(str) .kset = { .kobj = { .name = str } } 166 167 168 169 struct subsystem { 170 struct kset kset; 171 struct rw_semaphore rwsem; 172 }; 173 174 #define decl_subsys(_name,_type,_uevent_ops) \ 175 struct subsystem _name##_subsys = { \ 176 .kset = { \ 177 .kobj = { .name = __stringify(_name) }, \ 178 .ktype = _type, \ 179 .uevent_ops =_uevent_ops, \ 180 } \ 181 } 182 #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ 183 struct subsystem _varname##_subsys = { \ 184 .kset = { \ 185 .kobj = { .name = __stringify(_name) }, \ 186 .ktype = _type, \ 187 .uevent_ops =_uevent_ops, \ 188 } \ 189 } 190 191 /* The global /sys/kernel/ subsystem for people to chain off of */ 192 extern struct subsystem kernel_subsys; 193 /* The global /sys/hypervisor/ subsystem */ 194 extern struct subsystem hypervisor_subsys; 195 196 /** 197 * Helpers for setting the kset of registered objects. 198 * Often, a registered object belongs to a kset embedded in a 199 * subsystem. These do no magic, just make the resulting code 200 * easier to follow. 201 */ 202 203 /** 204 * kobj_set_kset_s(obj,subsys) - set kset for embedded kobject. 205 * @obj: ptr to some object type. 206 * @subsys: a subsystem object (not a ptr). 207 * 208 * Can be used for any object type with an embedded ->kobj. 209 */ 210 211 #define kobj_set_kset_s(obj,subsys) \ 212 (obj)->kobj.kset = &(subsys).kset 213 214 /** 215 * kset_set_kset_s(obj,subsys) - set kset for embedded kset. 216 * @obj: ptr to some object type. 217 * @subsys: a subsystem object (not a ptr). 218 * 219 * Can be used for any object type with an embedded ->kset. 220 * Sets the kset of @obj's embedded kobject (via its embedded 221 * kset) to @subsys.kset. This makes @obj a member of that 222 * kset. 223 */ 224 225 #define kset_set_kset_s(obj,subsys) \ 226 (obj)->kset.kobj.kset = &(subsys).kset 227 228 /** 229 * subsys_set_kset(obj,subsys) - set kset for subsystem 230 * @obj: ptr to some object type. 231 * @subsys: a subsystem object (not a ptr). 232 * 233 * Can be used for any object type with an embedded ->subsys. 234 * Sets the kset of @obj's kobject to @subsys.kset. This makes 235 * the object a member of that kset. 236 */ 237 238 #define subsys_set_kset(obj,_subsys) \ 239 (obj)->subsys.kset.kobj.kset = &(_subsys).kset 240 241 extern void subsystem_init(struct subsystem *); 242 extern int subsystem_register(struct subsystem *); 243 extern void subsystem_unregister(struct subsystem *); 244 245 static inline struct subsystem * subsys_get(struct subsystem * s) 246 { 247 return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL; 248 } 249 250 static inline void subsys_put(struct subsystem * s) 251 { 252 kset_put(&s->kset); 253 } 254 255 struct subsys_attribute { 256 struct attribute attr; 257 ssize_t (*show)(struct subsystem *, char *); 258 ssize_t (*store)(struct subsystem *, const char *, size_t); 259 }; 260 261 extern int subsys_create_file(struct subsystem * , struct subsys_attribute *); 262 263 #if defined(CONFIG_HOTPLUG) 264 void kobject_uevent(struct kobject *kobj, enum kobject_action action); 265 266 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 __attribute__((format (printf, 7, 8))); 270 #else 271 static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { } 272 273 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index, 274 char *buffer, int buffer_size, int *cur_len, 275 const char *format, ...) 276 { return 0; } 277 #endif 278 279 #endif /* __KERNEL__ */ 280 #endif /* _KOBJECT_H_ */ 281
