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 * Copyright (c) 2006-2008 Greg Kroah-Hartman <[email protected]> 7 * Copyright (c) 2006-2008 Novell Inc. 8 * 9 * This file is released under the GPLv2. 10 * 11 * Please read Documentation/kobject.txt before using the kobject 12 * interface, ESPECIALLY the parts about reference counts and object 13 * destructors. 14 */ 15 16 #ifndef _KOBJECT_H_ 17 #define _KOBJECT_H_ 18 19 #include <linux/types.h> 20 #include <linux/list.h> 21 #include <linux/sysfs.h> 22 #include <linux/compiler.h> 23 #include <linux/spinlock.h> 24 #include <linux/kref.h> 25 #include <linux/kernel.h> 26 #include <linux/wait.h> 27 #include <asm/atomic.h> 28 29 #define KOBJ_NAME_LEN 20 30 #define UEVENT_HELPER_PATH_LEN 256 31 #define UEVENT_NUM_ENVP 32 /* number of env pointers */ 32 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 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 /* 41 * The actions here must match the index to the string array 42 * in lib/kobject_uevent.c 43 * 44 * Do not add new actions here without checking with the driver-core 45 * maintainers. Action strings are not meant to express subsystem 46 * or device specific properties. In most cases you want to send a 47 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 48 * specific variables added to the event environment. 49 */ 50 enum kobject_action { 51 KOBJ_ADD, 52 KOBJ_REMOVE, 53 KOBJ_CHANGE, 54 KOBJ_MOVE, 55 KOBJ_ONLINE, 56 KOBJ_OFFLINE, 57 KOBJ_MAX 58 }; 59 60 struct kobject { 61 const char *name; 62 struct kref kref; 63 struct list_head entry; 64 struct kobject *parent; 65 struct kset *kset; 66 struct kobj_type *ktype; 67 struct sysfs_dirent *sd; 68 unsigned int state_initialized:1; 69 unsigned int state_in_sysfs:1; 70 unsigned int state_add_uevent_sent:1; 71 unsigned int state_remove_uevent_sent:1; 72 }; 73 74 extern int kobject_set_name(struct kobject *kobj, const char *name, ...) 75 __attribute__((format(printf, 2, 3))); 76 77 static inline const char *kobject_name(const struct kobject *kobj) 78 { 79 return kobj->name; 80 } 81 82 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 83 extern int __must_check kobject_add(struct kobject *kobj, 84 struct kobject *parent, 85 const char *fmt, ...); 86 extern int __must_check kobject_init_and_add(struct kobject *kobj, 87 struct kobj_type *ktype, 88 struct kobject *parent, 89 const char *fmt, ...); 90 91 extern void kobject_del(struct kobject *kobj); 92 93 extern struct kobject * __must_check kobject_create(void); 94 extern struct kobject * __must_check kobject_create_and_add(const char *name, 95 struct kobject *parent); 96 97 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 98 extern int __must_check kobject_move(struct kobject *, struct kobject *); 99 100 extern struct kobject *kobject_get(struct kobject *kobj); 101 extern void kobject_put(struct kobject *kobj); 102 103 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 104 105 struct kobj_type { 106 void (*release)(struct kobject *kobj); 107 struct sysfs_ops *sysfs_ops; 108 struct attribute **default_attrs; 109 }; 110 111 struct kobj_uevent_env { 112 char *envp[UEVENT_NUM_ENVP]; 113 int envp_idx; 114 char buf[UEVENT_BUFFER_SIZE]; 115 int buflen; 116 }; 117 118 struct kset_uevent_ops { 119 int (*filter)(struct kset *kset, struct kobject *kobj); 120 const char *(*name)(struct kset *kset, struct kobject *kobj); 121 int (*uevent)(struct kset *kset, struct kobject *kobj, 122 struct kobj_uevent_env *env); 123 }; 124 125 struct kobj_attribute { 126 struct attribute attr; 127 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 128 char *buf); 129 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 130 const char *buf, size_t count); 131 }; 132 133 extern struct sysfs_ops kobj_sysfs_ops; 134 135 /** 136 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 137 * 138 * A kset defines a group of kobjects. They can be individually 139 * different "types" but overall these kobjects all want to be grouped 140 * together and operated on in the same manner. ksets are used to 141 * define the attribute callbacks and other common events that happen to 142 * a kobject. 143 * 144 * @list: the list of all kobjects for this kset 145 * @list_lock: a lock for iterating over the kobjects 146 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 147 * @uevent_ops: the set of uevent operations for this kset. These are 148 * called whenever a kobject has something happen to it so that the kset 149 * can add new environment variables, or filter out the uevents if so 150 * desired. 151 */ 152 struct kset { 153 struct list_head list; 154 spinlock_t list_lock; 155 struct kobject kobj; 156 struct kset_uevent_ops *uevent_ops; 157 }; 158 159 extern void kset_init(struct kset *kset); 160 extern int __must_check kset_register(struct kset *kset); 161 extern void kset_unregister(struct kset *kset); 162 extern struct kset * __must_check kset_create_and_add(const char *name, 163 struct kset_uevent_ops *u, 164 struct kobject *parent_kobj); 165 166 static inline struct kset *to_kset(struct kobject *kobj) 167 { 168 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 169 } 170 171 static inline struct kset *kset_get(struct kset *k) 172 { 173 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 174 } 175 176 static inline void kset_put(struct kset *k) 177 { 178 kobject_put(&k->kobj); 179 } 180 181 static inline struct kobj_type *get_ktype(struct kobject *kobj) 182 { 183 return kobj->ktype; 184 } 185 186 extern struct kobject *kset_find_obj(struct kset *, const char *); 187 188 /* The global /sys/kernel/ kobject for people to chain off of */ 189 extern struct kobject *kernel_kobj; 190 /* The global /sys/hypervisor/ kobject for people to chain off of */ 191 extern struct kobject *hypervisor_kobj; 192 /* The global /sys/power/ kobject for people to chain off of */ 193 extern struct kobject *power_kobj; 194 /* The global /sys/firmware/ kobject for people to chain off of */ 195 extern struct kobject *firmware_kobj; 196 197 #if defined(CONFIG_HOTPLUG) 198 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 199 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 200 char *envp[]); 201 202 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 203 __attribute__((format (printf, 2, 3))); 204 205 int kobject_action_type(const char *buf, size_t count, 206 enum kobject_action *type); 207 #else 208 static inline int kobject_uevent(struct kobject *kobj, 209 enum kobject_action action) 210 { return 0; } 211 static inline int kobject_uevent_env(struct kobject *kobj, 212 enum kobject_action action, 213 char *envp[]) 214 { return 0; } 215 216 static inline int add_uevent_var(struct kobj_uevent_env *env, 217 const char *format, ...) 218 { return 0; } 219 220 static inline int kobject_action_type(const char *buf, size_t count, 221 enum kobject_action *type) 222 { return -EINVAL; } 223 #endif 224 225 #endif /* _KOBJECT_H_ */ 226