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 #ifdef __KERNEL__ 20 21 #include <linux/types.h> 22 #include <linux/list.h> 23 #include <linux/sysfs.h> 24 #include <linux/compiler.h> 25 #include <linux/spinlock.h> 26 #include <linux/kref.h> 27 #include <linux/kernel.h> 28 #include <linux/wait.h> 29 #include <asm/atomic.h> 30 31 #define KOBJ_NAME_LEN 20 32 #define UEVENT_HELPER_PATH_LEN 256 33 #define UEVENT_NUM_ENVP 32 /* number of env pointers */ 34 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 35 36 /* path to the userspace helper executed on an event */ 37 extern char uevent_helper[]; 38 39 /* counter to tag the uevent, read only except for the kobject core */ 40 extern u64 uevent_seqnum; 41 42 /* 43 * The actions here must match the index to the string array 44 * in lib/kobject_uevent.c 45 * 46 * Do not add new actions here without checking with the driver-core 47 * maintainers. Action strings are not meant to express subsystem 48 * or device specific properties. In most cases you want to send a 49 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 50 * specific variables added to the event environment. 51 */ 52 enum kobject_action { 53 KOBJ_ADD, 54 KOBJ_REMOVE, 55 KOBJ_CHANGE, 56 KOBJ_MOVE, 57 KOBJ_ONLINE, 58 KOBJ_OFFLINE, 59 KOBJ_MAX 60 }; 61 62 struct kobject { 63 const char *name; 64 struct kref kref; 65 struct list_head entry; 66 struct kobject *parent; 67 struct kset *kset; 68 struct kobj_type *ktype; 69 struct sysfs_dirent *sd; 70 unsigned int state_initialized:1; 71 unsigned int state_in_sysfs:1; 72 unsigned int state_add_uevent_sent:1; 73 unsigned int state_remove_uevent_sent:1; 74 }; 75 76 extern int kobject_set_name(struct kobject *kobj, const char *name, ...) 77 __attribute__((format(printf, 2, 3))); 78 79 static inline const char *kobject_name(const struct kobject *kobj) 80 { 81 return kobj->name; 82 } 83 84 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 85 extern int __must_check kobject_add(struct kobject *kobj, 86 struct kobject *parent, 87 const char *fmt, ...); 88 extern int __must_check kobject_init_and_add(struct kobject *kobj, 89 struct kobj_type *ktype, 90 struct kobject *parent, 91 const char *fmt, ...); 92 93 extern void kobject_del(struct kobject *kobj); 94 95 extern struct kobject * __must_check kobject_create(void); 96 extern struct kobject * __must_check kobject_create_and_add(const char *name, 97 struct kobject *parent); 98 99 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 100 extern int __must_check kobject_move(struct kobject *, struct kobject *); 101 102 extern struct kobject *kobject_get(struct kobject *kobj); 103 extern void kobject_put(struct kobject *kobj); 104 105 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 106 107 struct kobj_type { 108 void (*release)(struct kobject *kobj); 109 struct sysfs_ops *sysfs_ops; 110 struct attribute **default_attrs; 111 }; 112 113 struct kobj_uevent_env { 114 char *envp[UEVENT_NUM_ENVP]; 115 int envp_idx; 116 char buf[UEVENT_BUFFER_SIZE]; 117 int buflen; 118 }; 119 120 struct kset_uevent_ops { 121 int (*filter)(struct kset *kset, struct kobject *kobj); 122 const char *(*name)(struct kset *kset, struct kobject *kobj); 123 int (*uevent)(struct kset *kset, struct kobject *kobj, 124 struct kobj_uevent_env *env); 125 }; 126 127 struct kobj_attribute { 128 struct attribute attr; 129 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 130 char *buf); 131 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 132 const char *buf, size_t count); 133 }; 134 135 extern struct sysfs_ops kobj_sysfs_ops; 136 137 /** 138 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 139 * 140 * A kset defines a group of kobjects. They can be individually 141 * different "types" but overall these kobjects all want to be grouped 142 * together and operated on in the same manner. ksets are used to 143 * define the attribute callbacks and other common events that happen to 144 * a kobject. 145 * 146 * @list: the list of all kobjects for this kset 147 * @list_lock: a lock for iterating over the kobjects 148 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 149 * @uevent_ops: the set of uevent operations for this kset. These are 150 * called whenever a kobject has something happen to it so that the kset 151 * can add new environment variables, or filter out the uevents if so 152 * desired. 153 */ 154 struct kset { 155 struct list_head list; 156 spinlock_t list_lock; 157 struct kobject kobj; 158 struct kset_uevent_ops *uevent_ops; 159 }; 160 161 extern void kset_init(struct kset *kset); 162 extern int __must_check kset_register(struct kset *kset); 163 extern void kset_unregister(struct kset *kset); 164 extern struct kset * __must_check kset_create_and_add(const char *name, 165 struct kset_uevent_ops *u, 166 struct kobject *parent_kobj); 167 168 static inline struct kset *to_kset(struct kobject *kobj) 169 { 170 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 171 } 172 173 static inline struct kset *kset_get(struct kset *k) 174 { 175 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 176 } 177 178 static inline void kset_put(struct kset *k) 179 { 180 kobject_put(&k->kobj); 181 } 182 183 static inline struct kobj_type *get_ktype(struct kobject *kobj) 184 { 185 return kobj->ktype; 186 } 187 188 extern struct kobject *kset_find_obj(struct kset *, const char *); 189 190 /* The global /sys/kernel/ kobject for people to chain off of */ 191 extern struct kobject *kernel_kobj; 192 /* The global /sys/hypervisor/ kobject for people to chain off of */ 193 extern struct kobject *hypervisor_kobj; 194 /* The global /sys/power/ kobject for people to chain off of */ 195 extern struct kobject *power_kobj; 196 /* The global /sys/firmware/ kobject for people to chain off of */ 197 extern struct kobject *firmware_kobj; 198 199 #if defined(CONFIG_HOTPLUG) 200 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 201 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 202 char *envp[]); 203 204 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 205 __attribute__((format (printf, 2, 3))); 206 207 int kobject_action_type(const char *buf, size_t count, 208 enum kobject_action *type); 209 #else 210 static inline int kobject_uevent(struct kobject *kobj, 211 enum kobject_action action) 212 { return 0; } 213 static inline int kobject_uevent_env(struct kobject *kobj, 214 enum kobject_action action, 215 char *envp[]) 216 { return 0; } 217 218 static inline int add_uevent_var(struct kobj_uevent_env *env, 219 const char *format, ...) 220 { return 0; } 221 222 static inline int kobject_action_type(const char *buf, size_t count, 223 enum kobject_action *type) 224 { return -EINVAL; } 225 #endif 226 227 #endif /* __KERNEL__ */ 228 #endif /* _KOBJECT_H_ */ 229