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 UEVENT_HELPER_PATH_LEN 256 30 #define UEVENT_NUM_ENVP 32 /* number of env pointers */ 31 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 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 struct kobject { 60 const char *name; 61 struct list_head entry; 62 struct kobject *parent; 63 struct kset *kset; 64 struct kobj_type *ktype; 65 struct sysfs_dirent *sd; 66 struct kref kref; 67 unsigned int state_initialized:1; 68 unsigned int state_in_sysfs:1; 69 unsigned int state_add_uevent_sent:1; 70 unsigned int state_remove_uevent_sent:1; 71 }; 72 73 extern int kobject_set_name(struct kobject *kobj, const char *name, ...) 74 __attribute__((format(printf, 2, 3))); 75 76 static inline const char *kobject_name(const struct kobject *kobj) 77 { 78 return kobj->name; 79 } 80 81 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 82 extern int __must_check kobject_add(struct kobject *kobj, 83 struct kobject *parent, 84 const char *fmt, ...); 85 extern int __must_check kobject_init_and_add(struct kobject *kobj, 86 struct kobj_type *ktype, 87 struct kobject *parent, 88 const char *fmt, ...); 89 90 extern void kobject_del(struct kobject *kobj); 91 92 extern struct kobject * __must_check kobject_create(void); 93 extern struct kobject * __must_check kobject_create_and_add(const char *name, 94 struct kobject *parent); 95 96 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 97 extern int __must_check kobject_move(struct kobject *, struct kobject *); 98 99 extern struct kobject *kobject_get(struct kobject *kobj); 100 extern void kobject_put(struct kobject *kobj); 101 102 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 103 104 struct kobj_type { 105 void (*release)(struct kobject *kobj); 106 struct sysfs_ops *sysfs_ops; 107 struct attribute **default_attrs; 108 }; 109 110 struct kobj_uevent_env { 111 char *envp[UEVENT_NUM_ENVP]; 112 int envp_idx; 113 char buf[UEVENT_BUFFER_SIZE]; 114 int buflen; 115 }; 116 117 struct kset_uevent_ops { 118 int (*filter)(struct kset *kset, struct kobject *kobj); 119 const char *(*name)(struct kset *kset, struct kobject *kobj); 120 int (*uevent)(struct kset *kset, struct kobject *kobj, 121 struct kobj_uevent_env *env); 122 }; 123 124 struct kobj_attribute { 125 struct attribute attr; 126 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 127 char *buf); 128 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 129 const char *buf, size_t count); 130 }; 131 132 extern struct sysfs_ops kobj_sysfs_ops; 133 134 /** 135 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 136 * 137 * A kset defines a group of kobjects. They can be individually 138 * different "types" but overall these kobjects all want to be grouped 139 * together and operated on in the same manner. ksets are used to 140 * define the attribute callbacks and other common events that happen to 141 * a kobject. 142 * 143 * @list: the list of all kobjects for this kset 144 * @list_lock: a lock for iterating over the kobjects 145 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 146 * @uevent_ops: the set of uevent operations for this kset. These are 147 * called whenever a kobject has something happen to it so that the kset 148 * can add new environment variables, or filter out the uevents if so 149 * desired. 150 */ 151 struct kset { 152 struct list_head list; 153 spinlock_t list_lock; 154 struct kobject kobj; 155 struct kset_uevent_ops *uevent_ops; 156 }; 157 158 extern void kset_init(struct kset *kset); 159 extern int __must_check kset_register(struct kset *kset); 160 extern void kset_unregister(struct kset *kset); 161 extern struct kset * __must_check kset_create_and_add(const char *name, 162 struct kset_uevent_ops *u, 163 struct kobject *parent_kobj); 164 165 static inline struct kset *to_kset(struct kobject *kobj) 166 { 167 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 168 } 169 170 static inline struct kset *kset_get(struct kset *k) 171 { 172 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 173 } 174 175 static inline void kset_put(struct kset *k) 176 { 177 kobject_put(&k->kobj); 178 } 179 180 static inline struct kobj_type *get_ktype(struct kobject *kobj) 181 { 182 return kobj->ktype; 183 } 184 185 extern struct kobject *kset_find_obj(struct kset *, const char *); 186 187 /* The global /sys/kernel/ kobject for people to chain off of */ 188 extern struct kobject *kernel_kobj; 189 /* The global /sys/kernel/mm/ kobject for people to chain off of */ 190 extern struct kobject *mm_kobj; 191 /* The global /sys/hypervisor/ kobject for people to chain off of */ 192 extern struct kobject *hypervisor_kobj; 193 /* The global /sys/power/ kobject for people to chain off of */ 194 extern struct kobject *power_kobj; 195 /* The global /sys/firmware/ kobject for people to chain off of */ 196 extern struct kobject *firmware_kobj; 197 198 #if defined(CONFIG_HOTPLUG) 199 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 200 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 201 char *envp[]); 202 203 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 204 __attribute__((format (printf, 2, 3))); 205 206 int kobject_action_type(const char *buf, size_t count, 207 enum kobject_action *type); 208 #else 209 static inline int kobject_uevent(struct kobject *kobj, 210 enum kobject_action action) 211 { return 0; } 212 static inline int kobject_uevent_env(struct kobject *kobj, 213 enum kobject_action action, 214 char *envp[]) 215 { return 0; } 216 217 static inline int add_uevent_var(struct kobj_uevent_env *env, 218 const char *format, ...) 219 { return 0; } 220 221 static inline int kobject_action_type(const char *buf, size_t count, 222 enum kobject_action *type) 223 { return -EINVAL; } 224 #endif 225 226 #endif /* _KOBJECT_H_ */ 227