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 unsigned int uevent_suppress:1; 72 }; 73 74 extern int kobject_set_name(struct kobject *kobj, const char *name, ...) 75 __attribute__((format(printf, 2, 3))); 76 extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, 77 va_list vargs); 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 const struct sysfs_ops *sysfs_ops; 110 struct attribute **default_attrs; 111 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj); 112 const void *(*namespace)(struct kobject *kobj); 113 }; 114 115 struct kobj_uevent_env { 116 char *envp[UEVENT_NUM_ENVP]; 117 int envp_idx; 118 char buf[UEVENT_BUFFER_SIZE]; 119 int buflen; 120 }; 121 122 struct kset_uevent_ops { 123 int (* const filter)(struct kset *kset, struct kobject *kobj); 124 const char *(* const name)(struct kset *kset, struct kobject *kobj); 125 int (* const uevent)(struct kset *kset, struct kobject *kobj, 126 struct kobj_uevent_env *env); 127 }; 128 129 struct kobj_attribute { 130 struct attribute attr; 131 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 132 char *buf); 133 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 134 const char *buf, size_t count); 135 }; 136 137 extern const struct sysfs_ops kobj_sysfs_ops; 138 139 /* 140 * Namespace types which are used to tag kobjects and sysfs entries. 141 * Network namespace will likely be the first. 142 */ 143 enum kobj_ns_type { 144 KOBJ_NS_TYPE_NONE = 0, 145 KOBJ_NS_TYPE_NET, 146 KOBJ_NS_TYPES 147 }; 148 149 struct sock; 150 151 /* 152 * Callbacks so sysfs can determine namespaces 153 * @current_ns: return calling task's namespace 154 * @netlink_ns: return namespace to which a sock belongs (right?) 155 * @initial_ns: return the initial namespace (i.e. init_net_ns) 156 */ 157 struct kobj_ns_type_operations { 158 enum kobj_ns_type type; 159 const void *(*current_ns)(void); 160 const void *(*netlink_ns)(struct sock *sk); 161 const void *(*initial_ns)(void); 162 }; 163 164 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops); 165 int kobj_ns_type_registered(enum kobj_ns_type type); 166 const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent); 167 const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj); 168 169 const void *kobj_ns_current(enum kobj_ns_type type); 170 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk); 171 const void *kobj_ns_initial(enum kobj_ns_type type); 172 void kobj_ns_exit(enum kobj_ns_type type, const void *ns); 173 174 175 /** 176 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 177 * 178 * A kset defines a group of kobjects. They can be individually 179 * different "types" but overall these kobjects all want to be grouped 180 * together and operated on in the same manner. ksets are used to 181 * define the attribute callbacks and other common events that happen to 182 * a kobject. 183 * 184 * @list: the list of all kobjects for this kset 185 * @list_lock: a lock for iterating over the kobjects 186 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 187 * @uevent_ops: the set of uevent operations for this kset. These are 188 * called whenever a kobject has something happen to it so that the kset 189 * can add new environment variables, or filter out the uevents if so 190 * desired. 191 */ 192 struct kset { 193 struct list_head list; 194 spinlock_t list_lock; 195 struct kobject kobj; 196 const struct kset_uevent_ops *uevent_ops; 197 }; 198 199 extern void kset_init(struct kset *kset); 200 extern int __must_check kset_register(struct kset *kset); 201 extern void kset_unregister(struct kset *kset); 202 extern struct kset * __must_check kset_create_and_add(const char *name, 203 const struct kset_uevent_ops *u, 204 struct kobject *parent_kobj); 205 206 static inline struct kset *to_kset(struct kobject *kobj) 207 { 208 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 209 } 210 211 static inline struct kset *kset_get(struct kset *k) 212 { 213 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 214 } 215 216 static inline void kset_put(struct kset *k) 217 { 218 kobject_put(&k->kobj); 219 } 220 221 static inline struct kobj_type *get_ktype(struct kobject *kobj) 222 { 223 return kobj->ktype; 224 } 225 226 extern struct kobject *kset_find_obj(struct kset *, const char *); 227 228 /* The global /sys/kernel/ kobject for people to chain off of */ 229 extern struct kobject *kernel_kobj; 230 /* The global /sys/kernel/mm/ kobject for people to chain off of */ 231 extern struct kobject *mm_kobj; 232 /* The global /sys/hypervisor/ kobject for people to chain off of */ 233 extern struct kobject *hypervisor_kobj; 234 /* The global /sys/power/ kobject for people to chain off of */ 235 extern struct kobject *power_kobj; 236 /* The global /sys/firmware/ kobject for people to chain off of */ 237 extern struct kobject *firmware_kobj; 238 239 #if defined(CONFIG_HOTPLUG) 240 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 241 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 242 char *envp[]); 243 244 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 245 __attribute__((format (printf, 2, 3))); 246 247 int kobject_action_type(const char *buf, size_t count, 248 enum kobject_action *type); 249 #else 250 static inline int kobject_uevent(struct kobject *kobj, 251 enum kobject_action action) 252 { return 0; } 253 static inline int kobject_uevent_env(struct kobject *kobj, 254 enum kobject_action action, 255 char *envp[]) 256 { return 0; } 257 258 static inline int add_uevent_var(struct kobj_uevent_env *env, 259 const char *format, ...) 260 { return 0; } 261 262 static inline int kobject_action_type(const char *buf, size_t count, 263 enum kobject_action *type) 264 { return -EINVAL; } 265 #endif 266 267 #endif /* _KOBJECT_H_ */ 268