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) 2006-2007 Greg Kroah-Hartman <[email protected]> 7 * Copyright (c) 2006-2007 Novell Inc. 8 * 9 * This file is released under the GPLv2. 10 * 11 * 12 * Please read Documentation/kobject.txt before using the kobject 13 * interface, ESPECIALLY the parts about reference counts and object 14 * destructors. 15 */ 16 17 #ifndef _KOBJECT_H_ 18 #define _KOBJECT_H_ 19 20 #ifdef __KERNEL__ 21 22 #include <linux/types.h> 23 #include <linux/list.h> 24 #include <linux/sysfs.h> 25 #include <linux/compiler.h> 26 #include <linux/spinlock.h> 27 #include <linux/kref.h> 28 #include <linux/kernel.h> 29 #include <linux/wait.h> 30 #include <asm/atomic.h> 31 32 #define KOBJ_NAME_LEN 20 33 #define UEVENT_HELPER_PATH_LEN 256 34 #define UEVENT_NUM_ENVP 32 /* number of env pointers */ 35 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 36 37 /* path to the userspace helper executed on an event */ 38 extern char uevent_helper[]; 39 40 /* counter to tag the uevent, read only except for the kobject core */ 41 extern u64 uevent_seqnum; 42 43 /* 44 * The actions here must match the index to the string array 45 * in lib/kobject_uevent.c 46 * 47 * Do not add new actions here without checking with the driver-core 48 * maintainers. Action strings are not meant to express subsystem 49 * or device specific properties. In most cases you want to send a 50 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 51 * specific variables added to the event environment. 52 */ 53 enum kobject_action { 54 KOBJ_ADD, 55 KOBJ_REMOVE, 56 KOBJ_CHANGE, 57 KOBJ_MOVE, 58 KOBJ_ONLINE, 59 KOBJ_OFFLINE, 60 KOBJ_MAX 61 }; 62 63 struct kobject { 64 const char *name; 65 struct kref kref; 66 struct list_head entry; 67 struct kobject * parent; 68 struct kset * kset; 69 struct kobj_type * ktype; 70 struct sysfs_dirent * sd; 71 unsigned int state_initialized:1; 72 unsigned int state_in_sysfs:1; 73 unsigned int state_add_uevent_sent:1; 74 unsigned int state_remove_uevent_sent:1; 75 }; 76 77 extern int kobject_set_name(struct kobject *, const char *, ...) 78 __attribute__((format(printf,2,3))); 79 80 static inline const char * kobject_name(const struct kobject * kobj) 81 { 82 return kobj->name; 83 } 84 85 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 86 extern int __must_check kobject_add(struct kobject *kobj, 87 struct kobject *parent, 88 const char *fmt, ...); 89 extern int __must_check kobject_init_and_add(struct kobject *kobj, 90 struct kobj_type *ktype, 91 struct kobject *parent, 92 const char *fmt, ...); 93 94 extern void kobject_del(struct kobject *); 95 96 extern struct kobject * __must_check kobject_create(void); 97 extern struct kobject * __must_check kobject_create_and_add(const char *name, 98 struct kobject *parent); 99 100 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 101 extern int __must_check kobject_move(struct kobject *, struct kobject *); 102 103 extern struct kobject * kobject_get(struct kobject *); 104 extern void kobject_put(struct kobject *); 105 106 extern char * kobject_get_path(struct kobject *, gfp_t); 107 108 struct kobj_type { 109 void (*release)(struct kobject *); 110 struct sysfs_ops * sysfs_ops; 111 struct attribute ** default_attrs; 112 }; 113 114 struct kobj_uevent_env { 115 char *envp[UEVENT_NUM_ENVP]; 116 int envp_idx; 117 char buf[UEVENT_BUFFER_SIZE]; 118 int buflen; 119 }; 120 121 struct kset_uevent_ops { 122 int (*filter)(struct kset *kset, struct kobject *kobj); 123 const char *(*name)(struct kset *kset, struct kobject *kobj); 124 int (*uevent)(struct kset *kset, struct kobject *kobj, 125 struct kobj_uevent_env *env); 126 }; 127 128 struct kobj_attribute { 129 struct attribute attr; 130 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 131 char *buf); 132 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 133 const char *buf, size_t count); 134 }; 135 136 extern struct sysfs_ops kobj_sysfs_ops; 137 138 /** 139 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 140 * 141 * A kset defines a group of kobjects. They can be individually 142 * different "types" but overall these kobjects all want to be grouped 143 * together and operated on in the same manner. ksets are used to 144 * define the attribute callbacks and other common events that happen to 145 * a kobject. 146 * 147 * @list: the list of all kobjects for this kset 148 * @list_lock: a lock for iterating over the kobjects 149 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 150 * @uevent_ops: the set of uevent operations for this kset. These are 151 * called whenever a kobject has something happen to it so that the kset 152 * can add new environment variables, or filter out the uevents if so 153 * desired. 154 */ 155 struct kset { 156 struct list_head list; 157 spinlock_t list_lock; 158 struct kobject kobj; 159 struct kset_uevent_ops *uevent_ops; 160 }; 161 162 extern void kset_init(struct kset * k); 163 extern int __must_check kset_register(struct kset * k); 164 extern void kset_unregister(struct kset * k); 165 extern struct kset * __must_check kset_create_and_add(const char *name, 166 struct kset_uevent_ops *u, 167 struct kobject *parent_kobj); 168 169 static inline struct kset * to_kset(struct kobject * kobj) 170 { 171 return kobj ? container_of(kobj,struct kset,kobj) : NULL; 172 } 173 174 static inline struct kset * kset_get(struct kset * k) 175 { 176 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 177 } 178 179 static inline void kset_put(struct kset * k) 180 { 181 kobject_put(&k->kobj); 182 } 183 184 static inline struct kobj_type *get_ktype(struct kobject *kobj) 185 { 186 return kobj->ktype; 187 } 188 189 extern struct kobject * kset_find_obj(struct kset *, const char *); 190 191 /* The global /sys/kernel/ kobject for people to chain off of */ 192 extern struct kobject *kernel_kobj; 193 /* The global /sys/hypervisor/ kobject for people to chain off of */ 194 extern struct kobject *hypervisor_kobj; 195 /* The global /sys/power/ kobject for people to chain off of */ 196 extern struct kobject *power_kobj; 197 /* The global /sys/firmware/ kobject for people to chain off of */ 198 extern struct kobject *firmware_kobj; 199 200 #if defined(CONFIG_HOTPLUG) 201 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 202 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 203 char *envp[]); 204 205 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) 206 __attribute__((format (printf, 2, 3))); 207 208 int kobject_action_type(const char *buf, size_t count, 209 enum kobject_action *type); 210 #else 211 static inline int kobject_uevent(struct kobject *kobj, 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, 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 /* __KERNEL__ */ 227 #endif /* _KOBJECT_H_ */ 228