include/linux/kobject.h

   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 <greg@kroah.com>
   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/kobject_ns.h>
  26 #include <linux/kernel.h>
  27 #include <linux/wait.h>
  28 #include <linux/atomic.h>
  29 #include <linux/workqueue.h>
  30
  31 #define UEVENT_HELPER_PATH_LEN          256
  32 #define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  33 #define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  34
  35 /* path to the userspace helper executed on an event */
  36 extern char uevent_helper[];
  37
  38 /* counter to tag the uevent, read only except for the kobject core */
  39 extern u64 uevent_seqnum;
  40
  41 /*
  42  * The actions here must match the index to the string array
  43  * in lib/kobject_uevent.c
  44  *
  45  * Do not add new actions here without checking with the driver-core
  46  * maintainers. Action strings are not meant to express subsystem
  47  * or device specific properties. In most cases you want to send a
  48  * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  49  * specific variables added to the event environment.
  50  */
  51 enum kobject_action {
  52         KOBJ_ADD,
  53         KOBJ_REMOVE,
  54         KOBJ_CHANGE,
  55         KOBJ_MOVE,
  56         KOBJ_ONLINE,
  57         KOBJ_OFFLINE,
  58         KOBJ_MAX
  59 };
  60
  61 struct kobject {
  62         const char              *name;
  63         struct list_head        entry;
  64         struct kobject          *parent;
  65         struct kset             *kset;
  66         struct kobj_type        *ktype;
  67         struct sysfs_dirent     *sd;
  68         struct kref             kref;
  69 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
  70         struct delayed_work     release;
  71 #endif
  72         unsigned int state_initialized:1;
  73         unsigned int state_in_sysfs:1;
  74         unsigned int state_add_uevent_sent:1;
  75         unsigned int state_remove_uevent_sent:1;
  76         unsigned int uevent_suppress:1;
  77 };
  78
  79 extern __printf(2, 3)
  80 int kobject_set_name(struct kobject *kobj, const char *name, ...);
  81 extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  82                                   va_list vargs);
  83
  84 static inline const char *kobject_name(const struct kobject *kobj)
  85 {
  86         return kobj->name;
  87 }
  88
  89 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  90 extern __printf(3, 4) __must_check
  91 int kobject_add(struct kobject *kobj, struct kobject *parent,
  92                 const char *fmt, ...);
  93 extern __printf(4, 5) __must_check
  94 int kobject_init_and_add(struct kobject *kobj,
  95                          struct kobj_type *ktype, struct kobject *parent,
  96                          const char *fmt, ...);
  97
  98 extern void kobject_del(struct kobject *kobj);
  99
 100 extern struct kobject * __must_check kobject_create(void);
 101 extern struct kobject * __must_check kobject_create_and_add(const char *name,
 102                                                 struct kobject *parent);
 103
 104 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 105 extern int __must_check kobject_move(struct kobject *, struct kobject *);
 106
 107 extern struct kobject *kobject_get(struct kobject *kobj);
 108 extern void kobject_put(struct kobject *kobj);
 109
 110 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 111
 112 struct kobj_type {
 113         void (*release)(struct kobject *kobj);
 114         const struct sysfs_ops *sysfs_ops;
 115         struct attribute **default_attrs;
 116         const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 117         const void *(*namespace)(struct kobject *kobj);
 118 };
 119
 120 struct kobj_uevent_env {
 121         char *envp[UEVENT_NUM_ENVP];
 122         int envp_idx;
 123         char buf[UEVENT_BUFFER_SIZE];
 124         int buflen;
 125 };
 126
 127 struct kset_uevent_ops {
 128         int (* const filter)(struct kset *kset, struct kobject *kobj);
 129         const char *(* const name)(struct kset *kset, struct kobject *kobj);
 130         int (* const uevent)(struct kset *kset, struct kobject *kobj,
 131                       struct kobj_uevent_env *env);
 132 };
 133
 134 struct kobj_attribute {
 135         struct attribute attr;
 136         ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 137                         char *buf);
 138         ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 139                          const char *buf, size_t count);
 140 };
 141
 142 extern const struct sysfs_ops kobj_sysfs_ops;
 143
 144 struct sock;
 145
 146 /**
 147  * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 148  *
 149  * A kset defines a group of kobjects.  They can be individually
 150  * different "types" but overall these kobjects all want to be grouped
 151  * together and operated on in the same manner.  ksets are used to
 152  * define the attribute callbacks and other common events that happen to
 153  * a kobject.
 154  *
 155  * @list: the list of all kobjects for this kset
 156  * @list_lock: a lock for iterating over the kobjects
 157  * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 158  * @uevent_ops: the set of uevent operations for this kset.  These are
 159  * called whenever a kobject has something happen to it so that the kset
 160  * can add new environment variables, or filter out the uevents if so
 161  * desired.
 162  */
 163 struct kset {
 164         struct list_head list;
 165         spinlock_t list_lock;
 166         struct kobject kobj;
 167         const struct kset_uevent_ops *uevent_ops;
 168 };
 169
 170 extern void kset_init(struct kset *kset);
 171 extern int __must_check kset_register(struct kset *kset);
 172 extern void kset_unregister(struct kset *kset);
 173 extern struct kset * __must_check kset_create_and_add(const char *name,
 174                                                 const struct kset_uevent_ops *u,
 175                                                 struct kobject *parent_kobj);
 176
 177 static inline struct kset *to_kset(struct kobject *kobj)
 178 {
 179         return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 180 }
 181
 182 static inline struct kset *kset_get(struct kset *k)
 183 {
 184         return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 185 }
 186
 187 static inline void kset_put(struct kset *k)
 188 {
 189         kobject_put(&k->kobj);
 190 }
 191
 192 static inline struct kobj_type *get_ktype(struct kobject *kobj)
 193 {
 194         return kobj->ktype;
 195 }
 196
 197 extern struct kobject *kset_find_obj(struct kset *, const char *);
 198
 199 /* The global /sys/kernel/ kobject for people to chain off of */
 200 extern struct kobject *kernel_kobj;
 201 /* The global /sys/kernel/mm/ kobject for people to chain off of */
 202 extern struct kobject *mm_kobj;
 203 /* The global /sys/hypervisor/ kobject for people to chain off of */
 204 extern struct kobject *hypervisor_kobj;
 205 /* The global /sys/power/ kobject for people to chain off of */
 206 extern struct kobject *power_kobj;
 207 /* The global /sys/firmware/ kobject for people to chain off of */
 208 extern struct kobject *firmware_kobj;
 209
 210 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 211 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 212                         char *envp[]);
 213
 214 __printf(2, 3)
 215 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 216
 217 int kobject_action_type(const char *buf, size_t count,
 218                         enum kobject_action *type);
 219
 220 #endif /* _KOBJECT_H_ */