LXR linux/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#ifdef CONFIG_UEVENT_HELPER
  36/* path to the userspace helper executed on an event */
  37extern char uevent_helper[];
  38#endif
  39
  40/* counter to tag the uevent, read only except for the kobject core */
  41extern 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 */
  53enum kobject_action {
  54        KOBJ_ADD,
  55        KOBJ_REMOVE,
  56        KOBJ_CHANGE,
  57        KOBJ_MOVE,
  58        KOBJ_ONLINE,
  59        KOBJ_OFFLINE,
  60        KOBJ_BIND,
  61        KOBJ_UNBIND,
  62        KOBJ_MAX
  63};
  64
  65struct kobject {
  66        const char              *name;
  67        struct list_head        entry;
  68        struct kobject          *parent;
  69        struct kset             *kset;
  70        struct kobj_type        *ktype;
  71        struct kernfs_node      *sd; /* sysfs directory entry */
  72        struct kref             kref;
  73#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
  74        struct delayed_work     release;
  75#endif
  76        unsigned int state_initialized:1;
  77        unsigned int state_in_sysfs:1;
  78        unsigned int state_add_uevent_sent:1;
  79        unsigned int state_remove_uevent_sent:1;
  80        unsigned int uevent_suppress:1;
  81};
  82
  83extern __printf(2, 3)
  84int kobject_set_name(struct kobject *kobj, const char *name, ...);
  85extern __printf(2, 0)
  86int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  87                           va_list vargs);
  88
  89static inline const char *kobject_name(const struct kobject *kobj)
  90{
  91        return kobj->name;
  92}
  93
  94extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  95extern __printf(3, 4) __must_check
  96int kobject_add(struct kobject *kobj, struct kobject *parent,
  97                const char *fmt, ...);
  98extern __printf(4, 5) __must_check
  99int kobject_init_and_add(struct kobject *kobj,
 100                         struct kobj_type *ktype, struct kobject *parent,
 101                         const char *fmt, ...);
 102
 103extern void kobject_del(struct kobject *kobj);
 104
 105extern struct kobject * __must_check kobject_create(void);
 106extern struct kobject * __must_check kobject_create_and_add(const char *name,
 107                                                struct kobject *parent);
 108
 109extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 110extern int __must_check kobject_move(struct kobject *, struct kobject *);
 111
 112extern struct kobject *kobject_get(struct kobject *kobj);
 113extern struct kobject * __must_check kobject_get_unless_zero(
 114                                                struct kobject *kobj);
 115extern void kobject_put(struct kobject *kobj);
 116
 117extern const void *kobject_namespace(struct kobject *kobj);
 118extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 119
 120struct kobj_type {
 121        void (*release)(struct kobject *kobj);
 122        const struct sysfs_ops *sysfs_ops;
 123        struct attribute **default_attrs;
 124        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 125        const void *(*namespace)(struct kobject *kobj);
 126};
 127
 128struct kobj_uevent_env {
 129        char *argv[3];
 130        char *envp[UEVENT_NUM_ENVP];
 131        int envp_idx;
 132        char buf[UEVENT_BUFFER_SIZE];
 133        int buflen;
 134};
 135
 136struct kset_uevent_ops {
 137        int (* const filter)(struct kset *kset, struct kobject *kobj);
 138        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 139        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 140                      struct kobj_uevent_env *env);
 141};
 142
 143struct kobj_attribute {
 144        struct attribute attr;
 145        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 146                        char *buf);
 147        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 148                         const char *buf, size_t count);
 149};
 150
 151extern const struct sysfs_ops kobj_sysfs_ops;
 152
 153struct sock;
 154
 155/**
 156 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 157 *
 158 * A kset defines a group of kobjects.  They can be individually
 159 * different "types" but overall these kobjects all want to be grouped
 160 * together and operated on in the same manner.  ksets are used to
 161 * define the attribute callbacks and other common events that happen to
 162 * a kobject.
 163 *
 164 * @list: the list of all kobjects for this kset
 165 * @list_lock: a lock for iterating over the kobjects
 166 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 167 * @uevent_ops: the set of uevent operations for this kset.  These are
 168 * called whenever a kobject has something happen to it so that the kset
 169 * can add new environment variables, or filter out the uevents if so
 170 * desired.
 171 */
 172struct kset {
 173        struct list_head list;
 174        spinlock_t list_lock;
 175        struct kobject kobj;
 176        const struct kset_uevent_ops *uevent_ops;
 177} __randomize_layout;
 178
 179extern void kset_init(struct kset *kset);
 180extern int __must_check kset_register(struct kset *kset);
 181extern void kset_unregister(struct kset *kset);
 182extern struct kset * __must_check kset_create_and_add(const char *name,
 183                                                const struct kset_uevent_ops *u,
 184                                                struct kobject *parent_kobj);
 185
 186static inline struct kset *to_kset(struct kobject *kobj)
 187{
 188        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 189}
 190
 191static inline struct kset *kset_get(struct kset *k)
 192{
 193        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 194}
 195
 196static inline void kset_put(struct kset *k)
 197{
 198        kobject_put(&k->kobj);
 199}
 200
 201static inline struct kobj_type *get_ktype(struct kobject *kobj)
 202{
 203        return kobj->ktype;
 204}
 205
 206extern struct kobject *kset_find_obj(struct kset *, const char *);
 207
 208/* The global /sys/kernel/ kobject for people to chain off of */
 209extern struct kobject *kernel_kobj;
 210/* The global /sys/kernel/mm/ kobject for people to chain off of */
 211extern struct kobject *mm_kobj;
 212/* The global /sys/hypervisor/ kobject for people to chain off of */
 213extern struct kobject *hypervisor_kobj;
 214/* The global /sys/power/ kobject for people to chain off of */
 215extern struct kobject *power_kobj;
 216/* The global /sys/firmware/ kobject for people to chain off of */
 217extern struct kobject *firmware_kobj;
 218
 219int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 220int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 221                        char *envp[]);
 222int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 223
 224__printf(2, 3)
 225int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 226
 227#endif /* _KOBJECT_H_ */
 228