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