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/* path to the userspace helper executed on an event */
  36extern char uevent_helper[];
  37
  38/* counter to tag the uevent, read only except for the kobject core */
  39extern 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 */
  51enum 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
  61struct 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 kernfs_node      *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
  79extern __printf(2, 3)
  80int kobject_set_name(struct kobject *kobj, const char *name, ...);
  81extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  82                                  va_list vargs);
  83
  84static inline const char *kobject_name(const struct kobject *kobj)
  85{
  86        return kobj->name;
  87}
  88
  89extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  90extern __printf(3, 4) __must_check
  91int kobject_add(struct kobject *kobj, struct kobject *parent,
  92                const char *fmt, ...);
  93extern __printf(4, 5) __must_check
  94int kobject_init_and_add(struct kobject *kobj,
  95                         struct kobj_type *ktype, struct kobject *parent,
  96                         const char *fmt, ...);
  97
  98extern void kobject_del(struct kobject *kobj);
  99
 100extern struct kobject * __must_check kobject_create(void);
 101extern struct kobject * __must_check kobject_create_and_add(const char *name,
 102                                                struct kobject *parent);
 103
 104extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 105extern int __must_check kobject_move(struct kobject *, struct kobject *);
 106
 107extern struct kobject *kobject_get(struct kobject *kobj);
 108extern void kobject_put(struct kobject *kobj);
 109
 110extern const void *kobject_namespace(struct kobject *kobj);
 111extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 112
 113struct kobj_type {
 114        void (*release)(struct kobject *kobj);
 115        const struct sysfs_ops *sysfs_ops;
 116        struct attribute **default_attrs;
 117        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 118        const void *(*namespace)(struct kobject *kobj);
 119};
 120
 121struct kobj_uevent_env {
 122        char *argv[3];
 123        char *envp[UEVENT_NUM_ENVP];
 124        int envp_idx;
 125        char buf[UEVENT_BUFFER_SIZE];
 126        int buflen;
 127};
 128
 129struct kset_uevent_ops {
 130        int (* const filter)(struct kset *kset, struct kobject *kobj);
 131        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 132        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 133                      struct kobj_uevent_env *env);
 134};
 135
 136struct kobj_attribute {
 137        struct attribute attr;
 138        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 139                        char *buf);
 140        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 141                         const char *buf, size_t count);
 142};
 143
 144extern const struct sysfs_ops kobj_sysfs_ops;
 145
 146struct sock;
 147
 148/**
 149 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 150 *
 151 * A kset defines a group of kobjects.  They can be individually
 152 * different "types" but overall these kobjects all want to be grouped
 153 * together and operated on in the same manner.  ksets are used to
 154 * define the attribute callbacks and other common events that happen to
 155 * a kobject.
 156 *
 157 * @list: the list of all kobjects for this kset
 158 * @list_lock: a lock for iterating over the kobjects
 159 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 160 * @uevent_ops: the set of uevent operations for this kset.  These are
 161 * called whenever a kobject has something happen to it so that the kset
 162 * can add new environment variables, or filter out the uevents if so
 163 * desired.
 164 */
 165struct kset {
 166        struct list_head list;
 167        spinlock_t list_lock;
 168        struct kobject kobj;
 169        const struct kset_uevent_ops *uevent_ops;
 170};
 171
 172extern void kset_init(struct kset *kset);
 173extern int __must_check kset_register(struct kset *kset);
 174extern void kset_unregister(struct kset *kset);
 175extern struct kset * __must_check kset_create_and_add(const char *name,
 176                                                const struct kset_uevent_ops *u,
 177                                                struct kobject *parent_kobj);
 178
 179static inline struct kset *to_kset(struct kobject *kobj)
 180{
 181        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 182}
 183
 184static inline struct kset *kset_get(struct kset *k)
 185{
 186        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 187}
 188
 189static inline void kset_put(struct kset *k)
 190{
 191        kobject_put(&k->kobj);
 192}
 193
 194static inline struct kobj_type *get_ktype(struct kobject *kobj)
 195{
 196        return kobj->ktype;
 197}
 198
 199extern struct kobject *kset_find_obj(struct kset *, const char *);
 200
 201/* The global /sys/kernel/ kobject for people to chain off of */
 202extern struct kobject *kernel_kobj;
 203/* The global /sys/kernel/mm/ kobject for people to chain off of */
 204extern struct kobject *mm_kobj;
 205/* The global /sys/hypervisor/ kobject for people to chain off of */
 206extern struct kobject *hypervisor_kobj;
 207/* The global /sys/power/ kobject for people to chain off of */
 208extern struct kobject *power_kobj;
 209/* The global /sys/firmware/ kobject for people to chain off of */
 210extern struct kobject *firmware_kobj;
 211
 212int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 213int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 214                        char *envp[]);
 215
 216__printf(2, 3)
 217int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 218
 219int kobject_action_type(const char *buf, size_t count,
 220                        enum kobject_action *type);
 221
 222#endif /* _KOBJECT_H_ */
 223