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/kernel.h>
  26#include <linux/wait.h>
  27#include <asm/atomic.h>
  28
  29#define UEVENT_HELPER_PATH_LEN          256
  30#define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  31#define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  32
  33/* path to the userspace helper executed on an event */
  34extern char uevent_helper[];
  35
  36/* counter to tag the uevent, read only except for the kobject core */
  37extern u64 uevent_seqnum;
  38
  39/*
  40 * The actions here must match the index to the string array
  41 * in lib/kobject_uevent.c
  42 *
  43 * Do not add new actions here without checking with the driver-core
  44 * maintainers. Action strings are not meant to express subsystem
  45 * or device specific properties. In most cases you want to send a
  46 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  47 * specific variables added to the event environment.
  48 */
  49enum kobject_action {
  50        KOBJ_ADD,
  51        KOBJ_REMOVE,
  52        KOBJ_CHANGE,
  53        KOBJ_MOVE,
  54        KOBJ_ONLINE,
  55        KOBJ_OFFLINE,
  56        KOBJ_MAX
  57};
  58
  59struct kobject {
  60        const char              *name;
  61        struct list_head        entry;
  62        struct kobject          *parent;
  63        struct kset             *kset;
  64        struct kobj_type        *ktype;
  65        struct sysfs_dirent     *sd;
  66        struct kref             kref;
  67        unsigned int state_initialized:1;
  68        unsigned int state_in_sysfs:1;
  69        unsigned int state_add_uevent_sent:1;
  70        unsigned int state_remove_uevent_sent:1;
  71};
  72
  73extern int kobject_set_name(struct kobject *kobj, const char *name, ...)
  74                            __attribute__((format(printf, 2, 3)));
  75
  76static inline const char *kobject_name(const struct kobject *kobj)
  77{
  78        return kobj->name;
  79}
  80
  81extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  82extern int __must_check kobject_add(struct kobject *kobj,
  83                                    struct kobject *parent,
  84                                    const char *fmt, ...);
  85extern int __must_check kobject_init_and_add(struct kobject *kobj,
  86                                             struct kobj_type *ktype,
  87                                             struct kobject *parent,
  88                                             const char *fmt, ...);
  89
  90extern void kobject_del(struct kobject *kobj);
  91
  92extern struct kobject * __must_check kobject_create(void);
  93extern struct kobject * __must_check kobject_create_and_add(const char *name,
  94                                                struct kobject *parent);
  95
  96extern int __must_check kobject_rename(struct kobject *, const char *new_name);
  97extern int __must_check kobject_move(struct kobject *, struct kobject *);
  98
  99extern struct kobject *kobject_get(struct kobject *kobj);
 100extern void kobject_put(struct kobject *kobj);
 101
 102extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 103
 104struct kobj_type {
 105        void (*release)(struct kobject *kobj);
 106        struct sysfs_ops *sysfs_ops;
 107        struct attribute **default_attrs;
 108};
 109
 110struct kobj_uevent_env {
 111        char *envp[UEVENT_NUM_ENVP];
 112        int envp_idx;
 113        char buf[UEVENT_BUFFER_SIZE];
 114        int buflen;
 115};
 116
 117struct kset_uevent_ops {
 118        int (*filter)(struct kset *kset, struct kobject *kobj);
 119        const char *(*name)(struct kset *kset, struct kobject *kobj);
 120        int (*uevent)(struct kset *kset, struct kobject *kobj,
 121                      struct kobj_uevent_env *env);
 122};
 123
 124struct kobj_attribute {
 125        struct attribute attr;
 126        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 127                        char *buf);
 128        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 129                         const char *buf, size_t count);
 130};
 131
 132extern struct sysfs_ops kobj_sysfs_ops;
 133
 134/**
 135 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 136 *
 137 * A kset defines a group of kobjects.  They can be individually
 138 * different "types" but overall these kobjects all want to be grouped
 139 * together and operated on in the same manner.  ksets are used to
 140 * define the attribute callbacks and other common events that happen to
 141 * a kobject.
 142 *
 143 * @list: the list of all kobjects for this kset
 144 * @list_lock: a lock for iterating over the kobjects
 145 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 146 * @uevent_ops: the set of uevent operations for this kset.  These are
 147 * called whenever a kobject has something happen to it so that the kset
 148 * can add new environment variables, or filter out the uevents if so
 149 * desired.
 150 */
 151struct kset {
 152        struct list_head list;
 153        spinlock_t list_lock;
 154        struct kobject kobj;
 155        struct kset_uevent_ops *uevent_ops;
 156};
 157
 158extern void kset_init(struct kset *kset);
 159extern int __must_check kset_register(struct kset *kset);
 160extern void kset_unregister(struct kset *kset);
 161extern struct kset * __must_check kset_create_and_add(const char *name,
 162                                                struct kset_uevent_ops *u,
 163                                                struct kobject *parent_kobj);
 164
 165static inline struct kset *to_kset(struct kobject *kobj)
 166{
 167        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 168}
 169
 170static inline struct kset *kset_get(struct kset *k)
 171{
 172        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 173}
 174
 175static inline void kset_put(struct kset *k)
 176{
 177        kobject_put(&k->kobj);
 178}
 179
 180static inline struct kobj_type *get_ktype(struct kobject *kobj)
 181{
 182        return kobj->ktype;
 183}
 184
 185extern struct kobject *kset_find_obj(struct kset *, const char *);
 186
 187/* The global /sys/kernel/ kobject for people to chain off of */
 188extern struct kobject *kernel_kobj;
 189/* The global /sys/kernel/mm/ kobject for people to chain off of */
 190extern struct kobject *mm_kobj;
 191/* The global /sys/hypervisor/ kobject for people to chain off of */
 192extern struct kobject *hypervisor_kobj;
 193/* The global /sys/power/ kobject for people to chain off of */
 194extern struct kobject *power_kobj;
 195/* The global /sys/firmware/ kobject for people to chain off of */
 196extern struct kobject *firmware_kobj;
 197
 198#if defined(CONFIG_HOTPLUG)
 199int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 200int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 201                        char *envp[]);
 202
 203int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 204        __attribute__((format (printf, 2, 3)));
 205
 206int kobject_action_type(const char *buf, size_t count,
 207                        enum kobject_action *type);
 208#else
 209static inline int kobject_uevent(struct kobject *kobj,
 210                                 enum kobject_action action)
 211{ return 0; }
 212static inline int kobject_uevent_env(struct kobject *kobj,
 213                                      enum kobject_action action,
 214                                      char *envp[])
 215{ return 0; }
 216
 217static inline int add_uevent_var(struct kobj_uevent_env *env,
 218                                 const char *format, ...)
 219{ return 0; }
 220
 221static inline int kobject_action_type(const char *buf, size_t count,
 222                                      enum kobject_action *type)
 223{ return -EINVAL; }
 224#endif
 225
 226#endif /* _KOBJECT_H_ */
 227