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        unsigned int uevent_suppress:1;
  72};
  73
  74extern int kobject_set_name(struct kobject *kobj, const char *name, ...)
  75                            __attribute__((format(printf, 2, 3)));
  76extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  77                                  va_list vargs);
  78
  79static inline const char *kobject_name(const struct kobject *kobj)
  80{
  81        return kobj->name;
  82}
  83
  84extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  85extern int __must_check kobject_add(struct kobject *kobj,
  86                                    struct kobject *parent,
  87                                    const char *fmt, ...);
  88extern int __must_check kobject_init_and_add(struct kobject *kobj,
  89                                             struct kobj_type *ktype,
  90                                             struct kobject *parent,
  91                                             const char *fmt, ...);
  92
  93extern void kobject_del(struct kobject *kobj);
  94
  95extern struct kobject * __must_check kobject_create(void);
  96extern struct kobject * __must_check kobject_create_and_add(const char *name,
  97                                                struct kobject *parent);
  98
  99extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 100extern int __must_check kobject_move(struct kobject *, struct kobject *);
 101
 102extern struct kobject *kobject_get(struct kobject *kobj);
 103extern void kobject_put(struct kobject *kobj);
 104
 105extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 106
 107struct kobj_type {
 108        void (*release)(struct kobject *kobj);
 109        struct sysfs_ops *sysfs_ops;
 110        struct attribute **default_attrs;
 111};
 112
 113struct kobj_uevent_env {
 114        char *envp[UEVENT_NUM_ENVP];
 115        int envp_idx;
 116        char buf[UEVENT_BUFFER_SIZE];
 117        int buflen;
 118};
 119
 120struct kset_uevent_ops {
 121        int (*filter)(struct kset *kset, struct kobject *kobj);
 122        const char *(*name)(struct kset *kset, struct kobject *kobj);
 123        int (*uevent)(struct kset *kset, struct kobject *kobj,
 124                      struct kobj_uevent_env *env);
 125};
 126
 127struct kobj_attribute {
 128        struct attribute attr;
 129        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 130                        char *buf);
 131        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 132                         const char *buf, size_t count);
 133};
 134
 135extern struct sysfs_ops kobj_sysfs_ops;
 136
 137/**
 138 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 139 *
 140 * A kset defines a group of kobjects.  They can be individually
 141 * different "types" but overall these kobjects all want to be grouped
 142 * together and operated on in the same manner.  ksets are used to
 143 * define the attribute callbacks and other common events that happen to
 144 * a kobject.
 145 *
 146 * @list: the list of all kobjects for this kset
 147 * @list_lock: a lock for iterating over the kobjects
 148 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 149 * @uevent_ops: the set of uevent operations for this kset.  These are
 150 * called whenever a kobject has something happen to it so that the kset
 151 * can add new environment variables, or filter out the uevents if so
 152 * desired.
 153 */
 154struct kset {
 155        struct list_head list;
 156        spinlock_t list_lock;
 157        struct kobject kobj;
 158        struct kset_uevent_ops *uevent_ops;
 159};
 160
 161extern void kset_init(struct kset *kset);
 162extern int __must_check kset_register(struct kset *kset);
 163extern void kset_unregister(struct kset *kset);
 164extern struct kset * __must_check kset_create_and_add(const char *name,
 165                                                struct kset_uevent_ops *u,
 166                                                struct kobject *parent_kobj);
 167
 168static inline struct kset *to_kset(struct kobject *kobj)
 169{
 170        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 171}
 172
 173static inline struct kset *kset_get(struct kset *k)
 174{
 175        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 176}
 177
 178static inline void kset_put(struct kset *k)
 179{
 180        kobject_put(&k->kobj);
 181}
 182
 183static inline struct kobj_type *get_ktype(struct kobject *kobj)
 184{
 185        return kobj->ktype;
 186}
 187
 188extern struct kobject *kset_find_obj(struct kset *, const char *);
 189
 190/* The global /sys/kernel/ kobject for people to chain off of */
 191extern struct kobject *kernel_kobj;
 192/* The global /sys/kernel/mm/ kobject for people to chain off of */
 193extern struct kobject *mm_kobj;
 194/* The global /sys/hypervisor/ kobject for people to chain off of */
 195extern struct kobject *hypervisor_kobj;
 196/* The global /sys/power/ kobject for people to chain off of */
 197extern struct kobject *power_kobj;
 198/* The global /sys/firmware/ kobject for people to chain off of */
 199extern struct kobject *firmware_kobj;
 200
 201#if defined(CONFIG_HOTPLUG)
 202int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 203int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 204                        char *envp[]);
 205
 206int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 207        __attribute__((format (printf, 2, 3)));
 208
 209int kobject_action_type(const char *buf, size_t count,
 210                        enum kobject_action *type);
 211#else
 212static inline int kobject_uevent(struct kobject *kobj,
 213                                 enum kobject_action action)
 214{ return 0; }
 215static inline int kobject_uevent_env(struct kobject *kobj,
 216                                      enum kobject_action action,
 217                                      char *envp[])
 218{ return 0; }
 219
 220static inline int add_uevent_var(struct kobj_uevent_env *env,
 221                                 const char *format, ...)
 222{ return 0; }
 223
 224static inline int kobject_action_type(const char *buf, size_t count,
 225                                      enum kobject_action *type)
 226{ return -EINVAL; }
 227#endif
 228
 229#endif /* _KOBJECT_H_ */
 230