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
  30#define UEVENT_HELPER_PATH_LEN          256
  31#define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  32#define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  33
  34/* path to the userspace helper executed on an event */
  35extern char uevent_helper[];
  36
  37/* counter to tag the uevent, read only except for the kobject core */
  38extern u64 uevent_seqnum;
  39
  40/*
  41 * The actions here must match the index to the string array
  42 * in lib/kobject_uevent.c
  43 *
  44 * Do not add new actions here without checking with the driver-core
  45 * maintainers. Action strings are not meant to express subsystem
  46 * or device specific properties. In most cases you want to send a
  47 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  48 * specific variables added to the event environment.
  49 */
  50enum kobject_action {
  51        KOBJ_ADD,
  52        KOBJ_REMOVE,
  53        KOBJ_CHANGE,
  54        KOBJ_MOVE,
  55        KOBJ_ONLINE,
  56        KOBJ_OFFLINE,
  57        KOBJ_MAX
  58};
  59
  60struct kobject {
  61        const char              *name;
  62        struct list_head        entry;
  63        struct kobject          *parent;
  64        struct kset             *kset;
  65        struct kobj_type        *ktype;
  66        struct sysfs_dirent     *sd;
  67        struct kref             kref;
  68        unsigned int state_initialized:1;
  69        unsigned int state_in_sysfs:1;
  70        unsigned int state_add_uevent_sent:1;
  71        unsigned int state_remove_uevent_sent:1;
  72        unsigned int uevent_suppress:1;
  73};
  74
  75extern __printf(2, 3)
  76int kobject_set_name(struct kobject *kobj, const char *name, ...);
  77extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  78                                  va_list vargs);
  79
  80static inline const char *kobject_name(const struct kobject *kobj)
  81{
  82        return kobj->name;
  83}
  84
  85extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  86extern __printf(3, 4) __must_check
  87int kobject_add(struct kobject *kobj, struct kobject *parent,
  88                const char *fmt, ...);
  89extern __printf(4, 5) __must_check
  90int kobject_init_and_add(struct kobject *kobj,
  91                         struct kobj_type *ktype, struct kobject *parent,
  92                         const char *fmt, ...);
  93
  94extern void kobject_del(struct kobject *kobj);
  95
  96extern struct kobject * __must_check kobject_create(void);
  97extern struct kobject * __must_check kobject_create_and_add(const char *name,
  98                                                struct kobject *parent);
  99
 100extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 101extern int __must_check kobject_move(struct kobject *, struct kobject *);
 102
 103extern struct kobject *kobject_get(struct kobject *kobj);
 104extern void kobject_put(struct kobject *kobj);
 105
 106extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 107
 108struct kobj_type {
 109        void (*release)(struct kobject *kobj);
 110        const struct sysfs_ops *sysfs_ops;
 111        struct attribute **default_attrs;
 112        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 113        const void *(*namespace)(struct kobject *kobj);
 114};
 115
 116struct kobj_uevent_env {
 117        char *envp[UEVENT_NUM_ENVP];
 118        int envp_idx;
 119        char buf[UEVENT_BUFFER_SIZE];
 120        int buflen;
 121};
 122
 123struct kset_uevent_ops {
 124        int (* const filter)(struct kset *kset, struct kobject *kobj);
 125        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 126        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 127                      struct kobj_uevent_env *env);
 128};
 129
 130struct kobj_attribute {
 131        struct attribute attr;
 132        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 133                        char *buf);
 134        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 135                         const char *buf, size_t count);
 136};
 137
 138extern const struct sysfs_ops kobj_sysfs_ops;
 139
 140struct sock;
 141
 142/**
 143 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 144 *
 145 * A kset defines a group of kobjects.  They can be individually
 146 * different "types" but overall these kobjects all want to be grouped
 147 * together and operated on in the same manner.  ksets are used to
 148 * define the attribute callbacks and other common events that happen to
 149 * a kobject.
 150 *
 151 * @list: the list of all kobjects for this kset
 152 * @list_lock: a lock for iterating over the kobjects
 153 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 154 * @uevent_ops: the set of uevent operations for this kset.  These are
 155 * called whenever a kobject has something happen to it so that the kset
 156 * can add new environment variables, or filter out the uevents if so
 157 * desired.
 158 */
 159struct kset {
 160        struct list_head list;
 161        spinlock_t list_lock;
 162        struct kobject kobj;
 163        const struct kset_uevent_ops *uevent_ops;
 164};
 165
 166extern void kset_init(struct kset *kset);
 167extern int __must_check kset_register(struct kset *kset);
 168extern void kset_unregister(struct kset *kset);
 169extern struct kset * __must_check kset_create_and_add(const char *name,
 170                                                const struct kset_uevent_ops *u,
 171                                                struct kobject *parent_kobj);
 172
 173static inline struct kset *to_kset(struct kobject *kobj)
 174{
 175        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 176}
 177
 178static inline struct kset *kset_get(struct kset *k)
 179{
 180        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 181}
 182
 183static inline void kset_put(struct kset *k)
 184{
 185        kobject_put(&k->kobj);
 186}
 187
 188static inline struct kobj_type *get_ktype(struct kobject *kobj)
 189{
 190        return kobj->ktype;
 191}
 192
 193extern struct kobject *kset_find_obj(struct kset *, const char *);
 194
 195/* The global /sys/kernel/ kobject for people to chain off of */
 196extern struct kobject *kernel_kobj;
 197/* The global /sys/kernel/mm/ kobject for people to chain off of */
 198extern struct kobject *mm_kobj;
 199/* The global /sys/hypervisor/ kobject for people to chain off of */
 200extern struct kobject *hypervisor_kobj;
 201/* The global /sys/power/ kobject for people to chain off of */
 202extern struct kobject *power_kobj;
 203/* The global /sys/firmware/ kobject for people to chain off of */
 204extern struct kobject *firmware_kobj;
 205
 206#if defined(CONFIG_HOTPLUG)
 207int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 208int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 209                        char *envp[]);
 210
 211__printf(2, 3)
 212int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 213
 214int kobject_action_type(const char *buf, size_t count,
 215                        enum kobject_action *type);
 216#else
 217static inline int kobject_uevent(struct kobject *kobj,
 218                                 enum kobject_action action)
 219{ return 0; }
 220static inline int kobject_uevent_env(struct kobject *kobj,
 221                                      enum kobject_action action,
 222                                      char *envp[])
 223{ return 0; }
 224
 225static inline __printf(2, 3)
 226int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 227{ return 0; }
 228
 229static inline int kobject_action_type(const char *buf, size_t count,
 230                                      enum kobject_action *type)
 231{ return -EINVAL; }
 232#endif
 233
 234#endif /* _KOBJECT_H_ */
 235