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 <asm/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 int kobject_set_name(struct kobject *kobj, const char *name, ...)
  76                            __attribute__((format(printf, 2, 3)));
  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 int __must_check kobject_add(struct kobject *kobj,
  87                                    struct kobject *parent,
  88                                    const char *fmt, ...)
  89        __attribute__((format(printf, 3, 4)));
  90extern int __must_check kobject_init_and_add(struct kobject *kobj,
  91                                             struct kobj_type *ktype,
  92                                             struct kobject *parent,
  93                                             const char *fmt, ...)
  94        __attribute__((format(printf, 4, 5)));
  95
  96extern void kobject_del(struct kobject *kobj);
  97
  98extern struct kobject * __must_check kobject_create(void);
  99extern struct kobject * __must_check kobject_create_and_add(const char *name,
 100                                                struct kobject *parent);
 101
 102extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 103extern int __must_check kobject_move(struct kobject *, struct kobject *);
 104
 105extern struct kobject *kobject_get(struct kobject *kobj);
 106extern void kobject_put(struct kobject *kobj);
 107
 108extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 109
 110struct kobj_type {
 111        void (*release)(struct kobject *kobj);
 112        const struct sysfs_ops *sysfs_ops;
 113        struct attribute **default_attrs;
 114        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 115        const void *(*namespace)(struct kobject *kobj);
 116};
 117
 118struct kobj_uevent_env {
 119        char *envp[UEVENT_NUM_ENVP];
 120        int envp_idx;
 121        char buf[UEVENT_BUFFER_SIZE];
 122        int buflen;
 123};
 124
 125struct kset_uevent_ops {
 126        int (* const filter)(struct kset *kset, struct kobject *kobj);
 127        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 128        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 129                      struct kobj_uevent_env *env);
 130};
 131
 132struct kobj_attribute {
 133        struct attribute attr;
 134        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 135                        char *buf);
 136        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 137                         const char *buf, size_t count);
 138};
 139
 140extern const struct sysfs_ops kobj_sysfs_ops;
 141
 142struct sock;
 143
 144/**
 145 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 146 *
 147 * A kset defines a group of kobjects.  They can be individually
 148 * different "types" but overall these kobjects all want to be grouped
 149 * together and operated on in the same manner.  ksets are used to
 150 * define the attribute callbacks and other common events that happen to
 151 * a kobject.
 152 *
 153 * @list: the list of all kobjects for this kset
 154 * @list_lock: a lock for iterating over the kobjects
 155 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 156 * @uevent_ops: the set of uevent operations for this kset.  These are
 157 * called whenever a kobject has something happen to it so that the kset
 158 * can add new environment variables, or filter out the uevents if so
 159 * desired.
 160 */
 161struct kset {
 162        struct list_head list;
 163        spinlock_t list_lock;
 164        struct kobject kobj;
 165        const struct kset_uevent_ops *uevent_ops;
 166};
 167
 168extern void kset_init(struct kset *kset);
 169extern int __must_check kset_register(struct kset *kset);
 170extern void kset_unregister(struct kset *kset);
 171extern struct kset * __must_check kset_create_and_add(const char *name,
 172                                                const struct kset_uevent_ops *u,
 173                                                struct kobject *parent_kobj);
 174
 175static inline struct kset *to_kset(struct kobject *kobj)
 176{
 177        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 178}
 179
 180static inline struct kset *kset_get(struct kset *k)
 181{
 182        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 183}
 184
 185static inline void kset_put(struct kset *k)
 186{
 187        kobject_put(&k->kobj);
 188}
 189
 190static inline struct kobj_type *get_ktype(struct kobject *kobj)
 191{
 192        return kobj->ktype;
 193}
 194
 195extern struct kobject *kset_find_obj(struct kset *, const char *);
 196extern struct kobject *kset_find_obj_hinted(struct kset *, const char *,
 197                                                struct kobject *);
 198
 199/* The global /sys/kernel/ kobject for people to chain off of */
 200extern struct kobject *kernel_kobj;
 201/* The global /sys/kernel/mm/ kobject for people to chain off of */
 202extern struct kobject *mm_kobj;
 203/* The global /sys/hypervisor/ kobject for people to chain off of */
 204extern struct kobject *hypervisor_kobj;
 205/* The global /sys/power/ kobject for people to chain off of */
 206extern struct kobject *power_kobj;
 207/* The global /sys/firmware/ kobject for people to chain off of */
 208extern struct kobject *firmware_kobj;
 209
 210#if defined(CONFIG_HOTPLUG)
 211int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 212int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 213                        char *envp[]);
 214
 215int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 216        __attribute__((format (printf, 2, 3)));
 217
 218int kobject_action_type(const char *buf, size_t count,
 219                        enum kobject_action *type);
 220#else
 221static inline int kobject_uevent(struct kobject *kobj,
 222                                 enum kobject_action action)
 223{ return 0; }
 224static inline int kobject_uevent_env(struct kobject *kobj,
 225                                      enum kobject_action action,
 226                                      char *envp[])
 227{ return 0; }
 228
 229static inline __attribute__((format(printf, 2, 3)))
 230int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 231{ return 0; }
 232
 233static inline int kobject_action_type(const char *buf, size_t count,
 234                                      enum kobject_action *type)
 235{ return -EINVAL; }
 236#endif
 237
 238#endif /* _KOBJECT_H_ */
 239