LXR linux-bk/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 *
   7 * This file is released under the GPLv2.
   8 *
   9 * 
  10 * Please read Documentation/kobject.txt before using the kobject
  11 * interface, ESPECIALLY the parts about reference counts and object
  12 * destructors. 
  13 */
  14
  15#ifndef _KOBJECT_H_
  16#define _KOBJECT_H_
  17
  18#ifdef __KERNEL__
  19
  20#include <linux/types.h>
  21#include <linux/list.h>
  22#include <linux/sysfs.h>
  23#include <linux/rwsem.h>
  24#include <linux/kref.h>
  25#include <asm/atomic.h>
  26
  27#define KOBJ_NAME_LEN   20
  28
  29struct kobject {
  30        char                    * k_name;
  31        char                    name[KOBJ_NAME_LEN];
  32        struct kref             kref;
  33        struct list_head        entry;
  34        struct kobject          * parent;
  35        struct kset             * kset;
  36        struct kobj_type        * ktype;
  37        struct dentry           * dentry;
  38};
  39
  40extern int kobject_set_name(struct kobject *, const char *, ...)
  41        __attribute__((format(printf,2,3)));
  42
  43static inline char * kobject_name(struct kobject * kobj)
  44{
  45        return kobj->k_name;
  46}
  47
  48extern void kobject_init(struct kobject *);
  49extern void kobject_cleanup(struct kobject *);
  50
  51extern int kobject_add(struct kobject *);
  52extern void kobject_del(struct kobject *);
  53
  54extern int kobject_rename(struct kobject *, char *new_name);
  55
  56extern int kobject_register(struct kobject *);
  57extern void kobject_unregister(struct kobject *);
  58
  59extern struct kobject * kobject_get(struct kobject *);
  60extern void kobject_put(struct kobject *);
  61
  62extern void kobject_hotplug(const char *action, struct kobject *);
  63
  64extern char * kobject_get_path(struct kset *, struct kobject *, int);
  65
  66struct kobj_type {
  67        void (*release)(struct kobject *);
  68        struct sysfs_ops        * sysfs_ops;
  69        struct attribute        ** default_attrs;
  70};
  71
  72
  73/**
  74 *      kset - a set of kobjects of a specific type, belonging
  75 *      to a specific subsystem.
  76 *
  77 *      All kobjects of a kset should be embedded in an identical 
  78 *      type. This type may have a descriptor, which the kset points
  79 *      to. This allows there to exist sets of objects of the same
  80 *      type in different subsystems.
  81 *
  82 *      A subsystem does not have to be a list of only one type 
  83 *      of object; multiple ksets can belong to one subsystem. All 
  84 *      ksets of a subsystem share the subsystem's lock.
  85 *
  86 *      Each kset can support hotplugging; if it does, it will be given
  87 *      the opportunity to filter out specific kobjects from being
  88 *      reported, as well as to add its own "data" elements to the
  89 *      environment being passed to the hotplug helper.
  90 */
  91struct kset_hotplug_ops {
  92        int (*filter)(struct kset *kset, struct kobject *kobj);
  93        char *(*name)(struct kset *kset, struct kobject *kobj);
  94        int (*hotplug)(struct kset *kset, struct kobject *kobj, char **envp,
  95                        int num_envp, char *buffer, int buffer_size);
  96};
  97
  98struct kset {
  99        struct subsystem        * subsys;
 100        struct kobj_type        * ktype;
 101        struct list_head        list;
 102        struct kobject          kobj;
 103        struct kset_hotplug_ops * hotplug_ops;
 104};
 105
 106
 107extern void kset_init(struct kset * k);
 108extern int kset_add(struct kset * k);
 109extern int kset_register(struct kset * k);
 110extern void kset_unregister(struct kset * k);
 111
 112static inline struct kset * to_kset(struct kobject * kobj)
 113{
 114        return kobj ? container_of(kobj,struct kset,kobj) : NULL;
 115}
 116
 117static inline struct kset * kset_get(struct kset * k)
 118{
 119        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 120}
 121
 122static inline void kset_put(struct kset * k)
 123{
 124        kobject_put(&k->kobj);
 125}
 126
 127static inline struct kobj_type * get_ktype(struct kobject * k)
 128{
 129        if (k->kset && k->kset->ktype)
 130                return k->kset->ktype;
 131        else 
 132                return k->ktype;
 133}
 134
 135extern struct kobject * kset_find_obj(struct kset *, const char *);
 136
 137
 138/**
 139 * Use this when initializing an embedded kset with no other 
 140 * fields to initialize.
 141 */
 142#define set_kset_name(str)      .kset = { .kobj = { .name = str } }
 143
 144
 145
 146struct subsystem {
 147        struct kset             kset;
 148        struct rw_semaphore     rwsem;
 149};
 150
 151#define decl_subsys(_name,_type,_hotplug_ops) \
 152struct subsystem _name##_subsys = { \
 153        .kset = { \
 154                .kobj = { .name = __stringify(_name) }, \
 155                .ktype = _type, \
 156                .hotplug_ops =_hotplug_ops, \
 157        } \
 158}
 159#define decl_subsys_name(_varname,_name,_type,_hotplug_ops) \
 160struct subsystem _varname##_subsys = { \
 161        .kset = { \
 162                .kobj = { .name = __stringify(_name) }, \
 163                .ktype = _type, \
 164                .hotplug_ops =_hotplug_ops, \
 165        } \
 166}
 167
 168
 169/**
 170 * Helpers for setting the kset of registered objects.
 171 * Often, a registered object belongs to a kset embedded in a 
 172 * subsystem. These do no magic, just make the resulting code
 173 * easier to follow. 
 174 */
 175
 176/**
 177 *      kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
 178 *      @obj:           ptr to some object type.
 179 *      @subsys:        a subsystem object (not a ptr).
 180 *
 181 *      Can be used for any object type with an embedded ->kobj.
 182 */
 183
 184#define kobj_set_kset_s(obj,subsys) \
 185        (obj)->kobj.kset = &(subsys).kset
 186
 187/**
 188 *      kset_set_kset_s(obj,subsys) - set kset for embedded kset.
 189 *      @obj:           ptr to some object type.
 190 *      @subsys:        a subsystem object (not a ptr).
 191 *
 192 *      Can be used for any object type with an embedded ->kset.
 193 *      Sets the kset of @obj's  embedded kobject (via its embedded
 194 *      kset) to @subsys.kset. This makes @obj a member of that 
 195 *      kset.
 196 */
 197
 198#define kset_set_kset_s(obj,subsys) \
 199        (obj)->kset.kobj.kset = &(subsys).kset
 200
 201/**
 202 *      subsys_set_kset(obj,subsys) - set kset for subsystem
 203 *      @obj:           ptr to some object type.
 204 *      @subsys:        a subsystem object (not a ptr).
 205 *
 206 *      Can be used for any object type with an embedded ->subsys.
 207 *      Sets the kset of @obj's kobject to @subsys.kset. This makes
 208 *      the object a member of that kset.
 209 */
 210
 211#define subsys_set_kset(obj,_subsys) \
 212        (obj)->subsys.kset.kobj.kset = &(_subsys).kset
 213
 214extern void subsystem_init(struct subsystem *);
 215extern int subsystem_register(struct subsystem *);
 216extern void subsystem_unregister(struct subsystem *);
 217
 218static inline struct subsystem * subsys_get(struct subsystem * s)
 219{
 220        return s ? container_of(kset_get(&s->kset),struct subsystem,kset) : NULL;
 221}
 222
 223static inline void subsys_put(struct subsystem * s)
 224{
 225        kset_put(&s->kset);
 226}
 227
 228struct subsys_attribute {
 229        struct attribute attr;
 230        ssize_t (*show)(struct subsystem *, char *);
 231        ssize_t (*store)(struct subsystem *, const char *, size_t); 
 232};
 233
 234extern int subsys_create_file(struct subsystem * , struct subsys_attribute *);
 235extern void subsys_remove_file(struct subsystem * , struct subsys_attribute *);
 236
 237#endif /* __KERNEL__ */
 238#endif /* _KOBJECT_H_ */
 239