/*
* kobject.h - generic kernel object infrastructure.
*
* Copyright (c) 2002-2003 Patrick Mochel
* Copyright (c) 2002-2003 Open Source Development Labs
* Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2006-2007 Novell Inc.
*
* This file is released under the GPLv2.
*
*
* Please read Documentation/kobject.txt before using the kobject
* interface, ESPECIALLY the parts about reference counts and object
* destructors.
*/
#ifndef _KOBJECT_H_
#define _KOBJECT_H_
#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/list.h>
#include <linux/sysfs.h>
#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/kref.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#define KOBJ_NAME_LEN 20
#define UEVENT_HELPER_PATH_LEN 256
#define UEVENT_NUM_ENVP 32 /* number of env pointers */
#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
/* path to the userspace helper executed on an event */
extern char uevent_helper[];
/* counter to tag the uevent, read only except for the kobject core */
extern u64 uevent_seqnum;
/*
* The actions here must match the index to the string array
* in lib/kobject_uevent.c
*
* Do not add new actions here without checking with the driver-core
* maintainers. Action strings are not meant to express subsystem
* or device specific properties. In most cases you want to send a
* kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
* specific variables added to the event environment.
*/
enum kobject_action {
KOBJ_ADD,
KOBJ_REMOVE,
KOBJ_CHANGE,
KOBJ_MOVE,
KOBJ_ONLINE,
KOBJ_OFFLINE,
KOBJ_MAX
};
struct kobject {
const char * k_name;
struct kref kref;
struct list_head entry;
struct kobject * parent;
struct kset * kset;
struct kobj_type * ktype;
struct sysfs_dirent * sd;
};
extern int kobject_set_name(struct kobject *, const char *, ...)
__attribute__((format(printf,2,3)));
static inline const char * kobject_name(const struct kobject * kobj)
{
return kobj->k_name;
}
extern void kobject_init(struct kobject *);
extern void kobject_cleanup(struct kobject *);
extern int __must_check kobject_add(struct kobject *);
extern void kobject_del(struct kobject *);
extern int __must_check kobject_rename(struct kobject *, const char *new_name);
extern int __must_check kobject_move(struct kobject *, struct kobject *);
extern int __must_check kobject_register(struct kobject *);
extern void kobject_unregister(struct kobject *);
extern struct kobject * kobject_get(struct kobject *);
extern void kobject_put(struct kobject *);
extern struct kobject *kobject_kset_add_dir(struct kset *kset,
struct kobject *, const char *);
extern struct kobject *kobject_add_dir(struct kobject *, const char *);
extern char * kobject_get_path(struct kobject *, gfp_t);
struct kobj_type {
void (*release)(struct kobject *);
struct sysfs_ops * sysfs_ops;
struct attribute ** default_attrs;
};
struct kobj_uevent_env {
char *envp[UEVENT_NUM_ENVP];
int envp_idx;
char buf[UEVENT_BUFFER_SIZE];
int buflen;
};
struct kset_uevent_ops {
int (*filter)(struct kset *kset, struct kobject *kobj);
const char *(*name)(struct kset *kset, struct kobject *kobj);
int (*uevent)(struct kset *kset, struct kobject *kobj,
struct kobj_uevent_env *env);
};
/**
* struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
*
* A kset defines a group of kobjects. They can be individually
* different "types" but overall these kobjects all want to be grouped
* together and operated on in the same manner. ksets are used to
* define the attribute callbacks and other common events that happen to
* a kobject.
*
* @ktype: the struct kobj_type for this specific kset
* @list: the list of all kobjects for this kset
* @list_lock: a lock for iterating over the kobjects
* @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
* @uevent_ops: the set of uevent operations for this kset. These are
* called whenever a kobject has something happen to it so that the kset
* can add new environment variables, or filter out the uevents if so
* desired.
*/
struct kset {
struct kobj_type *ktype;
struct list_head list;
spinlock_t list_lock;
struct kobject kobj;
struct kset_uevent_ops *uevent_ops;
};
extern void kset_init(struct kset * k);
extern int __must_check kset_add(struct kset * k);
extern int __must_check kset_register(struct kset * k);
extern void kset_unregister(struct kset * k);
static inline struct kset * to_kset(struct kobject * kobj)
{
return kobj ? container_of(kobj,struct kset,kobj) : NULL;
}
static inline struct kset * kset_get(struct kset * k)
{
return k ? to_kset(kobject_get(&k->kobj)) : NULL;
}
static inline void kset_put(struct kset * k)
{
kobject_put(&k->kobj);
}
static inline struct kobj_type * get_ktype(struct kobject * k)
{
if (k->kset && k->kset->ktype)
return k->kset->ktype;
else
return k->ktype;
}
extern struct kobject * kset_find_obj(struct kset *, const char *);
/*
* Use this when initializing an embedded kset with no other
* fields to initialize.
*/
#define set_kset_name(str) .kset = { .kobj = { .k_name = str } }
#define decl_subsys(_name,_type,_uevent_ops) \
struct kset _name##_subsys = { \
.kobj = { .k_name = __stringify(_name) }, \
.ktype = _type, \
.uevent_ops =_uevent_ops, \
}
#define decl_subsys_name(_varname,_name,_type,_uevent_ops) \
struct kset _varname##_subsys = { \
.kobj = { .k_name = __stringify(_name) }, \
.ktype = _type, \
.uevent_ops =_uevent_ops, \
}
/* The global /sys/kernel/ subsystem for people to chain off of */
extern struct kset kernel_subsys;
/* The global /sys/hypervisor/ subsystem */
extern struct kset hypervisor_subsys;
/*
* Helpers for setting the kset of registered objects.
* Often, a registered object belongs to a kset embedded in a
* subsystem. These do no magic, just make the resulting code
* easier to follow.
*/
/**
* kobj_set_kset_s(obj,subsys) - set kset for embedded kobject.
* @obj: ptr to some object type.
* @subsys: a subsystem object (not a ptr).
*
* Can be used for any object type with an embedded ->kobj.
*/
#define kobj_set_kset_s(obj,subsys) \
(obj)->kobj.kset = &(subsys)
extern int __must_check subsystem_register(struct kset *);
extern void subsystem_unregister(struct kset *);
struct subsys_attribute {
struct attribute attr;
ssize_t (*show)(struct kset *, char *);
ssize_t (*store)(struct kset *, const char *, size_t);
};
extern int __must_check subsys_create_file(struct kset *,
struct subsys_attribute *);
#if defined(CONFIG_HOTPLUG)
int kobject_uevent(struct kobject *kobj, enum kobject_action action);
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
char *envp[]);
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
__attribute__((format (printf, 2, 3)));
int kobject_action_type(const char *buf, size_t count,
enum kobject_action *type);
#else
static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action)
{ return 0; }
static inline int kobject_uevent_env(struct kobject *kobj,
enum kobject_action action,
char *envp[])
{ return 0; }
static inline int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
{ return 0; }
static inline int kobject_action_type(const char *buf, size_t count,
enum kobject_action *type)
{ return -EINVAL; }
#endif
#endif /* __KERNEL__ */
#endif /* _KOBJECT_H_ */
