kobject.h

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/*
 * kobject.h - generic kernel object infrastructure.
 *
 * Copyright (c) 2002-2003 Patrick Mochel
 * Copyright (c) 2002-2003 Open Source Development Labs
 * Copyright (c) 2006-2008 Greg Kroah-Hartman <[email protected]>
 * Copyright (c) 2006-2008 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_

#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/kobject_ns.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/atomic.h>

#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      *name;
    struct list_head    entry;
    struct kobject      *parent;
    struct kset     *kset;
    struct kobj_type    *ktype;
    struct sysfs_dirent *sd;
    struct kref     kref;
    unsigned int state_initialized:1;
    unsigned int state_in_sysfs:1;
    unsigned int state_add_uevent_sent:1;
    unsigned int state_remove_uevent_sent:1;
    unsigned int uevent_suppress:1;
};

extern __printf(2, 3)
int kobject_set_name(struct kobject *kobj, const char *name, ...);
extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
                  va_list vargs);

static inline const char *kobject_name(const struct kobject *kobj)
{
    return kobj->name;
}

extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
extern __printf(3, 4) __must_check
int kobject_add(struct kobject *kobj, struct kobject *parent,
        const char *fmt, ...);
extern __printf(4, 5) __must_check
int kobject_init_and_add(struct kobject *kobj,
             struct kobj_type *ktype, struct kobject *parent,
             const char *fmt, ...);

extern void kobject_del(struct kobject *kobj);

extern struct kobject * __must_check kobject_create(void);
extern struct kobject * __must_check kobject_create_and_add(const char *name,
                        struct kobject *parent);

extern int __must_check kobject_rename(struct kobject *, const char *new_name);
extern int __must_check kobject_move(struct kobject *, struct kobject *);

extern struct kobject *kobject_get(struct kobject *kobj);
extern void kobject_put(struct kobject *kobj);

extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);

struct kobj_type {
    void (*release)(struct kobject *kobj);
    const struct sysfs_ops *sysfs_ops;
    struct attribute **default_attrs;
    const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
    const void *(*namespace)(struct kobject *kobj);
};

struct kobj_uevent_env {
    char *envp[UEVENT_NUM_ENVP];
    int envp_idx;
    char buf[UEVENT_BUFFER_SIZE];
    int buflen;
};

struct kset_uevent_ops {
    int (* const filter)(struct kset *kset, struct kobject *kobj);
    const char *(* const name)(struct kset *kset, struct kobject *kobj);
    int (* const uevent)(struct kset *kset, struct kobject *kobj,
              struct kobj_uevent_env *env);
};

struct kobj_attribute {
    struct attribute attr;
    ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
            char *buf);
    ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
             const char *buf, size_t count);
};

extern const struct sysfs_ops kobj_sysfs_ops;

struct sock;

struct kset {
    struct list_head list;
    spinlock_t list_lock;
    struct kobject kobj;
    const struct kset_uevent_ops *uevent_ops;
};

extern void kset_init(struct kset *kset);
extern int __must_check kset_register(struct kset *kset);
extern void kset_unregister(struct kset *kset);
extern struct kset * __must_check kset_create_and_add(const char *name,
                        const struct kset_uevent_ops *u,
                        struct kobject *parent_kobj);

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 *kobj)
{
    return kobj->ktype;
}

extern struct kobject *kset_find_obj(struct kset *, const char *);

/* The global /sys/kernel/ kobject for people to chain off of */
extern struct kobject *kernel_kobj;
/* The global /sys/kernel/mm/ kobject for people to chain off of */
extern struct kobject *mm_kobj;
/* The global /sys/hypervisor/ kobject for people to chain off of */
extern struct kobject *hypervisor_kobj;
/* The global /sys/power/ kobject for people to chain off of */
extern struct kobject *power_kobj;
/* The global /sys/firmware/ kobject for people to chain off of */
extern struct kobject *firmware_kobj;

#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[]);

__printf(2, 3)
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);

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 __printf(2, 3)
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
{ return -ENOMEM; }

static inline int kobject_action_type(const char *buf, size_t count,
                      enum kobject_action *type)
{ return -EINVAL; }
#endif

#endif /* _KOBJECT_H_ */