/*
   * 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 <greg@kroah.com>
   * 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 - 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.

   *

   * @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 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 0; }

  
  static inline int kobject_action_type(const char *buf, size_t count,

  				      enum kobject_action *type)

  { return -EINVAL; }

  #endif

  #endif /* _KOBJECT_H_ */