/* SPDX-License-Identifier: GPL-2.0-only */

  /*
   *	klist.h - Some generic list helpers, extending struct list_head a bit.
   *
   *	Implementations are found in lib/klist.c
   *

   *	Copyright (C) 2005 Patrick Mochel

   */

  #ifndef _LINUX_KLIST_H
  #define _LINUX_KLIST_H

  #include <linux/spinlock.h>

  #include <linux/kref.h>
  #include <linux/list.h>

  struct klist_node;

  struct klist {
  	spinlock_t		k_lock;
  	struct list_head	k_list;

  	void			(*get)(struct klist_node *);
  	void			(*put)(struct klist_node *);

  } __attribute__ ((aligned (sizeof(void *))));

  #define KLIST_INIT(_name, _get, _put)					\
  	{ .k_lock	= __SPIN_LOCK_UNLOCKED(_name.k_lock),		\
  	  .k_list	= LIST_HEAD_INIT(_name.k_list),			\
  	  .get		= _get,						\
  	  .put		= _put, }
  
  #define DEFINE_KLIST(_name, _get, _put)					\
  	struct klist _name = KLIST_INIT(_name, _get, _put)

  extern void klist_init(struct klist *k, void (*get)(struct klist_node *),

  		       void (*put)(struct klist_node *));

  
  struct klist_node {

  	void			*n_klist;	/* never access directly */

  	struct list_head	n_node;
  	struct kref		n_ref;

  };

  extern void klist_add_tail(struct klist_node *n, struct klist *k);
  extern void klist_add_head(struct klist_node *n, struct klist *k);

  extern void klist_add_behind(struct klist_node *n, struct klist_node *pos);

  extern void klist_add_before(struct klist_node *n, struct klist_node *pos);

  extern void klist_del(struct klist_node *n);
  extern void klist_remove(struct klist_node *n);

  extern int klist_node_attached(struct klist_node *n);

  
  struct klist_iter {

  	struct klist		*i_klist;

  	struct klist_node	*i_cur;

  };

  extern void klist_iter_init(struct klist *k, struct klist_iter *i);
  extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
  				 struct klist_node *n);
  extern void klist_iter_exit(struct klist_iter *i);

  extern struct klist_node *klist_prev(struct klist_iter *i);

  extern struct klist_node *klist_next(struct klist_iter *i);

  #endif