1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *	klist.h - Some generic list helpers, extending struct list_head a bit.
4 *
5 *	Implementations are found in lib/klist.c
6 *
7 *	Copyright (C) 2005 Patrick Mochel
8 */
9
10#ifndef _LINUX_KLIST_H
11#define _LINUX_KLIST_H
12
13#include <linux/spinlock.h>
14#include <linux/kref.h>
15#include <linux/list.h>
16
17struct klist_node;
18struct klist {
19	spinlock_t		k_lock;
20	struct list_head	k_list;
21	void			(*get)(struct klist_node *);
22	void			(*put)(struct klist_node *);
23} __attribute__ ((aligned (sizeof(void *))));
24
25#define KLIST_INIT(_name, _get, _put)					\
26	{ .k_lock	= __SPIN_LOCK_UNLOCKED(_name.k_lock),		\
27	  .k_list	= LIST_HEAD_INIT(_name.k_list),			\
28	  .get		= _get,						\
29	  .put		= _put, }
30
31#define DEFINE_KLIST(_name, _get, _put)					\
32	struct klist _name = KLIST_INIT(_name, _get, _put)
33
34extern void klist_init(struct klist *k, void (*get)(struct klist_node *),
35		       void (*put)(struct klist_node *));
36
37struct klist_node {
38	void			*n_klist;	/* never access directly */
39	struct list_head	n_node;
40	struct kref		n_ref;
41};
42
43extern void klist_add_tail(struct klist_node *n, struct klist *k);
44extern void klist_add_head(struct klist_node *n, struct klist *k);
45extern void klist_add_behind(struct klist_node *n, struct klist_node *pos);
46extern void klist_add_before(struct klist_node *n, struct klist_node *pos);
47
48extern void klist_del(struct klist_node *n);
49extern void klist_remove(struct klist_node *n);
50
51extern int klist_node_attached(struct klist_node *n);
52
53
54struct klist_iter {
55	struct klist		*i_klist;
56	struct klist_node	*i_cur;
57};
58
59
60extern void klist_iter_init(struct klist *k, struct klist_iter *i);
61extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
62				 struct klist_node *n);
63extern void klist_iter_exit(struct klist_iter *i);
64extern struct klist_node *klist_prev(struct klist_iter *i);
65extern struct klist_node *klist_next(struct klist_iter *i);
66
67#endif
68