1/* $OpenBSD: pclock.h,v 1.1 2025/05/31 10:24:50 dlg Exp $ */
2
3/*
4 * Copyright (c) 2023 David Gwynne <dlg@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#ifndef _SYS_PCLOCK_H
20#define _SYS_PCLOCK_H
21
22#include <sys/_lock.h>
23
24struct pc_lock {
25 volatile unsigned int pcl_gen;
26};
27
28#ifdef _KERNEL
29
30#define PC_LOCK_INITIALIZER() { .pcl_gen = 0 }
31
32void pc_lock_init(struct pc_lock *);
33
34/* single (non-interlocking) producer */
35unsigned int pc_sprod_enter(struct pc_lock *);
36void pc_sprod_leave(struct pc_lock *, unsigned int);
37
38/* multiple (interlocking) producers */
39unsigned int pc_mprod_enter(struct pc_lock *);
40void pc_mprod_leave(struct pc_lock *, unsigned int);
41
42/* consumer */
43void pc_cons_enter(struct pc_lock *, unsigned int *);
44__warn_unused_result int
45 pc_cons_leave(struct pc_lock *, unsigned int *);
46
47#endif /* _KERNEL */
48
49#endif /* _SYS_PCLOCK_H */