xref: /openbsd-src/sys/sys/mplock.h (revision af1a00f9e0048050db8ad368227d3917fd4b7c7b)
1 /*	$OpenBSD: mplock.h,v 1.14 2024/07/03 01:36:50 jsg Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 Niklas Hallqvist.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef _MPLOCK_H_
28 #define _MPLOCK_H_
29 
30 #include <machine/mplock.h>
31 
32 #ifdef __USE_MI_MPLOCK
33 
34 #include <sys/_lock.h>
35 
36 struct __mp_lock_cpu {
37 	u_int			mplc_ticket;
38 	u_int			mplc_depth;
39 };
40 
41 struct __mp_lock {
42 	struct __mp_lock_cpu	mpl_cpus[MAXCPUS];
43 	volatile u_int		mpl_ticket;
44 	u_int			mpl_users;
45 #ifdef WITNESS
46 	struct lock_object	mpl_lock_obj;
47 #endif
48 };
49 
50 void	___mp_lock_init(struct __mp_lock *, const struct lock_type *);
51 void	__mp_lock(struct __mp_lock *);
52 void	__mp_unlock(struct __mp_lock *);
53 int	__mp_release_all(struct __mp_lock *);
54 void	__mp_acquire_count(struct __mp_lock *, int);
55 int	__mp_lock_held(struct __mp_lock *, struct cpu_info *);
56 
57 #ifdef WITNESS
58 
59 #define __mp_lock_init(mpl) do {					\
60 	static const struct lock_type __lock_type = { .lt_name = #mpl };\
61 	___mp_lock_init((mpl), &__lock_type);				\
62 } while (0)
63 
64 #else /* WITNESS */
65 
66 #define __mp_lock_init(mpl)	___mp_lock_init((mpl), NULL)
67 
68 #endif /* WITNESS */
69 
70 #endif /* __USE_MI_MPLOCK */
71 
72 extern struct __mp_lock kernel_lock;
73 
74 #endif /* !_MPLOCK_H */
75