1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
24 * Copyright 2017 RackTop Systems.
25 */
26
27#ifndef _SYS_MUTEX_H
28#define	_SYS_MUTEX_H
29
30#include <sys/synch.h>	/* lwp_mutex_t */
31
32#ifdef	__cplusplus
33extern "C" {
34#endif
35
36/*
37 * Public interface to mutual exclusion locks.  See mutex(9F) for details.
38 *
39 * The basic mutex type is MUTEX_ADAPTIVE, which is expected to be used
40 * in almost all of the kernel.  MUTEX_SPIN provides interrupt blocking
41 * and must be used in interrupt handlers above LOCK_LEVEL.  The iblock
42 * cookie argument to mutex_init() encodes the interrupt level to block.
43 * The iblock cookie must be NULL for adaptive locks.
44 *
45 * MUTEX_DEFAULT is the type usually specified (except in drivers) to
46 * mutex_init().  It is identical to MUTEX_ADAPTIVE.
47 *
48 * MUTEX_DRIVER is always used by drivers.  mutex_init() converts this to
49 * either MUTEX_ADAPTIVE or MUTEX_SPIN depending on the iblock cookie.
50 *
51 * Mutex statistics can be gathered on the fly, without rebooting or
52 * recompiling the kernel, via the lockstat driver (lockstat(7D)).
53 */
54typedef enum {
55	MUTEX_ADAPTIVE = 0,	/* spin if owner is running, otherwise block */
56	MUTEX_SPIN = 1,		/* block interrupts and spin */
57	MUTEX_DRIVER = 4,	/* driver (DDI) mutex */
58	MUTEX_DEFAULT = 6	/* kernel default mutex */
59} kmutex_type_t;
60
61struct _kmutex {
62	lwp_mutex_t m_lock;
63	void *m_owner;
64};
65typedef struct _kmutex kmutex_t;
66
67#if defined(_KERNEL) || defined(_FAKE_KERNEL)
68/* See the real sys/mutex.h */
69typedef struct pad_mutex {
70	kmutex_t	pad_mutex;
71#ifdef _LP64
72	char		pad_pad[64 - sizeof (kmutex_t)];
73#endif
74} pad_mutex_t;
75#endif	/* _KERNEL */
76
77extern char *volatile panicstr;  /* panic string pointer */
78
79#define	MUTEX_HELD(x)		(mutex_owned(x))
80#define	MUTEX_NOT_HELD(x)	(!mutex_owned(x) || panicstr)
81
82/*
83 * We're simulating the kernel mutex API here, and the
84 * user-level has a different signature, so rename.
85 */
86#define	mutex_init	kmutex_init
87#define	mutex_destroy	kmutex_destroy
88
89/*
90 * We want to avoid binding against the versions of these
91 * functions in libc which causes bad things to happen.
92 */
93#define	mutex_enter	kmutex_enter
94#define	mutex_exit	kmutex_exit
95
96extern	void	kmutex_init(kmutex_t *, char *, kmutex_type_t, void *);
97extern	void	kmutex_destroy(kmutex_t *);
98
99extern	void	kmutex_enter(kmutex_t *);
100extern	void	kmutex_exit(kmutex_t *);
101
102extern	int	mutex_tryenter(kmutex_t *);
103extern	int	mutex_owned(const kmutex_t *);
104
105extern	void *mutex_owner(const kmutex_t *);
106
107#ifdef	__cplusplus
108}
109#endif
110
111#endif	/* _SYS_MUTEX_H */
112