1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2007 Stephan Uphoff <ups@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the author nor the names of any co-contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#ifndef _SYS_RMLOCK_H_
33#define _SYS_RMLOCK_H_
34
35#include <sys/mutex.h>
36#include <sys/sx.h>
37#include <sys/_lock.h>
38#include <sys/_rmlock.h>
39
40#ifdef _KERNEL
41
42/*
43 * Flags passed to rm_init_flags(9).
44 */
45#define	RM_NOWITNESS	0x00000001
46#define	RM_RECURSE	0x00000002
47#define	RM_SLEEPABLE	0x00000004
48#define	RM_NEW		0x00000008
49#define	RM_DUPOK	0x00000010
50
51void	rm_init(struct rmlock *rm, const char *name);
52void	rm_init_flags(struct rmlock *rm, const char *name, int opts);
53void	rm_destroy(struct rmlock *rm);
54int	rm_wowned(const struct rmlock *rm);
55void	rm_sysinit(void *arg);
56
57void	_rm_wlock_debug(struct rmlock *rm, const char *file, int line);
58void	_rm_wunlock_debug(struct rmlock *rm, const char *file, int line);
59int	_rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
60	    int trylock, const char *file, int line);
61void	_rm_runlock_debug(struct rmlock *rm,  struct rm_priotracker *tracker,
62	    const char *file, int line);
63
64void	_rm_wlock(struct rmlock *rm);
65void	_rm_wunlock(struct rmlock *rm);
66int	_rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
67	    int trylock);
68void	_rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
69#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
70void	_rm_assert(const struct rmlock *rm, int what, const char *file,
71	    int line);
72#endif
73
74/*
75 * Public interface for lock operations.
76 */
77#ifndef LOCK_DEBUG
78#error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/rmlock.h>
79#endif
80
81#if LOCK_DEBUG > 0
82#define	rm_wlock(rm)	_rm_wlock_debug((rm), LOCK_FILE, LOCK_LINE)
83#define	rm_wunlock(rm)	_rm_wunlock_debug((rm), LOCK_FILE, LOCK_LINE)
84#define	rm_rlock(rm,tracker)  \
85    ((void)_rm_rlock_debug((rm),(tracker), 0, LOCK_FILE, LOCK_LINE ))
86#define	rm_try_rlock(rm,tracker)  \
87    _rm_rlock_debug((rm),(tracker), 1, LOCK_FILE, LOCK_LINE )
88#define	rm_runlock(rm,tracker)	\
89    _rm_runlock_debug((rm), (tracker), LOCK_FILE, LOCK_LINE )
90#else
91#define	rm_wlock(rm)			_rm_wlock((rm))
92#define	rm_wunlock(rm)			_rm_wunlock((rm))
93#define	rm_rlock(rm,tracker)		((void)_rm_rlock((rm),(tracker), 0))
94#define	rm_try_rlock(rm,tracker)	_rm_rlock((rm),(tracker), 1)
95#define	rm_runlock(rm,tracker)		_rm_runlock((rm), (tracker))
96#endif
97#define	rm_sleep(chan, rm, pri, wmesg, timo)				\
98	_sleep((chan), &(rm)->lock_object, (pri), (wmesg),		\
99	    tick_sbt * (timo), 0, C_HARDCLOCK)
100
101struct rm_args {
102	struct rmlock	*ra_rm;
103	const char 	*ra_desc;
104	int		ra_flags;
105};
106
107#define	RM_SYSINIT_FLAGS(name, rm, desc, flags)				\
108	static struct rm_args name##_args = {				\
109		(rm),							\
110		(desc),							\
111		(flags),						\
112	};								\
113	SYSINIT(name##_rm_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
114	    rm_sysinit, &name##_args);					\
115	SYSUNINIT(name##_rm_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
116	    rm_destroy, (rm))
117
118#define	RM_SYSINIT(name, rm, desc)	RM_SYSINIT_FLAGS(name, rm, desc, 0)
119
120#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
121#define	RA_LOCKED		LA_LOCKED
122#define	RA_RLOCKED		LA_SLOCKED
123#define	RA_WLOCKED		LA_XLOCKED
124#define	RA_UNLOCKED		LA_UNLOCKED
125#define	RA_RECURSED		LA_RECURSED
126#define	RA_NOTRECURSED		LA_NOTRECURSED
127#endif
128
129#ifdef INVARIANTS
130#define	rm_assert(rm, what)	_rm_assert((rm), (what), LOCK_FILE, LOCK_LINE)
131#else
132#define	rm_assert(rm, what)
133#endif
134
135void	rms_init(struct rmslock *rms, const char *name);
136void	rms_destroy(struct rmslock *rms);
137void	rms_rlock(struct rmslock *rms);
138int	rms_try_rlock(struct rmslock *rms);
139void	rms_runlock(struct rmslock *rms);
140void	rms_wlock(struct rmslock *rms);
141void	rms_wunlock(struct rmslock *rms);
142void	rms_unlock(struct rmslock *rms);
143
144static inline int
145rms_wowned(struct rmslock *rms)
146{
147
148	return (rms->owner == curthread);
149}
150
151#ifdef INVARIANTS
152#define rms_assert_rlock_ok(x)	\
153	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
154#else
155#define rms_assert_rlock_ok(x)
156#endif
157
158#ifdef INVARIANTS
159/*
160 * For assertion purposes.
161 *
162 * Main limitation is that we at best can tell there are readers, but not
163 * whether curthread is one of them.
164 */
165static inline int
166rms_rowned(struct rmslock *rms)
167{
168
169	return (rms->debug_readers > 0);
170}
171
172static inline int
173rms_owned_any(struct rmslock *rms)
174{
175
176	if (rms_wowned(rms))
177		return (1);
178
179	return (rms_rowned(rms));
180}
181#endif
182
183#endif /* _KERNEL */
184#endif /* !_SYS_RMLOCK_H_ */
185