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
51 void rm_init(struct rmlock *rm, const char *name);
52 void rm_init_flags(struct rmlock *rm, const char *name, int opts);
53 void rm_destroy(struct rmlock *rm);
54 int rm_wowned(const struct rmlock *rm);
55 void rm_sysinit(void *arg);
56
57 void _rm_wlock_debug(struct rmlock *rm, const char *file, int line);
58 void _rm_wunlock_debug(struct rmlock *rm, const char *file, int line);
59 int _rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
60 int trylock, const char *file, int line);
61 void _rm_runlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
62 const char *file, int line);
63
64 void _rm_wlock(struct rmlock *rm);
65 void _rm_wunlock(struct rmlock *rm);
66 int _rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
67 int trylock);
68 void _rm_runlock(struct rmlock *rm, struct rm_priotracker *tracker);
69 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
70 void _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
101 struct 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
135 void rms_init(struct rmslock *rms, const char *name);
136 void rms_destroy(struct rmslock *rms);
137 void rms_rlock(struct rmslock *rms);
138 int rms_try_rlock(struct rmslock *rms);
139 void rms_runlock(struct rmslock *rms);
140 void rms_wlock(struct rmslock *rms);
141 void rms_wunlock(struct rmslock *rms);
142 void rms_unlock(struct rmslock *rms);
143
144 static inline int
rms_wowned(struct rmslock * rms)145 rms_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 */
165 static inline int
rms_rowned(struct rmslock * rms)166 rms_rowned(struct rmslock *rms)
167 {
168
169 return (rms->debug_readers > 0);
170 }
171
172 static inline int
rms_owned_any(struct rmslock * rms)173 rms_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