1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009 Konstantin Belousov <kib@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 unmodified, this list of conditions, and the following
12 * disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef _SYS_RANGELOCK_H
30#define _SYS_RANGELOCK_H
31
32#include <sys/types.h>
33#ifndef _KERNEL
34#include <stdbool.h>
35#endif
36
37#define RL_LOCK_READ 0x0001
38#define RL_LOCK_WRITE 0x0002
39#define RL_LOCK_TYPE_MASK 0x0003
40
41struct rl_q_entry;
42
43/*
44 * The structure representing the range lock. Caller may request
45 * read or write access to the range of bytes. Access is granted if
46 * all existing lock owners are compatible with the request. Two lock
47 * owners are compatible if their ranges do not overlap, or both
48 * owners are for read.
49 */
50struct rangelock {
51 uintptr_t head;
52 bool sleepers;
53};
54
55#ifdef _KERNEL
56
57void rangelock_init(struct rangelock *lock);
58void rangelock_destroy(struct rangelock *lock);
59void rangelock_unlock(struct rangelock *lock, void *cookie);
60void *rangelock_rlock(struct rangelock *lock, vm_ooffset_t start,
61 vm_ooffset_t end);
62void *rangelock_tryrlock(struct rangelock *lock, vm_ooffset_t start,
63 vm_ooffset_t end);
64void *rangelock_wlock(struct rangelock *lock, vm_ooffset_t start,
65 vm_ooffset_t end);
66void *rangelock_trywlock(struct rangelock *lock, vm_ooffset_t start,
67 vm_ooffset_t end);
68void rangelock_may_recurse(struct rangelock *lock);
69#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
70void _rangelock_cookie_assert(void *cookie, int what, const char *file,
71 int line);
72#endif
73
74#ifdef INVARIANTS
75#define rangelock_cookie_assert_(cookie, what, file, line) \
76 _rangelock_cookie_assert((cookie), (what), (file), (line))
77#else
78#define rangelock_cookie_assert_(cookie, what, file, line) (void)0
79#endif
80
81#define rangelock_cookie_assert(cookie, what) \
82 rangelock_cookie_assert_((cookie), (what), __FILE__, __LINE__)
83
84/*
85 * Assertion flags.
86 */
87#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
88#define RCA_LOCKED 0x0001
89#define RCA_RLOCKED 0x0002
90#define RCA_WLOCKED 0x0004
91#endif
92
93#endif /* _KERNEL */
94
95#endif /* _SYS_RANGELOCK_H */