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 41 struct 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 */ 50 struct rangelock { 51 uintptr_t head; 52 bool sleepers; 53 }; 54 55 #ifdef _KERNEL 56 57 void rangelock_init(struct rangelock *lock); 58 void rangelock_destroy(struct rangelock *lock); 59 void rangelock_unlock(struct rangelock *lock, void *cookie); 60 void *rangelock_rlock(struct rangelock *lock, vm_ooffset_t start, 61 vm_ooffset_t end); 62 void *rangelock_tryrlock(struct rangelock *lock, vm_ooffset_t start, 63 vm_ooffset_t end); 64 void *rangelock_wlock(struct rangelock *lock, vm_ooffset_t start, 65 vm_ooffset_t end); 66 void *rangelock_trywlock(struct rangelock *lock, vm_ooffset_t start, 67 vm_ooffset_t end); 68 void rangelock_may_recurse(struct rangelock *lock); 69 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 70 void _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 */ 96