1a9643ea8Slogwang /*- 2*22ce4affSfengbojiang * SPDX-License-Identifier: BSD-3-Clause 3*22ce4affSfengbojiang * 4a9643ea8Slogwang * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. 5a9643ea8Slogwang * 6a9643ea8Slogwang * Redistribution and use in source and binary forms, with or without 7a9643ea8Slogwang * modification, are permitted provided that the following conditions 8a9643ea8Slogwang * are met: 9a9643ea8Slogwang * 1. Redistributions of source code must retain the above copyright 10a9643ea8Slogwang * notice, this list of conditions and the following disclaimer. 11a9643ea8Slogwang * 2. Redistributions in binary form must reproduce the above copyright 12a9643ea8Slogwang * notice, this list of conditions and the following disclaimer in the 13a9643ea8Slogwang * documentation and/or other materials provided with the distribution. 14a9643ea8Slogwang * 3. Berkeley Software Design Inc's name may not be used to endorse or 15a9643ea8Slogwang * promote products derived from this software without specific prior 16a9643ea8Slogwang * written permission. 17a9643ea8Slogwang * 18a9643ea8Slogwang * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 19a9643ea8Slogwang * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20a9643ea8Slogwang * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21a9643ea8Slogwang * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 22a9643ea8Slogwang * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23a9643ea8Slogwang * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24a9643ea8Slogwang * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25a9643ea8Slogwang * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26a9643ea8Slogwang * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27a9643ea8Slogwang * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28a9643ea8Slogwang * SUCH DAMAGE. 29a9643ea8Slogwang * 30a9643ea8Slogwang * $FreeBSD$ 31a9643ea8Slogwang */ 32a9643ea8Slogwang 33a9643ea8Slogwang #ifndef _SYS__MUTEX_H_ 34a9643ea8Slogwang #define _SYS__MUTEX_H_ 35a9643ea8Slogwang 36a9643ea8Slogwang #include <machine/param.h> 37a9643ea8Slogwang 38a9643ea8Slogwang /* 39a9643ea8Slogwang * Sleep/spin mutex. 40a9643ea8Slogwang * 41a9643ea8Slogwang * All mutex implementations must always have a member called mtx_lock. 42a9643ea8Slogwang * Other locking primitive structures are not allowed to use this name 43a9643ea8Slogwang * for their members. 44a9643ea8Slogwang * If this rule needs to change, the bits in the mutex implementation must 45a9643ea8Slogwang * be modified appropriately. 46a9643ea8Slogwang */ 47a9643ea8Slogwang struct mtx { 48a9643ea8Slogwang struct lock_object lock_object; /* Common lock properties. */ 49a9643ea8Slogwang volatile uintptr_t mtx_lock; /* Owner and flags. */ 50a9643ea8Slogwang }; 51a9643ea8Slogwang 52a9643ea8Slogwang /* 53a9643ea8Slogwang * Members of struct mtx_padalign must mirror members of struct mtx. 54a9643ea8Slogwang * mtx_padalign mutexes can use the mtx(9) API transparently without 55a9643ea8Slogwang * modification. 56a9643ea8Slogwang * Pad-aligned mutexes used within structures should generally be the 57a9643ea8Slogwang * first member of the struct. Otherwise, the compiler can generate 58a9643ea8Slogwang * additional padding for the struct to keep a correct alignment for 59a9643ea8Slogwang * the mutex. 60a9643ea8Slogwang */ 61a9643ea8Slogwang struct mtx_padalign { 62a9643ea8Slogwang struct lock_object lock_object; /* Common lock properties. */ 63a9643ea8Slogwang volatile uintptr_t mtx_lock; /* Owner and flags. */ 64a9643ea8Slogwang } __aligned(CACHE_LINE_SIZE); 65a9643ea8Slogwang 66a9643ea8Slogwang #endif /* !_SYS__MUTEX_H_ */ 67