1 /* $NetBSD: lock.h,v 1.94 2024/05/12 10:45:13 rillig Exp $ */ 2 3 /*- 4 * Copyright (c) 1999, 2000, 2006, 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, by Ross Harvey, and by Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _SYS_LOCK_H_ 34 #define _SYS_LOCK_H_ 35 36 #include <sys/stdint.h> 37 #include <sys/mutex.h> 38 39 #include <machine/lock.h> 40 41 #ifdef _KERNEL 42 43 #ifdef _KERNEL_OPT 44 #include "opt_lockdebug.h" 45 #endif 46 47 /* 48 * From <machine/lock.h>. 49 */ 50 #ifndef SPINLOCK_SPIN_HOOK 51 #define SPINLOCK_SPIN_HOOK 52 #endif 53 #ifndef SPINLOCK_BACKOFF_HOOK 54 #include <sys/systm.h> 55 #define SPINLOCK_BACKOFF_HOOK nullop(NULL) 56 #endif 57 #ifndef SPINLOCK_BACKOFF_MIN 58 #define SPINLOCK_BACKOFF_MIN 4 59 #endif 60 #ifndef SPINLOCK_BACKOFF_MAX 61 #define SPINLOCK_BACKOFF_MAX 128 62 #endif 63 64 #define SPINLOCK_BACKOFF(count) \ 65 do { \ 66 int __i; \ 67 for (__i = (count); __i != 0; __i--) { \ 68 SPINLOCK_BACKOFF_HOOK; \ 69 } \ 70 if ((count) < SPINLOCK_BACKOFF_MAX) \ 71 (count) += (count); \ 72 } while (0) 73 74 #ifdef LOCKDEBUG 75 #define SPINLOCK_SPINOUT(spins) ((spins)++ > 0x0fffffff) 76 #else 77 #define SPINLOCK_SPINOUT(spins) ((void)(spins), 0) 78 #endif 79 80 extern __cpu_simple_lock_t kernel_lock[]; 81 82 #endif /* _KERNEL */ 83 84 #endif /* _SYS_LOCK_H_ */ 85