1 /* $NetBSD: lock.h,v 1.9 2005/04/16 07:45:59 yamt Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 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. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Machine-dependent spin lock operations. 41 */ 42 43 #ifndef _X86_LOCK_H_ 44 #define _X86_LOCK_H_ 45 46 #if defined(_KERNEL_OPT) 47 #include "opt_lockdebug.h" 48 #endif 49 50 #include <machine/cpufunc.h> 51 52 #ifdef LOCKDEBUG 53 54 extern void __cpu_simple_lock_init(__cpu_simple_lock_t *); 55 extern void __cpu_simple_lock(__cpu_simple_lock_t *); 56 extern int __cpu_simple_lock_try(__cpu_simple_lock_t *); 57 extern void __cpu_simple_unlock(__cpu_simple_lock_t *); 58 59 #else 60 61 #include <machine/atomic.h> 62 63 static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *) 64 __attribute__((__unused__)); 65 static __inline void __cpu_simple_lock(__cpu_simple_lock_t *) 66 __attribute__((__unused__)); 67 static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *) 68 __attribute__((__unused__)); 69 static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *) 70 __attribute__((__unused__)); 71 72 static __inline void 73 __cpu_simple_lock_init(__cpu_simple_lock_t *lockp) 74 { 75 76 *lockp = __SIMPLELOCK_UNLOCKED; 77 __insn_barrier(); 78 } 79 80 static __inline void 81 __cpu_simple_lock(__cpu_simple_lock_t *lockp) 82 { 83 84 while (x86_atomic_testset_i(lockp, __SIMPLELOCK_LOCKED) 85 != __SIMPLELOCK_UNLOCKED) { 86 do { 87 x86_pause(); 88 } while (*lockp == __SIMPLELOCK_LOCKED); 89 } 90 __insn_barrier(); 91 } 92 93 static __inline int 94 __cpu_simple_lock_try(__cpu_simple_lock_t *lockp) 95 { 96 int r = (x86_atomic_testset_i(lockp, __SIMPLELOCK_LOCKED) 97 == __SIMPLELOCK_UNLOCKED); 98 99 __insn_barrier(); 100 101 return (r); 102 } 103 104 static __inline void 105 __cpu_simple_unlock(__cpu_simple_lock_t *lockp) 106 { 107 108 __insn_barrier(); 109 *lockp = __SIMPLELOCK_UNLOCKED; 110 } 111 112 #endif /* !LOCKDEBUG */ 113 114 #ifdef _KERNEL 115 #define SPINLOCK_SPIN_HOOK x86_pause() 116 #endif 117 118 #endif /* _X86_LOCK_H_ */ 119