1 /* $NetBSD: lock.h,v 1.4 2009/07/20 04:41:37 kiyohara 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Machine-dependent spin lock operations. 34 */ 35 36 #ifndef _IA64_LOCK_H_ 37 #define _IA64_LOCK_H_ 38 39 static __inline int 40 __SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr) 41 { 42 return *__ptr == __SIMPLELOCK_LOCKED; 43 } 44 45 static __inline int 46 __SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr) 47 { 48 return *__ptr == __SIMPLELOCK_UNLOCKED; 49 } 50 51 static __inline void 52 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) 53 { 54 55 *__ptr = __SIMPLELOCK_LOCKED; 56 } 57 58 static __inline void 59 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr) 60 { 61 62 *__ptr = __SIMPLELOCK_UNLOCKED; 63 } 64 65 #ifdef _KERNEL 66 67 #define SPINLOCK_SPIN_HOOK /* nothing */ 68 #define SPINLOCK_BACKOFF_HOOK /* XXX(kochi): hint@pause */ 69 70 #endif 71 72 static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *) 73 __unused; 74 static __inline void __cpu_simple_lock(__cpu_simple_lock_t *) 75 __unused; 76 static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *) 77 __unused; 78 static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *) 79 __unused; 80 81 static __inline void 82 __cpu_simple_lock_init(__cpu_simple_lock_t *lockp) 83 { 84 85 *lockp = __SIMPLELOCK_UNLOCKED; 86 __insn_barrier(); 87 } 88 89 static __inline int 90 __cpu_simple_lock_try(__cpu_simple_lock_t *lockp) 91 { 92 uint8_t val; 93 94 val = __SIMPLELOCK_LOCKED; 95 __asm volatile ("xchg1 %0=[%1],%2" : 96 "=r" (val) 97 :"r" (lockp), "r" (val) 98 :"memory"); 99 return val == __SIMPLELOCK_UNLOCKED; 100 } 101 102 static __inline void 103 __cpu_simple_lock(__cpu_simple_lock_t *lockp) 104 { 105 106 while (!__cpu_simple_lock_try(lockp)) 107 /* nothing */; 108 __insn_barrier(); 109 } 110 111 static __inline void 112 __cpu_simple_unlock(__cpu_simple_lock_t *lockp) 113 { 114 115 __insn_barrier(); 116 *lockp = __SIMPLELOCK_UNLOCKED; 117 } 118 119 #endif /* _IA64_LOCK_H_ */ 120