1/* $NetBSD: lock.h,v 1.3 2008/04/28 20:23:25 martin 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 39static __inline int 40__SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr) 41{ 42 return *__ptr == __SIMPLELOCK_LOCKED; 43} 44 45static __inline int 46__SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr) 47{ 48 return *__ptr == __SIMPLELOCK_UNLOCKED; 49} 50 51static __inline void 52__cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) 53{ 54 55 *__ptr = __SIMPLELOCK_LOCKED; 56} 57 58static __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 72static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *) 73 __unused; 74static __inline void __cpu_simple_lock(__cpu_simple_lock_t *) 75 __unused; 76static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *) 77 __unused; 78static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *) 79 __unused; 80 81static __inline void 82__cpu_simple_lock_init(__cpu_simple_lock_t *lockp) 83{ 84 85 *lockp = __SIMPLELOCK_UNLOCKED; 86 __insn_barrier(); 87} 88 89static __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 102static __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 111static __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