1 /* $NetBSD: lock.h,v 1.20 2017/09/17 00:01:07 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999, 2000, 2001 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, and Matthew Fredette. 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 /* 34 * Machine-dependent spin lock operations. 35 */ 36 37 #ifndef _HPPA_LOCK_H_ 38 #define _HPPA_LOCK_H_ 39 40 #include <sys/stdint.h> 41 42 #define HPPA_LDCW_ALIGN 16UL 43 44 #define __SIMPLELOCK_ALIGN(p) \ 45 (volatile unsigned long *)((((uintptr_t)(p) + HPPA_LDCW_ALIGN - 1)) & \ 46 ~(HPPA_LDCW_ALIGN - 1)) 47 48 #define __SIMPLELOCK_RAW_LOCKED 0UL 49 #define __SIMPLELOCK_RAW_UNLOCKED 1UL 50 51 static __inline int 52 __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr) 53 { 54 return *__SIMPLELOCK_ALIGN(__ptr) == __SIMPLELOCK_RAW_LOCKED; 55 } 56 57 static __inline int 58 __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr) 59 { 60 return *__SIMPLELOCK_ALIGN(__ptr) == __SIMPLELOCK_RAW_UNLOCKED; 61 } 62 63 static __inline int 64 __ldcw(volatile unsigned long *__ptr) 65 { 66 int __val; 67 68 __asm volatile("ldcw 0(%1), %0" 69 : "=r" (__val) : "r" (__ptr) 70 : "memory"); 71 72 return __val; 73 } 74 75 static __inline void 76 __sync(void) 77 { 78 79 __asm volatile("sync\n" 80 : /* no outputs */ 81 : /* no inputs */ 82 : "memory"); 83 } 84 85 static __inline void 86 __cpu_simple_lock_init(__cpu_simple_lock_t *alp) 87 { 88 alp->csl_lock[0] = alp->csl_lock[1] = 89 alp->csl_lock[2] = alp->csl_lock[3] = 90 __SIMPLELOCK_RAW_UNLOCKED; 91 __sync(); 92 } 93 94 static __inline void 95 __cpu_simple_lock(__cpu_simple_lock_t *alp) 96 { 97 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 98 99 /* 100 * Note, if we detect that the lock is held when 101 * we do the initial load-clear-word, we spin using 102 * a non-locked load to save the coherency logic 103 * some work. 104 */ 105 106 while (__ldcw(__aptr) == __SIMPLELOCK_RAW_LOCKED) 107 while (*__aptr == __SIMPLELOCK_RAW_LOCKED) 108 ; 109 } 110 111 static __inline int 112 __cpu_simple_lock_try(__cpu_simple_lock_t *alp) 113 { 114 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 115 116 return (__ldcw(__aptr) != __SIMPLELOCK_RAW_LOCKED); 117 } 118 119 static __inline void 120 __cpu_simple_unlock(__cpu_simple_lock_t *alp) 121 { 122 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 123 124 __sync(); 125 *__aptr = __SIMPLELOCK_RAW_UNLOCKED; 126 } 127 128 static __inline void 129 __cpu_simple_lock_set(__cpu_simple_lock_t *alp) 130 { 131 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 132 133 *__aptr = __SIMPLELOCK_RAW_LOCKED; 134 } 135 136 static __inline void 137 __cpu_simple_lock_clear(__cpu_simple_lock_t *alp) 138 { 139 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 140 141 *__aptr = __SIMPLELOCK_RAW_UNLOCKED; 142 } 143 144 static __inline void 145 mb_read(void) 146 { 147 __sync(); 148 } 149 150 static __inline void 151 mb_write(void) 152 { 153 __sync(); 154 } 155 156 static __inline void 157 mb_memory(void) 158 { 159 __sync(); 160 } 161 162 #endif /* _HPPA_LOCK_H_ */ 163