1 /* $NetBSD: lock.h,v 1.34 2022/02/13 13:42:21 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 2000 Ludd, University of Lule}, Sweden. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef _VAX_LOCK_H_ 29 #define _VAX_LOCK_H_ 30 31 #include <sys/param.h> 32 33 #ifdef _KERNEL 34 #ifdef _KERNEL_OPT 35 #include "opt_multiprocessor.h" 36 #include <machine/intr.h> 37 #endif 38 #include <machine/cpu.h> 39 #endif 40 41 static __inline int 42 __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr) 43 { 44 return *__ptr == __SIMPLELOCK_LOCKED; 45 } 46 47 static __inline int 48 __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr) 49 { 50 return *__ptr == __SIMPLELOCK_UNLOCKED; 51 } 52 53 static __inline void 54 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr) 55 { 56 *__ptr = __SIMPLELOCK_UNLOCKED; 57 } 58 59 static __inline void 60 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) 61 { 62 *__ptr = __SIMPLELOCK_LOCKED; 63 } 64 65 static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *); 66 static __inline void 67 __cpu_simple_lock_init(__cpu_simple_lock_t *__alp) 68 { 69 *__alp = __SIMPLELOCK_UNLOCKED; 70 } 71 72 static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *); 73 static __inline int 74 __cpu_simple_lock_try(__cpu_simple_lock_t *__alp) 75 { 76 int ret; 77 78 #ifdef _HARDKERNEL 79 __asm __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0" 80 : "=&r"(ret) 81 : "g"(__alp) 82 : "r0","r1","cc","memory"); 83 #else 84 __asm __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:" 85 : "=&r"(ret) 86 : "m"(*__alp) 87 : "cc", "memory"); 88 #endif 89 90 return ret; 91 } 92 93 static __inline void __cpu_simple_lock(__cpu_simple_lock_t *); 94 static __inline void 95 __cpu_simple_lock(__cpu_simple_lock_t *__alp) 96 { 97 #if defined(_HARDKERNEL) && defined(MULTIPROCESSOR) 98 struct cpu_info * const __ci = curcpu(); 99 100 while (__cpu_simple_lock_try(__alp) == 0) { 101 #define VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB)) 102 if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) { 103 cpu_handle_ipi(); 104 } 105 } 106 #else /* _HARDKERNEL && MULTIPROCESSOR */ 107 __asm __volatile ("1:bbssi $0,%0,1b" 108 : /* No outputs */ 109 : "m"(*__alp) 110 : "cc", "memory"); 111 #endif /* _HARDKERNEL && MULTIPROCESSOR */ 112 } 113 114 static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *); 115 static __inline void 116 __cpu_simple_unlock(__cpu_simple_lock_t *__alp) 117 { 118 #ifdef _HARDKERNEL 119 __asm __volatile ("movl %0,%%r1;jsb Sunlock" 120 : /* No output */ 121 : "g"(__alp) 122 : "r1","cc","memory"); 123 #else 124 __asm __volatile ("bbcci $0,%0,1f;1:" 125 : /* No output */ 126 : "m"(*__alp) 127 : "cc", "memory"); 128 #endif 129 } 130 131 #if defined(MULTIPROCESSOR) 132 /* 133 * On the Vax, interprocessor interrupts can come in at device priority 134 * level or lower. This can cause some problems while waiting for r/w 135 * spinlocks from a high'ish priority level: IPIs that come in will not 136 * be processed. This can lead to deadlock. 137 * 138 * This hook allows IPIs to be processed while a spinlock's interlock 139 * is released. 140 */ 141 #define SPINLOCK_SPIN_HOOK \ 142 do { \ 143 struct cpu_info * const __ci = curcpu(); \ 144 \ 145 if (__ci->ci_ipimsgs != 0) { \ 146 /* printf("CPU %lu has IPIs pending\n", \ 147 __ci->ci_cpuid); */ \ 148 cpu_handle_ipi(); \ 149 } \ 150 } while (/*CONSTCOND*/0) 151 #endif /* MULTIPROCESSOR */ 152 153 #endif /* _VAX_LOCK_H_ */ 154