OsdSynch.c revision 71876
1/*- 2 * Copyright (c) 2000 Michael Smith 3 * Copyright (c) 2000 BSDi 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: head/sys/dev/acpica/Osd/OsdSynch.c 71876 2001-01-31 09:35:50Z msmith $ 28 */ 29 30/* 31 * 6.1 : Mutual Exclusion and Synchronisation 32 */ 33 34#include "acpi.h" 35 36#include <sys/kernel.h> 37#include <sys/malloc.h> 38#include <sys/mutex.h> 39 40#define _COMPONENT OS_DEPENDENT 41MODULE_NAME("SYNCH") 42 43static MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore"); 44 45/* disable semaphores - AML in the field doesn't use them correctly */ 46#define ACPI_NO_SEMAPHORES 47 48/* 49 * Simple counting semaphore implemented using a mutex. (Subsequently used 50 * in the OSI code to implement a mutex. Go figure.) 51 */ 52struct acpi_semaphore { 53 struct mtx as_mtx; 54 UINT32 as_units; 55 UINT32 as_maxunits; 56 char *as_name; 57}; 58 59ACPI_STATUS 60AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, ACPI_HANDLE *OutHandle) 61{ 62#ifndef ACPI_NO_SEMAPHORES 63 struct acpi_semaphore *as; 64 65 FUNCTION_TRACE(__FUNCTION__); 66 67 if (OutHandle == NULL) 68 return(AE_BAD_PARAMETER); 69 if (InitialUnits > MaxUnits) 70 return_ACPI_STATUS(AE_BAD_PARAMETER); 71 72 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT)) == NULL) 73 return_ACPI_STATUS(AE_NO_MEMORY); 74 75 mtx_init(&as->as_mtx, "ACPI semaphore", MTX_DEF); 76 as->as_units = InitialUnits; 77 as->as_maxunits = MaxUnits; 78 as->as_name = malloc(strlen(name) + 1, M_ACPISEM, M_NOWAIT); 79 strcpy(as->as_name, name); 80 81 DEBUG_PRINT(TRACE_MUTEX, ("created semaphore %p max %d, initial %d\n", 82 as, InitialUnits, MaxUnits)); 83 84 *OutHandle = (ACPI_HANDLE)as; 85 return_ACPI_STATUS(AE_OK); 86#else 87 *OutHandle = (ACPI_HANDLE)OutHandle; 88 return(AE_OK); 89#endif 90} 91 92ACPI_STATUS 93AcpiOsDeleteSemaphore (ACPI_HANDLE Handle) 94{ 95#ifndef ACPI_NO_SEMAPHORES 96 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 97 98 FUNCTION_TRACE(__FUNCTION__); 99 100#ifdef ACPI_TRACK_SEMAPHORE 101 printf("destroyed semaphore '%s' @ %p\n", as->as_name, as); 102#else 103 DEBUG_PRINT(TRACE_MUTEX, ("destroyed semaphore %p\n", as)); 104#endif 105 mtx_destroy(&as->as_mtx); 106 free(as->as_name, M_ACPISEM); 107 free(Handle, M_ACPISEM); 108 return_ACPI_STATUS(AE_OK); 109#else 110 return(AE_OK); 111#endif 112} 113 114/* 115 * This implementation has a bug, in that it has to stall for the entire 116 * timeout before it will return AE_TIME. A better implementation would 117 * use getmicrotime() to correctly adjust the timeout after being woken up. 118 */ 119ACPI_STATUS 120AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT32 Timeout) 121{ 122#ifndef ACPI_NO_SEMAPHORES 123 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 124 ACPI_STATUS result; 125 int rv, tmo; 126 127 FUNCTION_TRACE(__FUNCTION__); 128 129 if (as == NULL) 130 return_ACPI_STATUS(AE_BAD_PARAMETER); 131 132 /* a timeout of -1 means "forever" */ 133 if (Timeout == -1) { 134 tmo = 0; 135 } else { 136 /* compute timeout using microseconds per tick */ 137 tmo = (Timeout * 1000) / (1000000 / hz) 138 if (tmo <= 0) 139 tmo = 1; 140 } 141 142 mtx_enter(&as->as_mtx, MTX_DEF); 143 DEBUG_PRINT(TRACE_MUTEX, ("get %d units from semaphore %p (has %d), timeout %d\n", 144 Units, as, as->as_units, Timeout)); 145 for (;;) { 146 if (as->as_units >= Units) { 147 as->as_units -= Units; 148 result = AE_OK; 149 break; 150 } 151 if (Timeout < 0) { 152 result = AE_TIME; 153 break; 154 } 155 DEBUG_PRINT(TRACE_MUTEX, ("semaphore blocked, calling msleep(%p, %p, %d, \"acpisem\", %d)\n", 156 as, as->as_mtx, 0, tmo)); 157 for (;;) ; 158 159 rv = msleep(as, &as->as_mtx, 0, "acpisem", tmo); 160 DEBUG_PRINT(TRACE_MUTEX, ("msleep returned %d\n", rv)); 161 if (rv == EWOULDBLOCK) { 162 result = AE_TIME; 163 break; 164 } 165 } 166 mtx_exit(&as->as_mtx, MTX_DEF); 167 168 return_ACPI_STATUS(result); 169#else 170 return(AE_OK); 171#endif 172} 173 174ACPI_STATUS 175AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units) 176{ 177#ifndef ACPI_NO_SEMAPHORES 178 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 179 180 FUNCTION_TRACE(__FUNCTION__); 181 182 if (as == NULL) 183 return_ACPI_STATUS(AE_BAD_PARAMETER); 184 185 mtx_enter(&as->as_mtx, MTX_DEF); 186 DEBUG_PRINT(TRACE_MUTEX, ("return %d units to semaphore %p (has %d)\n", 187 Units, as, as->as_units)); 188 as->as_units += Units; 189 if (as->as_units > as->as_maxunits) 190 as->as_units = as->as_maxunits; 191 wakeup(as); 192 mtx_exit(&as->as_mtx, MTX_DEF); 193 return_ACPI_STATUS(AE_OK); 194#else 195 return(AE_OK); 196#endif 197} 198