1 /******************************************************************************* 2 * 3 * Module Name: utxfmutex - external AML mutex access functions 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2015, Intel Corp. 9 * All rights reserved. 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 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <acpi/acpi.h> 45 #include "accommon.h" 46 #include "acnamesp.h" 47 48 #define _COMPONENT ACPI_UTILITIES 49 ACPI_MODULE_NAME("utxfmutex") 50 51 /* Local prototypes */ 52 static acpi_status 53 acpi_ut_get_mutex_object(acpi_handle handle, 54 acpi_string pathname, 55 union acpi_operand_object **ret_obj); 56 57 /******************************************************************************* 58 * 59 * FUNCTION: acpi_ut_get_mutex_object 60 * 61 * PARAMETERS: handle - Mutex or prefix handle (optional) 62 * pathname - Mutex pathname (optional) 63 * ret_obj - Where the mutex object is returned 64 * 65 * RETURN: Status 66 * 67 * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by 68 * Handle:Pathname. Either Handle or Pathname can be NULL, but 69 * not both. 70 * 71 ******************************************************************************/ 72 73 static acpi_status 74 acpi_ut_get_mutex_object(acpi_handle handle, 75 acpi_string pathname, 76 union acpi_operand_object **ret_obj) 77 { 78 struct acpi_namespace_node *mutex_node; 79 union acpi_operand_object *mutex_obj; 80 acpi_status status; 81 82 /* Parameter validation */ 83 84 if (!ret_obj || (!handle && !pathname)) { 85 return (AE_BAD_PARAMETER); 86 } 87 88 /* Get a the namespace node for the mutex */ 89 90 mutex_node = handle; 91 if (pathname != NULL) { 92 status = acpi_get_handle(handle, pathname, 93 ACPI_CAST_PTR(acpi_handle, 94 &mutex_node)); 95 if (ACPI_FAILURE(status)) { 96 return (status); 97 } 98 } 99 100 /* Ensure that we actually have a Mutex object */ 101 102 if (!mutex_node || (mutex_node->type != ACPI_TYPE_MUTEX)) { 103 return (AE_TYPE); 104 } 105 106 /* Get the low-level mutex object */ 107 108 mutex_obj = acpi_ns_get_attached_object(mutex_node); 109 if (!mutex_obj) { 110 return (AE_NULL_OBJECT); 111 } 112 113 *ret_obj = mutex_obj; 114 return (AE_OK); 115 } 116 117 /******************************************************************************* 118 * 119 * FUNCTION: acpi_acquire_mutex 120 * 121 * PARAMETERS: handle - Mutex or prefix handle (optional) 122 * pathname - Mutex pathname (optional) 123 * timeout - Max time to wait for the lock (millisec) 124 * 125 * RETURN: Status 126 * 127 * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to 128 * AML mutex objects, and allows for transaction locking between 129 * drivers and AML code. The mutex node is pointed to by 130 * Handle:Pathname. Either Handle or Pathname can be NULL, but 131 * not both. 132 * 133 ******************************************************************************/ 134 135 acpi_status 136 acpi_acquire_mutex(acpi_handle handle, acpi_string pathname, u16 timeout) 137 { 138 acpi_status status; 139 union acpi_operand_object *mutex_obj; 140 141 /* Get the low-level mutex associated with Handle:Pathname */ 142 143 status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); 144 if (ACPI_FAILURE(status)) { 145 return (status); 146 } 147 148 /* Acquire the OS mutex */ 149 150 status = acpi_os_acquire_mutex(mutex_obj->mutex.os_mutex, timeout); 151 return (status); 152 } 153 154 /******************************************************************************* 155 * 156 * FUNCTION: acpi_release_mutex 157 * 158 * PARAMETERS: handle - Mutex or prefix handle (optional) 159 * pathname - Mutex pathname (optional) 160 * 161 * RETURN: Status 162 * 163 * DESCRIPTION: Release an AML mutex. This is a device driver interface to 164 * AML mutex objects, and allows for transaction locking between 165 * drivers and AML code. The mutex node is pointed to by 166 * Handle:Pathname. Either Handle or Pathname can be NULL, but 167 * not both. 168 * 169 ******************************************************************************/ 170 171 acpi_status acpi_release_mutex(acpi_handle handle, acpi_string pathname) 172 { 173 acpi_status status; 174 union acpi_operand_object *mutex_obj; 175 176 /* Get the low-level mutex associated with Handle:Pathname */ 177 178 status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); 179 if (ACPI_FAILURE(status)) { 180 return (status); 181 } 182 183 /* Release the OS mutex */ 184 185 acpi_os_release_mutex(mutex_obj->mutex.os_mutex); 186 return (AE_OK); 187 } 188