drivers/acpi/acpica/utxfmutex.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utxfmutex - external AML mutex access functions
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, 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 }