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
 49ACPI_MODULE_NAME("utxfmutex")
 50
 51/* Local prototypes */
 52static acpi_status
 53acpi_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
 73static acpi_status
 74acpi_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
135acpi_status
136acpi_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
171acpi_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}