1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/*******************************************************************************
  3 *
  4 * Module Name: utxfmutex - external AML mutex access functions
  5 *
  6 ******************************************************************************/
  7
  8#include <acpi/acpi.h>
  9#include "accommon.h"
 10#include "acnamesp.h"
 11
 12#define _COMPONENT          ACPI_UTILITIES
 13ACPI_MODULE_NAME("utxfmutex")
 14
 15/* Local prototypes */
 16static acpi_status
 17acpi_ut_get_mutex_object(acpi_handle handle,
 18			 acpi_string pathname,
 19			 union acpi_operand_object **ret_obj);
 20
 21/*******************************************************************************
 22 *
 23 * FUNCTION:    acpi_ut_get_mutex_object
 24 *
 25 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
 26 *              pathname            - Mutex pathname (optional)
 27 *              ret_obj             - Where the mutex object is returned
 28 *
 29 * RETURN:      Status
 30 *
 31 * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by
 32 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
 33 *              not both.
 34 *
 35 ******************************************************************************/
 36
 37static acpi_status
 38acpi_ut_get_mutex_object(acpi_handle handle,
 39			 acpi_string pathname,
 40			 union acpi_operand_object **ret_obj)
 41{
 42	struct acpi_namespace_node *mutex_node;
 43	union acpi_operand_object *mutex_obj;
 44	acpi_status status;
 45
 46	/* Parameter validation */
 47
 48	if (!ret_obj || (!handle && !pathname)) {
 49		return (AE_BAD_PARAMETER);
 50	}
 51
 52	/* Get a the namespace node for the mutex */
 53
 54	mutex_node = handle;
 55	if (pathname != NULL) {
 56		status =
 57		    acpi_get_handle(handle, pathname,
 58				    ACPI_CAST_PTR(acpi_handle, &mutex_node));
 59		if (ACPI_FAILURE(status)) {
 60			return (status);
 61		}
 62	}
 63
 64	/* Ensure that we actually have a Mutex object */
 65
 66	if (!mutex_node || (mutex_node->type != ACPI_TYPE_MUTEX)) {
 67		return (AE_TYPE);
 68	}
 69
 70	/* Get the low-level mutex object */
 71
 72	mutex_obj = acpi_ns_get_attached_object(mutex_node);
 73	if (!mutex_obj) {
 74		return (AE_NULL_OBJECT);
 75	}
 76
 77	*ret_obj = mutex_obj;
 78	return (AE_OK);
 79}
 80
 81/*******************************************************************************
 82 *
 83 * FUNCTION:    acpi_acquire_mutex
 84 *
 85 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
 86 *              pathname            - Mutex pathname (optional)
 87 *              timeout             - Max time to wait for the lock (millisec)
 88 *
 89 * RETURN:      Status
 90 *
 91 * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to
 92 *              AML mutex objects, and allows for transaction locking between
 93 *              drivers and AML code. The mutex node is pointed to by
 94 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
 95 *              not both.
 96 *
 97 ******************************************************************************/
 98
 99acpi_status
100acpi_acquire_mutex(acpi_handle handle, acpi_string pathname, u16 timeout)
101{
102	acpi_status status;
103	union acpi_operand_object *mutex_obj;
104
105	/* Get the low-level mutex associated with Handle:Pathname */
106
107	status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj);
108	if (ACPI_FAILURE(status)) {
109		return (status);
110	}
111
112	/* Acquire the OS mutex */
113
114	status = acpi_os_acquire_mutex(mutex_obj->mutex.os_mutex, timeout);
115	return (status);
116}
117
118ACPI_EXPORT_SYMBOL(acpi_acquire_mutex)
119
120/*******************************************************************************
121 *
122 * FUNCTION:    acpi_release_mutex
123 *
124 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
125 *              pathname            - Mutex pathname (optional)
126 *
127 * RETURN:      Status
128 *
129 * DESCRIPTION: Release an AML mutex. This is a device driver interface to
130 *              AML mutex objects, and allows for transaction locking between
131 *              drivers and AML code. The mutex node is pointed to by
132 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
133 *              not both.
134 *
135 ******************************************************************************/
136acpi_status acpi_release_mutex(acpi_handle handle, acpi_string pathname)
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	/* Release the OS mutex */
149
150	acpi_os_release_mutex(mutex_obj->mutex.os_mutex);
151	return (AE_OK);
152}
153
154ACPI_EXPORT_SYMBOL(acpi_release_mutex)