aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/acpica/utxfmutex.c
blob: be24db2544ce1f6cc934ec980f53a63b61459cfd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
 *
 * Module Name: utxfmutex - external AML mutex access functions
 *
 ******************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utxfmutex")

/* Local prototypes */
static acpi_status
acpi_ut_get_mutex_object(acpi_handle handle,
			 acpi_string pathname,
			 union acpi_operand_object **ret_obj);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_mutex_object
 *
 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
 *              pathname            - Mutex pathname (optional)
 *              ret_obj             - Where the mutex object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by
 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
 *              not both.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_get_mutex_object(acpi_handle handle,
			 acpi_string pathname,
			 union acpi_operand_object **ret_obj)
{
	struct acpi_namespace_node *mutex_node;
	union acpi_operand_object *mutex_obj;
	acpi_status status;

	/* Parameter validation */

	if (!ret_obj || (!handle && !pathname)) {
		return (AE_BAD_PARAMETER);
	}

	/* Get a the namespace node for the mutex */

	mutex_node = handle;
	if (pathname != NULL) {
		status =
		    acpi_get_handle(handle, pathname,
				    ACPI_CAST_PTR(acpi_handle, &mutex_node));
		if (ACPI_FAILURE(status)) {
			return (status);
		}
	}

	/* Ensure that we actually have a Mutex object */

	if (!mutex_node || (mutex_node->type != ACPI_TYPE_MUTEX)) {
		return (AE_TYPE);
	}

	/* Get the low-level mutex object */

	mutex_obj = acpi_ns_get_attached_object(mutex_node);
	if (!mutex_obj) {
		return (AE_NULL_OBJECT);
	}

	*ret_obj = mutex_obj;
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_acquire_mutex
 *
 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
 *              pathname            - Mutex pathname (optional)
 *              timeout             - Max time to wait for the lock (millisec)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to
 *              AML mutex objects, and allows for transaction locking between
 *              drivers and AML code. The mutex node is pointed to by
 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
 *              not both.
 *
 ******************************************************************************/

acpi_status
acpi_acquire_mutex(acpi_handle handle, acpi_string pathname, u16 timeout)
{
	acpi_status status;
	union acpi_operand_object *mutex_obj;

	/* Get the low-level mutex associated with Handle:Pathname */

	status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Acquire the OS mutex */

	status = acpi_os_acquire_mutex(mutex_obj->mutex.os_mutex, timeout);
	return (status);
}

ACPI_EXPORT_SYMBOL(acpi_acquire_mutex)

/*******************************************************************************
 *
 * FUNCTION:    acpi_release_mutex
 *
 * PARAMETERS:  handle              - Mutex or prefix handle (optional)
 *              pathname            - Mutex pathname (optional)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Release an AML mutex. This is a device driver interface to
 *              AML mutex objects, and allows for transaction locking between
 *              drivers and AML code. The mutex node is pointed to by
 *              Handle:Pathname. Either Handle or Pathname can be NULL, but
 *              not both.
 *
 ******************************************************************************/
acpi_status acpi_release_mutex(acpi_handle handle, acpi_string pathname)
{
	acpi_status status;
	union acpi_operand_object *mutex_obj;

	/* Get the low-level mutex associated with Handle:Pathname */

	status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Release the OS mutex */

	acpi_os_release_mutex(mutex_obj->mutex.os_mutex);
	return (AE_OK);
}

ACPI_EXPORT_SYMBOL(acpi_release_mutex)