exsystem.c revision 4f3ca640e97ba54df42789a7c3085c75630e863c 
1/******************************************************************************
2 *
3 * Module Name: exsystem - Interface to OS services
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 "acinterp.h"
47
48#define _COMPONENT          ACPI_EXECUTER
49ACPI_MODULE_NAME("exsystem")
50
51/*******************************************************************************
52 *
53 * FUNCTION:    acpi_ex_system_wait_semaphore
54 *
55 * PARAMETERS:  semaphore       - Semaphore to wait on
56 *              timeout         - Max time to wait
57 *
58 * RETURN:      Status
59 *
60 * DESCRIPTION: Implements a semaphore wait with a check to see if the
61 *              semaphore is available immediately.  If it is not, the
62 *              interpreter is released before waiting.
63 *
64 ******************************************************************************/
65acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
66{
67	acpi_status status;
68
69	ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
70
71	status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
72	if (ACPI_SUCCESS(status)) {
73		return_ACPI_STATUS(status);
74	}
75
76	if (status == AE_TIME) {
77
78		/* We must wait, so unlock the interpreter */
79
80		acpi_ex_relinquish_interpreter();
81
82		status = acpi_os_wait_semaphore(semaphore, 1, timeout);
83
84		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
85				  "*** Thread awake after blocking, %s\n",
86				  acpi_format_exception(status)));
87
88		/* Reacquire the interpreter */
89
90		acpi_ex_reacquire_interpreter();
91	}
92
93	return_ACPI_STATUS(status);
94}
95
96/*******************************************************************************
97 *
98 * FUNCTION:    acpi_ex_system_wait_mutex
99 *
100 * PARAMETERS:  mutex           - Mutex to wait on
101 *              timeout         - Max time to wait
102 *
103 * RETURN:      Status
104 *
105 * DESCRIPTION: Implements a mutex wait with a check to see if the
106 *              mutex is available immediately.  If it is not, the
107 *              interpreter is released before waiting.
108 *
109 ******************************************************************************/
110
111acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
112{
113	acpi_status status;
114
115	ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
116
117	status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
118	if (ACPI_SUCCESS(status)) {
119		return_ACPI_STATUS(status);
120	}
121
122	if (status == AE_TIME) {
123
124		/* We must wait, so unlock the interpreter */
125
126		acpi_ex_relinquish_interpreter();
127
128		status = acpi_os_acquire_mutex(mutex, timeout);
129
130		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
131				  "*** Thread awake after blocking, %s\n",
132				  acpi_format_exception(status)));
133
134		/* Reacquire the interpreter */
135
136		acpi_ex_reacquire_interpreter();
137	}
138
139	return_ACPI_STATUS(status);
140}
141
142/*******************************************************************************
143 *
144 * FUNCTION:    acpi_ex_system_do_stall
145 *
146 * PARAMETERS:  how_long        - The amount of time to stall,
147 *                                in microseconds
148 *
149 * RETURN:      Status
150 *
151 * DESCRIPTION: Suspend running thread for specified amount of time.
152 *              Note: ACPI specification requires that Stall() does not
153 *              relinquish the processor, and delays longer than 100 usec
154 *              should use Sleep() instead.  We allow stalls up to 255 usec
155 *              for compatibility with other interpreters and existing BIOSs.
156 *
157 ******************************************************************************/
158
159acpi_status acpi_ex_system_do_stall(u32 how_long)
160{
161	acpi_status status = AE_OK;
162
163	ACPI_FUNCTION_ENTRY();
164
165	if (how_long > 255) {	/* 255 microseconds */
166		/*
167		 * Longer than 255 usec, this is an error
168		 *
169		 * (ACPI specifies 100 usec as max, but this gives some slack in
170		 * order to support existing BIOSs)
171		 */
172		ACPI_ERROR((AE_INFO, "Time parameter is too large (%u)",
173			    how_long));
174		status = AE_AML_OPERAND_VALUE;
175	} else {
176		acpi_os_stall(how_long);
177	}
178
179	return (status);
180}
181
182/*******************************************************************************
183 *
184 * FUNCTION:    acpi_ex_system_do_sleep
185 *
186 * PARAMETERS:  how_long        - The amount of time to sleep,
187 *                                in milliseconds
188 *
189 * RETURN:      None
190 *
191 * DESCRIPTION: Sleep the running thread for specified amount of time.
192 *
193 ******************************************************************************/
194
195acpi_status acpi_ex_system_do_sleep(u64 how_long)
196{
197	ACPI_FUNCTION_ENTRY();
198
199	/* Since this thread will sleep, we must release the interpreter */
200
201	acpi_ex_relinquish_interpreter();
202
203	/*
204	 * For compatibility with other ACPI implementations and to prevent
205	 * accidental deep sleeps, limit the sleep time to something reasonable.
206	 */
207	if (how_long > ACPI_MAX_SLEEP) {
208		how_long = ACPI_MAX_SLEEP;
209	}
210
211	acpi_os_sleep(how_long);
212
213	/* And now we must get the interpreter again */
214
215	acpi_ex_reacquire_interpreter();
216	return (AE_OK);
217}
218
219/*******************************************************************************
220 *
221 * FUNCTION:    acpi_ex_system_signal_event
222 *
223 * PARAMETERS:  obj_desc        - The object descriptor for this op
224 *
225 * RETURN:      Status
226 *
227 * DESCRIPTION: Provides an access point to perform synchronization operations
228 *              within the AML.
229 *
230 ******************************************************************************/
231
232acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
233{
234	acpi_status status = AE_OK;
235
236	ACPI_FUNCTION_TRACE(ex_system_signal_event);
237
238	if (obj_desc) {
239		status =
240		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
241	}
242
243	return_ACPI_STATUS(status);
244}
245
246/*******************************************************************************
247 *
248 * FUNCTION:    acpi_ex_system_wait_event
249 *
250 * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
251 *              obj_desc        - The object descriptor for this op
252 *
253 * RETURN:      Status
254 *
255 * DESCRIPTION: Provides an access point to perform synchronization operations
256 *              within the AML.  This operation is a request to wait for an
257 *              event.
258 *
259 ******************************************************************************/
260
261acpi_status
262acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
263			  union acpi_operand_object *obj_desc)
264{
265	acpi_status status = AE_OK;
266
267	ACPI_FUNCTION_TRACE(ex_system_wait_event);
268
269	if (obj_desc) {
270		status =
271		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
272						  (u16) time_desc->integer.
273						  value);
274	}
275
276	return_ACPI_STATUS(status);
277}
278
279/*******************************************************************************
280 *
281 * FUNCTION:    acpi_ex_system_reset_event
282 *
283 * PARAMETERS:  obj_desc        - The object descriptor for this op
284 *
285 * RETURN:      Status
286 *
287 * DESCRIPTION: Reset an event to a known state.
288 *
289 ******************************************************************************/
290
291acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
292{
293	acpi_status status = AE_OK;
294	acpi_semaphore temp_semaphore;
295
296	ACPI_FUNCTION_ENTRY();
297
298	/*
299	 * We are going to simply delete the existing semaphore and
300	 * create a new one!
301	 */
302	status =
303	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
304	if (ACPI_SUCCESS(status)) {
305		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
306		obj_desc->event.os_semaphore = temp_semaphore;
307	}
308
309	return (status);
310}
311