Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
1
2/******************************************************************************
3 *
4 * Module Name: exsystem - Interface to OS services
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2007, R. Byron Moore
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include <acpi/acinterp.h>
47#include <acpi/acevents.h>
48
49#define _COMPONENT ACPI_EXECUTER
50ACPI_MODULE_NAME("exsystem")
51
52/*******************************************************************************
53 *
54 * FUNCTION: acpi_ex_system_wait_semaphore
55 *
56 * PARAMETERS: Semaphore - Semaphore to wait on
57 * Timeout - Max time to wait
58 *
59 * RETURN: Status
60 *
61 * DESCRIPTION: Implements a semaphore wait with a check to see if the
62 * semaphore is available immediately. If it is not, the
63 * interpreter is released before waiting.
64 *
65 ******************************************************************************/
66acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
67{
68 acpi_status status;
69 acpi_status status2;
70
71 ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
72
73 status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
74 if (ACPI_SUCCESS(status)) {
75 return_ACPI_STATUS(status);
76 }
77
78 if (status == AE_TIME) {
79
80 /* We must wait, so unlock the interpreter */
81
82 acpi_ex_exit_interpreter();
83
84 status = acpi_os_wait_semaphore(semaphore, 1, timeout);
85
86 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
87 "*** Thread awake after blocking, %s\n",
88 acpi_format_exception(status)));
89
90 /* Reacquire the interpreter */
91
92 status2 = acpi_ex_enter_interpreter();
93 if (ACPI_FAILURE(status2)) {
94
95 /* Report fatal error, could not acquire interpreter */
96
97 return_ACPI_STATUS(status2);
98 }
99 }
100
101 return_ACPI_STATUS(status);
102}
103
104/*******************************************************************************
105 *
106 * FUNCTION: acpi_ex_system_wait_mutex
107 *
108 * PARAMETERS: Mutex - Mutex to wait on
109 * Timeout - Max time to wait
110 *
111 * RETURN: Status
112 *
113 * DESCRIPTION: Implements a mutex wait with a check to see if the
114 * mutex is available immediately. If it is not, the
115 * interpreter is released before waiting.
116 *
117 ******************************************************************************/
118
119acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
120{
121 acpi_status status;
122 acpi_status status2;
123
124 ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
125
126 status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
127 if (ACPI_SUCCESS(status)) {
128 return_ACPI_STATUS(status);
129 }
130
131 if (status == AE_TIME) {
132
133 /* We must wait, so unlock the interpreter */
134
135 acpi_ex_exit_interpreter();
136
137 status = acpi_os_acquire_mutex(mutex, timeout);
138
139 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
140 "*** Thread awake after blocking, %s\n",
141 acpi_format_exception(status)));
142
143 /* Reacquire the interpreter */
144
145 status2 = acpi_ex_enter_interpreter();
146 if (ACPI_FAILURE(status2)) {
147
148 /* Report fatal error, could not acquire interpreter */
149
150 return_ACPI_STATUS(status2);
151 }
152 }
153
154 return_ACPI_STATUS(status);
155}
156
157/*******************************************************************************
158 *
159 * FUNCTION: acpi_ex_system_do_stall
160 *
161 * PARAMETERS: how_long - The amount of time to stall,
162 * in microseconds
163 *
164 * RETURN: Status
165 *
166 * DESCRIPTION: Suspend running thread for specified amount of time.
167 * Note: ACPI specification requires that Stall() does not
168 * relinquish the processor, and delays longer than 100 usec
169 * should use Sleep() instead. We allow stalls up to 255 usec
170 * for compatibility with other interpreters and existing BIOSs.
171 *
172 ******************************************************************************/
173
174acpi_status acpi_ex_system_do_stall(u32 how_long)
175{
176 acpi_status status = AE_OK;
177
178 ACPI_FUNCTION_ENTRY();
179
180 if (how_long > 255) { /* 255 microseconds */
181 /*
182 * Longer than 255 usec, this is an error
183 *
184 * (ACPI specifies 100 usec as max, but this gives some slack in
185 * order to support existing BIOSs)
186 */
187 ACPI_ERROR((AE_INFO, "Time parameter is too large (%d)",
188 how_long));
189 status = AE_AML_OPERAND_VALUE;
190 } else {
191 acpi_os_stall(how_long);
192 }
193
194 return (status);
195}
196
197/*******************************************************************************
198 *
199 * FUNCTION: acpi_ex_system_do_suspend
200 *
201 * PARAMETERS: how_long - The amount of time to suspend,
202 * in milliseconds
203 *
204 * RETURN: None
205 *
206 * DESCRIPTION: Suspend running thread for specified amount of time.
207 *
208 ******************************************************************************/
209
210acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
211{
212 acpi_status status;
213
214 ACPI_FUNCTION_ENTRY();
215
216 /* Since this thread will sleep, we must release the interpreter */
217
218 acpi_ex_exit_interpreter();
219
220 acpi_os_sleep(how_long);
221
222 /* And now we must get the interpreter again */
223
224 status = acpi_ex_enter_interpreter();
225 return (status);
226}
227
228/*******************************************************************************
229 *
230 * FUNCTION: acpi_ex_system_signal_event
231 *
232 * PARAMETERS: obj_desc - The object descriptor for this op
233 *
234 * RETURN: Status
235 *
236 * DESCRIPTION: Provides an access point to perform synchronization operations
237 * within the AML.
238 *
239 ******************************************************************************/
240
241acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
242{
243 acpi_status status = AE_OK;
244
245 ACPI_FUNCTION_TRACE(ex_system_signal_event);
246
247 if (obj_desc) {
248 status =
249 acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
250 }
251
252 return_ACPI_STATUS(status);
253}
254
255/*******************************************************************************
256 *
257 * FUNCTION: acpi_ex_system_wait_event
258 *
259 * PARAMETERS: time_desc - The 'time to delay' object descriptor
260 * obj_desc - The object descriptor for this op
261 *
262 * RETURN: Status
263 *
264 * DESCRIPTION: Provides an access point to perform synchronization operations
265 * within the AML. This operation is a request to wait for an
266 * event.
267 *
268 ******************************************************************************/
269
270acpi_status
271acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
272 union acpi_operand_object *obj_desc)
273{
274 acpi_status status = AE_OK;
275
276 ACPI_FUNCTION_TRACE(ex_system_wait_event);
277
278 if (obj_desc) {
279 status =
280 acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
281 (u16) time_desc->integer.
282 value);
283 }
284
285 return_ACPI_STATUS(status);
286}
287
288/*******************************************************************************
289 *
290 * FUNCTION: acpi_ex_system_reset_event
291 *
292 * PARAMETERS: obj_desc - The object descriptor for this op
293 *
294 * RETURN: Status
295 *
296 * DESCRIPTION: Reset an event to a known state.
297 *
298 ******************************************************************************/
299
300acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
301{
302 acpi_status status = AE_OK;
303 acpi_semaphore temp_semaphore;
304
305 ACPI_FUNCTION_ENTRY();
306
307 /*
308 * We are going to simply delete the existing semaphore and
309 * create a new one!
310 */
311 status =
312 acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
313 if (ACPI_SUCCESS(status)) {
314 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
315 obj_desc->event.os_semaphore = temp_semaphore;
316 }
317
318 return (status);
319}