xref: /openbmc/linux/drivers/acpi/acpica/exsystem.c (revision b6dcefde)
1 
2 /******************************************************************************
3  *
4  * Module Name: exsystem - Interface to OS services
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2008, Intel Corp.
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 "accommon.h"
47 #include "acinterp.h"
48 
49 #define _COMPONENT          ACPI_EXECUTER
50 ACPI_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  ******************************************************************************/
66 acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
67 {
68 	acpi_status status;
69 
70 	ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
71 
72 	status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
73 	if (ACPI_SUCCESS(status)) {
74 		return_ACPI_STATUS(status);
75 	}
76 
77 	if (status == AE_TIME) {
78 
79 		/* We must wait, so unlock the interpreter */
80 
81 		acpi_ex_relinquish_interpreter();
82 
83 		status = acpi_os_wait_semaphore(semaphore, 1, timeout);
84 
85 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
86 				  "*** Thread awake after blocking, %s\n",
87 				  acpi_format_exception(status)));
88 
89 		/* Reacquire the interpreter */
90 
91 		acpi_ex_reacquire_interpreter();
92 	}
93 
94 	return_ACPI_STATUS(status);
95 }
96 
97 /*******************************************************************************
98  *
99  * FUNCTION:    acpi_ex_system_wait_mutex
100  *
101  * PARAMETERS:  Mutex           - Mutex to wait on
102  *              Timeout         - Max time to wait
103  *
104  * RETURN:      Status
105  *
106  * DESCRIPTION: Implements a mutex wait with a check to see if the
107  *              mutex is available immediately.  If it is not, the
108  *              interpreter is released before waiting.
109  *
110  ******************************************************************************/
111 
112 acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
113 {
114 	acpi_status status;
115 
116 	ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
117 
118 	status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
119 	if (ACPI_SUCCESS(status)) {
120 		return_ACPI_STATUS(status);
121 	}
122 
123 	if (status == AE_TIME) {
124 
125 		/* We must wait, so unlock the interpreter */
126 
127 		acpi_ex_relinquish_interpreter();
128 
129 		status = acpi_os_acquire_mutex(mutex, timeout);
130 
131 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
132 				  "*** Thread awake after blocking, %s\n",
133 				  acpi_format_exception(status)));
134 
135 		/* Reacquire the interpreter */
136 
137 		acpi_ex_reacquire_interpreter();
138 	}
139 
140 	return_ACPI_STATUS(status);
141 }
142 
143 /*******************************************************************************
144  *
145  * FUNCTION:    acpi_ex_system_do_stall
146  *
147  * PARAMETERS:  how_long        - The amount of time to stall,
148  *                                in microseconds
149  *
150  * RETURN:      Status
151  *
152  * DESCRIPTION: Suspend running thread for specified amount of time.
153  *              Note: ACPI specification requires that Stall() does not
154  *              relinquish the processor, and delays longer than 100 usec
155  *              should use Sleep() instead.  We allow stalls up to 255 usec
156  *              for compatibility with other interpreters and existing BIOSs.
157  *
158  ******************************************************************************/
159 
160 acpi_status acpi_ex_system_do_stall(u32 how_long)
161 {
162 	acpi_status status = AE_OK;
163 
164 	ACPI_FUNCTION_ENTRY();
165 
166 	if (how_long > 255) {	/* 255 microseconds */
167 		/*
168 		 * Longer than 255 usec, this is an error
169 		 *
170 		 * (ACPI specifies 100 usec as max, but this gives some slack in
171 		 * order to support existing BIOSs)
172 		 */
173 		ACPI_ERROR((AE_INFO, "Time parameter is too large (%d)",
174 			    how_long));
175 		status = AE_AML_OPERAND_VALUE;
176 	} else {
177 		acpi_os_stall(how_long);
178 	}
179 
180 	return (status);
181 }
182 
183 /*******************************************************************************
184  *
185  * FUNCTION:    acpi_ex_system_do_suspend
186  *
187  * PARAMETERS:  how_long        - The amount of time to suspend,
188  *                                in milliseconds
189  *
190  * RETURN:      None
191  *
192  * DESCRIPTION: Suspend running thread for specified amount of time.
193  *
194  ******************************************************************************/
195 
196 acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
197 {
198 	ACPI_FUNCTION_ENTRY();
199 
200 	/* Since this thread will sleep, we must release the interpreter */
201 
202 	acpi_ex_relinquish_interpreter();
203 
204 	acpi_os_sleep(how_long);
205 
206 	/* And now we must get the interpreter again */
207 
208 	acpi_ex_reacquire_interpreter();
209 	return (AE_OK);
210 }
211 
212 /*******************************************************************************
213  *
214  * FUNCTION:    acpi_ex_system_signal_event
215  *
216  * PARAMETERS:  obj_desc        - The object descriptor for this op
217  *
218  * RETURN:      Status
219  *
220  * DESCRIPTION: Provides an access point to perform synchronization operations
221  *              within the AML.
222  *
223  ******************************************************************************/
224 
225 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
226 {
227 	acpi_status status = AE_OK;
228 
229 	ACPI_FUNCTION_TRACE(ex_system_signal_event);
230 
231 	if (obj_desc) {
232 		status =
233 		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
234 	}
235 
236 	return_ACPI_STATUS(status);
237 }
238 
239 /*******************************************************************************
240  *
241  * FUNCTION:    acpi_ex_system_wait_event
242  *
243  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
244  *              obj_desc        - The object descriptor for this op
245  *
246  * RETURN:      Status
247  *
248  * DESCRIPTION: Provides an access point to perform synchronization operations
249  *              within the AML.  This operation is a request to wait for an
250  *              event.
251  *
252  ******************************************************************************/
253 
254 acpi_status
255 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
256 			  union acpi_operand_object *obj_desc)
257 {
258 	acpi_status status = AE_OK;
259 
260 	ACPI_FUNCTION_TRACE(ex_system_wait_event);
261 
262 	if (obj_desc) {
263 		status =
264 		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
265 						  (u16) time_desc->integer.
266 						  value);
267 	}
268 
269 	return_ACPI_STATUS(status);
270 }
271 
272 /*******************************************************************************
273  *
274  * FUNCTION:    acpi_ex_system_reset_event
275  *
276  * PARAMETERS:  obj_desc        - The object descriptor for this op
277  *
278  * RETURN:      Status
279  *
280  * DESCRIPTION: Reset an event to a known state.
281  *
282  ******************************************************************************/
283 
284 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
285 {
286 	acpi_status status = AE_OK;
287 	acpi_semaphore temp_semaphore;
288 
289 	ACPI_FUNCTION_ENTRY();
290 
291 	/*
292 	 * We are going to simply delete the existing semaphore and
293 	 * create a new one!
294 	 */
295 	status =
296 	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
297 	if (ACPI_SUCCESS(status)) {
298 		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
299 		obj_desc->event.os_semaphore = temp_semaphore;
300 	}
301 
302 	return (status);
303 }
304