xref: /openbmc/linux/drivers/acpi/acpica/exsystem.c (revision 4800cd83)
1 
2 /******************************************************************************
3  *
4  * Module Name: exsystem - Interface to OS services
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2011, 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 (%u)",
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_sleep
186  *
187  * PARAMETERS:  how_long        - The amount of time to sleep,
188  *                                in milliseconds
189  *
190  * RETURN:      None
191  *
192  * DESCRIPTION: Sleep the running thread for specified amount of time.
193  *
194  ******************************************************************************/
195 
196 acpi_status acpi_ex_system_do_sleep(u64 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 	/*
205 	 * For compatibility with other ACPI implementations and to prevent
206 	 * accidental deep sleeps, limit the sleep time to something reasonable.
207 	 */
208 	if (how_long > ACPI_MAX_SLEEP) {
209 		how_long = ACPI_MAX_SLEEP;
210 	}
211 
212 	acpi_os_sleep(how_long);
213 
214 	/* And now we must get the interpreter again */
215 
216 	acpi_ex_reacquire_interpreter();
217 	return (AE_OK);
218 }
219 
220 /*******************************************************************************
221  *
222  * FUNCTION:    acpi_ex_system_signal_event
223  *
224  * PARAMETERS:  obj_desc        - The object descriptor for this op
225  *
226  * RETURN:      Status
227  *
228  * DESCRIPTION: Provides an access point to perform synchronization operations
229  *              within the AML.
230  *
231  ******************************************************************************/
232 
233 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
234 {
235 	acpi_status status = AE_OK;
236 
237 	ACPI_FUNCTION_TRACE(ex_system_signal_event);
238 
239 	if (obj_desc) {
240 		status =
241 		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
242 	}
243 
244 	return_ACPI_STATUS(status);
245 }
246 
247 /*******************************************************************************
248  *
249  * FUNCTION:    acpi_ex_system_wait_event
250  *
251  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
252  *              obj_desc        - The object descriptor for this op
253  *
254  * RETURN:      Status
255  *
256  * DESCRIPTION: Provides an access point to perform synchronization operations
257  *              within the AML.  This operation is a request to wait for an
258  *              event.
259  *
260  ******************************************************************************/
261 
262 acpi_status
263 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
264 			  union acpi_operand_object *obj_desc)
265 {
266 	acpi_status status = AE_OK;
267 
268 	ACPI_FUNCTION_TRACE(ex_system_wait_event);
269 
270 	if (obj_desc) {
271 		status =
272 		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
273 						  (u16) time_desc->integer.
274 						  value);
275 	}
276 
277 	return_ACPI_STATUS(status);
278 }
279 
280 /*******************************************************************************
281  *
282  * FUNCTION:    acpi_ex_system_reset_event
283  *
284  * PARAMETERS:  obj_desc        - The object descriptor for this op
285  *
286  * RETURN:      Status
287  *
288  * DESCRIPTION: Reset an event to a known state.
289  *
290  ******************************************************************************/
291 
292 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
293 {
294 	acpi_status status = AE_OK;
295 	acpi_semaphore temp_semaphore;
296 
297 	ACPI_FUNCTION_ENTRY();
298 
299 	/*
300 	 * We are going to simply delete the existing semaphore and
301 	 * create a new one!
302 	 */
303 	status =
304 	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
305 	if (ACPI_SUCCESS(status)) {
306 		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
307 		obj_desc->event.os_semaphore = temp_semaphore;
308 	}
309 
310 	return (status);
311 }
312