xref: /openbmc/linux/drivers/acpi/acpica/exsystem.c (revision 275876e2)
1 /******************************************************************************
2  *
3  * Module Name: exsystem - Interface to OS services
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2014, 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
49 ACPI_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  ******************************************************************************/
65 acpi_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_exit_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_enter_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 
111 acpi_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_exit_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_enter_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 
159 acpi_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 
195 acpi_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_exit_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_enter_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 
232 acpi_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 
261 acpi_status
262 acpi_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 
291 acpi_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