xref: /openbmc/linux/drivers/acpi/acpica/exsystem.c (revision 82e6fdd6)
1 /******************************************************************************
2  *
3  * Module Name: exsystem - Interface to OS services
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2018, 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 		status = acpi_os_wait_semaphore(semaphore, 1, timeout);
82 
83 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
84 				  "*** Thread awake after blocking, %s\n",
85 				  acpi_format_exception(status)));
86 
87 		/* Reacquire the interpreter */
88 
89 		acpi_ex_enter_interpreter();
90 	}
91 
92 	return_ACPI_STATUS(status);
93 }
94 
95 /*******************************************************************************
96  *
97  * FUNCTION:    acpi_ex_system_wait_mutex
98  *
99  * PARAMETERS:  mutex           - Mutex to wait on
100  *              timeout         - Max time to wait
101  *
102  * RETURN:      Status
103  *
104  * DESCRIPTION: Implements a mutex wait with a check to see if the
105  *              mutex is available immediately. If it is not, the
106  *              interpreter is released before waiting.
107  *
108  ******************************************************************************/
109 
110 acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
111 {
112 	acpi_status status;
113 
114 	ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
115 
116 	status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
117 	if (ACPI_SUCCESS(status)) {
118 		return_ACPI_STATUS(status);
119 	}
120 
121 	if (status == AE_TIME) {
122 
123 		/* We must wait, so unlock the interpreter */
124 
125 		acpi_ex_exit_interpreter();
126 		status = acpi_os_acquire_mutex(mutex, timeout);
127 
128 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
129 				  "*** Thread awake after blocking, %s\n",
130 				  acpi_format_exception(status)));
131 
132 		/* Reacquire the interpreter */
133 
134 		acpi_ex_enter_interpreter();
135 	}
136 
137 	return_ACPI_STATUS(status);
138 }
139 
140 /*******************************************************************************
141  *
142  * FUNCTION:    acpi_ex_system_do_stall
143  *
144  * PARAMETERS:  how_long        - The amount of time to stall,
145  *                                in microseconds
146  *
147  * RETURN:      Status
148  *
149  * DESCRIPTION: Suspend running thread for specified amount of time.
150  *              Note: ACPI specification requires that Stall() does not
151  *              relinquish the processor, and delays longer than 100 usec
152  *              should use Sleep() instead. We allow stalls up to 255 usec
153  *              for compatibility with other interpreters and existing BIOSs.
154  *
155  ******************************************************************************/
156 
157 acpi_status acpi_ex_system_do_stall(u32 how_long)
158 {
159 	acpi_status status = AE_OK;
160 
161 	ACPI_FUNCTION_ENTRY();
162 
163 	if (how_long > 255) {	/* 255 microseconds */
164 		/*
165 		 * Longer than 255 usec, this is an error
166 		 *
167 		 * (ACPI specifies 100 usec as max, but this gives some slack in
168 		 * order to support existing BIOSs)
169 		 */
170 		ACPI_ERROR((AE_INFO,
171 			    "Time parameter is too large (%u)", how_long));
172 		status = AE_AML_OPERAND_VALUE;
173 	} else {
174 		acpi_os_stall(how_long);
175 	}
176 
177 	return (status);
178 }
179 
180 /*******************************************************************************
181  *
182  * FUNCTION:    acpi_ex_system_do_sleep
183  *
184  * PARAMETERS:  how_long        - The amount of time to sleep,
185  *                                in milliseconds
186  *
187  * RETURN:      None
188  *
189  * DESCRIPTION: Sleep the running thread for specified amount of time.
190  *
191  ******************************************************************************/
192 
193 acpi_status acpi_ex_system_do_sleep(u64 how_long)
194 {
195 	ACPI_FUNCTION_ENTRY();
196 
197 	/* Since this thread will sleep, we must release the interpreter */
198 
199 	acpi_ex_exit_interpreter();
200 
201 	/*
202 	 * For compatibility with other ACPI implementations and to prevent
203 	 * accidental deep sleeps, limit the sleep time to something reasonable.
204 	 */
205 	if (how_long > ACPI_MAX_SLEEP) {
206 		how_long = ACPI_MAX_SLEEP;
207 	}
208 
209 	acpi_os_sleep(how_long);
210 
211 	/* And now we must get the interpreter again */
212 
213 	acpi_ex_enter_interpreter();
214 	return (AE_OK);
215 }
216 
217 /*******************************************************************************
218  *
219  * FUNCTION:    acpi_ex_system_signal_event
220  *
221  * PARAMETERS:  obj_desc        - The object descriptor for this op
222  *
223  * RETURN:      Status
224  *
225  * DESCRIPTION: Provides an access point to perform synchronization operations
226  *              within the AML.
227  *
228  ******************************************************************************/
229 
230 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
231 {
232 	acpi_status status = AE_OK;
233 
234 	ACPI_FUNCTION_TRACE(ex_system_signal_event);
235 
236 	if (obj_desc) {
237 		status =
238 		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
239 	}
240 
241 	return_ACPI_STATUS(status);
242 }
243 
244 /*******************************************************************************
245  *
246  * FUNCTION:    acpi_ex_system_wait_event
247  *
248  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
249  *              obj_desc        - The object descriptor for this op
250  *
251  * RETURN:      Status
252  *
253  * DESCRIPTION: Provides an access point to perform synchronization operations
254  *              within the AML. This operation is a request to wait for an
255  *              event.
256  *
257  ******************************************************************************/
258 
259 acpi_status
260 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
261 			  union acpi_operand_object *obj_desc)
262 {
263 	acpi_status status = AE_OK;
264 
265 	ACPI_FUNCTION_TRACE(ex_system_wait_event);
266 
267 	if (obj_desc) {
268 		status =
269 		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
270 						  (u16) time_desc->integer.
271 						  value);
272 	}
273 
274 	return_ACPI_STATUS(status);
275 }
276 
277 /*******************************************************************************
278  *
279  * FUNCTION:    acpi_ex_system_reset_event
280  *
281  * PARAMETERS:  obj_desc        - The object descriptor for this op
282  *
283  * RETURN:      Status
284  *
285  * DESCRIPTION: Reset an event to a known state.
286  *
287  ******************************************************************************/
288 
289 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
290 {
291 	acpi_status status = AE_OK;
292 	acpi_semaphore temp_semaphore;
293 
294 	ACPI_FUNCTION_ENTRY();
295 
296 	/*
297 	 * We are going to simply delete the existing semaphore and
298 	 * create a new one!
299 	 */
300 	status =
301 	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
302 	if (ACPI_SUCCESS(status)) {
303 		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
304 		obj_desc->event.os_semaphore = temp_semaphore;
305 	}
306 
307 	return (status);
308 }
309