xref: /linux/drivers/acpi/acpica/exsystem.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exsystem - Interface to OS services
5  *
6  * Copyright (C) 2000 - 2023, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acinterp.h"
13 
14 #define _COMPONENT          ACPI_EXECUTER
15 ACPI_MODULE_NAME("exsystem")
16 
17 /*******************************************************************************
18  *
19  * FUNCTION:    acpi_ex_system_wait_semaphore
20  *
21  * PARAMETERS:  semaphore       - Semaphore to wait on
22  *              timeout         - Max time to wait
23  *
24  * RETURN:      Status
25  *
26  * DESCRIPTION: Implements a semaphore wait with a check to see if the
27  *              semaphore is available immediately. If it is not, the
28  *              interpreter is released before waiting.
29  *
30  ******************************************************************************/
31 acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
32 {
33 	acpi_status status;
34 
35 	ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
36 
37 	status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
38 	if (ACPI_SUCCESS(status)) {
39 		return_ACPI_STATUS(status);
40 	}
41 
42 	if (status == AE_TIME) {
43 
44 		/* We must wait, so unlock the interpreter */
45 
46 		acpi_ex_exit_interpreter();
47 		status = acpi_os_wait_semaphore(semaphore, 1, timeout);
48 
49 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
50 				  "*** Thread awake after blocking, %s\n",
51 				  acpi_format_exception(status)));
52 
53 		/* Reacquire the interpreter */
54 
55 		acpi_ex_enter_interpreter();
56 	}
57 
58 	return_ACPI_STATUS(status);
59 }
60 
61 /*******************************************************************************
62  *
63  * FUNCTION:    acpi_ex_system_wait_mutex
64  *
65  * PARAMETERS:  mutex           - Mutex to wait on
66  *              timeout         - Max time to wait
67  *
68  * RETURN:      Status
69  *
70  * DESCRIPTION: Implements a mutex wait with a check to see if the
71  *              mutex is available immediately. If it is not, the
72  *              interpreter is released before waiting.
73  *
74  ******************************************************************************/
75 
76 acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
77 {
78 	acpi_status status;
79 
80 	ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
81 
82 	status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
83 	if (ACPI_SUCCESS(status)) {
84 		return_ACPI_STATUS(status);
85 	}
86 
87 	if (status == AE_TIME) {
88 
89 		/* We must wait, so unlock the interpreter */
90 
91 		acpi_ex_exit_interpreter();
92 		status = acpi_os_acquire_mutex(mutex, timeout);
93 
94 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
95 				  "*** Thread awake after blocking, %s\n",
96 				  acpi_format_exception(status)));
97 
98 		/* Reacquire the interpreter */
99 
100 		acpi_ex_enter_interpreter();
101 	}
102 
103 	return_ACPI_STATUS(status);
104 }
105 
106 /*******************************************************************************
107  *
108  * FUNCTION:    acpi_ex_system_do_stall
109  *
110  * PARAMETERS:  how_long_us     - The amount of time to stall,
111  *                                in microseconds
112  *
113  * RETURN:      Status
114  *
115  * DESCRIPTION: Suspend running thread for specified amount of time.
116  *              Note: ACPI specification requires that Stall() does not
117  *              relinquish the processor, and delays longer than 100 usec
118  *              should use Sleep() instead. We allow stalls up to 255 usec
119  *              for compatibility with other interpreters and existing BIOSs.
120  *
121  ******************************************************************************/
122 
123 acpi_status acpi_ex_system_do_stall(u32 how_long_us)
124 {
125 	acpi_status status = AE_OK;
126 
127 	ACPI_FUNCTION_ENTRY();
128 
129 	if (how_long_us > 255) {
130 		/*
131 		 * Longer than 255 microseconds, this is an error
132 		 *
133 		 * (ACPI specifies 100 usec as max, but this gives some slack in
134 		 * order to support existing BIOSs)
135 		 */
136 		ACPI_ERROR_ONCE((AE_INFO,
137 				 "Time parameter is too large (%u)",
138 				 how_long_us));
139 		status = AE_AML_OPERAND_VALUE;
140 	} else {
141 		if (how_long_us > 100) {
142 			ACPI_WARNING_ONCE((AE_INFO,
143 					   "Time parameter %u us > 100 us violating ACPI spec, please fix the firmware.",
144 					   how_long_us));
145 		}
146 		acpi_os_stall(how_long_us);
147 	}
148 
149 	return (status);
150 }
151 
152 /*******************************************************************************
153  *
154  * FUNCTION:    acpi_ex_system_do_sleep
155  *
156  * PARAMETERS:  how_long_ms     - The amount of time to sleep,
157  *                                in milliseconds
158  *
159  * RETURN:      None
160  *
161  * DESCRIPTION: Sleep the running thread for specified amount of time.
162  *
163  ******************************************************************************/
164 
165 acpi_status acpi_ex_system_do_sleep(u64 how_long_ms)
166 {
167 	ACPI_FUNCTION_ENTRY();
168 
169 	/* Since this thread will sleep, we must release the interpreter */
170 
171 	acpi_ex_exit_interpreter();
172 
173 	/*
174 	 * For compatibility with other ACPI implementations and to prevent
175 	 * accidental deep sleeps, limit the sleep time to something reasonable.
176 	 */
177 	if (how_long_ms > ACPI_MAX_SLEEP) {
178 		how_long_ms = ACPI_MAX_SLEEP;
179 	}
180 
181 	acpi_os_sleep(how_long_ms);
182 
183 	/* And now we must get the interpreter again */
184 
185 	acpi_ex_enter_interpreter();
186 	return (AE_OK);
187 }
188 
189 /*******************************************************************************
190  *
191  * FUNCTION:    acpi_ex_system_signal_event
192  *
193  * PARAMETERS:  obj_desc        - The object descriptor for this op
194  *
195  * RETURN:      Status
196  *
197  * DESCRIPTION: Provides an access point to perform synchronization operations
198  *              within the AML.
199  *
200  ******************************************************************************/
201 
202 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
203 {
204 	acpi_status status = AE_OK;
205 
206 	ACPI_FUNCTION_TRACE(ex_system_signal_event);
207 
208 	if (obj_desc) {
209 		status =
210 		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
211 	}
212 
213 	return_ACPI_STATUS(status);
214 }
215 
216 /*******************************************************************************
217  *
218  * FUNCTION:    acpi_ex_system_wait_event
219  *
220  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
221  *              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. This operation is a request to wait for an
227  *              event.
228  *
229  ******************************************************************************/
230 
231 acpi_status
232 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
233 			  union acpi_operand_object *obj_desc)
234 {
235 	acpi_status status = AE_OK;
236 
237 	ACPI_FUNCTION_TRACE(ex_system_wait_event);
238 
239 	if (obj_desc) {
240 		status =
241 		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
242 						  (u16) time_desc->integer.
243 						  value);
244 	}
245 
246 	return_ACPI_STATUS(status);
247 }
248 
249 /*******************************************************************************
250  *
251  * FUNCTION:    acpi_ex_system_reset_event
252  *
253  * PARAMETERS:  obj_desc        - The object descriptor for this op
254  *
255  * RETURN:      Status
256  *
257  * DESCRIPTION: Reset an event to a known state.
258  *
259  ******************************************************************************/
260 
261 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
262 {
263 	acpi_status status = AE_OK;
264 	acpi_semaphore temp_semaphore;
265 
266 	ACPI_FUNCTION_ENTRY();
267 
268 	/*
269 	 * We are going to simply delete the existing semaphore and
270 	 * create a new one!
271 	 */
272 	status =
273 	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
274 	if (ACPI_SUCCESS(status)) {
275 		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
276 		obj_desc->event.os_semaphore = temp_semaphore;
277 	}
278 
279 	return (status);
280 }
281