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
15ACPI_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 ******************************************************************************/
31acpi_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
76acpi_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
123acpi_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((AE_INFO,
137			    "Time parameter is too large (%u)", how_long_us));
138		status = AE_AML_OPERAND_VALUE;
139	} else {
140		if (how_long_us > 100) {
141			ACPI_WARNING((AE_INFO,
142				      "Time parameter %u us > 100 us violating ACPI spec, please fix the firmware.",
143				      how_long_us));
144		}
145		acpi_os_stall(how_long_us);
146	}
147
148	return (status);
149}
150
151/*******************************************************************************
152 *
153 * FUNCTION:    acpi_ex_system_do_sleep
154 *
155 * PARAMETERS:  how_long_ms     - The amount of time to sleep,
156 *                                in milliseconds
157 *
158 * RETURN:      None
159 *
160 * DESCRIPTION: Sleep the running thread for specified amount of time.
161 *
162 ******************************************************************************/
163
164acpi_status acpi_ex_system_do_sleep(u64 how_long_ms)
165{
166	ACPI_FUNCTION_ENTRY();
167
168	/* Since this thread will sleep, we must release the interpreter */
169
170	acpi_ex_exit_interpreter();
171
172	/*
173	 * For compatibility with other ACPI implementations and to prevent
174	 * accidental deep sleeps, limit the sleep time to something reasonable.
175	 */
176	if (how_long_ms > ACPI_MAX_SLEEP) {
177		how_long_ms = ACPI_MAX_SLEEP;
178	}
179
180	acpi_os_sleep(how_long_ms);
181
182	/* And now we must get the interpreter again */
183
184	acpi_ex_enter_interpreter();
185	return (AE_OK);
186}
187
188/*******************************************************************************
189 *
190 * FUNCTION:    acpi_ex_system_signal_event
191 *
192 * PARAMETERS:  obj_desc        - The object descriptor for this op
193 *
194 * RETURN:      Status
195 *
196 * DESCRIPTION: Provides an access point to perform synchronization operations
197 *              within the AML.
198 *
199 ******************************************************************************/
200
201acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
202{
203	acpi_status status = AE_OK;
204
205	ACPI_FUNCTION_TRACE(ex_system_signal_event);
206
207	if (obj_desc) {
208		status =
209		    acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
210	}
211
212	return_ACPI_STATUS(status);
213}
214
215/*******************************************************************************
216 *
217 * FUNCTION:    acpi_ex_system_wait_event
218 *
219 * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
220 *              obj_desc        - The object descriptor for this op
221 *
222 * RETURN:      Status
223 *
224 * DESCRIPTION: Provides an access point to perform synchronization operations
225 *              within the AML. This operation is a request to wait for an
226 *              event.
227 *
228 ******************************************************************************/
229
230acpi_status
231acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
232			  union acpi_operand_object *obj_desc)
233{
234	acpi_status status = AE_OK;
235
236	ACPI_FUNCTION_TRACE(ex_system_wait_event);
237
238	if (obj_desc) {
239		status =
240		    acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
241						  (u16) time_desc->integer.
242						  value);
243	}
244
245	return_ACPI_STATUS(status);
246}
247
248/*******************************************************************************
249 *
250 * FUNCTION:    acpi_ex_system_reset_event
251 *
252 * PARAMETERS:  obj_desc        - The object descriptor for this op
253 *
254 * RETURN:      Status
255 *
256 * DESCRIPTION: Reset an event to a known state.
257 *
258 ******************************************************************************/
259
260acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
261{
262	acpi_status status = AE_OK;
263	acpi_semaphore temp_semaphore;
264
265	ACPI_FUNCTION_ENTRY();
266
267	/*
268	 * We are going to simply delete the existing semaphore and
269	 * create a new one!
270	 */
271	status =
272	    acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
273	if (ACPI_SUCCESS(status)) {
274		(void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
275		obj_desc->event.os_semaphore = temp_semaphore;
276	}
277
278	return (status);
279}
280