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 - 2025, 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(handle: semaphore, units: 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(handle: semaphore, units: 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_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(microseconds: 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
165acpi_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(milliseconds: 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
202acpi_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(handle: obj_desc->event.os_semaphore, units: 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
231acpi_status
232acpi_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(semaphore: obj_desc->event.os_semaphore,
242 timeout: (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
261acpi_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, initial_units: 0, out_handle: &temp_semaphore);
274 if (ACPI_SUCCESS(status)) {
275 (void)acpi_os_delete_semaphore(handle: obj_desc->event.os_semaphore);
276 obj_desc->event.os_semaphore = temp_semaphore;
277 }
278
279 return (status);
280}
281