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 - 2020, 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 ******************************************************************************/
acpi_ex_system_wait_semaphore(acpi_semaphore semaphore,u16 timeout)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
acpi_ex_system_wait_mutex(acpi_mutex mutex,u16 timeout)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 - 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
acpi_ex_system_do_stall(u32 how_long)123 acpi_status acpi_ex_system_do_stall(u32 how_long)
124 {
125 acpi_status status = AE_OK;
126
127 ACPI_FUNCTION_ENTRY();
128
129 if (how_long > 255) { /* 255 microseconds */
130 /*
131 * Longer than 255 usec, 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));
138 status = AE_AML_OPERAND_VALUE;
139 } else {
140 acpi_os_stall(how_long);
141 }
142
143 return (status);
144 }
145
146 /*******************************************************************************
147 *
148 * FUNCTION: acpi_ex_system_do_sleep
149 *
150 * PARAMETERS: how_long - The amount of time to sleep,
151 * in milliseconds
152 *
153 * RETURN: None
154 *
155 * DESCRIPTION: Sleep the running thread for specified amount of time.
156 *
157 ******************************************************************************/
158
acpi_ex_system_do_sleep(u64 how_long)159 acpi_status acpi_ex_system_do_sleep(u64 how_long)
160 {
161 ACPI_FUNCTION_ENTRY();
162
163 /* Since this thread will sleep, we must release the interpreter */
164
165 acpi_ex_exit_interpreter();
166
167 /*
168 * For compatibility with other ACPI implementations and to prevent
169 * accidental deep sleeps, limit the sleep time to something reasonable.
170 */
171 if (how_long > ACPI_MAX_SLEEP) {
172 how_long = ACPI_MAX_SLEEP;
173 }
174
175 acpi_os_sleep(how_long);
176
177 /* And now we must get the interpreter again */
178
179 acpi_ex_enter_interpreter();
180 return (AE_OK);
181 }
182
183 /*******************************************************************************
184 *
185 * FUNCTION: acpi_ex_system_signal_event
186 *
187 * PARAMETERS: obj_desc - The object descriptor for this op
188 *
189 * RETURN: Status
190 *
191 * DESCRIPTION: Provides an access point to perform synchronization operations
192 * within the AML.
193 *
194 ******************************************************************************/
195
acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)196 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
197 {
198 acpi_status status = AE_OK;
199
200 ACPI_FUNCTION_TRACE(ex_system_signal_event);
201
202 if (obj_desc) {
203 status =
204 acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
205 }
206
207 return_ACPI_STATUS(status);
208 }
209
210 /*******************************************************************************
211 *
212 * FUNCTION: acpi_ex_system_wait_event
213 *
214 * PARAMETERS: time_desc - The 'time to delay' object descriptor
215 * obj_desc - The object descriptor for this op
216 *
217 * RETURN: Status
218 *
219 * DESCRIPTION: Provides an access point to perform synchronization operations
220 * within the AML. This operation is a request to wait for an
221 * event.
222 *
223 ******************************************************************************/
224
225 acpi_status
acpi_ex_system_wait_event(union acpi_operand_object * time_desc,union acpi_operand_object * obj_desc)226 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
227 union acpi_operand_object *obj_desc)
228 {
229 acpi_status status = AE_OK;
230
231 ACPI_FUNCTION_TRACE(ex_system_wait_event);
232
233 if (obj_desc) {
234 status =
235 acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
236 (u16) time_desc->integer.
237 value);
238 }
239
240 return_ACPI_STATUS(status);
241 }
242
243 /*******************************************************************************
244 *
245 * FUNCTION: acpi_ex_system_reset_event
246 *
247 * PARAMETERS: obj_desc - The object descriptor for this op
248 *
249 * RETURN: Status
250 *
251 * DESCRIPTION: Reset an event to a known state.
252 *
253 ******************************************************************************/
254
acpi_ex_system_reset_event(union acpi_operand_object * obj_desc)255 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
256 {
257 acpi_status status = AE_OK;
258 acpi_semaphore temp_semaphore;
259
260 ACPI_FUNCTION_ENTRY();
261
262 /*
263 * We are going to simply delete the existing semaphore and
264 * create a new one!
265 */
266 status =
267 acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
268 if (ACPI_SUCCESS(status)) {
269 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
270 obj_desc->event.os_semaphore = temp_semaphore;
271 }
272
273 return (status);
274 }
275
