drivers/acpi/acpica/exsystem.c

   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  ******************************************************************************/
  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        - 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)
 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
 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
 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
 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
 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 }