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 - 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 }