drivers/acpi/executer/exsystem.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exsystem - Interface to OS services
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2007, R. Byron Moore
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/acevents.h>
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exsystem")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ex_system_wait_semaphore
  55  *
  56  * PARAMETERS:  Semaphore       - Semaphore to wait on
  57  *              Timeout         - Max time to wait
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Implements a semaphore wait with a check to see if the
  62  *              semaphore is available immediately.  If it is not, the
  63  *              interpreter is released before waiting.
  64  *
  65  ******************************************************************************/
  66 acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
  67 {
  68         acpi_status status;
  69
  70         ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
  71
  72         status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
  73         if (ACPI_SUCCESS(status)) {
  74                 return_ACPI_STATUS(status);
  75         }
  76
  77         if (status == AE_TIME) {
  78
  79                 /* We must wait, so unlock the interpreter */
  80
  81                 acpi_ex_relinquish_interpreter();
  82
  83                 status = acpi_os_wait_semaphore(semaphore, 1, timeout);
  84
  85                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  86                                   "*** Thread awake after blocking, %s\n",
  87                                   acpi_format_exception(status)));
  88
  89                 /* Reacquire the interpreter */
  90
  91                 acpi_ex_reacquire_interpreter();
  92         }
  93
  94         return_ACPI_STATUS(status);
  95 }
  96
  97 /*******************************************************************************
  98  *
  99  * FUNCTION:    acpi_ex_system_wait_mutex
 100  *
 101  * PARAMETERS:  Mutex           - Mutex to wait on
 102  *              Timeout         - Max time to wait
 103  *
 104  * RETURN:      Status
 105  *
 106  * DESCRIPTION: Implements a mutex wait with a check to see if the
 107  *              mutex is available immediately.  If it is not, the
 108  *              interpreter is released before waiting.
 109  *
 110  ******************************************************************************/
 111
 112 acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
 113 {
 114         acpi_status status;
 115
 116         ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
 117
 118         status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
 119         if (ACPI_SUCCESS(status)) {
 120                 return_ACPI_STATUS(status);
 121         }
 122
 123         if (status == AE_TIME) {
 124
 125                 /* We must wait, so unlock the interpreter */
 126
 127                 acpi_ex_relinquish_interpreter();
 128
 129                 status = acpi_os_acquire_mutex(mutex, timeout);
 130
 131                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 132                                   "*** Thread awake after blocking, %s\n",
 133                                   acpi_format_exception(status)));
 134
 135                 /* Reacquire the interpreter */
 136
 137                 acpi_ex_reacquire_interpreter();
 138         }
 139
 140         return_ACPI_STATUS(status);
 141 }
 142
 143 /*******************************************************************************
 144  *
 145  * FUNCTION:    acpi_ex_system_do_stall
 146  *
 147  * PARAMETERS:  how_long        - The amount of time to stall,
 148  *                                in microseconds
 149  *
 150  * RETURN:      Status
 151  *
 152  * DESCRIPTION: Suspend running thread for specified amount of time.
 153  *              Note: ACPI specification requires that Stall() does not
 154  *              relinquish the processor, and delays longer than 100 usec
 155  *              should use Sleep() instead.  We allow stalls up to 255 usec
 156  *              for compatibility with other interpreters and existing BIOSs.
 157  *
 158  ******************************************************************************/
 159
 160 acpi_status acpi_ex_system_do_stall(u32 how_long)
 161 {
 162         acpi_status status = AE_OK;
 163
 164         ACPI_FUNCTION_ENTRY();
 165
 166         if (how_long > 255) {   /* 255 microseconds */
 167                 /*
 168                  * Longer than 255 usec, this is an error
 169                  *
 170                  * (ACPI specifies 100 usec as max, but this gives some slack in
 171                  * order to support existing BIOSs)
 172                  */
 173                 ACPI_ERROR((AE_INFO, "Time parameter is too large (%d)",
 174                             how_long));
 175                 status = AE_AML_OPERAND_VALUE;
 176         } else {
 177                 acpi_os_stall(how_long);
 178         }
 179
 180         return (status);
 181 }
 182
 183 /*******************************************************************************
 184  *
 185  * FUNCTION:    acpi_ex_system_do_suspend
 186  *
 187  * PARAMETERS:  how_long        - The amount of time to suspend,
 188  *                                in milliseconds
 189  *
 190  * RETURN:      None
 191  *
 192  * DESCRIPTION: Suspend running thread for specified amount of time.
 193  *
 194  ******************************************************************************/
 195
 196 acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
 197 {
 198         ACPI_FUNCTION_ENTRY();
 199
 200         /* Since this thread will sleep, we must release the interpreter */
 201
 202         acpi_ex_relinquish_interpreter();
 203
 204         acpi_os_sleep(how_long);
 205
 206         /* And now we must get the interpreter again */
 207
 208         acpi_ex_reacquire_interpreter();
 209         return (AE_OK);
 210 }
 211
 212 /*******************************************************************************
 213  *
 214  * FUNCTION:    acpi_ex_system_signal_event
 215  *
 216  * PARAMETERS:  obj_desc        - The object descriptor for this op
 217  *
 218  * RETURN:      Status
 219  *
 220  * DESCRIPTION: Provides an access point to perform synchronization operations
 221  *              within the AML.
 222  *
 223  ******************************************************************************/
 224
 225 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
 226 {
 227         acpi_status status = AE_OK;
 228
 229         ACPI_FUNCTION_TRACE(ex_system_signal_event);
 230
 231         if (obj_desc) {
 232                 status =
 233                     acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
 234         }
 235
 236         return_ACPI_STATUS(status);
 237 }
 238
 239 /*******************************************************************************
 240  *
 241  * FUNCTION:    acpi_ex_system_wait_event
 242  *
 243  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 244  *              obj_desc        - The object descriptor for this op
 245  *
 246  * RETURN:      Status
 247  *
 248  * DESCRIPTION: Provides an access point to perform synchronization operations
 249  *              within the AML.  This operation is a request to wait for an
 250  *              event.
 251  *
 252  ******************************************************************************/
 253
 254 acpi_status
 255 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 256                           union acpi_operand_object *obj_desc)
 257 {
 258         acpi_status status = AE_OK;
 259
 260         ACPI_FUNCTION_TRACE(ex_system_wait_event);
 261
 262         if (obj_desc) {
 263                 status =
 264                     acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
 265                                                   (u16) time_desc->integer.
 266                                                   value);
 267         }
 268
 269         return_ACPI_STATUS(status);
 270 }
 271
 272 /*******************************************************************************
 273  *
 274  * FUNCTION:    acpi_ex_system_reset_event
 275  *
 276  * PARAMETERS:  obj_desc        - The object descriptor for this op
 277  *
 278  * RETURN:      Status
 279  *
 280  * DESCRIPTION: Reset an event to a known state.
 281  *
 282  ******************************************************************************/
 283
 284 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 285 {
 286         acpi_status status = AE_OK;
 287         acpi_semaphore temp_semaphore;
 288
 289         ACPI_FUNCTION_ENTRY();
 290
 291         /*
 292          * We are going to simply delete the existing semaphore and
 293          * create a new one!
 294          */
 295         status =
 296             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 297         if (ACPI_SUCCESS(status)) {
 298                 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
 299                 obj_desc->event.os_semaphore = temp_semaphore;
 300         }
 301
 302         return (status);
 303 }