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
  48 #define _COMPONENT          ACPI_EXECUTER
  49 ACPI_MODULE_NAME("exsystem")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_ex_system_wait_semaphore
  54  *
  55  * PARAMETERS:  Semaphore       - Semaphore to wait on
  56  *              Timeout         - Max time to wait
  57  *
  58  * RETURN:      Status
  59  *
  60  * DESCRIPTION: Implements a semaphore wait with a check to see if the
  61  *              semaphore is available immediately.  If it is not, the
  62  *              interpreter is released before waiting.
  63  *
  64  ******************************************************************************/
  65 acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
  66 {
  67         acpi_status status;
  68
  69         ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);
  70
  71         status = acpi_os_wait_semaphore(semaphore, 1, ACPI_DO_NOT_WAIT);
  72         if (ACPI_SUCCESS(status)) {
  73                 return_ACPI_STATUS(status);
  74         }
  75
  76         if (status == AE_TIME) {
  77
  78                 /* We must wait, so unlock the interpreter */
  79
  80                 acpi_ex_relinquish_interpreter();
  81
  82                 status = acpi_os_wait_semaphore(semaphore, 1, timeout);
  83
  84                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  85                                   "*** Thread awake after blocking, %s\n",
  86                                   acpi_format_exception(status)));
  87
  88                 /* Reacquire the interpreter */
  89
  90                 acpi_ex_reacquire_interpreter();
  91         }
  92
  93         return_ACPI_STATUS(status);
  94 }
  95
  96 /*******************************************************************************
  97  *
  98  * FUNCTION:    acpi_ex_system_wait_mutex
  99  *
 100  * PARAMETERS:  Mutex           - Mutex to wait on
 101  *              Timeout         - Max time to wait
 102  *
 103  * RETURN:      Status
 104  *
 105  * DESCRIPTION: Implements a mutex wait with a check to see if the
 106  *              mutex is available immediately.  If it is not, the
 107  *              interpreter is released before waiting.
 108  *
 109  ******************************************************************************/
 110
 111 acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
 112 {
 113         acpi_status status;
 114
 115         ACPI_FUNCTION_TRACE(ex_system_wait_mutex);
 116
 117         status = acpi_os_acquire_mutex(mutex, ACPI_DO_NOT_WAIT);
 118         if (ACPI_SUCCESS(status)) {
 119                 return_ACPI_STATUS(status);
 120         }
 121
 122         if (status == AE_TIME) {
 123
 124                 /* We must wait, so unlock the interpreter */
 125
 126                 acpi_ex_relinquish_interpreter();
 127
 128                 status = acpi_os_acquire_mutex(mutex, timeout);
 129
 130                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 131                                   "*** Thread awake after blocking, %s\n",
 132                                   acpi_format_exception(status)));
 133
 134                 /* Reacquire the interpreter */
 135
 136                 acpi_ex_reacquire_interpreter();
 137         }
 138
 139         return_ACPI_STATUS(status);
 140 }
 141
 142 /*******************************************************************************
 143  *
 144  * FUNCTION:    acpi_ex_system_do_stall
 145  *
 146  * PARAMETERS:  how_long        - The amount of time to stall,
 147  *                                in microseconds
 148  *
 149  * RETURN:      Status
 150  *
 151  * DESCRIPTION: Suspend running thread for specified amount of time.
 152  *              Note: ACPI specification requires that Stall() does not
 153  *              relinquish the processor, and delays longer than 100 usec
 154  *              should use Sleep() instead.  We allow stalls up to 255 usec
 155  *              for compatibility with other interpreters and existing BIOSs.
 156  *
 157  ******************************************************************************/
 158
 159 acpi_status acpi_ex_system_do_stall(u32 how_long)
 160 {
 161         acpi_status status = AE_OK;
 162
 163         ACPI_FUNCTION_ENTRY();
 164
 165         if (how_long > 255) {   /* 255 microseconds */
 166                 /*
 167                  * Longer than 255 usec, this is an error
 168                  *
 169                  * (ACPI specifies 100 usec as max, but this gives some slack in
 170                  * order to support existing BIOSs)
 171                  */
 172                 ACPI_ERROR((AE_INFO, "Time parameter is too large (%d)",
 173                             how_long));
 174                 status = AE_AML_OPERAND_VALUE;
 175         } else {
 176                 acpi_os_stall(how_long);
 177         }
 178
 179         return (status);
 180 }
 181
 182 /*******************************************************************************
 183  *
 184  * FUNCTION:    acpi_ex_system_do_suspend
 185  *
 186  * PARAMETERS:  how_long        - The amount of time to suspend,
 187  *                                in milliseconds
 188  *
 189  * RETURN:      None
 190  *
 191  * DESCRIPTION: Suspend running thread for specified amount of time.
 192  *
 193  ******************************************************************************/
 194
 195 acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
 196 {
 197         ACPI_FUNCTION_ENTRY();
 198
 199         /* Since this thread will sleep, we must release the interpreter */
 200
 201         acpi_ex_relinquish_interpreter();
 202
 203         acpi_os_sleep(how_long);
 204
 205         /* And now we must get the interpreter again */
 206
 207         acpi_ex_reacquire_interpreter();
 208         return (AE_OK);
 209 }
 210
 211 /*******************************************************************************
 212  *
 213  * FUNCTION:    acpi_ex_system_signal_event
 214  *
 215  * PARAMETERS:  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.
 221  *
 222  ******************************************************************************/
 223
 224 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
 225 {
 226         acpi_status status = AE_OK;
 227
 228         ACPI_FUNCTION_TRACE(ex_system_signal_event);
 229
 230         if (obj_desc) {
 231                 status =
 232                     acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
 233         }
 234
 235         return_ACPI_STATUS(status);
 236 }
 237
 238 /*******************************************************************************
 239  *
 240  * FUNCTION:    acpi_ex_system_wait_event
 241  *
 242  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 243  *              obj_desc        - The object descriptor for this op
 244  *
 245  * RETURN:      Status
 246  *
 247  * DESCRIPTION: Provides an access point to perform synchronization operations
 248  *              within the AML.  This operation is a request to wait for an
 249  *              event.
 250  *
 251  ******************************************************************************/
 252
 253 acpi_status
 254 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 255                           union acpi_operand_object *obj_desc)
 256 {
 257         acpi_status status = AE_OK;
 258
 259         ACPI_FUNCTION_TRACE(ex_system_wait_event);
 260
 261         if (obj_desc) {
 262                 status =
 263                     acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
 264                                                   (u16) time_desc->integer.
 265                                                   value);
 266         }
 267
 268         return_ACPI_STATUS(status);
 269 }
 270
 271 /*******************************************************************************
 272  *
 273  * FUNCTION:    acpi_ex_system_reset_event
 274  *
 275  * PARAMETERS:  obj_desc        - The object descriptor for this op
 276  *
 277  * RETURN:      Status
 278  *
 279  * DESCRIPTION: Reset an event to a known state.
 280  *
 281  ******************************************************************************/
 282
 283 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 284 {
 285         acpi_status status = AE_OK;
 286         acpi_semaphore temp_semaphore;
 287
 288         ACPI_FUNCTION_ENTRY();
 289
 290         /*
 291          * We are going to simply delete the existing semaphore and
 292          * create a new one!
 293          */
 294         status =
 295             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 296         if (ACPI_SUCCESS(status)) {
 297                 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
 298                 obj_desc->event.os_semaphore = temp_semaphore;
 299         }
 300
 301         return (status);
 302 }