drivers/acpi/acpica/exsystem.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exsystem - Interface to OS services
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "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 (%u)",
 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_sleep
 185  *
 186  * PARAMETERS:  how_long        - The amount of time to sleep,
 187  *                                in milliseconds
 188  *
 189  * RETURN:      None
 190  *
 191  * DESCRIPTION: Sleep the running thread for specified amount of time.
 192  *
 193  ******************************************************************************/
 194
 195 acpi_status acpi_ex_system_do_sleep(u64 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         /*
 204          * For compatibility with other ACPI implementations and to prevent
 205          * accidental deep sleeps, limit the sleep time to something reasonable.
 206          */
 207         if (how_long > ACPI_MAX_SLEEP) {
 208                 how_long = ACPI_MAX_SLEEP;
 209         }
 210
 211         acpi_os_sleep(how_long);
 212
 213         /* And now we must get the interpreter again */
 214
 215         acpi_ex_reacquire_interpreter();
 216         return (AE_OK);
 217 }
 218
 219 /*******************************************************************************
 220  *
 221  * FUNCTION:    acpi_ex_system_signal_event
 222  *
 223  * PARAMETERS:  obj_desc        - The object descriptor for this op
 224  *
 225  * RETURN:      Status
 226  *
 227  * DESCRIPTION: Provides an access point to perform synchronization operations
 228  *              within the AML.
 229  *
 230  ******************************************************************************/
 231
 232 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
 233 {
 234         acpi_status status = AE_OK;
 235
 236         ACPI_FUNCTION_TRACE(ex_system_signal_event);
 237
 238         if (obj_desc) {
 239                 status =
 240                     acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
 241         }
 242
 243         return_ACPI_STATUS(status);
 244 }
 245
 246 /*******************************************************************************
 247  *
 248  * FUNCTION:    acpi_ex_system_wait_event
 249  *
 250  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 251  *              obj_desc        - The object descriptor for this op
 252  *
 253  * RETURN:      Status
 254  *
 255  * DESCRIPTION: Provides an access point to perform synchronization operations
 256  *              within the AML. This operation is a request to wait for an
 257  *              event.
 258  *
 259  ******************************************************************************/
 260
 261 acpi_status
 262 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 263                           union acpi_operand_object *obj_desc)
 264 {
 265         acpi_status status = AE_OK;
 266
 267         ACPI_FUNCTION_TRACE(ex_system_wait_event);
 268
 269         if (obj_desc) {
 270                 status =
 271                     acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
 272                                                   (u16) time_desc->integer.
 273                                                   value);
 274         }
 275
 276         return_ACPI_STATUS(status);
 277 }
 278
 279 /*******************************************************************************
 280  *
 281  * FUNCTION:    acpi_ex_system_reset_event
 282  *
 283  * PARAMETERS:  obj_desc        - The object descriptor for this op
 284  *
 285  * RETURN:      Status
 286  *
 287  * DESCRIPTION: Reset an event to a known state.
 288  *
 289  ******************************************************************************/
 290
 291 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 292 {
 293         acpi_status status = AE_OK;
 294         acpi_semaphore temp_semaphore;
 295
 296         ACPI_FUNCTION_ENTRY();
 297
 298         /*
 299          * We are going to simply delete the existing semaphore and
 300          * create a new one!
 301          */
 302         status =
 303             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 304         if (ACPI_SUCCESS(status)) {
 305                 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
 306                 obj_desc->event.os_semaphore = temp_semaphore;
 307         }
 308
 309         return (status);
 310 }