release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/acpi/acpica/exsystem.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exsystem - Interface to OS services
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2010, Intel Corp.
  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 "accommon.h"
  47 #include "acinterp.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 (%u)",
 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_sleep
 186  *
 187  * PARAMETERS:  how_long        - The amount of time to sleep,
 188  *                                in milliseconds
 189  *
 190  * RETURN:      None
 191  *
 192  * DESCRIPTION: Sleep the running thread for specified amount of time.
 193  *
 194  ******************************************************************************/
 195
 196 acpi_status acpi_ex_system_do_sleep(u64 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         /*
 205          * For compatibility with other ACPI implementations and to prevent
 206          * accidental deep sleeps, limit the sleep time to something reasonable.
 207          */
 208         if (how_long > ACPI_MAX_SLEEP) {
 209                 how_long = ACPI_MAX_SLEEP;
 210         }
 211
 212         acpi_os_sleep(how_long);
 213
 214         /* And now we must get the interpreter again */
 215
 216         acpi_ex_reacquire_interpreter();
 217         return (AE_OK);
 218 }
 219
 220 /*******************************************************************************
 221  *
 222  * FUNCTION:    acpi_ex_system_signal_event
 223  *
 224  * PARAMETERS:  obj_desc        - The object descriptor for this op
 225  *
 226  * RETURN:      Status
 227  *
 228  * DESCRIPTION: Provides an access point to perform synchronization operations
 229  *              within the AML.
 230  *
 231  ******************************************************************************/
 232
 233 acpi_status acpi_ex_system_signal_event(union acpi_operand_object * obj_desc)
 234 {
 235         acpi_status status = AE_OK;
 236
 237         ACPI_FUNCTION_TRACE(ex_system_signal_event);
 238
 239         if (obj_desc) {
 240                 status =
 241                     acpi_os_signal_semaphore(obj_desc->event.os_semaphore, 1);
 242         }
 243
 244         return_ACPI_STATUS(status);
 245 }
 246
 247 /*******************************************************************************
 248  *
 249  * FUNCTION:    acpi_ex_system_wait_event
 250  *
 251  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 252  *              obj_desc        - The object descriptor for this op
 253  *
 254  * RETURN:      Status
 255  *
 256  * DESCRIPTION: Provides an access point to perform synchronization operations
 257  *              within the AML.  This operation is a request to wait for an
 258  *              event.
 259  *
 260  ******************************************************************************/
 261
 262 acpi_status
 263 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 264                           union acpi_operand_object *obj_desc)
 265 {
 266         acpi_status status = AE_OK;
 267
 268         ACPI_FUNCTION_TRACE(ex_system_wait_event);
 269
 270         if (obj_desc) {
 271                 status =
 272                     acpi_ex_system_wait_semaphore(obj_desc->event.os_semaphore,
 273                                                   (u16) time_desc->integer.
 274                                                   value);
 275         }
 276
 277         return_ACPI_STATUS(status);
 278 }
 279
 280 /*******************************************************************************
 281  *
 282  * FUNCTION:    acpi_ex_system_reset_event
 283  *
 284  * PARAMETERS:  obj_desc        - The object descriptor for this op
 285  *
 286  * RETURN:      Status
 287  *
 288  * DESCRIPTION: Reset an event to a known state.
 289  *
 290  ******************************************************************************/
 291
 292 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 293 {
 294         acpi_status status = AE_OK;
 295         acpi_semaphore temp_semaphore;
 296
 297         ACPI_FUNCTION_ENTRY();
 298
 299         /*
 300          * We are going to simply delete the existing semaphore and
 301          * create a new one!
 302          */
 303         status =
 304             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 305         if (ACPI_SUCCESS(status)) {
 306                 (void)acpi_os_delete_semaphore(obj_desc->event.os_semaphore);
 307                 obj_desc->event.os_semaphore = temp_semaphore;
 308         }
 309
 310         return (status);
 311 }