git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/acpica/utmutex.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utmutex - local mutex support
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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
  47 #define _COMPONENT          ACPI_UTILITIES
  48 ACPI_MODULE_NAME("utmutex")
  49
  50 /* Local prototypes */
  51 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
  52
  53 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id);
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_ut_mutex_initialize
  58  *
  59  * PARAMETERS:  None.
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Create the system mutex objects.
  64  *
  65  ******************************************************************************/
  66
  67 acpi_status acpi_ut_mutex_initialize(void)
  68 {
  69         u32 i;
  70         acpi_status status;
  71
  72         ACPI_FUNCTION_TRACE(ut_mutex_initialize);
  73
  74         /*
  75          * Create each of the predefined mutex objects
  76          */
  77         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
  78                 status = acpi_ut_create_mutex(i);
  79                 if (ACPI_FAILURE(status)) {
  80                         return_ACPI_STATUS(status);
  81                 }
  82         }
  83
  84         /* Create the spinlocks for use at interrupt level */
  85
  86         spin_lock_init(acpi_gbl_gpe_lock);
  87         spin_lock_init(acpi_gbl_hardware_lock);
  88
  89         return_ACPI_STATUS(status);
  90 }
  91
  92 /*******************************************************************************
  93  *
  94  * FUNCTION:    acpi_ut_mutex_terminate
  95  *
  96  * PARAMETERS:  None.
  97  *
  98  * RETURN:      None.
  99  *
 100  * DESCRIPTION: Delete all of the system mutex objects.
 101  *
 102  ******************************************************************************/
 103
 104 void acpi_ut_mutex_terminate(void)
 105 {
 106         u32 i;
 107
 108         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
 109
 110         /*
 111          * Delete each predefined mutex object
 112          */
 113         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
 114                 (void)acpi_ut_delete_mutex(i);
 115         }
 116
 117         /* Delete the spinlocks */
 118
 119         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 120         acpi_os_delete_lock(acpi_gbl_hardware_lock);
 121         return_VOID;
 122 }
 123
 124 /*******************************************************************************
 125  *
 126  * FUNCTION:    acpi_ut_create_mutex
 127  *
 128  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 129  *
 130  * RETURN:      Status
 131  *
 132  * DESCRIPTION: Create a mutex object.
 133  *
 134  ******************************************************************************/
 135
 136 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 137 {
 138         acpi_status status = AE_OK;
 139
 140         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
 141
 142         if (mutex_id > ACPI_MAX_MUTEX) {
 143                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 144         }
 145
 146         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 147                 status =
 148                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
 149                 acpi_gbl_mutex_info[mutex_id].thread_id =
 150                     ACPI_MUTEX_NOT_ACQUIRED;
 151                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 152         }
 153
 154         return_ACPI_STATUS(status);
 155 }
 156
 157 /*******************************************************************************
 158  *
 159  * FUNCTION:    acpi_ut_delete_mutex
 160  *
 161  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 162  *
 163  * RETURN:      Status
 164  *
 165  * DESCRIPTION: Delete a mutex object.
 166  *
 167  ******************************************************************************/
 168
 169 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 170 {
 171
 172         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 173
 174         if (mutex_id > ACPI_MAX_MUTEX) {
 175                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 176         }
 177
 178         acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 179
 180         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
 181         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 182
 183         return_ACPI_STATUS(AE_OK);
 184 }
 185
 186 /*******************************************************************************
 187  *
 188  * FUNCTION:    acpi_ut_acquire_mutex
 189  *
 190  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 191  *
 192  * RETURN:      Status
 193  *
 194  * DESCRIPTION: Acquire a mutex object.
 195  *
 196  ******************************************************************************/
 197
 198 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 199 {
 200         acpi_status status;
 201         acpi_thread_id this_thread_id;
 202
 203         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 204
 205         if (mutex_id > ACPI_MAX_MUTEX) {
 206                 return (AE_BAD_PARAMETER);
 207         }
 208
 209         this_thread_id = acpi_os_get_thread_id();
 210
 211 #ifdef ACPI_MUTEX_DEBUG
 212         {
 213                 u32 i;
 214                 /*
 215                  * Mutex debug code, for internal debugging only.
 216                  *
 217                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 218                  * greater than or equal to this one.  If so, the thread has violated
 219                  * the mutex ordering rule.  This indicates a coding error somewhere in
 220                  * the ACPI subsystem code.
 221                  */
 222                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 223                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 224                                 if (i == mutex_id) {
 225                                         ACPI_ERROR((AE_INFO,
 226                                                     "Mutex [%s] already acquired by this thread [%X]",
 227                                                     acpi_ut_get_mutex_name
 228                                                     (mutex_id),
 229                                                     this_thread_id));
 230
 231                                         return (AE_ALREADY_ACQUIRED);
 232                                 }
 233
 234                                 ACPI_ERROR((AE_INFO,
 235                                             "Invalid acquire order: Thread %X owns [%s], wants [%s]",
 236                                             this_thread_id,
 237                                             acpi_ut_get_mutex_name(i),
 238                                             acpi_ut_get_mutex_name(mutex_id)));
 239
 240                                 return (AE_ACQUIRE_DEADLOCK);
 241                         }
 242                 }
 243         }
 244 #endif
 245
 246         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 247                           "Thread %lX attempting to acquire Mutex [%s]\n",
 248                           (unsigned long)this_thread_id,
 249                           acpi_ut_get_mutex_name(mutex_id)));
 250
 251         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
 252                                        ACPI_WAIT_FOREVER);
 253         if (ACPI_SUCCESS(status)) {
 254                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 255                                   "Thread %lX acquired Mutex [%s]\n",
 256                                   (unsigned long)this_thread_id,
 257                                   acpi_ut_get_mutex_name(mutex_id)));
 258
 259                 acpi_gbl_mutex_info[mutex_id].use_count++;
 260                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 261         } else {
 262                 ACPI_EXCEPTION((AE_INFO, status,
 263                                 "Thread %lX could not acquire Mutex [%X]",
 264                                 (unsigned long)this_thread_id, mutex_id));
 265         }
 266
 267         return (status);
 268 }
 269
 270 /*******************************************************************************
 271  *
 272  * FUNCTION:    acpi_ut_release_mutex
 273  *
 274  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 275  *
 276  * RETURN:      Status
 277  *
 278  * DESCRIPTION: Release a mutex object.
 279  *
 280  ******************************************************************************/
 281
 282 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 283 {
 284         acpi_thread_id this_thread_id;
 285
 286         ACPI_FUNCTION_NAME(ut_release_mutex);
 287
 288         this_thread_id = acpi_os_get_thread_id();
 289         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 290                           "Thread %lX releasing Mutex [%s]\n",
 291                           (unsigned long)this_thread_id,
 292                           acpi_ut_get_mutex_name(mutex_id)));
 293
 294         if (mutex_id > ACPI_MAX_MUTEX) {
 295                 return (AE_BAD_PARAMETER);
 296         }
 297
 298         /*
 299          * Mutex must be acquired in order to release it!
 300          */
 301         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 302                 ACPI_ERROR((AE_INFO,
 303                             "Mutex [%X] is not acquired, cannot release",
 304                             mutex_id));
 305
 306                 return (AE_NOT_ACQUIRED);
 307         }
 308 #ifdef ACPI_MUTEX_DEBUG
 309         {
 310                 u32 i;
 311                 /*
 312                  * Mutex debug code, for internal debugging only.
 313                  *
 314                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 315                  * greater than this one.  If so, the thread has violated the mutex
 316                  * ordering rule.  This indicates a coding error somewhere in
 317                  * the ACPI subsystem code.
 318                  */
 319                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 320                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 321                                 if (i == mutex_id) {
 322                                         continue;
 323                                 }
 324
 325                                 ACPI_ERROR((AE_INFO,
 326                                             "Invalid release order: owns [%s], releasing [%s]",
 327                                             acpi_ut_get_mutex_name(i),
 328                                             acpi_ut_get_mutex_name(mutex_id)));
 329
 330                                 return (AE_RELEASE_DEADLOCK);
 331                         }
 332                 }
 333         }
 334 #endif
 335
 336         /* Mark unlocked FIRST */
 337
 338         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 339
 340         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 341         return (AE_OK);
 342 }