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. This includes mutexes,
  64  *              spin locks, and reader/writer locks.
  65  *
  66  ******************************************************************************/
  67
  68 acpi_status acpi_ut_mutex_initialize(void)
  69 {
  70         u32 i;
  71         acpi_status status;
  72
  73         ACPI_FUNCTION_TRACE(ut_mutex_initialize);
  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         /* Create the reader/writer lock for namespace access */
  90
  91         status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
  92         return_ACPI_STATUS(status);
  93 }
  94
  95 /*******************************************************************************
  96  *
  97  * FUNCTION:    acpi_ut_mutex_terminate
  98  *
  99  * PARAMETERS:  None.
 100  *
 101  * RETURN:      None.
 102  *
 103  * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
 104  *              spin locks, and reader/writer locks.
 105  *
 106  ******************************************************************************/
 107
 108 void acpi_ut_mutex_terminate(void)
 109 {
 110         u32 i;
 111
 112         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
 113
 114         /* Delete each predefined mutex object */
 115
 116         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
 117                 (void)acpi_ut_delete_mutex(i);
 118         }
 119
 120         /* Delete the spinlocks */
 121
 122         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 123         acpi_os_delete_lock(acpi_gbl_hardware_lock);
 124
 125         /* Delete the reader/writer lock */
 126
 127         acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
 128         return_VOID;
 129 }
 130
 131 /*******************************************************************************
 132  *
 133  * FUNCTION:    acpi_ut_create_mutex
 134  *
 135  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 136  *
 137  * RETURN:      Status
 138  *
 139  * DESCRIPTION: Create a mutex object.
 140  *
 141  ******************************************************************************/
 142
 143 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 144 {
 145         acpi_status status = AE_OK;
 146
 147         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
 148
 149         if (mutex_id > ACPI_MAX_MUTEX) {
 150                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 151         }
 152
 153         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 154                 status =
 155                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
 156                 acpi_gbl_mutex_info[mutex_id].thread_id =
 157                     ACPI_MUTEX_NOT_ACQUIRED;
 158                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 159         }
 160
 161         return_ACPI_STATUS(status);
 162 }
 163
 164 /*******************************************************************************
 165  *
 166  * FUNCTION:    acpi_ut_delete_mutex
 167  *
 168  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 169  *
 170  * RETURN:      Status
 171  *
 172  * DESCRIPTION: Delete a mutex object.
 173  *
 174  ******************************************************************************/
 175
 176 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 177 {
 178
 179         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 180
 181         if (mutex_id > ACPI_MAX_MUTEX) {
 182                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 183         }
 184
 185         acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 186
 187         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
 188         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 189
 190         return_ACPI_STATUS(AE_OK);
 191 }
 192
 193 /*******************************************************************************
 194  *
 195  * FUNCTION:    acpi_ut_acquire_mutex
 196  *
 197  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 198  *
 199  * RETURN:      Status
 200  *
 201  * DESCRIPTION: Acquire a mutex object.
 202  *
 203  ******************************************************************************/
 204
 205 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 206 {
 207         acpi_status status;
 208         acpi_thread_id this_thread_id;
 209
 210         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 211
 212         if (mutex_id > ACPI_MAX_MUTEX) {
 213                 return (AE_BAD_PARAMETER);
 214         }
 215
 216         this_thread_id = acpi_os_get_thread_id();
 217
 218 #ifdef ACPI_MUTEX_DEBUG
 219         {
 220                 u32 i;
 221                 /*
 222                  * Mutex debug code, for internal debugging only.
 223                  *
 224                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 225                  * greater than or equal to this one.  If so, the thread has violated
 226                  * the mutex ordering rule.  This indicates a coding error somewhere in
 227                  * the ACPI subsystem code.
 228                  */
 229                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 230                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 231                                 if (i == mutex_id) {
 232                                         ACPI_ERROR((AE_INFO,
 233                                                     "Mutex [%s] already acquired by this thread [%X]",
 234                                                     acpi_ut_get_mutex_name
 235                                                     (mutex_id),
 236                                                     this_thread_id));
 237
 238                                         return (AE_ALREADY_ACQUIRED);
 239                                 }
 240
 241                                 ACPI_ERROR((AE_INFO,
 242                                             "Invalid acquire order: Thread %X owns [%s], wants [%s]",
 243                                             this_thread_id,
 244                                             acpi_ut_get_mutex_name(i),
 245                                             acpi_ut_get_mutex_name(mutex_id)));
 246
 247                                 return (AE_ACQUIRE_DEADLOCK);
 248                         }
 249                 }
 250         }
 251 #endif
 252
 253         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 254                           "Thread %lX attempting to acquire Mutex [%s]\n",
 255                           (unsigned long)this_thread_id,
 256                           acpi_ut_get_mutex_name(mutex_id)));
 257
 258         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
 259                                        ACPI_WAIT_FOREVER);
 260         if (ACPI_SUCCESS(status)) {
 261                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 262                                   "Thread %lX acquired Mutex [%s]\n",
 263                                   (unsigned long)this_thread_id,
 264                                   acpi_ut_get_mutex_name(mutex_id)));
 265
 266                 acpi_gbl_mutex_info[mutex_id].use_count++;
 267                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 268         } else {
 269                 ACPI_EXCEPTION((AE_INFO, status,
 270                                 "Thread %lX could not acquire Mutex [%X]",
 271                                 (unsigned long)this_thread_id, mutex_id));
 272         }
 273
 274         return (status);
 275 }
 276
 277 /*******************************************************************************
 278  *
 279  * FUNCTION:    acpi_ut_release_mutex
 280  *
 281  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 282  *
 283  * RETURN:      Status
 284  *
 285  * DESCRIPTION: Release a mutex object.
 286  *
 287  ******************************************************************************/
 288
 289 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 290 {
 291         acpi_thread_id this_thread_id;
 292
 293         ACPI_FUNCTION_NAME(ut_release_mutex);
 294
 295         this_thread_id = acpi_os_get_thread_id();
 296         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 297                           "Thread %lX releasing Mutex [%s]\n",
 298                           (unsigned long)this_thread_id,
 299                           acpi_ut_get_mutex_name(mutex_id)));
 300
 301         if (mutex_id > ACPI_MAX_MUTEX) {
 302                 return (AE_BAD_PARAMETER);
 303         }
 304
 305         /*
 306          * Mutex must be acquired in order to release it!
 307          */
 308         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 309                 ACPI_ERROR((AE_INFO,
 310                             "Mutex [%X] is not acquired, cannot release",
 311                             mutex_id));
 312
 313                 return (AE_NOT_ACQUIRED);
 314         }
 315 #ifdef ACPI_MUTEX_DEBUG
 316         {
 317                 u32 i;
 318                 /*
 319                  * Mutex debug code, for internal debugging only.
 320                  *
 321                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 322                  * greater than this one.  If so, the thread has violated the mutex
 323                  * ordering rule.  This indicates a coding error somewhere in
 324                  * the ACPI subsystem code.
 325                  */
 326                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 327                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 328                                 if (i == mutex_id) {
 329                                         continue;
 330                                 }
 331
 332                                 ACPI_ERROR((AE_INFO,
 333                                             "Invalid release order: owns [%s], releasing [%s]",
 334                                             acpi_ut_get_mutex_name(i),
 335                                             acpi_ut_get_mutex_name(mutex_id)));
 336
 337                                 return (AE_RELEASE_DEADLOCK);
 338                         }
 339                 }
 340         }
 341 #endif
 342
 343         /* Mark unlocked FIRST */
 344
 345         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 346
 347         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 348         return (AE_OK);
 349 }