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

   1 /*******************************************************************************
   2  *
   3  * Module Name: utmutex - local mutex support
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2006, R. Byron Moore
   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
  46 #define _COMPONENT          ACPI_UTILITIES
  47 ACPI_MODULE_NAME("utmutex")
  48
  49 /* Local prototypes */
  50 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
  51
  52 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id);
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ut_mutex_initialize
  57  *
  58  * PARAMETERS:  None.
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Create the system mutex objects.
  63  *
  64  ******************************************************************************/
  65
  66 acpi_status acpi_ut_mutex_initialize(void)
  67 {
  68         u32 i;
  69         acpi_status status;
  70
  71         ACPI_FUNCTION_TRACE(ut_mutex_initialize);
  72
  73         /*
  74          * Create each of the predefined mutex objects
  75          */
  76         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
  77                 status = acpi_ut_create_mutex(i);
  78                 if (ACPI_FAILURE(status)) {
  79                         return_ACPI_STATUS(status);
  80                 }
  81         }
  82
  83         /* Create the spinlocks for use at interrupt level */
  84
  85         status = acpi_os_create_lock(&acpi_gbl_gpe_lock);
  86         if (ACPI_FAILURE(status)) {
  87                 return_ACPI_STATUS(status);
  88         }
  89
  90         status = acpi_os_create_lock(&acpi_gbl_hardware_lock);
  91         return_ACPI_STATUS(status);
  92 }
  93
  94 /*******************************************************************************
  95  *
  96  * FUNCTION:    acpi_ut_mutex_terminate
  97  *
  98  * PARAMETERS:  None.
  99  *
 100  * RETURN:      None.
 101  *
 102  * DESCRIPTION: Delete all of the system mutex objects.
 103  *
 104  ******************************************************************************/
 105
 106 void acpi_ut_mutex_terminate(void)
 107 {
 108         u32 i;
 109
 110         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
 111
 112         /*
 113          * Delete each predefined mutex object
 114          */
 115         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
 116                 (void)acpi_ut_delete_mutex(i);
 117         }
 118
 119         /* Delete the spinlocks */
 120
 121         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 122         acpi_os_delete_lock(acpi_gbl_hardware_lock);
 123         return_VOID;
 124 }
 125
 126 /*******************************************************************************
 127  *
 128  * FUNCTION:    acpi_ut_create_mutex
 129  *
 130  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 131  *
 132  * RETURN:      Status
 133  *
 134  * DESCRIPTION: Create a mutex object.
 135  *
 136  ******************************************************************************/
 137
 138 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 139 {
 140         acpi_status status = AE_OK;
 141
 142         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
 143
 144         if (mutex_id > ACPI_MAX_MUTEX) {
 145                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 146         }
 147
 148         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 149                 status = acpi_os_create_semaphore(1, 1,
 150                                                   &acpi_gbl_mutex_info
 151                                                   [mutex_id].mutex);
 152                 acpi_gbl_mutex_info[mutex_id].thread_id =
 153                     ACPI_MUTEX_NOT_ACQUIRED;
 154                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 155         }
 156
 157         return_ACPI_STATUS(status);
 158 }
 159
 160 /*******************************************************************************
 161  *
 162  * FUNCTION:    acpi_ut_delete_mutex
 163  *
 164  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 165  *
 166  * RETURN:      Status
 167  *
 168  * DESCRIPTION: Delete a mutex object.
 169  *
 170  ******************************************************************************/
 171
 172 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 173 {
 174         acpi_status status;
 175
 176         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 177
 178         if (mutex_id > ACPI_MAX_MUTEX) {
 179                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 180         }
 181
 182         status = acpi_os_delete_semaphore(acpi_gbl_mutex_info[mutex_id].mutex);
 183
 184         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
 185         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 186
 187         return_ACPI_STATUS(status);
 188 }
 189
 190 /*******************************************************************************
 191  *
 192  * FUNCTION:    acpi_ut_acquire_mutex
 193  *
 194  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 195  *
 196  * RETURN:      Status
 197  *
 198  * DESCRIPTION: Acquire a mutex object.
 199  *
 200  ******************************************************************************/
 201
 202 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 203 {
 204         acpi_status status;
 205         acpi_thread_id this_thread_id;
 206
 207         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 208
 209         if (mutex_id > ACPI_MAX_MUTEX) {
 210                 return (AE_BAD_PARAMETER);
 211         }
 212
 213         this_thread_id = acpi_os_get_thread_id();
 214
 215 #ifdef ACPI_MUTEX_DEBUG
 216         {
 217                 u32 i;
 218                 /*
 219                  * Mutex debug code, for internal debugging only.
 220                  *
 221                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 222                  * greater than or equal to this one.  If so, the thread has violated
 223                  * the mutex ordering rule.  This indicates a coding error somewhere in
 224                  * the ACPI subsystem code.
 225                  */
 226                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
 227                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 228                                 if (i == mutex_id) {
 229                                         ACPI_ERROR((AE_INFO,
 230                                                     "Mutex [%s] already acquired by this thread [%X]",
 231                                                     acpi_ut_get_mutex_name
 232                                                     (mutex_id),
 233                                                     this_thread_id));
 234
 235                                         return (AE_ALREADY_ACQUIRED);
 236                                 }
 237
 238                                 ACPI_ERROR((AE_INFO,
 239                                             "Invalid acquire order: Thread %X owns [%s], wants [%s]",
 240                                             this_thread_id,
 241                                             acpi_ut_get_mutex_name(i),
 242                                             acpi_ut_get_mutex_name(mutex_id)));
 243
 244                                 return (AE_ACQUIRE_DEADLOCK);
 245                         }
 246                 }
 247         }
 248 #endif
 249
 250         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 251                           "Thread %X attempting to acquire Mutex [%s]\n",
 252                           this_thread_id, acpi_ut_get_mutex_name(mutex_id)));
 253
 254         status = acpi_os_wait_semaphore(acpi_gbl_mutex_info[mutex_id].mutex,
 255                                         1, ACPI_WAIT_FOREVER);
 256         if (ACPI_SUCCESS(status)) {
 257                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 258                                   "Thread %X acquired Mutex [%s]\n",
 259                                   this_thread_id,
 260                                   acpi_ut_get_mutex_name(mutex_id)));
 261
 262                 acpi_gbl_mutex_info[mutex_id].use_count++;
 263                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 264         } else {
 265                 ACPI_EXCEPTION((AE_INFO, status,
 266                                 "Thread %X could not acquire Mutex [%X]",
 267                                 this_thread_id, mutex_id));
 268         }
 269
 270         return (status);
 271 }
 272
 273 /*******************************************************************************
 274  *
 275  * FUNCTION:    acpi_ut_release_mutex
 276  *
 277  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 278  *
 279  * RETURN:      Status
 280  *
 281  * DESCRIPTION: Release a mutex object.
 282  *
 283  ******************************************************************************/
 284
 285 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 286 {
 287         acpi_status status;
 288         acpi_thread_id this_thread_id;
 289
 290         ACPI_FUNCTION_NAME(ut_release_mutex);
 291
 292         this_thread_id = acpi_os_get_thread_id();
 293         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 294                           "Thread %X releasing Mutex [%s]\n", this_thread_id,
 295                           acpi_ut_get_mutex_name(mutex_id)));
 296
 297         if (mutex_id > ACPI_MAX_MUTEX) {
 298                 return (AE_BAD_PARAMETER);
 299         }
 300
 301         /*
 302          * Mutex must be acquired in order to release it!
 303          */
 304         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 305                 ACPI_ERROR((AE_INFO,
 306                             "Mutex [%X] is not acquired, cannot release",
 307                             mutex_id));
 308
 309                 return (AE_NOT_ACQUIRED);
 310         }
 311 #ifdef ACPI_MUTEX_DEBUG
 312         {
 313                 u32 i;
 314                 /*
 315                  * Mutex debug code, for internal debugging only.
 316                  *
 317                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 318                  * greater than this one.  If so, the thread has violated the mutex
 319                  * ordering rule.  This indicates a coding error somewhere in
 320                  * the ACPI subsystem code.
 321                  */
 322                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
 323                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 324                                 if (i == mutex_id) {
 325                                         continue;
 326                                 }
 327
 328                                 ACPI_ERROR((AE_INFO,
 329                                             "Invalid release order: owns [%s], releasing [%s]",
 330                                             acpi_ut_get_mutex_name(i),
 331                                             acpi_ut_get_mutex_name(mutex_id)));
 332
 333                                 return (AE_RELEASE_DEADLOCK);
 334                         }
 335                 }
 336         }
 337 #endif
 338
 339         /* Mark unlocked FIRST */
 340
 341         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 342
 343         status =
 344             acpi_os_signal_semaphore(acpi_gbl_mutex_info[mutex_id].mutex, 1);
 345
 346         if (ACPI_FAILURE(status)) {
 347                 ACPI_EXCEPTION((AE_INFO, status,
 348                                 "Thread %X could not release Mutex [%X]",
 349                                 this_thread_id, mutex_id));
 350         } else {
 351                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 352                                   "Thread %X released Mutex [%s]\n",
 353                                   this_thread_id,
 354                                   acpi_ut_get_mutex_name(mutex_id)));
 355         }
 356
 357         return (status);
 358 }