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 - 2005, 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 < NUM_MUTEX; i++) {
  77                 status = acpi_ut_create_mutex(i);
  78                 if (ACPI_FAILURE(status)) {
  79                         return_ACPI_STATUS(status);
  80                 }
  81         }
  82
  83         status = acpi_os_create_lock(&acpi_gbl_gpe_lock);
  84         return_ACPI_STATUS(status);
  85 }
  86
  87 /*******************************************************************************
  88  *
  89  * FUNCTION:    acpi_ut_mutex_terminate
  90  *
  91  * PARAMETERS:  None.
  92  *
  93  * RETURN:      None.
  94  *
  95  * DESCRIPTION: Delete all of the system mutex objects.
  96  *
  97  ******************************************************************************/
  98
  99 void acpi_ut_mutex_terminate(void)
 100 {
 101         u32 i;
 102
 103         ACPI_FUNCTION_TRACE("ut_mutex_terminate");
 104
 105         /*
 106          * Delete each predefined mutex object
 107          */
 108         for (i = 0; i < NUM_MUTEX; i++) {
 109                 (void)acpi_ut_delete_mutex(i);
 110         }
 111
 112         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 113         return_VOID;
 114 }
 115
 116 /*******************************************************************************
 117  *
 118  * FUNCTION:    acpi_ut_create_mutex
 119  *
 120  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 121  *
 122  * RETURN:      Status
 123  *
 124  * DESCRIPTION: Create a mutex object.
 125  *
 126  ******************************************************************************/
 127
 128 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 129 {
 130         acpi_status status = AE_OK;
 131
 132         ACPI_FUNCTION_TRACE_U32("ut_create_mutex", mutex_id);
 133
 134         if (mutex_id > MAX_MUTEX) {
 135                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 136         }
 137
 138         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 139                 status = acpi_os_create_semaphore(1, 1,
 140                                                   &acpi_gbl_mutex_info
 141                                                   [mutex_id].mutex);
 142                 acpi_gbl_mutex_info[mutex_id].thread_id =
 143                     ACPI_MUTEX_NOT_ACQUIRED;
 144                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 145         }
 146
 147         return_ACPI_STATUS(status);
 148 }
 149
 150 /*******************************************************************************
 151  *
 152  * FUNCTION:    acpi_ut_delete_mutex
 153  *
 154  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 155  *
 156  * RETURN:      Status
 157  *
 158  * DESCRIPTION: Delete a mutex object.
 159  *
 160  ******************************************************************************/
 161
 162 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 163 {
 164         acpi_status status;
 165
 166         ACPI_FUNCTION_TRACE_U32("ut_delete_mutex", mutex_id);
 167
 168         if (mutex_id > MAX_MUTEX) {
 169                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 170         }
 171
 172         status = acpi_os_delete_semaphore(acpi_gbl_mutex_info[mutex_id].mutex);
 173
 174         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
 175         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 176
 177         return_ACPI_STATUS(status);
 178 }
 179
 180 /*******************************************************************************
 181  *
 182  * FUNCTION:    acpi_ut_acquire_mutex
 183  *
 184  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 185  *
 186  * RETURN:      Status
 187  *
 188  * DESCRIPTION: Acquire a mutex object.
 189  *
 190  ******************************************************************************/
 191
 192 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 193 {
 194         acpi_status status;
 195         u32 this_thread_id;
 196
 197         ACPI_FUNCTION_NAME("ut_acquire_mutex");
 198
 199         if (mutex_id > MAX_MUTEX) {
 200                 return (AE_BAD_PARAMETER);
 201         }
 202
 203         this_thread_id = acpi_os_get_thread_id();
 204
 205 #ifdef ACPI_MUTEX_DEBUG
 206         {
 207                 u32 i;
 208                 /*
 209                  * Mutex debug code, for internal debugging only.
 210                  *
 211                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 212                  * greater than or equal to this one.  If so, the thread has violated
 213                  * the mutex ordering rule.  This indicates a coding error somewhere in
 214                  * the ACPI subsystem code.
 215                  */
 216                 for (i = mutex_id; i < MAX_MUTEX; i++) {
 217                         if (acpi_gbl_mutex_info[i].owner_id == this_thread_id) {
 218                                 if (i == mutex_id) {
 219                                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 220                                                           "Mutex [%s] already acquired by this thread [%X]\n",
 221                                                           acpi_ut_get_mutex_name
 222                                                           (mutex_id),
 223                                                           this_thread_id));
 224
 225                                         return (AE_ALREADY_ACQUIRED);
 226                                 }
 227
 228                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 229                                                   "Invalid acquire order: Thread %X owns [%s], wants [%s]\n",
 230                                                   this_thread_id,
 231                                                   acpi_ut_get_mutex_name(i),
 232                                                   acpi_ut_get_mutex_name
 233                                                   (mutex_id)));
 234
 235                                 return (AE_ACQUIRE_DEADLOCK);
 236                         }
 237                 }
 238         }
 239 #endif
 240
 241         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 242                           "Thread %X attempting to acquire Mutex [%s]\n",
 243                           this_thread_id, acpi_ut_get_mutex_name(mutex_id)));
 244
 245         status = acpi_os_wait_semaphore(acpi_gbl_mutex_info[mutex_id].mutex,
 246                                         1, ACPI_WAIT_FOREVER);
 247         if (ACPI_SUCCESS(status)) {
 248                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 249                                   "Thread %X acquired Mutex [%s]\n",
 250                                   this_thread_id,
 251                                   acpi_ut_get_mutex_name(mutex_id)));
 252
 253                 acpi_gbl_mutex_info[mutex_id].use_count++;
 254                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 255         } else {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 257                                   "Thread %X could not acquire Mutex [%s] %s\n",
 258                                   this_thread_id,
 259                                   acpi_ut_get_mutex_name(mutex_id),
 260                                   acpi_format_exception(status)));
 261         }
 262
 263         return (status);
 264 }
 265
 266 /*******************************************************************************
 267  *
 268  * FUNCTION:    acpi_ut_release_mutex
 269  *
 270  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 271  *
 272  * RETURN:      Status
 273  *
 274  * DESCRIPTION: Release a mutex object.
 275  *
 276  ******************************************************************************/
 277
 278 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 279 {
 280         acpi_status status;
 281         u32 this_thread_id;
 282
 283         ACPI_FUNCTION_NAME("ut_release_mutex");
 284
 285         this_thread_id = acpi_os_get_thread_id();
 286         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 287                           "Thread %X releasing Mutex [%s]\n", this_thread_id,
 288                           acpi_ut_get_mutex_name(mutex_id)));
 289
 290         if (mutex_id > MAX_MUTEX) {
 291                 return (AE_BAD_PARAMETER);
 292         }
 293
 294         /*
 295          * Mutex must be acquired in order to release it!
 296          */
 297         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 298                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 299                                   "Mutex [%s] is not acquired, cannot release\n",
 300                                   acpi_ut_get_mutex_name(mutex_id)));
 301
 302                 return (AE_NOT_ACQUIRED);
 303         }
 304 #ifdef ACPI_MUTEX_DEBUG
 305         {
 306                 u32 i;
 307                 /*
 308                  * Mutex debug code, for internal debugging only.
 309                  *
 310                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 311                  * greater than this one.  If so, the thread has violated the mutex
 312                  * ordering rule.  This indicates a coding error somewhere in
 313                  * the ACPI subsystem code.
 314                  */
 315                 for (i = mutex_id; i < MAX_MUTEX; i++) {
 316                         if (acpi_gbl_mutex_info[i].owner_id == this_thread_id) {
 317                                 if (i == mutex_id) {
 318                                         continue;
 319                                 }
 320
 321                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 322                                                   "Invalid release order: owns [%s], releasing [%s]\n",
 323                                                   acpi_ut_get_mutex_name(i),
 324                                                   acpi_ut_get_mutex_name
 325                                                   (mutex_id)));
 326
 327                                 return (AE_RELEASE_DEADLOCK);
 328                         }
 329                 }
 330         }
 331 #endif
 332
 333         /* Mark unlocked FIRST */
 334
 335         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 336
 337         status =
 338             acpi_os_signal_semaphore(acpi_gbl_mutex_info[mutex_id].mutex, 1);
 339
 340         if (ACPI_FAILURE(status)) {
 341                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 342                                   "Thread %X could not release Mutex [%s] %s\n",
 343                                   this_thread_id,
 344                                   acpi_ut_get_mutex_name(mutex_id),
 345                                   acpi_format_exception(status)));
 346         } else {
 347                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 348                                   "Thread %X released Mutex [%s]\n",
 349                                   this_thread_id,
 350                                   acpi_ut_get_mutex_name(mutex_id)));
 351         }
 352
 353         return (status);
 354 }