err.no 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         spin_lock_init(acpi_gbl_gpe_lock);
  86         spin_lock_init(acpi_gbl_hardware_lock);
  87
  88         return_ACPI_STATUS(status);
  89 }
  90
  91 /*******************************************************************************
  92  *
  93  * FUNCTION:    acpi_ut_mutex_terminate
  94  *
  95  * PARAMETERS:  None.
  96  *
  97  * RETURN:      None.
  98  *
  99  * DESCRIPTION: Delete all of the system mutex objects.
 100  *
 101  ******************************************************************************/
 102
 103 void acpi_ut_mutex_terminate(void)
 104 {
 105         u32 i;
 106
 107         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
 108
 109         /*
 110          * Delete each predefined mutex object
 111          */
 112         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
 113                 (void)acpi_ut_delete_mutex(i);
 114         }
 115
 116         /* Delete the spinlocks */
 117
 118         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 119         acpi_os_delete_lock(acpi_gbl_hardware_lock);
 120         return_VOID;
 121 }
 122
 123 /*******************************************************************************
 124  *
 125  * FUNCTION:    acpi_ut_create_mutex
 126  *
 127  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 128  *
 129  * RETURN:      Status
 130  *
 131  * DESCRIPTION: Create a mutex object.
 132  *
 133  ******************************************************************************/
 134
 135 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 136 {
 137         acpi_status status = AE_OK;
 138
 139         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
 140
 141         if (mutex_id > ACPI_MAX_MUTEX) {
 142                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 143         }
 144
 145         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 146                 status =
 147                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
 148                 acpi_gbl_mutex_info[mutex_id].thread_id =
 149                     ACPI_MUTEX_NOT_ACQUIRED;
 150                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 151         }
 152
 153         return_ACPI_STATUS(status);
 154 }
 155
 156 /*******************************************************************************
 157  *
 158  * FUNCTION:    acpi_ut_delete_mutex
 159  *
 160  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 161  *
 162  * RETURN:      Status
 163  *
 164  * DESCRIPTION: Delete a mutex object.
 165  *
 166  ******************************************************************************/
 167
 168 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 169 {
 170
 171         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 172
 173         if (mutex_id > ACPI_MAX_MUTEX) {
 174                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 175         }
 176
 177         acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 178
 179         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
 180         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 181
 182         return_ACPI_STATUS(AE_OK);
 183 }
 184
 185 /*******************************************************************************
 186  *
 187  * FUNCTION:    acpi_ut_acquire_mutex
 188  *
 189  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 190  *
 191  * RETURN:      Status
 192  *
 193  * DESCRIPTION: Acquire a mutex object.
 194  *
 195  ******************************************************************************/
 196
 197 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 198 {
 199         acpi_status status;
 200         acpi_thread_id this_thread_id;
 201
 202         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 203
 204         if (mutex_id > ACPI_MAX_MUTEX) {
 205                 return (AE_BAD_PARAMETER);
 206         }
 207
 208         this_thread_id = acpi_os_get_thread_id();
 209
 210 #ifdef ACPI_MUTEX_DEBUG
 211         {
 212                 u32 i;
 213                 /*
 214                  * Mutex debug code, for internal debugging only.
 215                  *
 216                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 217                  * greater than or equal to this one.  If so, the thread has violated
 218                  * the mutex ordering rule.  This indicates a coding error somewhere in
 219                  * the ACPI subsystem code.
 220                  */
 221                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
 222                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 223                                 if (i == mutex_id) {
 224                                         ACPI_ERROR((AE_INFO,
 225                                                     "Mutex [%s] already acquired by this thread [%X]",
 226                                                     acpi_ut_get_mutex_name
 227                                                     (mutex_id),
 228                                                     this_thread_id));
 229
 230                                         return (AE_ALREADY_ACQUIRED);
 231                                 }
 232
 233                                 ACPI_ERROR((AE_INFO,
 234                                             "Invalid acquire order: Thread %X owns [%s], wants [%s]",
 235                                             this_thread_id,
 236                                             acpi_ut_get_mutex_name(i),
 237                                             acpi_ut_get_mutex_name(mutex_id)));
 238
 239                                 return (AE_ACQUIRE_DEADLOCK);
 240                         }
 241                 }
 242         }
 243 #endif
 244
 245         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 246                           "Thread %X attempting to acquire Mutex [%s]\n",
 247                           (u32) this_thread_id, acpi_ut_get_mutex_name(mutex_id)));
 248
 249         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
 250                                        ACPI_WAIT_FOREVER);
 251         if (ACPI_SUCCESS(status)) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 253                                   "Thread %X acquired Mutex [%s]\n",
 254                                   (u32) this_thread_id,
 255                                   acpi_ut_get_mutex_name(mutex_id)));
 256
 257                 acpi_gbl_mutex_info[mutex_id].use_count++;
 258                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 259         } else {
 260                 ACPI_EXCEPTION((AE_INFO, status,
 261                                 "Thread %X could not acquire Mutex [%X]",
 262                                 (u32) this_thread_id, mutex_id));
 263         }
 264
 265         return (status);
 266 }
 267
 268 /*******************************************************************************
 269  *
 270  * FUNCTION:    acpi_ut_release_mutex
 271  *
 272  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 273  *
 274  * RETURN:      Status
 275  *
 276  * DESCRIPTION: Release a mutex object.
 277  *
 278  ******************************************************************************/
 279
 280 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 281 {
 282         acpi_thread_id this_thread_id;
 283
 284         ACPI_FUNCTION_NAME(ut_release_mutex);
 285
 286         this_thread_id = acpi_os_get_thread_id();
 287         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 288                           "Thread %X releasing Mutex [%s]\n", (u32) this_thread_id,
 289                           acpi_ut_get_mutex_name(mutex_id)));
 290
 291         if (mutex_id > ACPI_MAX_MUTEX) {
 292                 return (AE_BAD_PARAMETER);
 293         }
 294
 295         /*
 296          * Mutex must be acquired in order to release it!
 297          */
 298         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 299                 ACPI_ERROR((AE_INFO,
 300                             "Mutex [%X] is not acquired, cannot release",
 301                             mutex_id));
 302
 303                 return (AE_NOT_ACQUIRED);
 304         }
 305 #ifdef ACPI_MUTEX_DEBUG
 306         {
 307                 u32 i;
 308                 /*
 309                  * Mutex debug code, for internal debugging only.
 310                  *
 311                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 312                  * greater than this one.  If so, the thread has violated the mutex
 313                  * ordering rule.  This indicates a coding error somewhere in
 314                  * the ACPI subsystem code.
 315                  */
 316                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
 317                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 318                                 if (i == mutex_id) {
 319                                         continue;
 320                                 }
 321
 322                                 ACPI_ERROR((AE_INFO,
 323                                             "Invalid release order: owns [%s], releasing [%s]",
 324                                             acpi_ut_get_mutex_name(i),
 325                                             acpi_ut_get_mutex_name(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         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 338         return (AE_OK);
 339 }