drivers/acpi/acpica/utmutex.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utmutex - local mutex support
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2010, 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 void 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         /* Mutex for _OSI support */
  90         status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
  91         if (ACPI_FAILURE(status)) {
  92                 return_ACPI_STATUS(status);
  93         }
  94
  95         /* Create the reader/writer lock for namespace access */
  96
  97         status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
  98         return_ACPI_STATUS(status);
  99 }
 100
 101 /*******************************************************************************
 102  *
 103  * FUNCTION:    acpi_ut_mutex_terminate
 104  *
 105  * PARAMETERS:  None.
 106  *
 107  * RETURN:      None.
 108  *
 109  * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
 110  *              spin locks, and reader/writer locks.
 111  *
 112  ******************************************************************************/
 113
 114 void acpi_ut_mutex_terminate(void)
 115 {
 116         u32 i;
 117
 118         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
 119
 120         /* Delete each predefined mutex object */
 121
 122         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
 123                 acpi_ut_delete_mutex(i);
 124         }
 125
 126         acpi_os_delete_mutex(acpi_gbl_osi_mutex);
 127
 128         /* Delete the spinlocks */
 129
 130         acpi_os_delete_lock(acpi_gbl_gpe_lock);
 131         acpi_os_delete_lock(acpi_gbl_hardware_lock);
 132
 133         /* Delete the reader/writer lock */
 134
 135         acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
 136         return_VOID;
 137 }
 138
 139 /*******************************************************************************
 140  *
 141  * FUNCTION:    acpi_ut_create_mutex
 142  *
 143  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
 144  *
 145  * RETURN:      Status
 146  *
 147  * DESCRIPTION: Create a mutex object.
 148  *
 149  ******************************************************************************/
 150
 151 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
 152 {
 153         acpi_status status = AE_OK;
 154
 155         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
 156
 157         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
 158                 status =
 159                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
 160                 acpi_gbl_mutex_info[mutex_id].thread_id =
 161                     ACPI_MUTEX_NOT_ACQUIRED;
 162                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
 163         }
 164
 165         return_ACPI_STATUS(status);
 166 }
 167
 168 /*******************************************************************************
 169  *
 170  * FUNCTION:    acpi_ut_delete_mutex
 171  *
 172  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
 173  *
 174  * RETURN:      Status
 175  *
 176  * DESCRIPTION: Delete a mutex object.
 177  *
 178  ******************************************************************************/
 179
 180 static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 181 {
 182
 183         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 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
 191 /*******************************************************************************
 192  *
 193  * FUNCTION:    acpi_ut_acquire_mutex
 194  *
 195  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 196  *
 197  * RETURN:      Status
 198  *
 199  * DESCRIPTION: Acquire a mutex object.
 200  *
 201  ******************************************************************************/
 202
 203 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 204 {
 205         acpi_status status;
 206         acpi_thread_id this_thread_id;
 207
 208         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 209
 210         if (mutex_id > ACPI_MAX_MUTEX) {
 211                 return (AE_BAD_PARAMETER);
 212         }
 213
 214         this_thread_id = acpi_os_get_thread_id();
 215
 216 #ifdef ACPI_MUTEX_DEBUG
 217         {
 218                 u32 i;
 219                 /*
 220                  * Mutex debug code, for internal debugging only.
 221                  *
 222                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 223                  * greater than or equal to this one.  If so, the thread has violated
 224                  * the mutex ordering rule.  This indicates a coding error somewhere in
 225                  * the ACPI subsystem code.
 226                  */
 227                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 228                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 229                                 if (i == mutex_id) {
 230                                         ACPI_ERROR((AE_INFO,
 231                                                     "Mutex [%s] already acquired by this thread [%u]",
 232                                                     acpi_ut_get_mutex_name
 233                                                     (mutex_id),
 234                                                     (u32)this_thread_id));
 235
 236                                         return (AE_ALREADY_ACQUIRED);
 237                                 }
 238
 239                                 ACPI_ERROR((AE_INFO,
 240                                             "Invalid acquire order: Thread %u owns [%s], wants [%s]",
 241                                             (u32)this_thread_id,
 242                                             acpi_ut_get_mutex_name(i),
 243                                             acpi_ut_get_mutex_name(mutex_id)));
 244
 245                                 return (AE_ACQUIRE_DEADLOCK);
 246                         }
 247                 }
 248         }
 249 #endif
 250
 251         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 252                           "Thread %u attempting to acquire Mutex [%s]\n",
 253                           (u32)this_thread_id,
 254                           acpi_ut_get_mutex_name(mutex_id)));
 255
 256         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
 257                                        ACPI_WAIT_FOREVER);
 258         if (ACPI_SUCCESS(status)) {
 259                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 260                                   "Thread %u acquired Mutex [%s]\n",
 261                                   (u32)this_thread_id,
 262                                   acpi_ut_get_mutex_name(mutex_id)));
 263
 264                 acpi_gbl_mutex_info[mutex_id].use_count++;
 265                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
 266         } else {
 267                 ACPI_EXCEPTION((AE_INFO, status,
 268                                 "Thread %u could not acquire Mutex [0x%X]",
 269                                 (u32)this_thread_id, mutex_id));
 270         }
 271
 272         return (status);
 273 }
 274
 275 /*******************************************************************************
 276  *
 277  * FUNCTION:    acpi_ut_release_mutex
 278  *
 279  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
 280  *
 281  * RETURN:      Status
 282  *
 283  * DESCRIPTION: Release a mutex object.
 284  *
 285  ******************************************************************************/
 286
 287 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
 288 {
 289         acpi_thread_id this_thread_id;
 290
 291         ACPI_FUNCTION_NAME(ut_release_mutex);
 292
 293         this_thread_id = acpi_os_get_thread_id();
 294
 295         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
 296                           (u32)this_thread_id,
 297                           acpi_ut_get_mutex_name(mutex_id)));
 298
 299         if (mutex_id > ACPI_MAX_MUTEX) {
 300                 return (AE_BAD_PARAMETER);
 301         }
 302
 303         /*
 304          * Mutex must be acquired in order to release it!
 305          */
 306         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 307                 ACPI_ERROR((AE_INFO,
 308                             "Mutex [0x%X] is not acquired, cannot release",
 309                             mutex_id));
 310
 311                 return (AE_NOT_ACQUIRED);
 312         }
 313 #ifdef ACPI_MUTEX_DEBUG
 314         {
 315                 u32 i;
 316                 /*
 317                  * Mutex debug code, for internal debugging only.
 318                  *
 319                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 320                  * greater than this one.  If so, the thread has violated the mutex
 321                  * ordering rule.  This indicates a coding error somewhere in
 322                  * the ACPI subsystem code.
 323                  */
 324                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 325                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 326                                 if (i == mutex_id) {
 327                                         continue;
 328                                 }
 329
 330                                 ACPI_ERROR((AE_INFO,
 331                                             "Invalid release order: owns [%s], releasing [%s]",
 332                                             acpi_ut_get_mutex_name(i),
 333                                             acpi_ut_get_mutex_name(mutex_id)));
 334
 335                                 return (AE_RELEASE_DEADLOCK);
 336                         }
 337                 }
 338         }
 339 #endif
 340
 341         /* Mark unlocked FIRST */
 342
 343         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 344
 345         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 346         return (AE_OK);
 347 }