release/src-rt-6.x.4708/linux/linux-2.6.36/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         /* 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                 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 (!acpi_gbl_mutex_info[mutex_id].mutex) {
 150                 status =
 151                     acpi_os_create_mutex(&acpi_gbl_mutex_info[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 void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
 173 {
 174
 175         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
 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
 183 /*******************************************************************************
 184  *
 185  * FUNCTION:    acpi_ut_acquire_mutex
 186  *
 187  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
 188  *
 189  * RETURN:      Status
 190  *
 191  * DESCRIPTION: Acquire a mutex object.
 192  *
 193  ******************************************************************************/
 194
 195 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
 196 {
 197         acpi_status status;
 198         acpi_thread_id this_thread_id;
 199
 200         ACPI_FUNCTION_NAME(ut_acquire_mutex);
 201
 202         if (mutex_id > ACPI_MAX_MUTEX) {
 203                 return (AE_BAD_PARAMETER);
 204         }
 205
 206         this_thread_id = acpi_os_get_thread_id();
 207
 208 #ifdef ACPI_MUTEX_DEBUG
 209         {
 210                 u32 i;
 211                 /*
 212                  * Mutex debug code, for internal debugging only.
 213                  *
 214                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 215                  * greater than or equal to this one.  If so, the thread has violated
 216                  * the mutex ordering rule.  This indicates a coding error somewhere in
 217                  * the ACPI subsystem code.
 218                  */
 219                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 220                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 221                                 if (i == mutex_id) {
 222                                         ACPI_ERROR((AE_INFO,
 223                                                     "Mutex [%s] already acquired by this thread [%p]",
 224                                                     acpi_ut_get_mutex_name
 225                                                     (mutex_id),
 226                                                     ACPI_CAST_PTR(void,
 227                                                                   this_thread_id)));
 228
 229                                         return (AE_ALREADY_ACQUIRED);
 230                                 }
 231
 232                                 ACPI_ERROR((AE_INFO,
 233                                             "Invalid acquire order: Thread %p owns [%s], wants [%s]",
 234                                             ACPI_CAST_PTR(void, this_thread_id),
 235                                             acpi_ut_get_mutex_name(i),
 236                                             acpi_ut_get_mutex_name(mutex_id)));
 237
 238                                 return (AE_ACQUIRE_DEADLOCK);
 239                         }
 240                 }
 241         }
 242 #endif
 243
 244         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
 245                           "Thread %p attempting to acquire Mutex [%s]\n",
 246                           ACPI_CAST_PTR(void, this_thread_id),
 247                           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 %p acquired Mutex [%s]\n",
 254                                   ACPI_CAST_PTR(void, 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 %p could not acquire Mutex [0x%X]",
 262                                 ACPI_CAST_PTR(void, 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_FUNCTION_NAME(ut_release_mutex);
 283
 284         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %p releasing Mutex [%s]\n",
 285                           ACPI_CAST_PTR(void, acpi_os_get_thread_id()),
 286                           acpi_ut_get_mutex_name(mutex_id)));
 287
 288         if (mutex_id > ACPI_MAX_MUTEX) {
 289                 return (AE_BAD_PARAMETER);
 290         }
 291
 292         /*
 293          * Mutex must be acquired in order to release it!
 294          */
 295         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
 296                 ACPI_ERROR((AE_INFO,
 297                             "Mutex [0x%X] is not acquired, cannot release",
 298                             mutex_id));
 299
 300                 return (AE_NOT_ACQUIRED);
 301         }
 302 #ifdef ACPI_MUTEX_DEBUG
 303         {
 304                 u32 i;
 305                 /*
 306                  * Mutex debug code, for internal debugging only.
 307                  *
 308                  * Deadlock prevention.  Check if this thread owns any mutexes of value
 309                  * greater than this one.  If so, the thread has violated the mutex
 310                  * ordering rule.  This indicates a coding error somewhere in
 311                  * the ACPI subsystem code.
 312                  */
 313                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
 314                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
 315                                 if (i == mutex_id) {
 316                                         continue;
 317                                 }
 318
 319                                 ACPI_ERROR((AE_INFO,
 320                                             "Invalid release order: owns [%s], releasing [%s]",
 321                                             acpi_ut_get_mutex_name(i),
 322                                             acpi_ut_get_mutex_name(mutex_id)));
 323
 324                                 return (AE_RELEASE_DEADLOCK);
 325                         }
 326                 }
 327         }
 328 #endif
 329
 330         /* Mark unlocked FIRST */
 331
 332         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 333
 334         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
 335         return (AE_OK);
 336 }