git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/executer/exmutex.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exmutex - ASL Mutex Acquire/Release functions
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2005, R. Byron Moore
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45
  46 #include <acpi/acpi.h>
  47 #include <acpi/acinterp.h>
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50          ACPI_MODULE_NAME    ("exmutex")
  51
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    acpi_ex_unlink_mutex
  56  *
  57  * PARAMETERS:  obj_desc            - The mutex to be unlinked
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Remove a mutex from the "acquired_mutex" list
  62  *
  63  ******************************************************************************/
  64
  65 void
  66 acpi_ex_unlink_mutex (
  67         union acpi_operand_object       *obj_desc)
  68 {
  69         struct acpi_thread_state        *thread = obj_desc->mutex.owner_thread;
  70
  71
  72         if (!thread) {
  73                 return;
  74         }
  75
  76         /* Doubly linked list */
  77
  78         if (obj_desc->mutex.next) {
  79                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
  80         }
  81
  82         if (obj_desc->mutex.prev) {
  83                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
  84         }
  85         else {
  86                 thread->acquired_mutex_list = obj_desc->mutex.next;
  87         }
  88 }
  89
  90
  91 /*******************************************************************************
  92  *
  93  * FUNCTION:    acpi_ex_link_mutex
  94  *
  95  * PARAMETERS:  obj_desc            - The mutex to be linked
  96  *              list_head           - head of the "acquired_mutex" list
  97  *
  98  * RETURN:      Status
  99  *
 100  * DESCRIPTION: Add a mutex to the "acquired_mutex" list for this walk
 101  *
 102  ******************************************************************************/
 103
 104 void
 105 acpi_ex_link_mutex (
 106         union acpi_operand_object       *obj_desc,
 107         struct acpi_thread_state        *thread)
 108 {
 109         union acpi_operand_object       *list_head;
 110
 111
 112         list_head = thread->acquired_mutex_list;
 113
 114         /* This object will be the first object in the list */
 115
 116         obj_desc->mutex.prev = NULL;
 117         obj_desc->mutex.next = list_head;
 118
 119         /* Update old first object to point back to this object */
 120
 121         if (list_head) {
 122                 list_head->mutex.prev = obj_desc;
 123         }
 124
 125         /* Update list head */
 126
 127         thread->acquired_mutex_list = obj_desc;
 128 }
 129
 130
 131 /*******************************************************************************
 132  *
 133  * FUNCTION:    acpi_ex_acquire_mutex
 134  *
 135  * PARAMETERS:  time_desc           - The 'time to delay' object descriptor
 136  *              obj_desc            - The object descriptor for this op
 137  *
 138  * RETURN:      Status
 139  *
 140  * DESCRIPTION: Acquire an AML mutex
 141  *
 142  ******************************************************************************/
 143
 144 acpi_status
 145 acpi_ex_acquire_mutex (
 146         union acpi_operand_object       *time_desc,
 147         union acpi_operand_object       *obj_desc,
 148         struct acpi_walk_state          *walk_state)
 149 {
 150         acpi_status                     status;
 151
 152
 153         ACPI_FUNCTION_TRACE_PTR ("ex_acquire_mutex", obj_desc);
 154
 155
 156         if (!obj_desc) {
 157                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 158         }
 159
 160         /* Sanity check -- we must have a valid thread ID */
 161
 162         if (!walk_state->thread) {
 163                 ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], null thread info\n",
 164                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 165                 return_ACPI_STATUS (AE_AML_INTERNAL);
 166         }
 167
 168         /*
 169          * Current Sync must be less than or equal to the sync level of the
 170          * mutex.  This mechanism provides some deadlock prevention
 171          */
 172         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 173                 ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], incorrect sync_level\n",
 174                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 175                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 176         }
 177
 178         /* Support for multiple acquires by the owning thread */
 179
 180         if (obj_desc->mutex.owner_thread) {
 181                 /* Special case for Global Lock, allow all threads */
 182
 183                 if ((obj_desc->mutex.owner_thread->thread_id == walk_state->thread->thread_id) ||
 184                         (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore)) {
 185                         /*
 186                          * The mutex is already owned by this thread,
 187                          * just increment the acquisition depth
 188                          */
 189                         obj_desc->mutex.acquisition_depth++;
 190                         return_ACPI_STATUS (AE_OK);
 191                 }
 192         }
 193
 194         /* Acquire the mutex, wait if necessary */
 195
 196         status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);
 197         if (ACPI_FAILURE (status)) {
 198                 /* Includes failure from a timeout on time_desc */
 199
 200                 return_ACPI_STATUS (status);
 201         }
 202
 203         /* Have the mutex: update mutex and walk info and save the sync_level */
 204
 205         obj_desc->mutex.owner_thread     = walk_state->thread;
 206         obj_desc->mutex.acquisition_depth = 1;
 207         obj_desc->mutex.original_sync_level = walk_state->thread->current_sync_level;
 208
 209         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 210
 211         /* Link the mutex to the current thread for force-unlock at method exit */
 212
 213         acpi_ex_link_mutex (obj_desc, walk_state->thread);
 214
 215         return_ACPI_STATUS (AE_OK);
 216 }
 217
 218
 219 /*******************************************************************************
 220  *
 221  * FUNCTION:    acpi_ex_release_mutex
 222  *
 223  * PARAMETERS:  obj_desc            - The object descriptor for this op
 224  *
 225  * RETURN:      Status
 226  *
 227  * DESCRIPTION: Release a previously acquired Mutex.
 228  *
 229  ******************************************************************************/
 230
 231 acpi_status
 232 acpi_ex_release_mutex (
 233         union acpi_operand_object       *obj_desc,
 234         struct acpi_walk_state          *walk_state)
 235 {
 236         acpi_status                     status;
 237
 238
 239         ACPI_FUNCTION_TRACE ("ex_release_mutex");
 240
 241
 242         if (!obj_desc) {
 243                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 244         }
 245
 246         /* The mutex must have been previously acquired in order to release it */
 247
 248         if (!obj_desc->mutex.owner_thread) {
 249                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], not acquired\n",
 250                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 251                 return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
 252         }
 253
 254         /* Sanity check -- we must have a valid thread ID */
 255
 256         if (!walk_state->thread) {
 257                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], null thread info\n",
 258                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 259                 return_ACPI_STATUS (AE_AML_INTERNAL);
 260         }
 261
 262         /*
 263          * The Mutex is owned, but this thread must be the owner.
 264          * Special case for Global Lock, any thread can release
 265          */
 266         if ((obj_desc->mutex.owner_thread->thread_id != walk_state->thread->thread_id) &&
 267                 (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {
 268                 ACPI_REPORT_ERROR ((
 269                         "Thread %X cannot release Mutex [%4.4s] acquired by thread %X\n",
 270                         walk_state->thread->thread_id,
 271                         acpi_ut_get_node_name (obj_desc->mutex.node),
 272                         obj_desc->mutex.owner_thread->thread_id));
 273                 return_ACPI_STATUS (AE_AML_NOT_OWNER);
 274         }
 275
 276         /*
 277          * The sync level of the mutex must be less than or
 278          * equal to the current sync level
 279          */
 280         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 281                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], incorrect sync_level\n",
 282                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 283                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 284         }
 285
 286         /* Match multiple Acquires with multiple Releases */
 287
 288         obj_desc->mutex.acquisition_depth--;
 289         if (obj_desc->mutex.acquisition_depth != 0) {
 290                 /* Just decrement the depth and return */
 291
 292                 return_ACPI_STATUS (AE_OK);
 293         }
 294
 295         /* Unlink the mutex from the owner's list */
 296
 297         acpi_ex_unlink_mutex (obj_desc);
 298
 299         /* Release the mutex */
 300
 301         status = acpi_ex_system_release_mutex (obj_desc);
 302
 303         /* Update the mutex and walk state, restore sync_level before acquire */
 304
 305         obj_desc->mutex.owner_thread = NULL;
 306         walk_state->thread->current_sync_level = obj_desc->mutex.original_sync_level;
 307
 308         return_ACPI_STATUS (status);
 309 }
 310
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ex_release_all_mutexes
 315  *
 316  * PARAMETERS:  mutex_list            - Head of the mutex list
 317  *
 318  * RETURN:      Status
 319  *
 320  * DESCRIPTION: Release all mutexes in the list
 321  *
 322  ******************************************************************************/
 323
 324 void
 325 acpi_ex_release_all_mutexes (
 326         struct acpi_thread_state        *thread)
 327 {
 328         union acpi_operand_object       *next = thread->acquired_mutex_list;
 329         union acpi_operand_object       *this;
 330         acpi_status                     status;
 331
 332
 333         ACPI_FUNCTION_ENTRY ();
 334
 335
 336         /* Traverse the list of owned mutexes, releasing each one */
 337
 338         while (next) {
 339                 this = next;
 340                 next = this->mutex.next;
 341
 342                 this->mutex.acquisition_depth = 1;
 343                 this->mutex.prev             = NULL;
 344                 this->mutex.next             = NULL;
 345
 346                  /* Release the mutex */
 347
 348                 status = acpi_ex_system_release_mutex (this);
 349                 if (ACPI_FAILURE (status)) {
 350                         continue;
 351                 }
 352
 353                 /* Mark mutex unowned */
 354
 355                 this->mutex.owner_thread = NULL;
 356
 357                 /* Update Thread sync_level (Last mutex is the important one) */
 358
 359                 thread->current_sync_level = this->mutex.original_sync_level;
 360         }
 361 }
 362
 363