err.no 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 - 2007, 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 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/acevents.h>
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exmutex")
  51
  52 /* Local prototypes */
  53 static void
  54 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
  55                    struct acpi_thread_state *thread);
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_ex_unlink_mutex
  60  *
  61  * PARAMETERS:  obj_desc            - The mutex to be unlinked
  62  *
  63  * RETURN:      None
  64  *
  65  * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
  66  *
  67  ******************************************************************************/
  68
  69 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
  70 {
  71         struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
  72
  73         if (!thread) {
  74                 return;
  75         }
  76
  77         /* Doubly linked list */
  78
  79         if (obj_desc->mutex.next) {
  80                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
  81         }
  82
  83         if (obj_desc->mutex.prev) {
  84                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
  85         } else {
  86                 thread->acquired_mutex_list = obj_desc->mutex.next;
  87         }
  88 }
  89
  90 /*******************************************************************************
  91  *
  92  * FUNCTION:    acpi_ex_link_mutex
  93  *
  94  * PARAMETERS:  obj_desc        - The mutex to be linked
  95  *              Thread          - Current executing thread object
  96  *
  97  * RETURN:      None
  98  *
  99  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
 100  *
 101  ******************************************************************************/
 102
 103 static void
 104 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
 105                    struct acpi_thread_state *thread)
 106 {
 107         union acpi_operand_object *list_head;
 108
 109         list_head = thread->acquired_mutex_list;
 110
 111         /* This object will be the first object in the list */
 112
 113         obj_desc->mutex.prev = NULL;
 114         obj_desc->mutex.next = list_head;
 115
 116         /* Update old first object to point back to this object */
 117
 118         if (list_head) {
 119                 list_head->mutex.prev = obj_desc;
 120         }
 121
 122         /* Update list head */
 123
 124         thread->acquired_mutex_list = obj_desc;
 125 }
 126
 127 /*******************************************************************************
 128  *
 129  * FUNCTION:    acpi_ex_acquire_mutex_object
 130  *
 131  * PARAMETERS:  time_desc           - Timeout in milliseconds
 132  *              obj_desc            - Mutex object
 133  *              Thread              - Current thread state
 134  *
 135  * RETURN:      Status
 136  *
 137  * DESCRIPTION: Acquire an AML mutex, low-level interface
 138  *
 139  ******************************************************************************/
 140
 141 acpi_status
 142 acpi_ex_acquire_mutex_object(u16 timeout,
 143                              union acpi_operand_object *obj_desc,
 144                              acpi_thread_id thread_id)
 145 {
 146         acpi_status status;
 147
 148         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
 149
 150         /* Support for multiple acquires by the owning thread */
 151
 152         if (obj_desc->mutex.thread_id == thread_id) {
 153                 /*
 154                  * The mutex is already owned by this thread, just increment the
 155                  * acquisition depth
 156                  */
 157                 obj_desc->mutex.acquisition_depth++;
 158                 return_ACPI_STATUS(AE_OK);
 159         }
 160
 161         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
 162
 163         if (obj_desc == acpi_gbl_global_lock_mutex) {
 164                 status = acpi_ev_acquire_global_lock(timeout);
 165         } else {
 166                 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
 167                                                    timeout);
 168         }
 169
 170         if (ACPI_FAILURE(status)) {
 171
 172                 /* Includes failure from a timeout on time_desc */
 173
 174                 return_ACPI_STATUS(status);
 175         }
 176
 177         /* Have the mutex: update mutex and save the sync_level */
 178
 179         obj_desc->mutex.thread_id = thread_id;
 180         obj_desc->mutex.acquisition_depth = 1;
 181         obj_desc->mutex.original_sync_level = 0;
 182         obj_desc->mutex.owner_thread = NULL;    /* Used only for AML Acquire() */
 183
 184         return_ACPI_STATUS(AE_OK);
 185 }
 186
 187 /*******************************************************************************
 188  *
 189  * FUNCTION:    acpi_ex_acquire_mutex
 190  *
 191  * PARAMETERS:  time_desc           - Timeout integer
 192  *              obj_desc            - Mutex object
 193  *              walk_state          - Current method execution state
 194  *
 195  * RETURN:      Status
 196  *
 197  * DESCRIPTION: Acquire an AML mutex
 198  *
 199  ******************************************************************************/
 200
 201 acpi_status
 202 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
 203                       union acpi_operand_object *obj_desc,
 204                       struct acpi_walk_state *walk_state)
 205 {
 206         acpi_status status;
 207
 208         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
 209
 210         if (!obj_desc) {
 211                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 212         }
 213
 214         /* Sanity check: we must have a valid thread ID */
 215
 216         if (!walk_state->thread) {
 217                 ACPI_ERROR((AE_INFO,
 218                             "Cannot acquire Mutex [%4.4s], null thread info",
 219                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 220                 return_ACPI_STATUS(AE_AML_INTERNAL);
 221         }
 222
 223         /*
 224          * Current Sync level must be less than or equal to the sync level of the
 225          * mutex. This mechanism provides some deadlock prevention
 226          */
 227         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 228                 ACPI_ERROR((AE_INFO,
 229                             "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
 230                             acpi_ut_get_node_name(obj_desc->mutex.node),
 231                             walk_state->thread->current_sync_level));
 232                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 233         }
 234
 235         status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
 236                                               obj_desc,
 237                                               walk_state->thread->thread_id);
 238         if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
 239                 obj_desc->mutex.owner_thread = walk_state->thread;
 240                 obj_desc->mutex.original_sync_level =
 241                     walk_state->thread->current_sync_level;
 242                 walk_state->thread->current_sync_level =
 243                     obj_desc->mutex.sync_level;
 244
 245                 /* Link the mutex to the current thread for force-unlock at method exit */
 246
 247                 acpi_ex_link_mutex(obj_desc, walk_state->thread);
 248         }
 249
 250         return_ACPI_STATUS(status);
 251 }
 252
 253 /*******************************************************************************
 254  *
 255  * FUNCTION:    acpi_ex_release_mutex_object
 256  *
 257  * PARAMETERS:  obj_desc            - The object descriptor for this op
 258  *
 259  * RETURN:      Status
 260  *
 261  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
 262  *
 263  ******************************************************************************/
 264
 265 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
 266 {
 267         acpi_status status = AE_OK;
 268
 269         ACPI_FUNCTION_TRACE(ex_release_mutex_object);
 270
 271         /* Match multiple Acquires with multiple Releases */
 272
 273         obj_desc->mutex.acquisition_depth--;
 274         if (obj_desc->mutex.acquisition_depth != 0) {
 275
 276                 /* Just decrement the depth and return */
 277
 278                 return_ACPI_STATUS(AE_OK);
 279         }
 280
 281         if (obj_desc->mutex.owner_thread) {
 282
 283                 /* Unlink the mutex from the owner's list */
 284
 285                 acpi_ex_unlink_mutex(obj_desc);
 286                 obj_desc->mutex.owner_thread = NULL;
 287         }
 288
 289         /* Release the mutex, special case for Global Lock */
 290
 291         if (obj_desc == acpi_gbl_global_lock_mutex) {
 292                 status = acpi_ev_release_global_lock();
 293         } else {
 294                 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 295         }
 296
 297         obj_desc->mutex.thread_id = 0;
 298         return_ACPI_STATUS(status);
 299 }
 300
 301 /*******************************************************************************
 302  *
 303  * FUNCTION:    acpi_ex_release_mutex
 304  *
 305  * PARAMETERS:  obj_desc            - The object descriptor for this op
 306  *              walk_state          - Current method execution state
 307  *
 308  * RETURN:      Status
 309  *
 310  * DESCRIPTION: Release a previously acquired Mutex.
 311  *
 312  ******************************************************************************/
 313
 314 acpi_status
 315 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 316                       struct acpi_walk_state *walk_state)
 317 {
 318         acpi_status status = AE_OK;
 319
 320         ACPI_FUNCTION_TRACE(ex_release_mutex);
 321
 322         if (!obj_desc) {
 323                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 324         }
 325
 326         /* The mutex must have been previously acquired in order to release it */
 327
 328         if (!obj_desc->mutex.owner_thread) {
 329                 ACPI_ERROR((AE_INFO,
 330                             "Cannot release Mutex [%4.4s], not acquired",
 331                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 332                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 333         }
 334
 335         /*
 336          * The Mutex is owned, but this thread must be the owner.
 337          * Special case for Global Lock, any thread can release
 338          */
 339         if ((obj_desc->mutex.owner_thread->thread_id !=
 340              walk_state->thread->thread_id)
 341             && (obj_desc != acpi_gbl_global_lock_mutex)) {
 342                 ACPI_ERROR((AE_INFO,
 343                             "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
 344                             (unsigned long)walk_state->thread->thread_id,
 345                             acpi_ut_get_node_name(obj_desc->mutex.node),
 346                             (unsigned long)obj_desc->mutex.owner_thread->
 347                             thread_id));
 348                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 349         }
 350
 351         /* Sanity check: we must have a valid thread ID */
 352
 353         if (!walk_state->thread) {
 354                 ACPI_ERROR((AE_INFO,
 355                             "Cannot release Mutex [%4.4s], null thread info",
 356                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 357                 return_ACPI_STATUS(AE_AML_INTERNAL);
 358         }
 359
 360         /*
 361          * The sync level of the mutex must be less than or equal to the current
 362          * sync level
 363          */
 364         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 365                 ACPI_ERROR((AE_INFO,
 366                             "Cannot release Mutex [%4.4s], incorrect SyncLevel",
 367                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 368                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 369         }
 370
 371         status = acpi_ex_release_mutex_object(obj_desc);
 372
 373         /* Restore sync_level */
 374
 375         walk_state->thread->current_sync_level =
 376             obj_desc->mutex.original_sync_level;
 377         return_ACPI_STATUS(status);
 378 }
 379
 380 /*******************************************************************************
 381  *
 382  * FUNCTION:    acpi_ex_release_all_mutexes
 383  *
 384  * PARAMETERS:  Thread          - Current executing thread object
 385  *
 386  * RETURN:      Status
 387  *
 388  * DESCRIPTION: Release all mutexes held by this thread
 389  *
 390  * NOTE: This function is called as the thread is exiting the interpreter.
 391  * Mutexes are not released when an individual control method is exited, but
 392  * only when the parent thread actually exits the interpreter. This allows one
 393  * method to acquire a mutex, and a different method to release it, as long as
 394  * this is performed underneath a single parent control method.
 395  *
 396  ******************************************************************************/
 397
 398 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 399 {
 400         union acpi_operand_object *next = thread->acquired_mutex_list;
 401         union acpi_operand_object *obj_desc;
 402
 403         ACPI_FUNCTION_ENTRY();
 404
 405         /* Traverse the list of owned mutexes, releasing each one */
 406
 407         while (next) {
 408                 obj_desc = next;
 409                 next = obj_desc->mutex.next;
 410
 411                 obj_desc->mutex.prev = NULL;
 412                 obj_desc->mutex.next = NULL;
 413                 obj_desc->mutex.acquisition_depth = 0;
 414
 415                 /* Release the mutex, special case for Global Lock */
 416
 417                 if (obj_desc == acpi_gbl_global_lock_mutex) {
 418
 419                         /* Ignore errors */
 420
 421                         (void)acpi_ev_release_global_lock();
 422                 } else {
 423                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 424                 }
 425
 426                 /* Mark mutex unowned */
 427
 428                 obj_desc->mutex.owner_thread = NULL;
 429                 obj_desc->mutex.thread_id = 0;
 430
 431                 /* Update Thread sync_level (Last mutex is the important one) */
 432
 433                 thread->current_sync_level =
 434                     obj_desc->mutex.original_sync_level;
 435         }
 436 }