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 - 2008, Intel Corp.
  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. Provides a common
 138  *              path that supports multiple acquires by the same thread.
 139  *
 140  * MUTEX:       Interpreter must be locked
 141  *
 142  * NOTE: This interface is called from three places:
 143  * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
 144  * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
 145  *    global lock
 146  * 3) From the external interface, acpi_acquire_global_lock
 147  *
 148  ******************************************************************************/
 149
 150 acpi_status
 151 acpi_ex_acquire_mutex_object(u16 timeout,
 152                              union acpi_operand_object *obj_desc,
 153                              acpi_thread_id thread_id)
 154 {
 155         acpi_status status;
 156
 157         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
 158
 159         if (!obj_desc) {
 160                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 161         }
 162
 163         /* Support for multiple acquires by the owning thread */
 164
 165         if (obj_desc->mutex.thread_id == thread_id) {
 166                 /*
 167                  * The mutex is already owned by this thread, just increment the
 168                  * acquisition depth
 169                  */
 170                 obj_desc->mutex.acquisition_depth++;
 171                 return_ACPI_STATUS(AE_OK);
 172         }
 173
 174         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
 175
 176         if (obj_desc == acpi_gbl_global_lock_mutex) {
 177                 status = acpi_ev_acquire_global_lock(timeout);
 178         } else {
 179                 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
 180                                                    timeout);
 181         }
 182
 183         if (ACPI_FAILURE(status)) {
 184
 185                 /* Includes failure from a timeout on time_desc */
 186
 187                 return_ACPI_STATUS(status);
 188         }
 189
 190         /* Acquired the mutex: update mutex object */
 191
 192         obj_desc->mutex.thread_id = thread_id;
 193         obj_desc->mutex.acquisition_depth = 1;
 194         obj_desc->mutex.original_sync_level = 0;
 195         obj_desc->mutex.owner_thread = NULL;    /* Used only for AML Acquire() */
 196
 197         return_ACPI_STATUS(AE_OK);
 198 }
 199
 200 /*******************************************************************************
 201  *
 202  * FUNCTION:    acpi_ex_acquire_mutex
 203  *
 204  * PARAMETERS:  time_desc           - Timeout integer
 205  *              obj_desc            - Mutex object
 206  *              walk_state          - Current method execution state
 207  *
 208  * RETURN:      Status
 209  *
 210  * DESCRIPTION: Acquire an AML mutex
 211  *
 212  ******************************************************************************/
 213
 214 acpi_status
 215 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
 216                       union acpi_operand_object *obj_desc,
 217                       struct acpi_walk_state *walk_state)
 218 {
 219         acpi_status status;
 220
 221         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
 222
 223         if (!obj_desc) {
 224                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 225         }
 226
 227         /* Must have a valid thread ID */
 228
 229         if (!walk_state->thread) {
 230                 ACPI_ERROR((AE_INFO,
 231                             "Cannot acquire Mutex [%4.4s], null thread info",
 232                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 233                 return_ACPI_STATUS(AE_AML_INTERNAL);
 234         }
 235
 236         /*
 237          * Current sync level must be less than or equal to the sync level of the
 238          * mutex. This mechanism provides some deadlock prevention
 239          */
 240         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 241                 ACPI_ERROR((AE_INFO,
 242                             "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
 243                             acpi_ut_get_node_name(obj_desc->mutex.node),
 244                             walk_state->thread->current_sync_level));
 245                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 246         }
 247
 248         status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
 249                                               obj_desc,
 250                                               walk_state->thread->thread_id);
 251         if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
 252
 253                 /* Save Thread object, original/current sync levels */
 254
 255                 obj_desc->mutex.owner_thread = walk_state->thread;
 256                 obj_desc->mutex.original_sync_level =
 257                     walk_state->thread->current_sync_level;
 258                 walk_state->thread->current_sync_level =
 259                     obj_desc->mutex.sync_level;
 260
 261                 /* Link the mutex to the current thread for force-unlock at method exit */
 262
 263                 acpi_ex_link_mutex(obj_desc, walk_state->thread);
 264         }
 265
 266         return_ACPI_STATUS(status);
 267 }
 268
 269 /*******************************************************************************
 270  *
 271  * FUNCTION:    acpi_ex_release_mutex_object
 272  *
 273  * PARAMETERS:  obj_desc            - The object descriptor for this op
 274  *
 275  * RETURN:      Status
 276  *
 277  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
 278  *              Provides a common path that supports multiple releases (after
 279  *              previous multiple acquires) by the same thread.
 280  *
 281  * MUTEX:       Interpreter must be locked
 282  *
 283  * NOTE: This interface is called from three places:
 284  * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
 285  * 2) From acpi_ex_release_global_lock when an AML Field access requires the
 286  *    global lock
 287  * 3) From the external interface, acpi_release_global_lock
 288  *
 289  ******************************************************************************/
 290
 291 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
 292 {
 293         acpi_status status = AE_OK;
 294
 295         ACPI_FUNCTION_TRACE(ex_release_mutex_object);
 296
 297         if (obj_desc->mutex.acquisition_depth == 0) {
 298                 return (AE_NOT_ACQUIRED);
 299         }
 300
 301         /* Match multiple Acquires with multiple Releases */
 302
 303         obj_desc->mutex.acquisition_depth--;
 304         if (obj_desc->mutex.acquisition_depth != 0) {
 305
 306                 /* Just decrement the depth and return */
 307
 308                 return_ACPI_STATUS(AE_OK);
 309         }
 310
 311         if (obj_desc->mutex.owner_thread) {
 312
 313                 /* Unlink the mutex from the owner's list */
 314
 315                 acpi_ex_unlink_mutex(obj_desc);
 316                 obj_desc->mutex.owner_thread = NULL;
 317         }
 318
 319         /* Release the mutex, special case for Global Lock */
 320
 321         if (obj_desc == acpi_gbl_global_lock_mutex) {
 322                 status = acpi_ev_release_global_lock();
 323         } else {
 324                 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 325         }
 326
 327         /* Clear mutex info */
 328
 329         obj_desc->mutex.thread_id = NULL;
 330         return_ACPI_STATUS(status);
 331 }
 332
 333 /*******************************************************************************
 334  *
 335  * FUNCTION:    acpi_ex_release_mutex
 336  *
 337  * PARAMETERS:  obj_desc            - The object descriptor for this op
 338  *              walk_state          - Current method execution state
 339  *
 340  * RETURN:      Status
 341  *
 342  * DESCRIPTION: Release a previously acquired Mutex.
 343  *
 344  ******************************************************************************/
 345
 346 acpi_status
 347 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 348                       struct acpi_walk_state *walk_state)
 349 {
 350         acpi_status status = AE_OK;
 351
 352         ACPI_FUNCTION_TRACE(ex_release_mutex);
 353
 354         if (!obj_desc) {
 355                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 356         }
 357
 358         /* The mutex must have been previously acquired in order to release it */
 359
 360         if (!obj_desc->mutex.owner_thread) {
 361                 ACPI_ERROR((AE_INFO,
 362                             "Cannot release Mutex [%4.4s], not acquired",
 363                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 364                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 365         }
 366
 367         /*
 368          * The Mutex is owned, but this thread must be the owner.
 369          * Special case for Global Lock, any thread can release
 370          */
 371         if ((obj_desc->mutex.owner_thread->thread_id !=
 372              walk_state->thread->thread_id)
 373             && (obj_desc != acpi_gbl_global_lock_mutex)) {
 374                 ACPI_ERROR((AE_INFO,
 375                             "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
 376                             (unsigned long)walk_state->thread->thread_id,
 377                             acpi_ut_get_node_name(obj_desc->mutex.node),
 378                             (unsigned long)obj_desc->mutex.owner_thread->
 379                             thread_id));
 380                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 381         }
 382
 383         /* Must have a valid thread ID */
 384
 385         if (!walk_state->thread) {
 386                 ACPI_ERROR((AE_INFO,
 387                             "Cannot release Mutex [%4.4s], null thread info",
 388                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 389                 return_ACPI_STATUS(AE_AML_INTERNAL);
 390         }
 391
 392         /*
 393          * The sync level of the mutex must be less than or equal to the current
 394          * sync level
 395          */
 396         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 397                 ACPI_ERROR((AE_INFO,
 398                             "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %d current %d",
 399                             acpi_ut_get_node_name(obj_desc->mutex.node),
 400                             obj_desc->mutex.sync_level,
 401                             walk_state->thread->current_sync_level));
 402                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 403         }
 404
 405         status = acpi_ex_release_mutex_object(obj_desc);
 406
 407         if (obj_desc->mutex.acquisition_depth == 0) {
 408
 409                 /* Restore the original sync_level */
 410
 411                 walk_state->thread->current_sync_level =
 412                     obj_desc->mutex.original_sync_level;
 413         }
 414         return_ACPI_STATUS(status);
 415 }
 416
 417 /*******************************************************************************
 418  *
 419  * FUNCTION:    acpi_ex_release_all_mutexes
 420  *
 421  * PARAMETERS:  Thread          - Current executing thread object
 422  *
 423  * RETURN:      Status
 424  *
 425  * DESCRIPTION: Release all mutexes held by this thread
 426  *
 427  * NOTE: This function is called as the thread is exiting the interpreter.
 428  * Mutexes are not released when an individual control method is exited, but
 429  * only when the parent thread actually exits the interpreter. This allows one
 430  * method to acquire a mutex, and a different method to release it, as long as
 431  * this is performed underneath a single parent control method.
 432  *
 433  ******************************************************************************/
 434
 435 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 436 {
 437         union acpi_operand_object *next = thread->acquired_mutex_list;
 438         union acpi_operand_object *obj_desc;
 439
 440         ACPI_FUNCTION_ENTRY();
 441
 442         /* Traverse the list of owned mutexes, releasing each one */
 443
 444         while (next) {
 445                 obj_desc = next;
 446                 next = obj_desc->mutex.next;
 447
 448                 obj_desc->mutex.prev = NULL;
 449                 obj_desc->mutex.next = NULL;
 450                 obj_desc->mutex.acquisition_depth = 0;
 451
 452                 /* Release the mutex, special case for Global Lock */
 453
 454                 if (obj_desc == acpi_gbl_global_lock_mutex) {
 455
 456                         /* Ignore errors */
 457
 458                         (void)acpi_ev_release_global_lock();
 459                 } else {
 460                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 461                 }
 462
 463                 /* Mark mutex unowned */
 464
 465                 obj_desc->mutex.owner_thread = NULL;
 466                 obj_desc->mutex.thread_id = NULL;
 467
 468                 /* Update Thread sync_level (Last mutex is the important one) */
 469
 470                 thread->current_sync_level =
 471                     obj_desc->mutex.original_sync_level;
 472         }
 473 }