drivers/acpi/acpica/exmutex.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exmutex - ASL Mutex Acquire/Release functions
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2016, 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 #include "acinterp.h"
  47 #include "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
  86                 /*
  87                  * Migrate the previous sync level associated with this mutex to
  88                  * the previous mutex on the list so that it may be preserved.
  89                  * This handles the case where several mutexes have been acquired
  90                  * at the same level, but are not released in opposite order.
  91                  */
  92                 (obj_desc->mutex.prev)->mutex.original_sync_level =
  93                     obj_desc->mutex.original_sync_level;
  94         } else {
  95                 thread->acquired_mutex_list = obj_desc->mutex.next;
  96         }
  97 }
  98
  99 /*******************************************************************************
 100  *
 101  * FUNCTION:    acpi_ex_link_mutex
 102  *
 103  * PARAMETERS:  obj_desc            - The mutex to be linked
 104  *              thread              - Current executing thread object
 105  *
 106  * RETURN:      None
 107  *
 108  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
 109  *
 110  ******************************************************************************/
 111
 112 static void
 113 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
 114                    struct acpi_thread_state *thread)
 115 {
 116         union acpi_operand_object *list_head;
 117
 118         list_head = thread->acquired_mutex_list;
 119
 120         /* This object will be the first object in the list */
 121
 122         obj_desc->mutex.prev = NULL;
 123         obj_desc->mutex.next = list_head;
 124
 125         /* Update old first object to point back to this object */
 126
 127         if (list_head) {
 128                 list_head->mutex.prev = obj_desc;
 129         }
 130
 131         /* Update list head */
 132
 133         thread->acquired_mutex_list = obj_desc;
 134 }
 135
 136 /*******************************************************************************
 137  *
 138  * FUNCTION:    acpi_ex_acquire_mutex_object
 139  *
 140  * PARAMETERS:  timeout             - Timeout in milliseconds
 141  *              obj_desc            - Mutex object
 142  *              thread_id           - Current thread state
 143  *
 144  * RETURN:      Status
 145  *
 146  * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
 147  *              path that supports multiple acquires by the same thread.
 148  *
 149  * MUTEX:       Interpreter must be locked
 150  *
 151  * NOTE: This interface is called from three places:
 152  * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
 153  * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
 154  *    global lock
 155  * 3) From the external interface, acpi_acquire_global_lock
 156  *
 157  ******************************************************************************/
 158
 159 acpi_status
 160 acpi_ex_acquire_mutex_object(u16 timeout,
 161                              union acpi_operand_object *obj_desc,
 162                              acpi_thread_id thread_id)
 163 {
 164         acpi_status status;
 165
 166         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
 167
 168         if (!obj_desc) {
 169                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 170         }
 171
 172         /* Support for multiple acquires by the owning thread */
 173
 174         if (obj_desc->mutex.thread_id == thread_id) {
 175                 /*
 176                  * The mutex is already owned by this thread, just increment the
 177                  * acquisition depth
 178                  */
 179                 obj_desc->mutex.acquisition_depth++;
 180                 return_ACPI_STATUS(AE_OK);
 181         }
 182
 183         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
 184
 185         if (obj_desc == acpi_gbl_global_lock_mutex) {
 186                 status = acpi_ev_acquire_global_lock(timeout);
 187         } else {
 188                 status =
 189                     acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
 190                                               timeout);
 191         }
 192
 193         if (ACPI_FAILURE(status)) {
 194
 195                 /* Includes failure from a timeout on time_desc */
 196
 197                 return_ACPI_STATUS(status);
 198         }
 199
 200         /* Acquired the mutex: update mutex object */
 201
 202         obj_desc->mutex.thread_id = thread_id;
 203         obj_desc->mutex.acquisition_depth = 1;
 204         obj_desc->mutex.original_sync_level = 0;
 205         obj_desc->mutex.owner_thread = NULL;    /* Used only for AML Acquire() */
 206
 207         return_ACPI_STATUS(AE_OK);
 208 }
 209
 210 /*******************************************************************************
 211  *
 212  * FUNCTION:    acpi_ex_acquire_mutex
 213  *
 214  * PARAMETERS:  time_desc           - Timeout integer
 215  *              obj_desc            - Mutex object
 216  *              walk_state          - Current method execution state
 217  *
 218  * RETURN:      Status
 219  *
 220  * DESCRIPTION: Acquire an AML mutex
 221  *
 222  ******************************************************************************/
 223
 224 acpi_status
 225 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
 226                       union acpi_operand_object *obj_desc,
 227                       struct acpi_walk_state *walk_state)
 228 {
 229         acpi_status status;
 230
 231         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
 232
 233         if (!obj_desc) {
 234                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 235         }
 236
 237         /* Must have a valid thread state struct */
 238
 239         if (!walk_state->thread) {
 240                 ACPI_ERROR((AE_INFO,
 241                             "Cannot acquire Mutex [%4.4s], null thread info",
 242                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 243                 return_ACPI_STATUS(AE_AML_INTERNAL);
 244         }
 245
 246         /*
 247          * Current sync level must be less than or equal to the sync level
 248          * of the mutex. This mechanism provides some deadlock prevention.
 249          */
 250         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 251                 ACPI_ERROR((AE_INFO,
 252                             "Cannot acquire Mutex [%4.4s], "
 253                             "current SyncLevel is too large (%u)",
 254                             acpi_ut_get_node_name(obj_desc->mutex.node),
 255                             walk_state->thread->current_sync_level));
 256                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 257         }
 258
 259         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 260                           "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, "
 261                           "Depth %u TID %p\n",
 262                           obj_desc->mutex.sync_level,
 263                           walk_state->thread->current_sync_level,
 264                           obj_desc->mutex.acquisition_depth,
 265                           walk_state->thread));
 266
 267         status = acpi_ex_acquire_mutex_object((u16)time_desc->integer.value,
 268                                               obj_desc,
 269                                               walk_state->thread->thread_id);
 270
 271         if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
 272
 273                 /* Save Thread object, original/current sync levels */
 274
 275                 obj_desc->mutex.owner_thread = walk_state->thread;
 276                 obj_desc->mutex.original_sync_level =
 277                     walk_state->thread->current_sync_level;
 278                 walk_state->thread->current_sync_level =
 279                     obj_desc->mutex.sync_level;
 280
 281                 /* Link the mutex to the current thread for force-unlock at method exit */
 282
 283                 acpi_ex_link_mutex(obj_desc, walk_state->thread);
 284         }
 285
 286         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 287                           "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n",
 288                           obj_desc->mutex.sync_level,
 289                           walk_state->thread->current_sync_level,
 290                           obj_desc->mutex.acquisition_depth));
 291
 292         return_ACPI_STATUS(status);
 293 }
 294
 295 /*******************************************************************************
 296  *
 297  * FUNCTION:    acpi_ex_release_mutex_object
 298  *
 299  * PARAMETERS:  obj_desc            - The object descriptor for this op
 300  *
 301  * RETURN:      Status
 302  *
 303  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
 304  *              Provides a common path that supports multiple releases (after
 305  *              previous multiple acquires) by the same thread.
 306  *
 307  * MUTEX:       Interpreter must be locked
 308  *
 309  * NOTE: This interface is called from three places:
 310  * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
 311  * 2) From acpi_ex_release_global_lock when an AML Field access requires the
 312  *    global lock
 313  * 3) From the external interface, acpi_release_global_lock
 314  *
 315  ******************************************************************************/
 316
 317 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
 318 {
 319         acpi_status status = AE_OK;
 320
 321         ACPI_FUNCTION_TRACE(ex_release_mutex_object);
 322
 323         if (obj_desc->mutex.acquisition_depth == 0) {
 324                 return_ACPI_STATUS(AE_NOT_ACQUIRED);
 325         }
 326
 327         /* Match multiple Acquires with multiple Releases */
 328
 329         obj_desc->mutex.acquisition_depth--;
 330         if (obj_desc->mutex.acquisition_depth != 0) {
 331
 332                 /* Just decrement the depth and return */
 333
 334                 return_ACPI_STATUS(AE_OK);
 335         }
 336
 337         if (obj_desc->mutex.owner_thread) {
 338
 339                 /* Unlink the mutex from the owner's list */
 340
 341                 acpi_ex_unlink_mutex(obj_desc);
 342                 obj_desc->mutex.owner_thread = NULL;
 343         }
 344
 345         /* Release the mutex, special case for Global Lock */
 346
 347         if (obj_desc == acpi_gbl_global_lock_mutex) {
 348                 status = acpi_ev_release_global_lock();
 349         } else {
 350                 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 351         }
 352
 353         /* Clear mutex info */
 354
 355         obj_desc->mutex.thread_id = 0;
 356         return_ACPI_STATUS(status);
 357 }
 358
 359 /*******************************************************************************
 360  *
 361  * FUNCTION:    acpi_ex_release_mutex
 362  *
 363  * PARAMETERS:  obj_desc            - The object descriptor for this op
 364  *              walk_state          - Current method execution state
 365  *
 366  * RETURN:      Status
 367  *
 368  * DESCRIPTION: Release a previously acquired Mutex.
 369  *
 370  ******************************************************************************/
 371
 372 acpi_status
 373 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 374                       struct acpi_walk_state *walk_state)
 375 {
 376         u8 previous_sync_level;
 377         struct acpi_thread_state *owner_thread;
 378         acpi_status status = AE_OK;
 379
 380         ACPI_FUNCTION_TRACE(ex_release_mutex);
 381
 382         if (!obj_desc) {
 383                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 384         }
 385
 386         owner_thread = obj_desc->mutex.owner_thread;
 387
 388         /* The mutex must have been previously acquired in order to release it */
 389
 390         if (!owner_thread) {
 391                 ACPI_ERROR((AE_INFO,
 392                             "Cannot release Mutex [%4.4s], not acquired",
 393                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 394                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 395         }
 396
 397         /* Must have a valid thread ID */
 398
 399         if (!walk_state->thread) {
 400                 ACPI_ERROR((AE_INFO,
 401                             "Cannot release Mutex [%4.4s], null thread info",
 402                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 403                 return_ACPI_STATUS(AE_AML_INTERNAL);
 404         }
 405
 406         /*
 407          * The Mutex is owned, but this thread must be the owner.
 408          * Special case for Global Lock, any thread can release
 409          */
 410         if ((owner_thread->thread_id != walk_state->thread->thread_id) &&
 411             (obj_desc != acpi_gbl_global_lock_mutex)) {
 412                 ACPI_ERROR((AE_INFO,
 413                             "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
 414                             (u32)walk_state->thread->thread_id,
 415                             acpi_ut_get_node_name(obj_desc->mutex.node),
 416                             (u32)owner_thread->thread_id));
 417                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 418         }
 419
 420         /*
 421          * The sync level of the mutex must be equal to the current sync level. In
 422          * other words, the current level means that at least one mutex at that
 423          * level is currently being held. Attempting to release a mutex of a
 424          * different level can only mean that the mutex ordering rule is being
 425          * violated. This behavior is clarified in ACPI 4.0 specification.
 426          */
 427         if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) {
 428                 ACPI_ERROR((AE_INFO,
 429                             "Cannot release Mutex [%4.4s], SyncLevel mismatch: "
 430                             "mutex %u current %u",
 431                             acpi_ut_get_node_name(obj_desc->mutex.node),
 432                             obj_desc->mutex.sync_level,
 433                             walk_state->thread->current_sync_level));
 434                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 435         }
 436
 437         /*
 438          * Get the previous sync_level from the head of the acquired mutex list.
 439          * This handles the case where several mutexes at the same level have been
 440          * acquired, but are not released in reverse order.
 441          */
 442         previous_sync_level =
 443             owner_thread->acquired_mutex_list->mutex.original_sync_level;
 444
 445         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 446                           "Releasing: Object SyncLevel %u, Thread SyncLevel %u, "
 447                           "Prev SyncLevel %u, Depth %u TID %p\n",
 448                           obj_desc->mutex.sync_level,
 449                           walk_state->thread->current_sync_level,
 450                           previous_sync_level,
 451                           obj_desc->mutex.acquisition_depth,
 452                           walk_state->thread));
 453
 454         status = acpi_ex_release_mutex_object(obj_desc);
 455         if (ACPI_FAILURE(status)) {
 456                 return_ACPI_STATUS(status);
 457         }
 458
 459         if (obj_desc->mutex.acquisition_depth == 0) {
 460
 461                 /* Restore the previous sync_level */
 462
 463                 owner_thread->current_sync_level = previous_sync_level;
 464         }
 465
 466         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 467                           "Released: Object SyncLevel %u, Thread SyncLevel, %u, "
 468                           "Prev SyncLevel %u, Depth %u\n",
 469                           obj_desc->mutex.sync_level,
 470                           walk_state->thread->current_sync_level,
 471                           previous_sync_level,
 472                           obj_desc->mutex.acquisition_depth));
 473
 474         return_ACPI_STATUS(status);
 475 }
 476
 477 /*******************************************************************************
 478  *
 479  * FUNCTION:    acpi_ex_release_all_mutexes
 480  *
 481  * PARAMETERS:  thread              - Current executing thread object
 482  *
 483  * RETURN:      Status
 484  *
 485  * DESCRIPTION: Release all mutexes held by this thread
 486  *
 487  * NOTE: This function is called as the thread is exiting the interpreter.
 488  * Mutexes are not released when an individual control method is exited, but
 489  * only when the parent thread actually exits the interpreter. This allows one
 490  * method to acquire a mutex, and a different method to release it, as long as
 491  * this is performed underneath a single parent control method.
 492  *
 493  ******************************************************************************/
 494
 495 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 496 {
 497         union acpi_operand_object *next = thread->acquired_mutex_list;
 498         union acpi_operand_object *obj_desc;
 499
 500         ACPI_FUNCTION_TRACE(ex_release_all_mutexes);
 501
 502         /* Traverse the list of owned mutexes, releasing each one */
 503
 504         while (next) {
 505                 obj_desc = next;
 506                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 507                                   "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n",
 508                                   obj_desc->mutex.node->name.ascii,
 509                                   obj_desc->mutex.sync_level,
 510                                   obj_desc->mutex.acquisition_depth));
 511
 512                 /* Release the mutex, special case for Global Lock */
 513
 514                 if (obj_desc == acpi_gbl_global_lock_mutex) {
 515
 516                         /* Ignore errors */
 517
 518                         (void)acpi_ev_release_global_lock();
 519                 } else {
 520                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 521                 }
 522
 523                 /* Update Thread sync_level (Last mutex is the important one) */
 524
 525                 thread->current_sync_level =
 526                     obj_desc->mutex.original_sync_level;
 527
 528                 /* Mark mutex unowned */
 529
 530                 next = obj_desc->mutex.next;
 531
 532                 obj_desc->mutex.prev = NULL;
 533                 obj_desc->mutex.next = NULL;
 534                 obj_desc->mutex.acquisition_depth = 0;
 535                 obj_desc->mutex.owner_thread = NULL;
 536                 obj_desc->mutex.thread_id = 0;
 537         }
 538
 539         return_VOID;
 540 }