drivers/acpi/dispatcher/dsmethod.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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 <acpi/amlcode.h>
  46 #include <acpi/acdispat.h>
  47 #include <acpi/acinterp.h>
  48 #include <acpi/acnamesp.h>
  49 #include <acpi/acdisasm.h>
  50
  51 #define _COMPONENT          ACPI_DISPATCHER
  52 ACPI_MODULE_NAME("dsmethod")
  53
  54 /* Local prototypes */
  55 static acpi_status
  56 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
  57
  58 /*******************************************************************************
  59  *
  60  * FUNCTION:    acpi_ds_method_error
  61  *
  62  * PARAMETERS:  Status          - Execution status
  63  *              walk_state      - Current state
  64  *
  65  * RETURN:      Status
  66  *
  67  * DESCRIPTION: Called on method error. Invoke the global exception handler if
  68  *              present, dump the method data if the disassembler is configured
  69  *
  70  *              Note: Allows the exception handler to change the status code
  71  *
  72  ******************************************************************************/
  73
  74 acpi_status
  75 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
  76 {
  77         ACPI_FUNCTION_ENTRY();
  78
  79         /* Ignore AE_OK and control exception codes */
  80
  81         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
  82                 return (status);
  83         }
  84
  85         /* Invoke the global exception handler */
  86
  87         if (acpi_gbl_exception_handler) {
  88
  89                 /* Exit the interpreter, allow handler to execute methods */
  90
  91                 acpi_ex_exit_interpreter();
  92
  93                 /*
  94                  * Handler can map the exception code to anything it wants, including
  95                  * AE_OK, in which case the executing method will not be aborted.
  96                  */
  97                 status = acpi_gbl_exception_handler(status,
  98                                                     walk_state->method_node ?
  99                                                     walk_state->method_node->
 100                                                     name.integer : 0,
 101                                                     walk_state->opcode,
 102                                                     walk_state->aml_offset,
 103                                                     NULL);
 104                 acpi_ex_enter_interpreter();
 105         }
 106 #ifdef ACPI_DISASSEMBLER
 107         if (ACPI_FAILURE(status)) {
 108
 109                 /* Display method locals/args if disassembler is present */
 110
 111                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
 112         }
 113 #endif
 114
 115         return (status);
 116 }
 117
 118 /*******************************************************************************
 119  *
 120  * FUNCTION:    acpi_ds_create_method_mutex
 121  *
 122  * PARAMETERS:  obj_desc            - The method object
 123  *
 124  * RETURN:      Status
 125  *
 126  * DESCRIPTION: Create a mutex object for a serialized control method
 127  *
 128  ******************************************************************************/
 129
 130 static acpi_status
 131 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
 132 {
 133         union acpi_operand_object *mutex_desc;
 134         acpi_status status;
 135
 136         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
 137
 138         /* Create the new mutex object */
 139
 140         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
 141         if (!mutex_desc) {
 142                 return_ACPI_STATUS(AE_NO_MEMORY);
 143         }
 144
 145         /* Create the actual OS Mutex */
 146
 147         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
 148         if (ACPI_FAILURE(status)) {
 149                 return_ACPI_STATUS(status);
 150         }
 151
 152         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
 153         method_desc->method.mutex = mutex_desc;
 154         return_ACPI_STATUS(AE_OK);
 155 }
 156
 157 /*******************************************************************************
 158  *
 159  * FUNCTION:    acpi_ds_begin_method_execution
 160  *
 161  * PARAMETERS:  method_node         - Node of the method
 162  *              obj_desc            - The method object
 163  *              walk_state          - current state, NULL if not yet executing
 164  *                                    a method.
 165  *
 166  * RETURN:      Status
 167  *
 168  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 169  *              increments the thread count, and waits at the method semaphore
 170  *              for clearance to execute.
 171  *
 172  ******************************************************************************/
 173
 174 acpi_status
 175 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 176                                union acpi_operand_object *obj_desc,
 177                                struct acpi_walk_state *walk_state)
 178 {
 179         acpi_status status = AE_OK;
 180
 181         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 182
 183         if (!method_node) {
 184                 return_ACPI_STATUS(AE_NULL_ENTRY);
 185         }
 186
 187         /* Prevent wraparound of thread count */
 188
 189         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 190                 ACPI_ERROR((AE_INFO,
 191                             "Method reached maximum reentrancy limit (255)"));
 192                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 193         }
 194
 195         /*
 196          * If this method is serialized, we need to acquire the method mutex.
 197          */
 198         if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) {
 199                 /*
 200                  * Create a mutex for the method if it is defined to be Serialized
 201                  * and a mutex has not already been created. We defer the mutex creation
 202                  * until a method is actually executed, to minimize the object count
 203                  */
 204                 if (!obj_desc->method.mutex) {
 205                         status = acpi_ds_create_method_mutex(obj_desc);
 206                         if (ACPI_FAILURE(status)) {
 207                                 return_ACPI_STATUS(status);
 208                         }
 209                 }
 210
 211                 /*
 212                  * The current_sync_level (per-thread) must be less than or equal to
 213                  * the sync level of the method. This mechanism provides some
 214                  * deadlock prevention
 215                  *
 216                  * Top-level method invocation has no walk state at this point
 217                  */
 218                 if (walk_state &&
 219                     (walk_state->thread->current_sync_level >
 220                      obj_desc->method.mutex->mutex.sync_level)) {
 221                         ACPI_ERROR((AE_INFO,
 222                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
 223                                     acpi_ut_get_node_name(method_node),
 224                                     walk_state->thread->current_sync_level));
 225
 226                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 227                 }
 228
 229                 /*
 230                  * Obtain the method mutex if necessary. Do not acquire mutex for a
 231                  * recursive call.
 232                  */
 233                 if (!walk_state ||
 234                     !obj_desc->method.mutex->mutex.thread_id ||
 235                     (walk_state->thread->thread_id !=
 236                      obj_desc->method.mutex->mutex.thread_id)) {
 237                         /*
 238                          * Acquire the method mutex. This releases the interpreter if we
 239                          * block (and reacquires it before it returns)
 240                          */
 241                         status =
 242                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
 243                                                       mutex.os_mutex,
 244                                                       ACPI_WAIT_FOREVER);
 245                         if (ACPI_FAILURE(status)) {
 246                                 return_ACPI_STATUS(status);
 247                         }
 248
 249                         /* Update the mutex and walk info and save the original sync_level */
 250
 251                         if (walk_state) {
 252                                 obj_desc->method.mutex->mutex.
 253                                     original_sync_level =
 254                                     walk_state->thread->current_sync_level;
 255
 256                                 obj_desc->method.mutex->mutex.thread_id =
 257                                     walk_state->thread->thread_id;
 258                                 walk_state->thread->current_sync_level =
 259                                     obj_desc->method.sync_level;
 260                         } else {
 261                                 obj_desc->method.mutex->mutex.
 262                                     original_sync_level =
 263                                     obj_desc->method.mutex->mutex.sync_level;
 264                         }
 265                 }
 266
 267                 /* Always increase acquisition depth */
 268
 269                 obj_desc->method.mutex->mutex.acquisition_depth++;
 270         }
 271
 272         /*
 273          * Allocate an Owner ID for this method, only if this is the first thread
 274          * to begin concurrent execution. We only need one owner_id, even if the
 275          * method is invoked recursively.
 276          */
 277         if (!obj_desc->method.owner_id) {
 278                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 279                 if (ACPI_FAILURE(status)) {
 280                         goto cleanup;
 281                 }
 282         }
 283
 284         /*
 285          * Increment the method parse tree thread count since it has been
 286          * reentered one more time (even if it is the same thread)
 287          */
 288         obj_desc->method.thread_count++;
 289         return_ACPI_STATUS(status);
 290
 291       cleanup:
 292         /* On error, must release the method mutex (if present) */
 293
 294         if (obj_desc->method.mutex) {
 295                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
 296         }
 297         return_ACPI_STATUS(status);
 298 }
 299
 300 /*******************************************************************************
 301  *
 302  * FUNCTION:    acpi_ds_call_control_method
 303  *
 304  * PARAMETERS:  Thread              - Info for this thread
 305  *              this_walk_state     - Current walk state
 306  *              Op                  - Current Op to be walked
 307  *
 308  * RETURN:      Status
 309  *
 310  * DESCRIPTION: Transfer execution to a called control method
 311  *
 312  ******************************************************************************/
 313
 314 acpi_status
 315 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 316                             struct acpi_walk_state *this_walk_state,
 317                             union acpi_parse_object *op)
 318 {
 319         acpi_status status;
 320         struct acpi_namespace_node *method_node;
 321         struct acpi_walk_state *next_walk_state = NULL;
 322         union acpi_operand_object *obj_desc;
 323         struct acpi_evaluate_info *info;
 324         u32 i;
 325
 326         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 327
 328         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 329                           "Calling method %p, currentstate=%p\n",
 330                           this_walk_state->prev_op, this_walk_state));
 331
 332         /*
 333          * Get the namespace entry for the control method we are about to call
 334          */
 335         method_node = this_walk_state->method_call_node;
 336         if (!method_node) {
 337                 return_ACPI_STATUS(AE_NULL_ENTRY);
 338         }
 339
 340         obj_desc = acpi_ns_get_attached_object(method_node);
 341         if (!obj_desc) {
 342                 return_ACPI_STATUS(AE_NULL_OBJECT);
 343         }
 344
 345         /* Init for new method, possibly wait on method mutex */
 346
 347         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 348                                                 this_walk_state);
 349         if (ACPI_FAILURE(status)) {
 350                 return_ACPI_STATUS(status);
 351         }
 352
 353         /* Begin method parse/execution. Create a new walk state */
 354
 355         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 356                                                     NULL, obj_desc, thread);
 357         if (!next_walk_state) {
 358                 status = AE_NO_MEMORY;
 359                 goto cleanup;
 360         }
 361
 362         /*
 363          * The resolved arguments were put on the previous walk state's operand
 364          * stack. Operands on the previous walk state stack always
 365          * start at index 0. Also, null terminate the list of arguments
 366          */
 367         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 368
 369         /*
 370          * Allocate and initialize the evaluation information block
 371          * TBD: this is somewhat inefficient, should change interface to
 372          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
 373          */
 374         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 375         if (!info) {
 376                 return_ACPI_STATUS(AE_NO_MEMORY);
 377         }
 378
 379         info->parameters = &this_walk_state->operands[0];
 380
 381         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 382                                        obj_desc->method.aml_start,
 383                                        obj_desc->method.aml_length, info,
 384                                        ACPI_IMODE_EXECUTE);
 385
 386         ACPI_FREE(info);
 387         if (ACPI_FAILURE(status)) {
 388                 goto cleanup;
 389         }
 390
 391         /*
 392          * Delete the operands on the previous walkstate operand stack
 393          * (they were copied to new objects)
 394          */
 395         for (i = 0; i < obj_desc->method.param_count; i++) {
 396                 acpi_ut_remove_reference(this_walk_state->operands[i]);
 397                 this_walk_state->operands[i] = NULL;
 398         }
 399
 400         /* Clear the operand stack */
 401
 402         this_walk_state->num_operands = 0;
 403
 404         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 405                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
 406                           method_node->name.ascii, next_walk_state));
 407
 408         /* Invoke an internal method if necessary */
 409
 410         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 411                 status = obj_desc->method.implementation(next_walk_state);
 412         }
 413
 414         return_ACPI_STATUS(status);
 415
 416       cleanup:
 417
 418         /* On error, we must terminate the method properly */
 419
 420         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
 421         if (next_walk_state) {
 422                 acpi_ds_delete_walk_state(next_walk_state);
 423         }
 424
 425         return_ACPI_STATUS(status);
 426 }
 427
 428 /*******************************************************************************
 429  *
 430  * FUNCTION:    acpi_ds_restart_control_method
 431  *
 432  * PARAMETERS:  walk_state          - State for preempted method (caller)
 433  *              return_desc         - Return value from the called method
 434  *
 435  * RETURN:      Status
 436  *
 437  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 438  *              invocation.  Handle the return value (if any) from the callee.
 439  *
 440  ******************************************************************************/
 441
 442 acpi_status
 443 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 444                                union acpi_operand_object *return_desc)
 445 {
 446         acpi_status status;
 447         int same_as_implicit_return;
 448
 449         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
 450
 451         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 452                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
 453                           acpi_ut_get_node_name(walk_state->method_node),
 454                           walk_state->method_call_op, return_desc));
 455
 456         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 457                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
 458                           walk_state->return_used,
 459                           walk_state->results, walk_state));
 460
 461         /* Did the called method return a value? */
 462
 463         if (return_desc) {
 464
 465                 /* Is the implicit return object the same as the return desc? */
 466
 467                 same_as_implicit_return =
 468                     (walk_state->implicit_return_obj == return_desc);
 469
 470                 /* Are we actually going to use the return value? */
 471
 472                 if (walk_state->return_used) {
 473
 474                         /* Save the return value from the previous method */
 475
 476                         status = acpi_ds_result_push(return_desc, walk_state);
 477                         if (ACPI_FAILURE(status)) {
 478                                 acpi_ut_remove_reference(return_desc);
 479                                 return_ACPI_STATUS(status);
 480                         }
 481
 482                         /*
 483                          * Save as THIS method's return value in case it is returned
 484                          * immediately to yet another method
 485                          */
 486                         walk_state->return_desc = return_desc;
 487                 }
 488
 489                 /*
 490                  * The following code is the optional support for the so-called
 491                  * "implicit return". Some AML code assumes that the last value of the
 492                  * method is "implicitly" returned to the caller, in the absence of an
 493                  * explicit return value.
 494                  *
 495                  * Just save the last result of the method as the return value.
 496                  *
 497                  * NOTE: this is optional because the ASL language does not actually
 498                  * support this behavior.
 499                  */
 500                 else if (!acpi_ds_do_implicit_return
 501                          (return_desc, walk_state, FALSE)
 502                          || same_as_implicit_return) {
 503                         /*
 504                          * Delete the return value if it will not be used by the
 505                          * calling method or remove one reference if the explicit return
 506                          * is the same as the implicit return value.
 507                          */
 508                         acpi_ut_remove_reference(return_desc);
 509                 }
 510         }
 511
 512         return_ACPI_STATUS(AE_OK);
 513 }
 514
 515 /*******************************************************************************
 516  *
 517  * FUNCTION:    acpi_ds_terminate_control_method
 518  *
 519  * PARAMETERS:  method_desc         - Method object
 520  *              walk_state          - State associated with the method
 521  *
 522  * RETURN:      None
 523  *
 524  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 525  *              created, delete all locals and arguments, and delete the parse
 526  *              tree if requested.
 527  *
 528  * MUTEX:       Interpreter is locked
 529  *
 530  ******************************************************************************/
 531
 532 void
 533 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 534                                  struct acpi_walk_state *walk_state)
 535 {
 536
 537         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 538
 539         /* method_desc is required, walk_state is optional */
 540
 541         if (!method_desc) {
 542                 return_VOID;
 543         }
 544
 545         if (walk_state) {
 546
 547                 /* Delete all arguments and locals */
 548
 549                 acpi_ds_method_data_delete_all(walk_state);
 550
 551                 /*
 552                  * If method is serialized, release the mutex and restore the
 553                  * current sync level for this thread
 554                  */
 555                 if (method_desc->method.mutex) {
 556
 557                         /* Acquisition Depth handles recursive calls */
 558
 559                         method_desc->method.mutex->mutex.acquisition_depth--;
 560                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
 561                                 walk_state->thread->current_sync_level =
 562                                     method_desc->method.mutex->mutex.
 563                                     original_sync_level;
 564
 565                                 acpi_os_release_mutex(method_desc->method.
 566                                                       mutex->mutex.os_mutex);
 567                                 method_desc->method.mutex->mutex.thread_id = NULL;
 568                         }
 569                 }
 570
 571                 /*
 572                  * Delete any namespace objects created anywhere within
 573                  * the namespace by the execution of this method
 574                  */
 575                 acpi_ns_delete_namespace_by_owner(method_desc->method.owner_id);
 576         }
 577
 578         /* Decrement the thread count on the method */
 579
 580         if (method_desc->method.thread_count) {
 581                 method_desc->method.thread_count--;
 582         } else {
 583                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
 584         }
 585
 586         /* Are there any other threads currently executing this method? */
 587
 588         if (method_desc->method.thread_count) {
 589                 /*
 590                  * Additional threads. Do not release the owner_id in this case,
 591                  * we immediately reuse it for the next thread executing this method
 592                  */
 593                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 594                                   "*** Completed execution of one thread, %d threads remaining\n",
 595                                   method_desc->method.thread_count));
 596         } else {
 597                 /* This is the only executing thread for this method */
 598
 599                 /*
 600                  * Support to dynamically change a method from not_serialized to
 601                  * Serialized if it appears that the method is incorrectly written and
 602                  * does not support multiple thread execution. The best example of this
 603                  * is if such a method creates namespace objects and blocks. A second
 604                  * thread will fail with an AE_ALREADY_EXISTS exception
 605                  *
 606                  * This code is here because we must wait until the last thread exits
 607                  * before creating the synchronization semaphore.
 608                  */
 609                 if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED)
 610                     && (!method_desc->method.mutex)) {
 611                         (void)acpi_ds_create_method_mutex(method_desc);
 612                 }
 613
 614                 /* No more threads, we can free the owner_id */
 615
 616                 acpi_ut_release_owner_id(&method_desc->method.owner_id);
 617         }
 618
 619         return_VOID;
 620 }