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
 107         acpi_ds_clear_implicit_return(walk_state);
 108
 109 #ifdef ACPI_DISASSEMBLER
 110         if (ACPI_FAILURE(status)) {
 111
 112                 /* Display method locals/args if disassembler is present */
 113
 114                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
 115         }
 116 #endif
 117
 118         return (status);
 119 }
 120
 121 /*******************************************************************************
 122  *
 123  * FUNCTION:    acpi_ds_create_method_mutex
 124  *
 125  * PARAMETERS:  obj_desc            - The method object
 126  *
 127  * RETURN:      Status
 128  *
 129  * DESCRIPTION: Create a mutex object for a serialized control method
 130  *
 131  ******************************************************************************/
 132
 133 static acpi_status
 134 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
 135 {
 136         union acpi_operand_object *mutex_desc;
 137         acpi_status status;
 138
 139         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
 140
 141         /* Create the new mutex object */
 142
 143         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
 144         if (!mutex_desc) {
 145                 return_ACPI_STATUS(AE_NO_MEMORY);
 146         }
 147
 148         /* Create the actual OS Mutex */
 149
 150         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
 151         if (ACPI_FAILURE(status)) {
 152                 return_ACPI_STATUS(status);
 153         }
 154
 155         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
 156         method_desc->method.mutex = mutex_desc;
 157         return_ACPI_STATUS(AE_OK);
 158 }
 159
 160 /*******************************************************************************
 161  *
 162  * FUNCTION:    acpi_ds_begin_method_execution
 163  *
 164  * PARAMETERS:  method_node         - Node of the method
 165  *              obj_desc            - The method object
 166  *              walk_state          - current state, NULL if not yet executing
 167  *                                    a method.
 168  *
 169  * RETURN:      Status
 170  *
 171  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 172  *              increments the thread count, and waits at the method semaphore
 173  *              for clearance to execute.
 174  *
 175  ******************************************************************************/
 176
 177 acpi_status
 178 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 179                                union acpi_operand_object *obj_desc,
 180                                struct acpi_walk_state *walk_state)
 181 {
 182         acpi_status status = AE_OK;
 183
 184         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 185
 186         if (!method_node) {
 187                 return_ACPI_STATUS(AE_NULL_ENTRY);
 188         }
 189
 190         /* Prevent wraparound of thread count */
 191
 192         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 193                 ACPI_ERROR((AE_INFO,
 194                             "Method reached maximum reentrancy limit (255)"));
 195                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 196         }
 197
 198         /*
 199          * If this method is serialized, we need to acquire the method mutex.
 200          */
 201         if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) {
 202                 /*
 203                  * Create a mutex for the method if it is defined to be Serialized
 204                  * and a mutex has not already been created. We defer the mutex creation
 205                  * until a method is actually executed, to minimize the object count
 206                  */
 207                 if (!obj_desc->method.mutex) {
 208                         status = acpi_ds_create_method_mutex(obj_desc);
 209                         if (ACPI_FAILURE(status)) {
 210                                 return_ACPI_STATUS(status);
 211                         }
 212                 }
 213
 214                 /*
 215                  * The current_sync_level (per-thread) must be less than or equal to
 216                  * the sync level of the method. This mechanism provides some
 217                  * deadlock prevention
 218                  *
 219                  * Top-level method invocation has no walk state at this point
 220                  */
 221                 if (walk_state &&
 222                     (walk_state->thread->current_sync_level >
 223                      obj_desc->method.mutex->mutex.sync_level)) {
 224                         ACPI_ERROR((AE_INFO,
 225                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
 226                                     acpi_ut_get_node_name(method_node),
 227                                     walk_state->thread->current_sync_level));
 228
 229                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 230                 }
 231
 232                 /*
 233                  * Obtain the method mutex if necessary. Do not acquire mutex for a
 234                  * recursive call.
 235                  */
 236                 if (!walk_state ||
 237                     !obj_desc->method.mutex->mutex.thread_id ||
 238                     (walk_state->thread->thread_id !=
 239                      obj_desc->method.mutex->mutex.thread_id)) {
 240                         /*
 241                          * Acquire the method mutex. This releases the interpreter if we
 242                          * block (and reacquires it before it returns)
 243                          */
 244                         status =
 245                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
 246                                                       mutex.os_mutex,
 247                                                       ACPI_WAIT_FOREVER);
 248                         if (ACPI_FAILURE(status)) {
 249                                 return_ACPI_STATUS(status);
 250                         }
 251
 252                         /* Update the mutex and walk info and save the original sync_level */
 253
 254                         if (walk_state) {
 255                                 obj_desc->method.mutex->mutex.
 256                                     original_sync_level =
 257                                     walk_state->thread->current_sync_level;
 258
 259                                 obj_desc->method.mutex->mutex.thread_id =
 260                                     walk_state->thread->thread_id;
 261                                 walk_state->thread->current_sync_level =
 262                                     obj_desc->method.sync_level;
 263                         } else {
 264                                 obj_desc->method.mutex->mutex.
 265                                     original_sync_level =
 266                                     obj_desc->method.mutex->mutex.sync_level;
 267                         }
 268                 }
 269
 270                 /* Always increase acquisition depth */
 271
 272                 obj_desc->method.mutex->mutex.acquisition_depth++;
 273         }
 274
 275         /*
 276          * Allocate an Owner ID for this method, only if this is the first thread
 277          * to begin concurrent execution. We only need one owner_id, even if the
 278          * method is invoked recursively.
 279          */
 280         if (!obj_desc->method.owner_id) {
 281                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 282                 if (ACPI_FAILURE(status)) {
 283                         goto cleanup;
 284                 }
 285         }
 286
 287         /*
 288          * Increment the method parse tree thread count since it has been
 289          * reentered one more time (even if it is the same thread)
 290          */
 291         obj_desc->method.thread_count++;
 292         return_ACPI_STATUS(status);
 293
 294       cleanup:
 295         /* On error, must release the method mutex (if present) */
 296
 297         if (obj_desc->method.mutex) {
 298                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
 299         }
 300         return_ACPI_STATUS(status);
 301 }
 302
 303 /*******************************************************************************
 304  *
 305  * FUNCTION:    acpi_ds_call_control_method
 306  *
 307  * PARAMETERS:  Thread              - Info for this thread
 308  *              this_walk_state     - Current walk state
 309  *              Op                  - Current Op to be walked
 310  *
 311  * RETURN:      Status
 312  *
 313  * DESCRIPTION: Transfer execution to a called control method
 314  *
 315  ******************************************************************************/
 316
 317 acpi_status
 318 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 319                             struct acpi_walk_state *this_walk_state,
 320                             union acpi_parse_object *op)
 321 {
 322         acpi_status status;
 323         struct acpi_namespace_node *method_node;
 324         struct acpi_walk_state *next_walk_state = NULL;
 325         union acpi_operand_object *obj_desc;
 326         struct acpi_evaluate_info *info;
 327         u32 i;
 328
 329         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 330
 331         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 332                           "Calling method %p, currentstate=%p\n",
 333                           this_walk_state->prev_op, this_walk_state));
 334
 335         /*
 336          * Get the namespace entry for the control method we are about to call
 337          */
 338         method_node = this_walk_state->method_call_node;
 339         if (!method_node) {
 340                 return_ACPI_STATUS(AE_NULL_ENTRY);
 341         }
 342
 343         obj_desc = acpi_ns_get_attached_object(method_node);
 344         if (!obj_desc) {
 345                 return_ACPI_STATUS(AE_NULL_OBJECT);
 346         }
 347
 348         /* Init for new method, possibly wait on method mutex */
 349
 350         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 351                                                 this_walk_state);
 352         if (ACPI_FAILURE(status)) {
 353                 return_ACPI_STATUS(status);
 354         }
 355
 356         /* Begin method parse/execution. Create a new walk state */
 357
 358         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 359                                                     NULL, obj_desc, thread);
 360         if (!next_walk_state) {
 361                 status = AE_NO_MEMORY;
 362                 goto cleanup;
 363         }
 364
 365         /*
 366          * The resolved arguments were put on the previous walk state's operand
 367          * stack. Operands on the previous walk state stack always
 368          * start at index 0. Also, null terminate the list of arguments
 369          */
 370         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 371
 372         /*
 373          * Allocate and initialize the evaluation information block
 374          * TBD: this is somewhat inefficient, should change interface to
 375          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
 376          */
 377         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 378         if (!info) {
 379                 return_ACPI_STATUS(AE_NO_MEMORY);
 380         }
 381
 382         info->parameters = &this_walk_state->operands[0];
 383
 384         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 385                                        obj_desc->method.aml_start,
 386                                        obj_desc->method.aml_length, info,
 387                                        ACPI_IMODE_EXECUTE);
 388
 389         ACPI_FREE(info);
 390         if (ACPI_FAILURE(status)) {
 391                 goto cleanup;
 392         }
 393
 394         /*
 395          * Delete the operands on the previous walkstate operand stack
 396          * (they were copied to new objects)
 397          */
 398         for (i = 0; i < obj_desc->method.param_count; i++) {
 399                 acpi_ut_remove_reference(this_walk_state->operands[i]);
 400                 this_walk_state->operands[i] = NULL;
 401         }
 402
 403         /* Clear the operand stack */
 404
 405         this_walk_state->num_operands = 0;
 406
 407         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 408                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
 409                           method_node->name.ascii, next_walk_state));
 410
 411         /* Invoke an internal method if necessary */
 412
 413         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 414                 status = obj_desc->method.implementation(next_walk_state);
 415         }
 416
 417         return_ACPI_STATUS(status);
 418
 419       cleanup:
 420
 421         /* On error, we must terminate the method properly */
 422
 423         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
 424         if (next_walk_state) {
 425                 acpi_ds_delete_walk_state(next_walk_state);
 426         }
 427
 428         return_ACPI_STATUS(status);
 429 }
 430
 431 /*******************************************************************************
 432  *
 433  * FUNCTION:    acpi_ds_restart_control_method
 434  *
 435  * PARAMETERS:  walk_state          - State for preempted method (caller)
 436  *              return_desc         - Return value from the called method
 437  *
 438  * RETURN:      Status
 439  *
 440  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 441  *              invocation.  Handle the return value (if any) from the callee.
 442  *
 443  ******************************************************************************/
 444
 445 acpi_status
 446 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 447                                union acpi_operand_object *return_desc)
 448 {
 449         acpi_status status;
 450         int same_as_implicit_return;
 451
 452         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
 453
 454         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 455                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
 456                           acpi_ut_get_node_name(walk_state->method_node),
 457                           walk_state->method_call_op, return_desc));
 458
 459         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 460                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
 461                           walk_state->return_used,
 462                           walk_state->results, walk_state));
 463
 464         /* Did the called method return a value? */
 465
 466         if (return_desc) {
 467
 468                 /* Is the implicit return object the same as the return desc? */
 469
 470                 same_as_implicit_return =
 471                     (walk_state->implicit_return_obj == return_desc);
 472
 473                 /* Are we actually going to use the return value? */
 474
 475                 if (walk_state->return_used) {
 476
 477                         /* Save the return value from the previous method */
 478
 479                         status = acpi_ds_result_push(return_desc, walk_state);
 480                         if (ACPI_FAILURE(status)) {
 481                                 acpi_ut_remove_reference(return_desc);
 482                                 return_ACPI_STATUS(status);
 483                         }
 484
 485                         /*
 486                          * Save as THIS method's return value in case it is returned
 487                          * immediately to yet another method
 488                          */
 489                         walk_state->return_desc = return_desc;
 490                 }
 491
 492                 /*
 493                  * The following code is the optional support for the so-called
 494                  * "implicit return". Some AML code assumes that the last value of the
 495                  * method is "implicitly" returned to the caller, in the absence of an
 496                  * explicit return value.
 497                  *
 498                  * Just save the last result of the method as the return value.
 499                  *
 500                  * NOTE: this is optional because the ASL language does not actually
 501                  * support this behavior.
 502                  */
 503                 else if (!acpi_ds_do_implicit_return
 504                          (return_desc, walk_state, FALSE)
 505                          || same_as_implicit_return) {
 506                         /*
 507                          * Delete the return value if it will not be used by the
 508                          * calling method or remove one reference if the explicit return
 509                          * is the same as the implicit return value.
 510                          */
 511                         acpi_ut_remove_reference(return_desc);
 512                 }
 513         }
 514
 515         return_ACPI_STATUS(AE_OK);
 516 }
 517
 518 /*******************************************************************************
 519  *
 520  * FUNCTION:    acpi_ds_terminate_control_method
 521  *
 522  * PARAMETERS:  method_desc         - Method object
 523  *              walk_state          - State associated with the method
 524  *
 525  * RETURN:      None
 526  *
 527  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 528  *              created, delete all locals and arguments, and delete the parse
 529  *              tree if requested.
 530  *
 531  * MUTEX:       Interpreter is locked
 532  *
 533  ******************************************************************************/
 534
 535 void
 536 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 537                                  struct acpi_walk_state *walk_state)
 538 {
 539
 540         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 541
 542         /* method_desc is required, walk_state is optional */
 543
 544         if (!method_desc) {
 545                 return_VOID;
 546         }
 547
 548         if (walk_state) {
 549
 550                 /* Delete all arguments and locals */
 551
 552                 acpi_ds_method_data_delete_all(walk_state);
 553
 554                 /*
 555                  * If method is serialized, release the mutex and restore the
 556                  * current sync level for this thread
 557                  */
 558                 if (method_desc->method.mutex) {
 559
 560                         /* Acquisition Depth handles recursive calls */
 561
 562                         method_desc->method.mutex->mutex.acquisition_depth--;
 563                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
 564                                 walk_state->thread->current_sync_level =
 565                                     method_desc->method.mutex->mutex.
 566                                     original_sync_level;
 567
 568                                 acpi_os_release_mutex(method_desc->method.
 569                                                       mutex->mutex.os_mutex);
 570                                 method_desc->method.mutex->mutex.thread_id = NULL;
 571                         }
 572                 }
 573
 574                 /*
 575                  * Delete any namespace objects created anywhere within
 576                  * the namespace by the execution of this method
 577                  */
 578                 acpi_ns_delete_namespace_by_owner(method_desc->method.owner_id);
 579         }
 580
 581         /* Decrement the thread count on the method */
 582
 583         if (method_desc->method.thread_count) {
 584                 method_desc->method.thread_count--;
 585         } else {
 586                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
 587         }
 588
 589         /* Are there any other threads currently executing this method? */
 590
 591         if (method_desc->method.thread_count) {
 592                 /*
 593                  * Additional threads. Do not release the owner_id in this case,
 594                  * we immediately reuse it for the next thread executing this method
 595                  */
 596                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 597                                   "*** Completed execution of one thread, %d threads remaining\n",
 598                                   method_desc->method.thread_count));
 599         } else {
 600                 /* This is the only executing thread for this method */
 601
 602                 /*
 603                  * Support to dynamically change a method from not_serialized to
 604                  * Serialized if it appears that the method is incorrectly written and
 605                  * does not support multiple thread execution. The best example of this
 606                  * is if such a method creates namespace objects and blocks. A second
 607                  * thread will fail with an AE_ALREADY_EXISTS exception
 608                  *
 609                  * This code is here because we must wait until the last thread exits
 610                  * before creating the synchronization semaphore.
 611                  */
 612                 if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED)
 613                     && (!method_desc->method.mutex)) {
 614                         (void)acpi_ds_create_method_mutex(method_desc);
 615                 }
 616
 617                 /* No more threads, we can free the owner_id */
 618
 619                 acpi_ut_release_owner_id(&method_desc->method.owner_id);
 620         }
 621
 622         return_VOID;
 623 }