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 - 2007, R. Byron Moore
   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/acparser.h>
  46 #include <acpi/amlcode.h>
  47 #include <acpi/acdispat.h>
  48 #include <acpi/acinterp.h>
  49 #include <acpi/acnamesp.h>
  50 #include <acpi/acdisasm.h>
  51
  52 #define _COMPONENT          ACPI_DISPATCHER
  53 ACPI_MODULE_NAME("dsmethod")
  54
  55 /* Local prototypes */
  56 static acpi_status
  57 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
  58
  59 /*******************************************************************************
  60  *
  61  * FUNCTION:    acpi_ds_method_error
  62  *
  63  * PARAMETERS:  Status          - Execution status
  64  *              walk_state      - Current state
  65  *
  66  * RETURN:      Status
  67  *
  68  * DESCRIPTION: Called on method error. Invoke the global exception handler if
  69  *              present, dump the method data if the disassembler is configured
  70  *
  71  *              Note: Allows the exception handler to change the status code
  72  *
  73  ******************************************************************************/
  74
  75 acpi_status
  76 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
  77 {
  78         ACPI_FUNCTION_ENTRY();
  79
  80         /* Ignore AE_OK and control exception codes */
  81
  82         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
  83                 return (status);
  84         }
  85
  86         /* Invoke the global exception handler */
  87
  88         if (acpi_gbl_exception_handler) {
  89
  90                 /* Exit the interpreter, allow handler to execute methods */
  91
  92                 acpi_ex_exit_interpreter();
  93
  94                 /*
  95                  * Handler can map the exception code to anything it wants, including
  96                  * AE_OK, in which case the executing method will not be aborted.
  97                  */
  98                 status = acpi_gbl_exception_handler(status,
  99                                                     walk_state->method_node ?
 100                                                     walk_state->method_node->
 101                                                     name.integer : 0,
 102                                                     walk_state->opcode,
 103                                                     walk_state->aml_offset,
 104                                                     NULL);
 105                 (void)acpi_ex_enter_interpreter();
 106         }
 107 #ifdef ACPI_DISASSEMBLER
 108         if (ACPI_FAILURE(status)) {
 109
 110                 /* Display method locals/args if disassembler is present */
 111
 112                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
 113         }
 114 #endif
 115
 116         return (status);
 117 }
 118
 119 /*******************************************************************************
 120  *
 121  * FUNCTION:    acpi_ds_create_method_mutex
 122  *
 123  * PARAMETERS:  obj_desc            - The method object
 124  *
 125  * RETURN:      Status
 126  *
 127  * DESCRIPTION: Create a mutex object for a serialized control method
 128  *
 129  ******************************************************************************/
 130
 131 static acpi_status
 132 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
 133 {
 134         union acpi_operand_object *mutex_desc;
 135         acpi_status status;
 136
 137         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
 138
 139         /* Create the new mutex object */
 140
 141         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
 142         if (!mutex_desc) {
 143                 return_ACPI_STATUS(AE_NO_MEMORY);
 144         }
 145
 146         /* Create the actual OS Mutex */
 147
 148         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
 149         if (ACPI_FAILURE(status)) {
 150                 return_ACPI_STATUS(status);
 151         }
 152
 153         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
 154         method_desc->method.mutex = mutex_desc;
 155         return_ACPI_STATUS(AE_OK);
 156 }
 157
 158 /*******************************************************************************
 159  *
 160  * FUNCTION:    acpi_ds_begin_method_execution
 161  *
 162  * PARAMETERS:  method_node         - Node of the method
 163  *              obj_desc            - The method object
 164  *              walk_state          - current state, NULL if not yet executing
 165  *                                    a method.
 166  *
 167  * RETURN:      Status
 168  *
 169  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 170  *              increments the thread count, and waits at the method semaphore
 171  *              for clearance to execute.
 172  *
 173  ******************************************************************************/
 174
 175 acpi_status
 176 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 177                                union acpi_operand_object *obj_desc,
 178                                struct acpi_walk_state *walk_state)
 179 {
 180         acpi_status status = AE_OK;
 181
 182         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 183
 184         if (!method_node) {
 185                 return_ACPI_STATUS(AE_NULL_ENTRY);
 186         }
 187
 188         /* Prevent wraparound of thread count */
 189
 190         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 191                 ACPI_ERROR((AE_INFO,
 192                             "Method reached maximum reentrancy limit (255)"));
 193                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 194         }
 195
 196         /*
 197          * If this method is serialized, we need to acquire the method mutex.
 198          */
 199         if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) {
 200                 /*
 201                  * Create a mutex for the method if it is defined to be Serialized
 202                  * and a mutex has not already been created. We defer the mutex creation
 203                  * until a method is actually executed, to minimize the object count
 204                  */
 205                 if (!obj_desc->method.mutex) {
 206                         status = acpi_ds_create_method_mutex(obj_desc);
 207                         if (ACPI_FAILURE(status)) {
 208                                 return_ACPI_STATUS(status);
 209                         }
 210                 }
 211
 212                 /*
 213                  * The current_sync_level (per-thread) must be less than or equal to
 214                  * the sync level of the method. This mechanism provides some
 215                  * deadlock prevention
 216                  *
 217                  * Top-level method invocation has no walk state at this point
 218                  */
 219                 if (walk_state &&
 220                     (walk_state->thread->current_sync_level >
 221                      obj_desc->method.mutex->mutex.sync_level)) {
 222                         ACPI_ERROR((AE_INFO,
 223                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
 224                                     acpi_ut_get_node_name(method_node),
 225                                     walk_state->thread->current_sync_level));
 226
 227                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 228                 }
 229
 230                 /*
 231                  * Obtain the method mutex if necessary. Do not acquire mutex for a
 232                  * recursive call.
 233                  */
 234                 if (acpi_os_get_thread_id() !=
 235                     obj_desc->method.mutex->mutex.owner_thread_id) {
 236                         /*
 237                          * Acquire the method mutex. This releases the interpreter if we
 238                          * block (and reacquires it before it returns)
 239                          */
 240                         status =
 241                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
 242                                                       mutex.os_mutex,
 243                                                       ACPI_WAIT_FOREVER);
 244                         if (ACPI_FAILURE(status)) {
 245                                 return_ACPI_STATUS(status);
 246                         }
 247
 248                         /* Update the mutex and walk info and save the original sync_level */
 249                         obj_desc->method.mutex->mutex.owner_thread_id =
 250                                 acpi_os_get_thread_id();
 251
 252                         if (walk_state) {
 253                                 obj_desc->method.mutex->mutex.
 254                                     original_sync_level =
 255                                     walk_state->thread->current_sync_level;
 256
 257                                 walk_state->thread->current_sync_level =
 258                                     obj_desc->method.sync_level;
 259                         } else {
 260                                 obj_desc->method.mutex->mutex.
 261                                     original_sync_level =
 262                                     obj_desc->method.mutex->mutex.sync_level;
 263                         }
 264                 }
 265
 266                 /* Always increase acquisition depth */
 267
 268                 obj_desc->method.mutex->mutex.acquisition_depth++;
 269         }
 270
 271         /*
 272          * Allocate an Owner ID for this method, only if this is the first thread
 273          * to begin concurrent execution. We only need one owner_id, even if the
 274          * method is invoked recursively.
 275          */
 276         if (!obj_desc->method.owner_id) {
 277                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 278                 if (ACPI_FAILURE(status)) {
 279                         goto cleanup;
 280                 }
 281         }
 282
 283         /*
 284          * Increment the method parse tree thread count since it has been
 285          * reentered one more time (even if it is the same thread)
 286          */
 287         obj_desc->method.thread_count++;
 288         return_ACPI_STATUS(status);
 289
 290       cleanup:
 291         /* On error, must release the method mutex (if present) */
 292
 293         if (obj_desc->method.mutex) {
 294                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
 295         }
 296         return_ACPI_STATUS(status);
 297 }
 298
 299 /*******************************************************************************
 300  *
 301  * FUNCTION:    acpi_ds_call_control_method
 302  *
 303  * PARAMETERS:  Thread              - Info for this thread
 304  *              this_walk_state     - Current walk state
 305  *              Op                  - Current Op to be walked
 306  *
 307  * RETURN:      Status
 308  *
 309  * DESCRIPTION: Transfer execution to a called control method
 310  *
 311  ******************************************************************************/
 312
 313 acpi_status
 314 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 315                             struct acpi_walk_state *this_walk_state,
 316                             union acpi_parse_object *op)
 317 {
 318         acpi_status status;
 319         struct acpi_namespace_node *method_node;
 320         struct acpi_walk_state *next_walk_state = NULL;
 321         union acpi_operand_object *obj_desc;
 322         struct acpi_evaluate_info *info;
 323         u32 i;
 324
 325         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 326
 327         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 328                           "Calling method %p, currentstate=%p\n",
 329                           this_walk_state->prev_op, this_walk_state));
 330
 331         /*
 332          * Get the namespace entry for the control method we are about to call
 333          */
 334         method_node = this_walk_state->method_call_node;
 335         if (!method_node) {
 336                 return_ACPI_STATUS(AE_NULL_ENTRY);
 337         }
 338
 339         obj_desc = acpi_ns_get_attached_object(method_node);
 340         if (!obj_desc) {
 341                 return_ACPI_STATUS(AE_NULL_OBJECT);
 342         }
 343
 344         /* Init for new method, possibly wait on method mutex */
 345
 346         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 347                                                 this_walk_state);
 348         if (ACPI_FAILURE(status)) {
 349                 return_ACPI_STATUS(status);
 350         }
 351
 352         /* Begin method parse/execution. Create a new walk state */
 353
 354         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 355                                                     NULL, obj_desc, thread);
 356         if (!next_walk_state) {
 357                 status = AE_NO_MEMORY;
 358                 goto cleanup;
 359         }
 360
 361         /*
 362          * The resolved arguments were put on the previous walk state's operand
 363          * stack. Operands on the previous walk state stack always
 364          * start at index 0. Also, null terminate the list of arguments
 365          */
 366         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 367
 368         /*
 369          * Allocate and initialize the evaluation information block
 370          * TBD: this is somewhat inefficient, should change interface to
 371          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
 372          */
 373         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 374         if (!info) {
 375                 return_ACPI_STATUS(AE_NO_MEMORY);
 376         }
 377
 378         info->parameters = &this_walk_state->operands[0];
 379         info->parameter_type = ACPI_PARAM_ARGS;
 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         struct acpi_namespace_node *method_node;
 537         acpi_status status;
 538
 539         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 540
 541         /* method_desc is required, walk_state is optional */
 542
 543         if (!method_desc) {
 544                 return_VOID;
 545         }
 546
 547         if (walk_state) {
 548
 549                 /* Delete all arguments and locals */
 550
 551                 acpi_ds_method_data_delete_all(walk_state);
 552         }
 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.mutex->mutex.
 569                                               os_mutex);
 570                         method_desc->method.mutex->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 571                 }
 572         }
 573
 574         if (walk_state) {
 575                 /*
 576                  * Delete any objects created by this method during execution.
 577                  * The method Node is stored in the walk state
 578                  */
 579                 method_node = walk_state->method_node;
 580
 581                 /*
 582                  * Delete any namespace objects created anywhere within
 583                  * the namespace by the execution of this method
 584                  */
 585                 acpi_ns_delete_namespace_by_owner(method_desc->method.owner_id);
 586         }
 587
 588         /* Decrement the thread count on the method */
 589
 590         if (method_desc->method.thread_count) {
 591                 method_desc->method.thread_count--;
 592         } else {
 593                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
 594         }
 595
 596         /* Are there any other threads currently executing this method? */
 597
 598         if (method_desc->method.thread_count) {
 599                 /*
 600                  * Additional threads. Do not release the owner_id in this case,
 601                  * we immediately reuse it for the next thread executing this method
 602                  */
 603                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 604                                   "*** Completed execution of one thread, %d threads remaining\n",
 605                                   method_desc->method.thread_count));
 606         } else {
 607                 /* This is the only executing thread for this method */
 608
 609                 /*
 610                  * Support to dynamically change a method from not_serialized to
 611                  * Serialized if it appears that the method is incorrectly written and
 612                  * does not support multiple thread execution. The best example of this
 613                  * is if such a method creates namespace objects and blocks. A second
 614                  * thread will fail with an AE_ALREADY_EXISTS exception
 615                  *
 616                  * This code is here because we must wait until the last thread exits
 617                  * before creating the synchronization semaphore.
 618                  */
 619                 if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED)
 620                     && (!method_desc->method.mutex)) {
 621                         status = acpi_ds_create_method_mutex(method_desc);
 622                 }
 623
 624                 /* No more threads, we can free the owner_id */
 625
 626                 acpi_ut_release_owner_id(&method_desc->method.owner_id);
 627         }
 628
 629         return_VOID;
 630 }