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 - 2006, 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 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_ds_method_error
  58  *
  59  * PARAMETERS:  Status          - Execution status
  60  *              walk_state      - Current state
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Called on method error. Invoke the global exception handler if
  65  *              present, dump the method data if the disassembler is configured
  66  *
  67  *              Note: Allows the exception handler to change the status code
  68  *
  69  ******************************************************************************/
  70 acpi_status
  71 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
  72 {
  73         ACPI_FUNCTION_ENTRY();
  74
  75         /* Ignore AE_OK and control exception codes */
  76
  77         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
  78                 return (status);
  79         }
  80
  81         /* Invoke the global exception handler */
  82
  83         if (acpi_gbl_exception_handler) {
  84                 /* Exit the interpreter, allow handler to execute methods */
  85
  86                 acpi_ex_exit_interpreter();
  87
  88                 /*
  89                  * Handler can map the exception code to anything it wants, including
  90                  * AE_OK, in which case the executing method will not be aborted.
  91                  */
  92                 status = acpi_gbl_exception_handler(status,
  93                                                     walk_state->method_node ?
  94                                                     walk_state->method_node->
  95                                                     name.integer : 0,
  96                                                     walk_state->opcode,
  97                                                     walk_state->aml_offset,
  98                                                     NULL);
  99                 (void)acpi_ex_enter_interpreter();
 100         }
 101 #ifdef ACPI_DISASSEMBLER
 102         if (ACPI_FAILURE(status)) {
 103                 /* Display method locals/args if disassembler is present */
 104
 105                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
 106         }
 107 #endif
 108
 109         return (status);
 110 }
 111
 112 /*******************************************************************************
 113  *
 114  * FUNCTION:    acpi_ds_begin_method_execution
 115  *
 116  * PARAMETERS:  method_node         - Node of the method
 117  *              obj_desc            - The method object
 118  *              calling_method_node - Caller of this method (if non-null)
 119  *
 120  * RETURN:      Status
 121  *
 122  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 123  *              increments the thread count, and waits at the method semaphore
 124  *              for clearance to execute.
 125  *
 126  ******************************************************************************/
 127
 128 acpi_status
 129 acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,
 130                                union acpi_operand_object * obj_desc,
 131                                struct acpi_namespace_node * calling_method_node)
 132 {
 133         acpi_status status = AE_OK;
 134
 135         ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node);
 136
 137         if (!method_node) {
 138                 return_ACPI_STATUS(AE_NULL_ENTRY);
 139         }
 140
 141         /* Prevent wraparound of thread count */
 142
 143         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 144                 ACPI_ERROR((AE_INFO,
 145                             "Method reached maximum reentrancy limit (255)"));
 146                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 147         }
 148
 149         /*
 150          * If there is a concurrency limit on this method, we need to
 151          * obtain a unit from the method semaphore.
 152          */
 153         if (obj_desc->method.semaphore) {
 154                 /*
 155                  * Allow recursive method calls, up to the reentrancy/concurrency
 156                  * limit imposed by the SERIALIZED rule and the sync_level method
 157                  * parameter.
 158                  *
 159                  * The point of this code is to avoid permanently blocking a
 160                  * thread that is making recursive method calls.
 161                  */
 162                 if (method_node == calling_method_node) {
 163                         if (obj_desc->method.thread_count >=
 164                             obj_desc->method.concurrency) {
 165                                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 166                         }
 167                 }
 168
 169                 /*
 170                  * Get a unit from the method semaphore. This releases the
 171                  * interpreter if we block
 172                  */
 173                 status =
 174                     acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
 175                                                   ACPI_WAIT_FOREVER);
 176         }
 177
 178         /*
 179          * Allocate an Owner ID for this method, only if this is the first thread
 180          * to begin concurrent execution. We only need one owner_id, even if the
 181          * method is invoked recursively.
 182          */
 183         if (!obj_desc->method.owner_id) {
 184                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 185                 if (ACPI_FAILURE(status)) {
 186                         return_ACPI_STATUS(status);
 187                 }
 188         }
 189
 190         /*
 191          * Increment the method parse tree thread count since it has been
 192          * reentered one more time (even if it is the same thread)
 193          */
 194         obj_desc->method.thread_count++;
 195         return_ACPI_STATUS(status);
 196 }
 197
 198 /*******************************************************************************
 199  *
 200  * FUNCTION:    acpi_ds_call_control_method
 201  *
 202  * PARAMETERS:  Thread              - Info for this thread
 203  *              this_walk_state     - Current walk state
 204  *              Op                  - Current Op to be walked
 205  *
 206  * RETURN:      Status
 207  *
 208  * DESCRIPTION: Transfer execution to a called control method
 209  *
 210  ******************************************************************************/
 211
 212 acpi_status
 213 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 214                             struct acpi_walk_state *this_walk_state,
 215                             union acpi_parse_object *op)
 216 {
 217         acpi_status status;
 218         struct acpi_namespace_node *method_node;
 219         struct acpi_walk_state *next_walk_state = NULL;
 220         union acpi_operand_object *obj_desc;
 221         struct acpi_parameter_info info;
 222         u32 i;
 223
 224         ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);
 225
 226         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 227                           "Execute method %p, currentstate=%p\n",
 228                           this_walk_state->prev_op, this_walk_state));
 229
 230         /*
 231          * Get the namespace entry for the control method we are about to call
 232          */
 233         method_node = this_walk_state->method_call_node;
 234         if (!method_node) {
 235                 return_ACPI_STATUS(AE_NULL_ENTRY);
 236         }
 237
 238         obj_desc = acpi_ns_get_attached_object(method_node);
 239         if (!obj_desc) {
 240                 return_ACPI_STATUS(AE_NULL_OBJECT);
 241         }
 242
 243         /* Init for new method, wait on concurrency semaphore */
 244
 245         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 246                                                 this_walk_state->method_node);
 247         if (ACPI_FAILURE(status)) {
 248                 goto cleanup;
 249         }
 250
 251         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 252                 /* 1) Parse: Create a new walk state for the preempting walk */
 253
 254                 next_walk_state =
 255                     acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
 256                                               obj_desc, NULL);
 257                 if (!next_walk_state) {
 258                         return_ACPI_STATUS(AE_NO_MEMORY);
 259                 }
 260
 261                 /* Create and init a Root Node */
 262
 263                 op = acpi_ps_create_scope_op();
 264                 if (!op) {
 265                         status = AE_NO_MEMORY;
 266                         goto cleanup;
 267                 }
 268
 269                 status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
 270                                                obj_desc->method.aml_start,
 271                                                obj_desc->method.aml_length,
 272                                                NULL, 1);
 273                 if (ACPI_FAILURE(status)) {
 274                         acpi_ds_delete_walk_state(next_walk_state);
 275                         goto cleanup;
 276                 }
 277
 278                 /* Begin AML parse */
 279
 280                 status = acpi_ps_parse_aml(next_walk_state);
 281                 acpi_ps_delete_parse_tree(op);
 282         }
 283
 284         /* 2) Execute: Create a new state for the preempting walk */
 285
 286         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 287                                                     NULL, obj_desc, thread);
 288         if (!next_walk_state) {
 289                 status = AE_NO_MEMORY;
 290                 goto cleanup;
 291         }
 292         /*
 293          * The resolved arguments were put on the previous walk state's operand
 294          * stack. Operands on the previous walk state stack always
 295          * start at index 0. Also, null terminate the list of arguments
 296          */
 297         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 298
 299         info.parameters = &this_walk_state->operands[0];
 300         info.parameter_type = ACPI_PARAM_ARGS;
 301
 302         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 303                                        obj_desc->method.aml_start,
 304                                        obj_desc->method.aml_length, &info, 3);
 305         if (ACPI_FAILURE(status)) {
 306                 goto cleanup;
 307         }
 308
 309         /*
 310          * Delete the operands on the previous walkstate operand stack
 311          * (they were copied to new objects)
 312          */
 313         for (i = 0; i < obj_desc->method.param_count; i++) {
 314                 acpi_ut_remove_reference(this_walk_state->operands[i]);
 315                 this_walk_state->operands[i] = NULL;
 316         }
 317
 318         /* Clear the operand stack */
 319
 320         this_walk_state->num_operands = 0;
 321
 322         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 323                           "Starting nested execution, newstate=%p\n",
 324                           next_walk_state));
 325
 326         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 327                 status = obj_desc->method.implementation(next_walk_state);
 328         }
 329
 330         return_ACPI_STATUS(status);
 331
 332       cleanup:
 333         /* Decrement the thread count on the method parse tree */
 334
 335         if (next_walk_state && (next_walk_state->method_desc)) {
 336                 next_walk_state->method_desc->method.thread_count--;
 337         }
 338
 339         /* On error, we must delete the new walk state */
 340
 341         acpi_ds_terminate_control_method(next_walk_state);
 342         acpi_ds_delete_walk_state(next_walk_state);
 343         return_ACPI_STATUS(status);
 344 }
 345
 346 /*******************************************************************************
 347  *
 348  * FUNCTION:    acpi_ds_restart_control_method
 349  *
 350  * PARAMETERS:  walk_state          - State for preempted method (caller)
 351  *              return_desc         - Return value from the called method
 352  *
 353  * RETURN:      Status
 354  *
 355  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 356  *              invocation.  Handle the return value (if any) from the callee.
 357  *
 358  ******************************************************************************/
 359
 360 acpi_status
 361 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 362                                union acpi_operand_object *return_desc)
 363 {
 364         acpi_status status;
 365
 366         ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state);
 367
 368         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 369                           "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
 370                           (char *)&walk_state->method_node->name,
 371                           walk_state->method_call_op, return_desc));
 372
 373         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 374                           "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
 375                           walk_state->return_used,
 376                           walk_state->results, walk_state));
 377
 378         /* Did the called method return a value? */
 379
 380         if (return_desc) {
 381                 /* Are we actually going to use the return value? */
 382
 383                 if (walk_state->return_used) {
 384                         /* Save the return value from the previous method */
 385
 386                         status = acpi_ds_result_push(return_desc, walk_state);
 387                         if (ACPI_FAILURE(status)) {
 388                                 acpi_ut_remove_reference(return_desc);
 389                                 return_ACPI_STATUS(status);
 390                         }
 391
 392                         /*
 393                          * Save as THIS method's return value in case it is returned
 394                          * immediately to yet another method
 395                          */
 396                         walk_state->return_desc = return_desc;
 397                 }
 398
 399                 /*
 400                  * The following code is the
 401                  * optional support for a so-called "implicit return". Some AML code
 402                  * assumes that the last value of the method is "implicitly" returned
 403                  * to the caller. Just save the last result as the return value.
 404                  * NOTE: this is optional because the ASL language does not actually
 405                  * support this behavior.
 406                  */
 407                 else if (!acpi_ds_do_implicit_return
 408                          (return_desc, walk_state, FALSE)) {
 409                         /*
 410                          * Delete the return value if it will not be used by the
 411                          * calling method
 412                          */
 413                         acpi_ut_remove_reference(return_desc);
 414                 }
 415         }
 416
 417         return_ACPI_STATUS(AE_OK);
 418 }
 419
 420 /*******************************************************************************
 421  *
 422  * FUNCTION:    acpi_ds_terminate_control_method
 423  *
 424  * PARAMETERS:  walk_state          - State of the method
 425  *
 426  * RETURN:      None
 427  *
 428  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 429  *              created, delete all locals and arguments, and delete the parse
 430  *              tree if requested.
 431  *
 432  ******************************************************************************/
 433
 434 void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
 435 {
 436         union acpi_operand_object *obj_desc;
 437         struct acpi_namespace_node *method_node;
 438         acpi_status status;
 439
 440         ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state);
 441
 442         if (!walk_state) {
 443                 return_VOID;
 444         }
 445
 446         /* The current method object was saved in the walk state */
 447
 448         obj_desc = walk_state->method_desc;
 449         if (!obj_desc) {
 450                 return_VOID;
 451         }
 452
 453         /* Delete all arguments and locals */
 454
 455         acpi_ds_method_data_delete_all(walk_state);
 456
 457         /*
 458          * Lock the parser while we terminate this method.
 459          * If this is the last thread executing the method,
 460          * we have additional cleanup to perform
 461          */
 462         status = acpi_ut_acquire_mutex(ACPI_MTX_PARSER);
 463         if (ACPI_FAILURE(status)) {
 464                 return_VOID;
 465         }
 466
 467         /* Signal completion of the execution of this method if necessary */
 468
 469         if (walk_state->method_desc->method.semaphore) {
 470                 status =
 471                     acpi_os_signal_semaphore(walk_state->method_desc->method.
 472                                              semaphore, 1);
 473                 if (ACPI_FAILURE(status)) {
 474                         ACPI_ERROR((AE_INFO,
 475                                     "Could not signal method semaphore"));
 476
 477                         /* Ignore error and continue cleanup */
 478                 }
 479         }
 480
 481         /*
 482          * There are no more threads executing this method.  Perform
 483          * additional cleanup.
 484          *
 485          * The method Node is stored in the walk state
 486          */
 487         method_node = walk_state->method_node;
 488
 489         /* Lock namespace for possible update */
 490
 491         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 492         if (ACPI_FAILURE(status)) {
 493                 goto exit;
 494         }
 495
 496         /*
 497          * Delete any namespace entries created immediately underneath
 498          * the method
 499          */
 500         if (method_node->child) {
 501                 acpi_ns_delete_namespace_subtree(method_node);
 502         }
 503
 504         /*
 505          * Delete any namespace entries created anywhere else within
 506          * the namespace by the execution of this method
 507          */
 508         acpi_ns_delete_namespace_by_owner(walk_state->method_desc->method.
 509                                           owner_id);
 510         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 511
 512         /* Are there any other threads currently executing this method? */
 513
 514         if (walk_state->method_desc->method.thread_count) {
 515                 /*
 516                  * Additional threads. Do not release the owner_id in this case,
 517                  * we immediately reuse it for the next thread executing this method
 518                  */
 519                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 520                                   "*** Completed execution of one thread, %d threads remaining\n",
 521                                   walk_state->method_desc->method.
 522                                   thread_count));
 523         } else {
 524                 /* This is the only executing thread for this method */
 525
 526                 /*
 527                  * Support to dynamically change a method from not_serialized to
 528                  * Serialized if it appears that the method is incorrectly written and
 529                  * does not support multiple thread execution.  The best example of this
 530                  * is if such a method creates namespace objects and blocks.  A second
 531                  * thread will fail with an AE_ALREADY_EXISTS exception
 532                  *
 533                  * This code is here because we must wait until the last thread exits
 534                  * before creating the synchronization semaphore.
 535                  */
 536                 if ((walk_state->method_desc->method.concurrency == 1) &&
 537                     (!walk_state->method_desc->method.semaphore)) {
 538                         status = acpi_os_create_semaphore(1, 1,
 539                                                           &walk_state->
 540                                                           method_desc->method.
 541                                                           semaphore);
 542                 }
 543
 544                 /* No more threads, we can free the owner_id */
 545
 546                 acpi_ut_release_owner_id(&walk_state->method_desc->method.
 547                                          owner_id);
 548         }
 549
 550       exit:
 551         (void)acpi_ut_release_mutex(ACPI_MTX_PARSER);
 552         return_VOID;
 553 }
 554
 555 #ifdef ACPI_INIT_PARSE_METHODS
 556         /*
 557          * Note 11/2005: Removed this code to parse all methods during table
 558          * load because it causes problems if there are any errors during the
 559          * parse. Also, it seems like overkill and we probably don't want to
 560          * abort a table load because of an issue with a single method.
 561          */
 562
 563 /*******************************************************************************
 564  *
 565  * FUNCTION:    acpi_ds_parse_method
 566  *
 567  * PARAMETERS:  Node        - Method node
 568  *
 569  * RETURN:      Status
 570  *
 571  * DESCRIPTION: Parse the AML that is associated with the method.
 572  *
 573  * MUTEX:       Assumes parser is locked
 574  *
 575  ******************************************************************************/
 576
 577 acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
 578 {
 579         acpi_status status;
 580         union acpi_operand_object *obj_desc;
 581         union acpi_parse_object *op;
 582         struct acpi_walk_state *walk_state;
 583
 584         ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);
 585
 586         /* Parameter Validation */
 587
 588         if (!node) {
 589                 return_ACPI_STATUS(AE_NULL_ENTRY);
 590         }
 591
 592         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 593                           "**** Parsing [%4.4s] **** named_obj=%p\n",
 594                           acpi_ut_get_node_name(node), node));
 595
 596         /* Extract the method object from the method Node */
 597
 598         obj_desc = acpi_ns_get_attached_object(node);
 599         if (!obj_desc) {
 600                 return_ACPI_STATUS(AE_NULL_OBJECT);
 601         }
 602
 603         /* Create a mutex for the method if there is a concurrency limit */
 604
 605         if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
 606             (!obj_desc->method.semaphore)) {
 607                 status = acpi_os_create_semaphore(obj_desc->method.concurrency,
 608                                                   obj_desc->method.concurrency,
 609                                                   &obj_desc->method.semaphore);
 610                 if (ACPI_FAILURE(status)) {
 611                         return_ACPI_STATUS(status);
 612                 }
 613         }
 614
 615         /*
 616          * Allocate a new parser op to be the root of the parsed
 617          * method tree
 618          */
 619         op = acpi_ps_alloc_op(AML_METHOD_OP);
 620         if (!op) {
 621                 return_ACPI_STATUS(AE_NO_MEMORY);
 622         }
 623
 624         /* Init new op with the method name and pointer back to the Node */
 625
 626         acpi_ps_set_name(op, node->name.integer);
 627         op->common.node = node;
 628
 629         /*
 630          * Get a new owner_id for objects created by this method. Namespace
 631          * objects (such as Operation Regions) can be created during the
 632          * first pass parse.
 633          */
 634         status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 635         if (ACPI_FAILURE(status)) {
 636                 goto cleanup;
 637         }
 638
 639         /* Create and initialize a new walk state */
 640
 641         walk_state =
 642             acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, NULL,
 643                                       NULL);
 644         if (!walk_state) {
 645                 status = AE_NO_MEMORY;
 646                 goto cleanup2;
 647         }
 648
 649         status = acpi_ds_init_aml_walk(walk_state, op, node,
 650                                        obj_desc->method.aml_start,
 651                                        obj_desc->method.aml_length, NULL, 1);
 652         if (ACPI_FAILURE(status)) {
 653                 acpi_ds_delete_walk_state(walk_state);
 654                 goto cleanup2;
 655         }
 656
 657         /*
 658          * Parse the method, first pass
 659          *
 660          * The first pass load is where newly declared named objects are added into
 661          * the namespace.  Actual evaluation of the named objects (what would be
 662          * called a "second pass") happens during the actual execution of the
 663          * method so that operands to the named objects can take on dynamic
 664          * run-time values.
 665          */
 666         status = acpi_ps_parse_aml(walk_state);
 667         if (ACPI_FAILURE(status)) {
 668                 goto cleanup2;
 669         }
 670
 671         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 672                           "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
 673                           acpi_ut_get_node_name(node), node, op));
 674
 675         /*
 676          * Delete the parse tree. We simply re-parse the method for every
 677          * execution since there isn't much overhead (compared to keeping lots
 678          * of parse trees around)
 679          */
 680         acpi_ns_delete_namespace_subtree(node);
 681         acpi_ns_delete_namespace_by_owner(obj_desc->method.owner_id);
 682
 683       cleanup2:
 684         acpi_ut_release_owner_id(&obj_desc->method.owner_id);
 685
 686       cleanup:
 687         acpi_ps_delete_parse_tree(op);
 688         return_ACPI_STATUS(status);
 689 }
 690 #endif