drivers/acpi/parser/psparse.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psparse - Parser top level AML parse routines
   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 /*
  45  * Parse the AML and build an operation tree as most interpreters,
  46  * like Perl, do.  Parsing is done by hand rather than with a YACC
  47  * generated parser to tightly constrain stack and dynamic memory
  48  * usage.  At the same time, parsing is kept flexible and the code
  49  * fairly compact by parsing based on a list of AML opcode
  50  * templates in aml_op_info[]
  51  */
  52
  53 #include <acpi/acpi.h>
  54 #include <acpi/acparser.h>
  55 #include <acpi/acdispat.h>
  56 #include <acpi/amlcode.h>
  57 #include <acpi/acnamesp.h>
  58 #include <acpi/acinterp.h>
  59
  60 #define _COMPONENT          ACPI_PARSER
  61 ACPI_MODULE_NAME("psparse")
  62
  63 /*******************************************************************************
  64  *
  65  * FUNCTION:    acpi_ps_get_opcode_size
  66  *
  67  * PARAMETERS:  Opcode          - An AML opcode
  68  *
  69  * RETURN:      Size of the opcode, in bytes (1 or 2)
  70  *
  71  * DESCRIPTION: Get the size of the current opcode.
  72  *
  73  ******************************************************************************/
  74 u32 acpi_ps_get_opcode_size(u32 opcode)
  75 {
  76
  77         /* Extended (2-byte) opcode if > 255 */
  78
  79         if (opcode > 0x00FF) {
  80                 return (2);
  81         }
  82
  83         /* Otherwise, just a single byte opcode */
  84
  85         return (1);
  86 }
  87
  88 /*******************************************************************************
  89  *
  90  * FUNCTION:    acpi_ps_peek_opcode
  91  *
  92  * PARAMETERS:  parser_state        - A parser state object
  93  *
  94  * RETURN:      Next AML opcode
  95  *
  96  * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
  97  *
  98  ******************************************************************************/
  99
 100 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
 101 {
 102         u8 *aml;
 103         u16 opcode;
 104
 105         aml = parser_state->aml;
 106         opcode = (u16) ACPI_GET8(aml);
 107
 108         if (opcode == AML_EXTENDED_OP_PREFIX) {
 109                 /* Extended opcode, get the second opcode byte */
 110
 111                 aml++;
 112                 opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
 113         }
 114
 115         return (opcode);
 116 }
 117
 118 /*******************************************************************************
 119  *
 120  * FUNCTION:    acpi_ps_complete_this_op
 121  *
 122  * PARAMETERS:  walk_state      - Current State
 123  *              Op              - Op to complete
 124  *
 125  * RETURN:      Status
 126  *
 127  * DESCRIPTION: Perform any cleanup at the completion of an Op.
 128  *
 129  ******************************************************************************/
 130
 131 acpi_status
 132 acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
 133                          union acpi_parse_object * op)
 134 {
 135         union acpi_parse_object *prev;
 136         union acpi_parse_object *next;
 137         const struct acpi_opcode_info *parent_info;
 138         union acpi_parse_object *replacement_op = NULL;
 139
 140         ACPI_FUNCTION_TRACE_PTR("ps_complete_this_op", op);
 141
 142         /* Check for null Op, can happen if AML code is corrupt */
 143
 144         if (!op) {
 145                 return_ACPI_STATUS(AE_OK);      /* OK for now */
 146         }
 147
 148         /* Delete this op and the subtree below it if asked to */
 149
 150         if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
 151              ACPI_PARSE_DELETE_TREE)
 152             || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
 153                 return_ACPI_STATUS(AE_OK);
 154         }
 155
 156         /* Make sure that we only delete this subtree */
 157
 158         if (op->common.parent) {
 159                 prev = op->common.parent->common.value.arg;
 160                 if (!prev) {
 161                         /* Nothing more to do */
 162
 163                         goto cleanup;
 164                 }
 165
 166                 /*
 167                  * Check if we need to replace the operator and its subtree
 168                  * with a return value op (placeholder op)
 169                  */
 170                 parent_info =
 171                     acpi_ps_get_opcode_info(op->common.parent->common.
 172                                             aml_opcode);
 173
 174                 switch (parent_info->class) {
 175                 case AML_CLASS_CONTROL:
 176                         break;
 177
 178                 case AML_CLASS_CREATE:
 179
 180                         /*
 181                          * These opcodes contain term_arg operands. The current
 182                          * op must be replaced by a placeholder return op
 183                          */
 184                         replacement_op =
 185                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
 186                         if (!replacement_op) {
 187                                 goto allocate_error;
 188                         }
 189                         break;
 190
 191                 case AML_CLASS_NAMED_OBJECT:
 192
 193                         /*
 194                          * These opcodes contain term_arg operands. The current
 195                          * op must be replaced by a placeholder return op
 196                          */
 197                         if ((op->common.parent->common.aml_opcode ==
 198                              AML_REGION_OP)
 199                             || (op->common.parent->common.aml_opcode ==
 200                                 AML_DATA_REGION_OP)
 201                             || (op->common.parent->common.aml_opcode ==
 202                                 AML_BUFFER_OP)
 203                             || (op->common.parent->common.aml_opcode ==
 204                                 AML_PACKAGE_OP)
 205                             || (op->common.parent->common.aml_opcode ==
 206                                 AML_VAR_PACKAGE_OP)) {
 207                                 replacement_op =
 208                                     acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
 209                                 if (!replacement_op) {
 210                                         goto allocate_error;
 211                                 }
 212                         } else
 213                             if ((op->common.parent->common.aml_opcode ==
 214                                  AML_NAME_OP)
 215                                 && (walk_state->pass_number <=
 216                                     ACPI_IMODE_LOAD_PASS2)) {
 217                                 if ((op->common.aml_opcode == AML_BUFFER_OP)
 218                                     || (op->common.aml_opcode == AML_PACKAGE_OP)
 219                                     || (op->common.aml_opcode ==
 220                                         AML_VAR_PACKAGE_OP)) {
 221                                         replacement_op =
 222                                             acpi_ps_alloc_op(op->common.
 223                                                              aml_opcode);
 224                                         if (!replacement_op) {
 225                                                 goto allocate_error;
 226                                         }
 227
 228                                         replacement_op->named.data =
 229                                             op->named.data;
 230                                         replacement_op->named.length =
 231                                             op->named.length;
 232                                 }
 233                         }
 234                         break;
 235
 236                 default:
 237
 238                         replacement_op =
 239                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
 240                         if (!replacement_op) {
 241                                 goto allocate_error;
 242                         }
 243                 }
 244
 245                 /* We must unlink this op from the parent tree */
 246
 247                 if (prev == op) {
 248                         /* This op is the first in the list */
 249
 250                         if (replacement_op) {
 251                                 replacement_op->common.parent =
 252                                     op->common.parent;
 253                                 replacement_op->common.value.arg = NULL;
 254                                 replacement_op->common.node = op->common.node;
 255                                 op->common.parent->common.value.arg =
 256                                     replacement_op;
 257                                 replacement_op->common.next = op->common.next;
 258                         } else {
 259                                 op->common.parent->common.value.arg =
 260                                     op->common.next;
 261                         }
 262                 }
 263
 264                 /* Search the parent list */
 265
 266                 else
 267                         while (prev) {
 268                                 /* Traverse all siblings in the parent's argument list */
 269
 270                                 next = prev->common.next;
 271                                 if (next == op) {
 272                                         if (replacement_op) {
 273                                                 replacement_op->common.parent =
 274                                                     op->common.parent;
 275                                                 replacement_op->common.value.
 276                                                     arg = NULL;
 277                                                 replacement_op->common.node =
 278                                                     op->common.node;
 279                                                 prev->common.next =
 280                                                     replacement_op;
 281                                                 replacement_op->common.next =
 282                                                     op->common.next;
 283                                                 next = NULL;
 284                                         } else {
 285                                                 prev->common.next =
 286                                                     op->common.next;
 287                                                 next = NULL;
 288                                         }
 289                                 }
 290                                 prev = next;
 291                         }
 292         }
 293
 294       cleanup:
 295
 296         /* Now we can actually delete the subtree rooted at Op */
 297
 298         acpi_ps_delete_parse_tree(op);
 299         return_ACPI_STATUS(AE_OK);
 300
 301       allocate_error:
 302
 303         /* Always delete the subtree, even on error */
 304
 305         acpi_ps_delete_parse_tree(op);
 306         return_ACPI_STATUS(AE_NO_MEMORY);
 307 }
 308
 309 /*******************************************************************************
 310  *
 311  * FUNCTION:    acpi_ps_next_parse_state
 312  *
 313  * PARAMETERS:  walk_state          - Current state
 314  *              Op                  - Current parse op
 315  *              callback_status     - Status from previous operation
 316  *
 317  * RETURN:      Status
 318  *
 319  * DESCRIPTION: Update the parser state based upon the return exception from
 320  *              the parser callback.
 321  *
 322  ******************************************************************************/
 323
 324 acpi_status
 325 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
 326                          union acpi_parse_object *op,
 327                          acpi_status callback_status)
 328 {
 329         struct acpi_parse_state *parser_state = &walk_state->parser_state;
 330         acpi_status status = AE_CTRL_PENDING;
 331
 332         ACPI_FUNCTION_TRACE_PTR("ps_next_parse_state", op);
 333
 334         switch (callback_status) {
 335         case AE_CTRL_TERMINATE:
 336                 /*
 337                  * A control method was terminated via a RETURN statement.
 338                  * The walk of this method is complete.
 339                  */
 340                 parser_state->aml = parser_state->aml_end;
 341                 status = AE_CTRL_TERMINATE;
 342                 break;
 343
 344         case AE_CTRL_BREAK:
 345
 346                 parser_state->aml = walk_state->aml_last_while;
 347                 walk_state->control_state->common.value = FALSE;
 348                 status = acpi_ds_result_stack_pop(walk_state);
 349                 if (ACPI_SUCCESS(status)) {
 350                         status = AE_CTRL_BREAK;
 351                 }
 352                 break;
 353
 354         case AE_CTRL_CONTINUE:
 355
 356                 parser_state->aml = walk_state->aml_last_while;
 357                 status = acpi_ds_result_stack_pop(walk_state);
 358                 if (ACPI_SUCCESS(status)) {
 359                         status = AE_CTRL_CONTINUE;
 360                 }
 361                 break;
 362
 363         case AE_CTRL_PENDING:
 364
 365                 parser_state->aml = walk_state->aml_last_while;
 366                 break;
 367
 368 #if 0
 369         case AE_CTRL_SKIP:
 370
 371                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
 372                 status = AE_OK;
 373                 break;
 374 #endif
 375
 376         case AE_CTRL_TRUE:
 377                 /*
 378                  * Predicate of an IF was true, and we are at the matching ELSE.
 379                  * Just close out this package
 380                  */
 381                 parser_state->aml = acpi_ps_get_next_package_end(parser_state);
 382                 status = acpi_ds_result_stack_pop(walk_state);
 383                 if (ACPI_SUCCESS(status)) {
 384                         status = AE_CTRL_PENDING;
 385                 }
 386                 break;
 387
 388         case AE_CTRL_FALSE:
 389                 /*
 390                  * Either an IF/WHILE Predicate was false or we encountered a BREAK
 391                  * opcode.  In both cases, we do not execute the rest of the
 392                  * package;  We simply close out the parent (finishing the walk of
 393                  * this branch of the tree) and continue execution at the parent
 394                  * level.
 395                  */
 396                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
 397
 398                 /* In the case of a BREAK, just force a predicate (if any) to FALSE */
 399
 400                 walk_state->control_state->common.value = FALSE;
 401                 status = AE_CTRL_END;
 402                 break;
 403
 404         case AE_CTRL_TRANSFER:
 405
 406                 /* A method call (invocation) -- transfer control */
 407
 408                 status = AE_CTRL_TRANSFER;
 409                 walk_state->prev_op = op;
 410                 walk_state->method_call_op = op;
 411                 walk_state->method_call_node =
 412                     (op->common.value.arg)->common.node;
 413
 414                 /* Will return value (if any) be used by the caller? */
 415
 416                 walk_state->return_used =
 417                     acpi_ds_is_result_used(op, walk_state);
 418                 break;
 419
 420         default:
 421
 422                 status = callback_status;
 423                 if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
 424                         status = AE_OK;
 425                 }
 426                 break;
 427         }
 428
 429         return_ACPI_STATUS(status);
 430 }
 431
 432 /*******************************************************************************
 433  *
 434  * FUNCTION:    acpi_ps_parse_aml
 435  *
 436  * PARAMETERS:  walk_state      - Current state
 437  *
 438  *
 439  * RETURN:      Status
 440  *
 441  * DESCRIPTION: Parse raw AML and return a tree of ops
 442  *
 443  ******************************************************************************/
 444
 445 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
 446 {
 447         acpi_status status;
 448         struct acpi_thread_state *thread;
 449         struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
 450         struct acpi_walk_state *previous_walk_state;
 451
 452         ACPI_FUNCTION_TRACE("ps_parse_aml");
 453
 454         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 455                           "Entered with walk_state=%p Aml=%p size=%X\n",
 456                           walk_state, walk_state->parser_state.aml,
 457                           walk_state->parser_state.aml_size));
 458
 459         /* Create and initialize a new thread state */
 460
 461         thread = acpi_ut_create_thread_state();
 462         if (!thread) {
 463                 return_ACPI_STATUS(AE_NO_MEMORY);
 464         }
 465
 466         walk_state->thread = thread;
 467         acpi_ds_push_walk_state(walk_state, thread);
 468
 469         /*
 470          * This global allows the AML debugger to get a handle to the currently
 471          * executing control method.
 472          */
 473         acpi_gbl_current_walk_list = thread;
 474
 475         /*
 476          * Execute the walk loop as long as there is a valid Walk State.  This
 477          * handles nested control method invocations without recursion.
 478          */
 479         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
 480
 481         status = AE_OK;
 482         while (walk_state) {
 483                 if (ACPI_SUCCESS(status)) {
 484                         /*
 485                          * The parse_loop executes AML until the method terminates
 486                          * or calls another method.
 487                          */
 488                         status = acpi_ps_parse_loop(walk_state);
 489                 }
 490
 491                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 492                                   "Completed one call to walk loop, %s State=%p\n",
 493                                   acpi_format_exception(status), walk_state));
 494
 495                 if (status == AE_CTRL_TRANSFER) {
 496                         /*
 497                          * A method call was detected.
 498                          * Transfer control to the called control method
 499                          */
 500                         status =
 501                             acpi_ds_call_control_method(thread, walk_state,
 502                                                         NULL);
 503
 504                         /*
 505                          * If the transfer to the new method method call worked, a new walk
 506                          * state was created -- get it
 507                          */
 508                         walk_state = acpi_ds_get_current_walk_state(thread);
 509                         continue;
 510                 } else if (status == AE_CTRL_TERMINATE) {
 511                         status = AE_OK;
 512                 } else if ((status != AE_OK) && (walk_state->method_desc)) {
 513                         /* Either the method parse or actual execution failed */
 514
 515                         ACPI_ERROR_METHOD("Method parse/execution failed",
 516                                           walk_state->method_node, NULL,
 517                                           status);
 518
 519                         /* Check for possible multi-thread reentrancy problem */
 520
 521                         if ((status == AE_ALREADY_EXISTS) &&
 522                             (!walk_state->method_desc->method.semaphore)) {
 523                                 /*
 524                                  * Method tried to create an object twice. The probable cause is
 525                                  * that the method cannot handle reentrancy.
 526                                  *
 527                                  * The method is marked not_serialized, but it tried to create
 528                                  * a named object, causing the second thread entrance to fail.
 529                                  * Workaround this problem by marking the method permanently
 530                                  * as Serialized.
 531                                  */
 532                                 walk_state->method_desc->method.method_flags |=
 533                                     AML_METHOD_SERIALIZED;
 534                                 walk_state->method_desc->method.concurrency = 1;
 535                         }
 536                 }
 537
 538                 /* We are done with this walk, move on to the parent if any */
 539
 540                 walk_state = acpi_ds_pop_walk_state(thread);
 541
 542                 /* Reset the current scope to the beginning of scope stack */
 543
 544                 acpi_ds_scope_stack_clear(walk_state);
 545
 546                 /*
 547                  * If we just returned from the execution of a control method or if we
 548                  * encountered an error during the method parse phase, there's lots of
 549                  * cleanup to do
 550                  */
 551                 if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
 552                      ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
 553                         if (walk_state->method_desc) {
 554                                 /* Decrement the thread count on the method parse tree */
 555
 556                                 if (walk_state->method_desc->method.
 557                                     thread_count) {
 558                                         walk_state->method_desc->method.
 559                                             thread_count--;
 560                                 } else {
 561                                         ACPI_ERROR((AE_INFO,
 562                                                     "Invalid zero thread count in method"));
 563                                 }
 564                         }
 565
 566                         acpi_ds_terminate_control_method(walk_state);
 567                 }
 568
 569                 /* Delete this walk state and all linked control states */
 570
 571                 acpi_ps_cleanup_scope(&walk_state->parser_state);
 572                 previous_walk_state = walk_state;
 573
 574                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 575                                   "return_value=%p, implicit_value=%p State=%p\n",
 576                                   walk_state->return_desc,
 577                                   walk_state->implicit_return_obj, walk_state));
 578
 579                 /* Check if we have restarted a preempted walk */
 580
 581                 walk_state = acpi_ds_get_current_walk_state(thread);
 582                 if (walk_state) {
 583                         if (ACPI_SUCCESS(status)) {
 584                                 /*
 585                                  * There is another walk state, restart it.
 586                                  * If the method return value is not used by the parent,
 587                                  * The object is deleted
 588                                  */
 589                                 if (!previous_walk_state->return_desc) {
 590                                         status =
 591                                             acpi_ds_restart_control_method
 592                                             (walk_state,
 593                                              previous_walk_state->
 594                                              implicit_return_obj);
 595                                 } else {
 596                                         /*
 597                                          * We have a valid return value, delete any implicit
 598                                          * return value.
 599                                          */
 600                                         acpi_ds_clear_implicit_return
 601                                             (previous_walk_state);
 602
 603                                         status =
 604                                             acpi_ds_restart_control_method
 605                                             (walk_state,
 606                                              previous_walk_state->return_desc);
 607                                 }
 608                                 if (ACPI_SUCCESS(status)) {
 609                                         walk_state->walk_type |=
 610                                             ACPI_WALK_METHOD_RESTART;
 611                                 }
 612                         } else {
 613                                 /* On error, delete any return object */
 614
 615                                 acpi_ut_remove_reference(previous_walk_state->
 616                                                          return_desc);
 617                         }
 618                 }
 619
 620                 /*
 621                  * Just completed a 1st-level method, save the final internal return
 622                  * value (if any)
 623                  */
 624                 else if (previous_walk_state->caller_return_desc) {
 625                         if (previous_walk_state->implicit_return_obj) {
 626                                 *(previous_walk_state->caller_return_desc) =
 627                                     previous_walk_state->implicit_return_obj;
 628                         } else {
 629                                 /* NULL if no return value */
 630
 631                                 *(previous_walk_state->caller_return_desc) =
 632                                     previous_walk_state->return_desc;
 633                         }
 634                 } else {
 635                         if (previous_walk_state->return_desc) {
 636                                 /* Caller doesn't want it, must delete it */
 637
 638                                 acpi_ut_remove_reference(previous_walk_state->
 639                                                          return_desc);
 640                         }
 641                         if (previous_walk_state->implicit_return_obj) {
 642                                 /* Caller doesn't want it, must delete it */
 643
 644                                 acpi_ut_remove_reference(previous_walk_state->
 645                                                          implicit_return_obj);
 646                         }
 647                 }
 648
 649                 acpi_ds_delete_walk_state(previous_walk_state);
 650         }
 651
 652         /* Normal exit */
 653
 654         acpi_ex_release_all_mutexes(thread);
 655         acpi_ut_delete_generic_state(ACPI_CAST_PTR
 656                                      (union acpi_generic_state, thread));
 657         acpi_gbl_current_walk_list = prev_walk_list;
 658         return_ACPI_STATUS(status);
 659 }