1 /****************************************************************************** 2 * 3 * Module Name: psparse - Parser top level AML parse routines 4 * 5 *****************************************************************************/ 6 7 /****************************************************************************** 8 * 9 * 1. Copyright Notice 10 * 11 * Some or all of this work - Copyright (c) 1999 - 2012, Intel Corp. 12 * All rights reserved. 13 * 14 * 2. License 15 * 16 * 2.1. This is your license from Intel Corp. under its intellectual property 17 * rights. You may have additional license terms from the party that provided 18 * you this software, covering your right to use that party's intellectual 19 * property rights. 20 * 21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 22 * copy of the source code appearing in this file ("Covered Code") an 23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 24 * base code distributed originally by Intel ("Original Intel Code") to copy, 25 * make derivatives, distribute, use and display any portion of the Covered 26 * Code in any form, with the right to sublicense such rights; and 27 * 28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 29 * license (with the right to sublicense), under only those claims of Intel 30 * patents that are infringed by the Original Intel Code, to make, use, sell, 31 * offer to sell, and import the Covered Code and derivative works thereof 32 * solely to the minimum extent necessary to exercise the above copyright 33 * license, and in no event shall the patent license extend to any additions 34 * to or modifications of the Original Intel Code. No other license or right 35 * is granted directly or by implication, estoppel or otherwise; 36 * 37 * The above copyright and patent license is granted only if the following 38 * conditions are met: 39 * 40 * 3. Conditions 41 * 42 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 43 * Redistribution of source code of any substantial portion of the Covered 44 * Code or modification with rights to further distribute source must include 45 * the above Copyright Notice, the above License, this list of Conditions, 46 * and the following Disclaimer and Export Compliance provision. In addition, 47 * Licensee must cause all Covered Code to which Licensee contributes to 48 * contain a file documenting the changes Licensee made to create that Covered 49 * Code and the date of any change. Licensee must include in that file the 50 * documentation of any changes made by any predecessor Licensee. Licensee 51 * must include a prominent statement that the modification is derived, 52 * directly or indirectly, from Original Intel Code. 53 * 54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 55 * Redistribution of source code of any substantial portion of the Covered 56 * Code or modification without rights to further distribute source must 57 * include the following Disclaimer and Export Compliance provision in the 58 * documentation and/or other materials provided with distribution. In 59 * addition, Licensee may not authorize further sublicense of source of any 60 * portion of the Covered Code, and must include terms to the effect that the 61 * license from Licensee to its licensee is limited to the intellectual 62 * property embodied in the software Licensee provides to its licensee, and 63 * not to intellectual property embodied in modifications its licensee may 64 * make. 65 * 66 * 3.3. Redistribution of Executable. Redistribution in executable form of any 67 * substantial portion of the Covered Code or modification must reproduce the 68 * above Copyright Notice, and the following Disclaimer and Export Compliance 69 * provision in the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3.4. Intel retains all right, title, and interest in and to the Original 73 * Intel Code. 74 * 75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 76 * Intel shall be used in advertising or otherwise to promote the sale, use or 77 * other dealings in products derived from or relating to the Covered Code 78 * without prior written authorization from Intel. 79 * 80 * 4. Disclaimer and Export Compliance 81 * 82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 88 * PARTICULAR PURPOSE. 89 * 90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 97 * LIMITED REMEDY. 98 * 99 * 4.3. Licensee shall not export, either directly or indirectly, any of this 100 * software or system incorporating such software without first obtaining any 101 * required license or other approval from the U. S. Department of Commerce or 102 * any other agency or department of the United States Government. In the 103 * event Licensee exports any such software from the United States or 104 * re-exports any such software from a foreign destination, Licensee shall 105 * ensure that the distribution and export/re-export of the software is in 106 * compliance with all laws, regulations, orders, or other restrictions of the 107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 108 * any of its subsidiaries will export/re-export any technical data, process, 109 * software, or service, directly or indirectly, to any country for which the 110 * United States government or any agency thereof requires an export license, 111 * other governmental approval, or letter of assurance, without first obtaining 112 * such license, approval or letter. 113 * 114 *****************************************************************************/ 115 116 117 /* 118 * Parse the AML and build an operation tree as most interpreters, 119 * like Perl, do. Parsing is done by hand rather than with a YACC 120 * generated parser to tightly constrain stack and dynamic memory 121 * usage. At the same time, parsing is kept flexible and the code 122 * fairly compact by parsing based on a list of AML opcode 123 * templates in AmlOpInfo[] 124 */ 125 126 #include "acpi.h" 127 #include "accommon.h" 128 #include "acparser.h" 129 #include "acdispat.h" 130 #include "amlcode.h" 131 #include "acinterp.h" 132 133 #define _COMPONENT ACPI_PARSER 134 ACPI_MODULE_NAME ("psparse") 135 136 137 /******************************************************************************* 138 * 139 * FUNCTION: AcpiPsGetOpcodeSize 140 * 141 * PARAMETERS: Opcode - An AML opcode 142 * 143 * RETURN: Size of the opcode, in bytes (1 or 2) 144 * 145 * DESCRIPTION: Get the size of the current opcode. 146 * 147 ******************************************************************************/ 148 149 UINT32 150 AcpiPsGetOpcodeSize ( 151 UINT32 Opcode) 152 { 153 154 /* Extended (2-byte) opcode if > 255 */ 155 156 if (Opcode > 0x00FF) 157 { 158 return (2); 159 } 160 161 /* Otherwise, just a single byte opcode */ 162 163 return (1); 164 } 165 166 167 /******************************************************************************* 168 * 169 * FUNCTION: AcpiPsPeekOpcode 170 * 171 * PARAMETERS: ParserState - A parser state object 172 * 173 * RETURN: Next AML opcode 174 * 175 * DESCRIPTION: Get next AML opcode (without incrementing AML pointer) 176 * 177 ******************************************************************************/ 178 179 UINT16 180 AcpiPsPeekOpcode ( 181 ACPI_PARSE_STATE *ParserState) 182 { 183 UINT8 *Aml; 184 UINT16 Opcode; 185 186 187 Aml = ParserState->Aml; 188 Opcode = (UINT16) ACPI_GET8 (Aml); 189 190 if (Opcode == AML_EXTENDED_OP_PREFIX) 191 { 192 /* Extended opcode, get the second opcode byte */ 193 194 Aml++; 195 Opcode = (UINT16) ((Opcode << 8) | ACPI_GET8 (Aml)); 196 } 197 198 return (Opcode); 199 } 200 201 202 /******************************************************************************* 203 * 204 * FUNCTION: AcpiPsCompleteThisOp 205 * 206 * PARAMETERS: WalkState - Current State 207 * Op - Op to complete 208 * 209 * RETURN: Status 210 * 211 * DESCRIPTION: Perform any cleanup at the completion of an Op. 212 * 213 ******************************************************************************/ 214 215 ACPI_STATUS 216 AcpiPsCompleteThisOp ( 217 ACPI_WALK_STATE *WalkState, 218 ACPI_PARSE_OBJECT *Op) 219 { 220 ACPI_PARSE_OBJECT *Prev; 221 ACPI_PARSE_OBJECT *Next; 222 const ACPI_OPCODE_INFO *ParentInfo; 223 ACPI_PARSE_OBJECT *ReplacementOp = NULL; 224 ACPI_STATUS Status = AE_OK; 225 226 227 ACPI_FUNCTION_TRACE_PTR (PsCompleteThisOp, Op); 228 229 230 /* Check for null Op, can happen if AML code is corrupt */ 231 232 if (!Op) 233 { 234 return_ACPI_STATUS (AE_OK); /* OK for now */ 235 } 236 237 /* Delete this op and the subtree below it if asked to */ 238 239 if (((WalkState->ParseFlags & ACPI_PARSE_TREE_MASK) != ACPI_PARSE_DELETE_TREE) || 240 (WalkState->OpInfo->Class == AML_CLASS_ARGUMENT)) 241 { 242 return_ACPI_STATUS (AE_OK); 243 } 244 245 /* Make sure that we only delete this subtree */ 246 247 if (Op->Common.Parent) 248 { 249 Prev = Op->Common.Parent->Common.Value.Arg; 250 if (!Prev) 251 { 252 /* Nothing more to do */ 253 254 goto Cleanup; 255 } 256 257 /* 258 * Check if we need to replace the operator and its subtree 259 * with a return value op (placeholder op) 260 */ 261 ParentInfo = AcpiPsGetOpcodeInfo (Op->Common.Parent->Common.AmlOpcode); 262 263 switch (ParentInfo->Class) 264 { 265 case AML_CLASS_CONTROL: 266 break; 267 268 case AML_CLASS_CREATE: 269 270 /* 271 * These opcodes contain TermArg operands. The current 272 * op must be replaced by a placeholder return op 273 */ 274 ReplacementOp = AcpiPsAllocOp (AML_INT_RETURN_VALUE_OP); 275 if (!ReplacementOp) 276 { 277 Status = AE_NO_MEMORY; 278 } 279 break; 280 281 case AML_CLASS_NAMED_OBJECT: 282 283 /* 284 * These opcodes contain TermArg operands. The current 285 * op must be replaced by a placeholder return op 286 */ 287 if ((Op->Common.Parent->Common.AmlOpcode == AML_REGION_OP) || 288 (Op->Common.Parent->Common.AmlOpcode == AML_DATA_REGION_OP) || 289 (Op->Common.Parent->Common.AmlOpcode == AML_BUFFER_OP) || 290 (Op->Common.Parent->Common.AmlOpcode == AML_PACKAGE_OP) || 291 (Op->Common.Parent->Common.AmlOpcode == AML_BANK_FIELD_OP) || 292 (Op->Common.Parent->Common.AmlOpcode == AML_VAR_PACKAGE_OP)) 293 { 294 ReplacementOp = AcpiPsAllocOp (AML_INT_RETURN_VALUE_OP); 295 if (!ReplacementOp) 296 { 297 Status = AE_NO_MEMORY; 298 } 299 } 300 else if ((Op->Common.Parent->Common.AmlOpcode == AML_NAME_OP) && 301 (WalkState->PassNumber <= ACPI_IMODE_LOAD_PASS2)) 302 { 303 if ((Op->Common.AmlOpcode == AML_BUFFER_OP) || 304 (Op->Common.AmlOpcode == AML_PACKAGE_OP) || 305 (Op->Common.AmlOpcode == AML_VAR_PACKAGE_OP)) 306 { 307 ReplacementOp = AcpiPsAllocOp (Op->Common.AmlOpcode); 308 if (!ReplacementOp) 309 { 310 Status = AE_NO_MEMORY; 311 } 312 else 313 { 314 ReplacementOp->Named.Data = Op->Named.Data; 315 ReplacementOp->Named.Length = Op->Named.Length; 316 } 317 } 318 } 319 break; 320 321 default: 322 323 ReplacementOp = AcpiPsAllocOp (AML_INT_RETURN_VALUE_OP); 324 if (!ReplacementOp) 325 { 326 Status = AE_NO_MEMORY; 327 } 328 } 329 330 /* We must unlink this op from the parent tree */ 331 332 if (Prev == Op) 333 { 334 /* This op is the first in the list */ 335 336 if (ReplacementOp) 337 { 338 ReplacementOp->Common.Parent = Op->Common.Parent; 339 ReplacementOp->Common.Value.Arg = NULL; 340 ReplacementOp->Common.Node = Op->Common.Node; 341 Op->Common.Parent->Common.Value.Arg = ReplacementOp; 342 ReplacementOp->Common.Next = Op->Common.Next; 343 } 344 else 345 { 346 Op->Common.Parent->Common.Value.Arg = Op->Common.Next; 347 } 348 } 349 350 /* Search the parent list */ 351 352 else while (Prev) 353 { 354 /* Traverse all siblings in the parent's argument list */ 355 356 Next = Prev->Common.Next; 357 if (Next == Op) 358 { 359 if (ReplacementOp) 360 { 361 ReplacementOp->Common.Parent = Op->Common.Parent; 362 ReplacementOp->Common.Value.Arg = NULL; 363 ReplacementOp->Common.Node = Op->Common.Node; 364 Prev->Common.Next = ReplacementOp; 365 ReplacementOp->Common.Next = Op->Common.Next; 366 Next = NULL; 367 } 368 else 369 { 370 Prev->Common.Next = Op->Common.Next; 371 Next = NULL; 372 } 373 } 374 Prev = Next; 375 } 376 } 377 378 379 Cleanup: 380 381 /* Now we can actually delete the subtree rooted at Op */ 382 383 AcpiPsDeleteParseTree (Op); 384 return_ACPI_STATUS (Status); 385 } 386 387 388 /******************************************************************************* 389 * 390 * FUNCTION: AcpiPsNextParseState 391 * 392 * PARAMETERS: WalkState - Current state 393 * Op - Current parse op 394 * CallbackStatus - Status from previous operation 395 * 396 * RETURN: Status 397 * 398 * DESCRIPTION: Update the parser state based upon the return exception from 399 * the parser callback. 400 * 401 ******************************************************************************/ 402 403 ACPI_STATUS 404 AcpiPsNextParseState ( 405 ACPI_WALK_STATE *WalkState, 406 ACPI_PARSE_OBJECT *Op, 407 ACPI_STATUS CallbackStatus) 408 { 409 ACPI_PARSE_STATE *ParserState = &WalkState->ParserState; 410 ACPI_STATUS Status = AE_CTRL_PENDING; 411 412 413 ACPI_FUNCTION_TRACE_PTR (PsNextParseState, Op); 414 415 416 switch (CallbackStatus) 417 { 418 case AE_CTRL_TERMINATE: 419 /* 420 * A control method was terminated via a RETURN statement. 421 * The walk of this method is complete. 422 */ 423 ParserState->Aml = ParserState->AmlEnd; 424 Status = AE_CTRL_TERMINATE; 425 break; 426 427 428 case AE_CTRL_BREAK: 429 430 ParserState->Aml = WalkState->AmlLastWhile; 431 WalkState->ControlState->Common.Value = FALSE; 432 Status = AE_CTRL_BREAK; 433 break; 434 435 436 case AE_CTRL_CONTINUE: 437 438 ParserState->Aml = WalkState->AmlLastWhile; 439 Status = AE_CTRL_CONTINUE; 440 break; 441 442 443 case AE_CTRL_PENDING: 444 445 ParserState->Aml = WalkState->AmlLastWhile; 446 break; 447 448 #if 0 449 case AE_CTRL_SKIP: 450 451 ParserState->Aml = ParserState->Scope->ParseScope.PkgEnd; 452 Status = AE_OK; 453 break; 454 #endif 455 456 case AE_CTRL_TRUE: 457 /* 458 * Predicate of an IF was true, and we are at the matching ELSE. 459 * Just close out this package 460 */ 461 ParserState->Aml = AcpiPsGetNextPackageEnd (ParserState); 462 Status = AE_CTRL_PENDING; 463 break; 464 465 466 case AE_CTRL_FALSE: 467 /* 468 * Either an IF/WHILE Predicate was false or we encountered a BREAK 469 * opcode. In both cases, we do not execute the rest of the 470 * package; We simply close out the parent (finishing the walk of 471 * this branch of the tree) and continue execution at the parent 472 * level. 473 */ 474 ParserState->Aml = ParserState->Scope->ParseScope.PkgEnd; 475 476 /* In the case of a BREAK, just force a predicate (if any) to FALSE */ 477 478 WalkState->ControlState->Common.Value = FALSE; 479 Status = AE_CTRL_END; 480 break; 481 482 483 case AE_CTRL_TRANSFER: 484 485 /* A method call (invocation) -- transfer control */ 486 487 Status = AE_CTRL_TRANSFER; 488 WalkState->PrevOp = Op; 489 WalkState->MethodCallOp = Op; 490 WalkState->MethodCallNode = (Op->Common.Value.Arg)->Common.Node; 491 492 /* Will return value (if any) be used by the caller? */ 493 494 WalkState->ReturnUsed = AcpiDsIsResultUsed (Op, WalkState); 495 break; 496 497 498 default: 499 500 Status = CallbackStatus; 501 if ((CallbackStatus & AE_CODE_MASK) == AE_CODE_CONTROL) 502 { 503 Status = AE_OK; 504 } 505 break; 506 } 507 508 return_ACPI_STATUS (Status); 509 } 510 511 512 /******************************************************************************* 513 * 514 * FUNCTION: AcpiPsParseAml 515 * 516 * PARAMETERS: WalkState - Current state 517 * 518 * 519 * RETURN: Status 520 * 521 * DESCRIPTION: Parse raw AML and return a tree of ops 522 * 523 ******************************************************************************/ 524 525 ACPI_STATUS 526 AcpiPsParseAml ( 527 ACPI_WALK_STATE *WalkState) 528 { 529 ACPI_STATUS Status; 530 ACPI_THREAD_STATE *Thread; 531 ACPI_THREAD_STATE *PrevWalkList = AcpiGbl_CurrentWalkList; 532 ACPI_WALK_STATE *PreviousWalkState; 533 534 535 ACPI_FUNCTION_TRACE (PsParseAml); 536 537 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 538 "Entered with WalkState=%p Aml=%p size=%X\n", 539 WalkState, WalkState->ParserState.Aml, 540 WalkState->ParserState.AmlSize)); 541 542 if (!WalkState->ParserState.Aml) 543 { 544 return_ACPI_STATUS (AE_NULL_OBJECT); 545 } 546 547 /* Create and initialize a new thread state */ 548 549 Thread = AcpiUtCreateThreadState (); 550 if (!Thread) 551 { 552 if (WalkState->MethodDesc) 553 { 554 /* Executing a control method - additional cleanup */ 555 556 AcpiDsTerminateControlMethod (WalkState->MethodDesc, WalkState); 557 } 558 559 AcpiDsDeleteWalkState (WalkState); 560 return_ACPI_STATUS (AE_NO_MEMORY); 561 } 562 563 WalkState->Thread = Thread; 564 565 /* 566 * If executing a method, the starting SyncLevel is this method's 567 * SyncLevel 568 */ 569 if (WalkState->MethodDesc) 570 { 571 WalkState->Thread->CurrentSyncLevel = WalkState->MethodDesc->Method.SyncLevel; 572 } 573 574 AcpiDsPushWalkState (WalkState, Thread); 575 576 /* 577 * This global allows the AML debugger to get a handle to the currently 578 * executing control method. 579 */ 580 AcpiGbl_CurrentWalkList = Thread; 581 582 /* 583 * Execute the walk loop as long as there is a valid Walk State. This 584 * handles nested control method invocations without recursion. 585 */ 586 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "State=%p\n", WalkState)); 587 588 Status = AE_OK; 589 while (WalkState) 590 { 591 if (ACPI_SUCCESS (Status)) 592 { 593 /* 594 * The ParseLoop executes AML until the method terminates 595 * or calls another method. 596 */ 597 Status = AcpiPsParseLoop (WalkState); 598 } 599 600 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 601 "Completed one call to walk loop, %s State=%p\n", 602 AcpiFormatException (Status), WalkState)); 603 604 if (Status == AE_CTRL_TRANSFER) 605 { 606 /* 607 * A method call was detected. 608 * Transfer control to the called control method 609 */ 610 Status = AcpiDsCallControlMethod (Thread, WalkState, NULL); 611 if (ACPI_FAILURE (Status)) 612 { 613 Status = AcpiDsMethodError (Status, WalkState); 614 } 615 616 /* 617 * If the transfer to the new method method call worked, a new walk 618 * state was created -- get it 619 */ 620 WalkState = AcpiDsGetCurrentWalkState (Thread); 621 continue; 622 } 623 else if (Status == AE_CTRL_TERMINATE) 624 { 625 Status = AE_OK; 626 } 627 else if ((Status != AE_OK) && (WalkState->MethodDesc)) 628 { 629 /* Either the method parse or actual execution failed */ 630 631 ACPI_ERROR_METHOD ("Method parse/execution failed", 632 WalkState->MethodNode, NULL, Status); 633 634 /* Check for possible multi-thread reentrancy problem */ 635 636 if ((Status == AE_ALREADY_EXISTS) && 637 (!(WalkState->MethodDesc->Method.InfoFlags & ACPI_METHOD_SERIALIZED))) 638 { 639 /* 640 * Method is not serialized and tried to create an object 641 * twice. The probable cause is that the method cannot 642 * handle reentrancy. Mark as "pending serialized" now, and 643 * then mark "serialized" when the last thread exits. 644 */ 645 WalkState->MethodDesc->Method.InfoFlags |= 646 ACPI_METHOD_SERIALIZED_PENDING; 647 } 648 } 649 650 /* We are done with this walk, move on to the parent if any */ 651 652 WalkState = AcpiDsPopWalkState (Thread); 653 654 /* Reset the current scope to the beginning of scope stack */ 655 656 AcpiDsScopeStackClear (WalkState); 657 658 /* 659 * If we just returned from the execution of a control method or if we 660 * encountered an error during the method parse phase, there's lots of 661 * cleanup to do 662 */ 663 if (((WalkState->ParseFlags & ACPI_PARSE_MODE_MASK) == ACPI_PARSE_EXECUTE) || 664 (ACPI_FAILURE (Status))) 665 { 666 AcpiDsTerminateControlMethod (WalkState->MethodDesc, WalkState); 667 } 668 669 /* Delete this walk state and all linked control states */ 670 671 AcpiPsCleanupScope (&WalkState->ParserState); 672 PreviousWalkState = WalkState; 673 674 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 675 "ReturnValue=%p, ImplicitValue=%p State=%p\n", 676 WalkState->ReturnDesc, WalkState->ImplicitReturnObj, WalkState)); 677 678 /* Check if we have restarted a preempted walk */ 679 680 WalkState = AcpiDsGetCurrentWalkState (Thread); 681 if (WalkState) 682 { 683 if (ACPI_SUCCESS (Status)) 684 { 685 /* 686 * There is another walk state, restart it. 687 * If the method return value is not used by the parent, 688 * The object is deleted 689 */ 690 if (!PreviousWalkState->ReturnDesc) 691 { 692 /* 693 * In slack mode execution, if there is no return value 694 * we should implicitly return zero (0) as a default value. 695 */ 696 if (AcpiGbl_EnableInterpreterSlack && 697 !PreviousWalkState->ImplicitReturnObj) 698 { 699 PreviousWalkState->ImplicitReturnObj = 700 AcpiUtCreateIntegerObject ((UINT64) 0); 701 if (!PreviousWalkState->ImplicitReturnObj) 702 { 703 return_ACPI_STATUS (AE_NO_MEMORY); 704 } 705 } 706 707 /* Restart the calling control method */ 708 709 Status = AcpiDsRestartControlMethod (WalkState, 710 PreviousWalkState->ImplicitReturnObj); 711 } 712 else 713 { 714 /* 715 * We have a valid return value, delete any implicit 716 * return value. 717 */ 718 AcpiDsClearImplicitReturn (PreviousWalkState); 719 720 Status = AcpiDsRestartControlMethod (WalkState, 721 PreviousWalkState->ReturnDesc); 722 } 723 if (ACPI_SUCCESS (Status)) 724 { 725 WalkState->WalkType |= ACPI_WALK_METHOD_RESTART; 726 } 727 } 728 else 729 { 730 /* On error, delete any return object or implicit return */ 731 732 AcpiUtRemoveReference (PreviousWalkState->ReturnDesc); 733 AcpiDsClearImplicitReturn (PreviousWalkState); 734 } 735 } 736 737 /* 738 * Just completed a 1st-level method, save the final internal return 739 * value (if any) 740 */ 741 else if (PreviousWalkState->CallerReturnDesc) 742 { 743 if (PreviousWalkState->ImplicitReturnObj) 744 { 745 *(PreviousWalkState->CallerReturnDesc) = 746 PreviousWalkState->ImplicitReturnObj; 747 } 748 else 749 { 750 /* NULL if no return value */ 751 752 *(PreviousWalkState->CallerReturnDesc) = 753 PreviousWalkState->ReturnDesc; 754 } 755 } 756 else 757 { 758 if (PreviousWalkState->ReturnDesc) 759 { 760 /* Caller doesn't want it, must delete it */ 761 762 AcpiUtRemoveReference (PreviousWalkState->ReturnDesc); 763 } 764 if (PreviousWalkState->ImplicitReturnObj) 765 { 766 /* Caller doesn't want it, must delete it */ 767 768 AcpiUtRemoveReference (PreviousWalkState->ImplicitReturnObj); 769 } 770 } 771 772 AcpiDsDeleteWalkState (PreviousWalkState); 773 } 774 775 /* Normal exit */ 776 777 AcpiExReleaseAllMutexes (Thread); 778 AcpiUtDeleteGenericState (ACPI_CAST_PTR (ACPI_GENERIC_STATE, Thread)); 779 AcpiGbl_CurrentWalkList = PrevWalkList; 780 return_ACPI_STATUS (Status); 781 } 782