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 - 2016, 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 * Parse the AML and build an operation tree as most interpreters, 118 * like Perl, do. Parsing is done by hand rather than with a YACC 119 * generated parser to tightly constrain stack and dynamic memory 120 * usage. At the same time, parsing is kept flexible and the code 121 * fairly compact by parsing based on a list of AML opcode 122 * templates in AmlOpInfo[] 123 */ 124 125 #include "acpi.h" 126 #include "accommon.h" 127 #include "acparser.h" 128 #include "acdispat.h" 129 #include "amlcode.h" 130 #include "acinterp.h" 131 132 #define _COMPONENT ACPI_PARSER 133 ACPI_MODULE_NAME ("psparse") 134 135 136 /******************************************************************************* 137 * 138 * FUNCTION: AcpiPsGetOpcodeSize 139 * 140 * PARAMETERS: Opcode - An AML opcode 141 * 142 * RETURN: Size of the opcode, in bytes (1 or 2) 143 * 144 * DESCRIPTION: Get the size of the current opcode. 145 * 146 ******************************************************************************/ 147 148 UINT32 149 AcpiPsGetOpcodeSize ( 150 UINT32 Opcode) 151 { 152 153 /* Extended (2-byte) opcode if > 255 */ 154 155 if (Opcode > 0x00FF) 156 { 157 return (2); 158 } 159 160 /* Otherwise, just a single byte opcode */ 161 162 return (1); 163 } 164 165 166 /******************************************************************************* 167 * 168 * FUNCTION: AcpiPsPeekOpcode 169 * 170 * PARAMETERS: ParserState - A parser state object 171 * 172 * RETURN: Next AML opcode 173 * 174 * DESCRIPTION: Get next AML opcode (without incrementing AML pointer) 175 * 176 ******************************************************************************/ 177 178 UINT16 179 AcpiPsPeekOpcode ( 180 ACPI_PARSE_STATE *ParserState) 181 { 182 UINT8 *Aml; 183 UINT16 Opcode; 184 185 186 Aml = ParserState->Aml; 187 Opcode = (UINT16) ACPI_GET8 (Aml); 188 189 if (Opcode == AML_EXTENDED_OP_PREFIX) 190 { 191 /* Extended opcode, get the second opcode byte */ 192 193 Aml++; 194 Opcode = (UINT16) ((Opcode << 8) | ACPI_GET8 (Aml)); 195 } 196 197 return (Opcode); 198 } 199 200 201 /******************************************************************************* 202 * 203 * FUNCTION: AcpiPsCompleteThisOp 204 * 205 * PARAMETERS: WalkState - Current State 206 * Op - Op to complete 207 * 208 * RETURN: Status 209 * 210 * DESCRIPTION: Perform any cleanup at the completion of an Op. 211 * 212 ******************************************************************************/ 213 214 ACPI_STATUS 215 AcpiPsCompleteThisOp ( 216 ACPI_WALK_STATE *WalkState, 217 ACPI_PARSE_OBJECT *Op) 218 { 219 ACPI_PARSE_OBJECT *Prev; 220 ACPI_PARSE_OBJECT *Next; 221 const ACPI_OPCODE_INFO *ParentInfo; 222 ACPI_PARSE_OBJECT *ReplacementOp = NULL; 223 ACPI_STATUS Status = AE_OK; 224 225 226 ACPI_FUNCTION_TRACE_PTR (PsCompleteThisOp, Op); 227 228 229 /* Check for null Op, can happen if AML code is corrupt */ 230 231 if (!Op) 232 { 233 return_ACPI_STATUS (AE_OK); /* OK for now */ 234 } 235 236 AcpiExStopTraceOpcode (Op, WalkState); 237 238 /* Delete this op and the subtree below it if asked to */ 239 240 if (((WalkState->ParseFlags & ACPI_PARSE_TREE_MASK) != ACPI_PARSE_DELETE_TREE) || 241 (WalkState->OpInfo->Class == AML_CLASS_ARGUMENT)) 242 { 243 return_ACPI_STATUS (AE_OK); 244 } 245 246 /* Make sure that we only delete this subtree */ 247 248 if (Op->Common.Parent) 249 { 250 Prev = Op->Common.Parent->Common.Value.Arg; 251 if (!Prev) 252 { 253 /* Nothing more to do */ 254 255 goto Cleanup; 256 } 257 258 /* 259 * Check if we need to replace the operator and its subtree 260 * with a return value op (placeholder op) 261 */ 262 ParentInfo = AcpiPsGetOpcodeInfo (Op->Common.Parent->Common.AmlOpcode); 263 264 switch (ParentInfo->Class) 265 { 266 case AML_CLASS_CONTROL: 267 268 break; 269 270 case AML_CLASS_CREATE: 271 /* 272 * These opcodes contain TermArg operands. The current 273 * op must be replaced by a placeholder return op 274 */ 275 ReplacementOp = AcpiPsAllocOp ( 276 AML_INT_RETURN_VALUE_OP, Op->Common.Aml); 277 if (!ReplacementOp) 278 { 279 Status = AE_NO_MEMORY; 280 } 281 break; 282 283 case AML_CLASS_NAMED_OBJECT: 284 /* 285 * These opcodes contain TermArg operands. The current 286 * op must be replaced by a placeholder return op 287 */ 288 if ((Op->Common.Parent->Common.AmlOpcode == AML_REGION_OP) || 289 (Op->Common.Parent->Common.AmlOpcode == AML_DATA_REGION_OP) || 290 (Op->Common.Parent->Common.AmlOpcode == AML_BUFFER_OP) || 291 (Op->Common.Parent->Common.AmlOpcode == AML_PACKAGE_OP) || 292 (Op->Common.Parent->Common.AmlOpcode == AML_BANK_FIELD_OP) || 293 (Op->Common.Parent->Common.AmlOpcode == AML_VAR_PACKAGE_OP)) 294 { 295 ReplacementOp = AcpiPsAllocOp ( 296 AML_INT_RETURN_VALUE_OP, Op->Common.Aml); 297 if (!ReplacementOp) 298 { 299 Status = AE_NO_MEMORY; 300 } 301 } 302 else if ((Op->Common.Parent->Common.AmlOpcode == AML_NAME_OP) && 303 (WalkState->PassNumber <= ACPI_IMODE_LOAD_PASS2)) 304 { 305 if ((Op->Common.AmlOpcode == AML_BUFFER_OP) || 306 (Op->Common.AmlOpcode == AML_PACKAGE_OP) || 307 (Op->Common.AmlOpcode == AML_VAR_PACKAGE_OP)) 308 { 309 ReplacementOp = AcpiPsAllocOp (Op->Common.AmlOpcode, 310 Op->Common.Aml); 311 if (!ReplacementOp) 312 { 313 Status = AE_NO_MEMORY; 314 } 315 else 316 { 317 ReplacementOp->Named.Data = Op->Named.Data; 318 ReplacementOp->Named.Length = Op->Named.Length; 319 } 320 } 321 } 322 break; 323 324 default: 325 326 ReplacementOp = AcpiPsAllocOp ( 327 AML_INT_RETURN_VALUE_OP, Op->Common.Aml); 328 if (!ReplacementOp) 329 { 330 Status = AE_NO_MEMORY; 331 } 332 } 333 334 /* We must unlink this op from the parent tree */ 335 336 if (Prev == Op) 337 { 338 /* This op is the first in the list */ 339 340 if (ReplacementOp) 341 { 342 ReplacementOp->Common.Parent = Op->Common.Parent; 343 ReplacementOp->Common.Value.Arg = NULL; 344 ReplacementOp->Common.Node = Op->Common.Node; 345 Op->Common.Parent->Common.Value.Arg = ReplacementOp; 346 ReplacementOp->Common.Next = Op->Common.Next; 347 } 348 else 349 { 350 Op->Common.Parent->Common.Value.Arg = Op->Common.Next; 351 } 352 } 353 354 /* Search the parent list */ 355 356 else while (Prev) 357 { 358 /* Traverse all siblings in the parent's argument list */ 359 360 Next = Prev->Common.Next; 361 if (Next == Op) 362 { 363 if (ReplacementOp) 364 { 365 ReplacementOp->Common.Parent = Op->Common.Parent; 366 ReplacementOp->Common.Value.Arg = NULL; 367 ReplacementOp->Common.Node = Op->Common.Node; 368 Prev->Common.Next = ReplacementOp; 369 ReplacementOp->Common.Next = Op->Common.Next; 370 Next = NULL; 371 } 372 else 373 { 374 Prev->Common.Next = Op->Common.Next; 375 Next = NULL; 376 } 377 } 378 Prev = Next; 379 } 380 } 381 382 383 Cleanup: 384 385 /* Now we can actually delete the subtree rooted at Op */ 386 387 AcpiPsDeleteParseTree (Op); 388 return_ACPI_STATUS (Status); 389 } 390 391 392 /******************************************************************************* 393 * 394 * FUNCTION: AcpiPsNextParseState 395 * 396 * PARAMETERS: WalkState - Current state 397 * Op - Current parse op 398 * CallbackStatus - Status from previous operation 399 * 400 * RETURN: Status 401 * 402 * DESCRIPTION: Update the parser state based upon the return exception from 403 * the parser callback. 404 * 405 ******************************************************************************/ 406 407 ACPI_STATUS 408 AcpiPsNextParseState ( 409 ACPI_WALK_STATE *WalkState, 410 ACPI_PARSE_OBJECT *Op, 411 ACPI_STATUS CallbackStatus) 412 { 413 ACPI_PARSE_STATE *ParserState = &WalkState->ParserState; 414 ACPI_STATUS Status = AE_CTRL_PENDING; 415 416 417 ACPI_FUNCTION_TRACE_PTR (PsNextParseState, Op); 418 419 420 switch (CallbackStatus) 421 { 422 case AE_CTRL_TERMINATE: 423 /* 424 * A control method was terminated via a RETURN statement. 425 * The walk of this method is complete. 426 */ 427 ParserState->Aml = ParserState->AmlEnd; 428 Status = AE_CTRL_TERMINATE; 429 break; 430 431 case AE_CTRL_BREAK: 432 433 ParserState->Aml = WalkState->AmlLastWhile; 434 WalkState->ControlState->Common.Value = FALSE; 435 Status = AE_CTRL_BREAK; 436 break; 437 438 case AE_CTRL_CONTINUE: 439 440 ParserState->Aml = WalkState->AmlLastWhile; 441 Status = AE_CTRL_CONTINUE; 442 break; 443 444 case AE_CTRL_PENDING: 445 446 ParserState->Aml = WalkState->AmlLastWhile; 447 break; 448 449 #if 0 450 case AE_CTRL_SKIP: 451 452 ParserState->Aml = ParserState->Scope->ParseScope.PkgEnd; 453 Status = AE_OK; 454 break; 455 #endif 456 457 case AE_CTRL_TRUE: 458 /* 459 * Predicate of an IF was true, and we are at the matching ELSE. 460 * Just close out this package 461 */ 462 ParserState->Aml = AcpiPsGetNextPackageEnd (ParserState); 463 Status = AE_CTRL_PENDING; 464 break; 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 case AE_CTRL_TRANSFER: 483 484 /* A method call (invocation) -- transfer control */ 485 486 Status = AE_CTRL_TRANSFER; 487 WalkState->PrevOp = Op; 488 WalkState->MethodCallOp = Op; 489 WalkState->MethodCallNode = (Op->Common.Value.Arg)->Common.Node; 490 491 /* Will return value (if any) be used by the caller? */ 492 493 WalkState->ReturnUsed = AcpiDsIsResultUsed (Op, WalkState); 494 break; 495 496 default: 497 498 Status = CallbackStatus; 499 if ((CallbackStatus & AE_CODE_MASK) == AE_CODE_CONTROL) 500 { 501 Status = AE_OK; 502 } 503 break; 504 } 505 506 return_ACPI_STATUS (Status); 507 } 508 509 510 /******************************************************************************* 511 * 512 * FUNCTION: AcpiPsParseAml 513 * 514 * PARAMETERS: WalkState - Current state 515 * 516 * 517 * RETURN: Status 518 * 519 * DESCRIPTION: Parse raw AML and return a tree of ops 520 * 521 ******************************************************************************/ 522 523 ACPI_STATUS 524 AcpiPsParseAml ( 525 ACPI_WALK_STATE *WalkState) 526 { 527 ACPI_STATUS Status; 528 ACPI_THREAD_STATE *Thread; 529 ACPI_THREAD_STATE *PrevWalkList = AcpiGbl_CurrentWalkList; 530 ACPI_WALK_STATE *PreviousWalkState; 531 532 533 ACPI_FUNCTION_TRACE (PsParseAml); 534 535 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 536 "Entered with WalkState=%p Aml=%p size=%X\n", 537 WalkState, WalkState->ParserState.Aml, 538 WalkState->ParserState.AmlSize)); 539 540 if (!WalkState->ParserState.Aml) 541 { 542 return_ACPI_STATUS (AE_NULL_OBJECT); 543 } 544 545 /* Create and initialize a new thread state */ 546 547 Thread = AcpiUtCreateThreadState (); 548 if (!Thread) 549 { 550 if (WalkState->MethodDesc) 551 { 552 /* Executing a control method - additional cleanup */ 553 554 AcpiDsTerminateControlMethod (WalkState->MethodDesc, WalkState); 555 } 556 557 AcpiDsDeleteWalkState (WalkState); 558 return_ACPI_STATUS (AE_NO_MEMORY); 559 } 560 561 WalkState->Thread = Thread; 562 563 /* 564 * If executing a method, the starting SyncLevel is this method's 565 * SyncLevel 566 */ 567 if (WalkState->MethodDesc) 568 { 569 WalkState->Thread->CurrentSyncLevel = 570 WalkState->MethodDesc->Method.SyncLevel; 571 } 572 573 AcpiDsPushWalkState (WalkState, Thread); 574 575 /* 576 * This global allows the AML debugger to get a handle to the currently 577 * executing control method. 578 */ 579 AcpiGbl_CurrentWalkList = Thread; 580 581 /* 582 * Execute the walk loop as long as there is a valid Walk State. This 583 * handles nested control method invocations without recursion. 584 */ 585 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "State=%p\n", WalkState)); 586 587 Status = AE_OK; 588 while (WalkState) 589 { 590 if (ACPI_SUCCESS (Status)) 591 { 592 /* 593 * The ParseLoop executes AML until the method terminates 594 * or calls another method. 595 */ 596 Status = AcpiPsParseLoop (WalkState); 597 } 598 599 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 600 "Completed one call to walk loop, %s State=%p\n", 601 AcpiFormatException (Status), WalkState)); 602 603 if (Status == AE_CTRL_TRANSFER) 604 { 605 /* 606 * A method call was detected. 607 * Transfer control to the called control method 608 */ 609 Status = AcpiDsCallControlMethod (Thread, WalkState, NULL); 610 if (ACPI_FAILURE (Status)) 611 { 612 Status = AcpiDsMethodError (Status, WalkState); 613 } 614 615 /* 616 * If the transfer to the new method method call worked 617 *, a new walk state was created -- get it 618 */ 619 WalkState = AcpiDsGetCurrentWalkState (Thread); 620 continue; 621 } 622 else if (Status == AE_CTRL_TERMINATE) 623 { 624 Status = AE_OK; 625 } 626 else if ((Status != AE_OK) && (WalkState->MethodDesc)) 627 { 628 /* Either the method parse or actual execution failed */ 629 630 ACPI_ERROR_METHOD ("Method parse/execution failed", 631 WalkState->MethodNode, NULL, Status); 632 633 /* Check for possible multi-thread reentrancy problem */ 634 635 if ((Status == AE_ALREADY_EXISTS) && 636 (!(WalkState->MethodDesc->Method.InfoFlags & 637 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) == 664 ACPI_PARSE_EXECUTE) || 665 (ACPI_FAILURE (Status))) 666 { 667 AcpiDsTerminateControlMethod (WalkState->MethodDesc, WalkState); 668 } 669 670 /* Delete this walk state and all linked control states */ 671 672 AcpiPsCleanupScope (&WalkState->ParserState); 673 PreviousWalkState = WalkState; 674 675 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, 676 "ReturnValue=%p, ImplicitValue=%p State=%p\n", 677 WalkState->ReturnDesc, WalkState->ImplicitReturnObj, WalkState)); 678 679 /* Check if we have restarted a preempted walk */ 680 681 WalkState = AcpiDsGetCurrentWalkState (Thread); 682 if (WalkState) 683 { 684 if (ACPI_SUCCESS (Status)) 685 { 686 /* 687 * There is another walk state, restart it. 688 * If the method return value is not used by the parent, 689 * The object is deleted 690 */ 691 if (!PreviousWalkState->ReturnDesc) 692 { 693 /* 694 * In slack mode execution, if there is no return value 695 * we should implicitly return zero (0) as a default value. 696 */ 697 if (AcpiGbl_EnableInterpreterSlack && 698 !PreviousWalkState->ImplicitReturnObj) 699 { 700 PreviousWalkState->ImplicitReturnObj = 701 AcpiUtCreateIntegerObject ((UINT64) 0); 702 if (!PreviousWalkState->ImplicitReturnObj) 703 { 704 return_ACPI_STATUS (AE_NO_MEMORY); 705 } 706 } 707 708 /* Restart the calling control method */ 709 710 Status = AcpiDsRestartControlMethod (WalkState, 711 PreviousWalkState->ImplicitReturnObj); 712 } 713 else 714 { 715 /* 716 * We have a valid return value, delete any implicit 717 * return value. 718 */ 719 AcpiDsClearImplicitReturn (PreviousWalkState); 720 721 Status = AcpiDsRestartControlMethod (WalkState, 722 PreviousWalkState->ReturnDesc); 723 } 724 if (ACPI_SUCCESS (Status)) 725 { 726 WalkState->WalkType |= ACPI_WALK_METHOD_RESTART; 727 } 728 } 729 else 730 { 731 /* On error, delete any return object or implicit return */ 732 733 AcpiUtRemoveReference (PreviousWalkState->ReturnDesc); 734 AcpiDsClearImplicitReturn (PreviousWalkState); 735 } 736 } 737 738 /* 739 * Just completed a 1st-level method, save the final internal return 740 * value (if any) 741 */ 742 else if (PreviousWalkState->CallerReturnDesc) 743 { 744 if (PreviousWalkState->ImplicitReturnObj) 745 { 746 *(PreviousWalkState->CallerReturnDesc) = 747 PreviousWalkState->ImplicitReturnObj; 748 } 749 else 750 { 751 /* NULL if no return value */ 752 753 *(PreviousWalkState->CallerReturnDesc) = 754 PreviousWalkState->ReturnDesc; 755 } 756 } 757 else 758 { 759 if (PreviousWalkState->ReturnDesc) 760 { 761 /* Caller doesn't want it, must delete it */ 762 763 AcpiUtRemoveReference (PreviousWalkState->ReturnDesc); 764 } 765 if (PreviousWalkState->ImplicitReturnObj) 766 { 767 /* Caller doesn't want it, must delete it */ 768 769 AcpiUtRemoveReference (PreviousWalkState->ImplicitReturnObj); 770 } 771 } 772 773 AcpiDsDeleteWalkState (PreviousWalkState); 774 } 775 776 /* Normal exit */ 777 778 AcpiExReleaseAllMutexes (Thread); 779 AcpiUtDeleteGenericState (ACPI_CAST_PTR (ACPI_GENERIC_STATE, Thread)); 780 AcpiGbl_CurrentWalkList = PrevWalkList; 781 return_ACPI_STATUS (Status); 782 } 783