1 /****************************************************************************** 2 * 3 * Module Name: aslopt- Compiler optimizations 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2017, Intel Corp. 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 <contrib/dev/acpica/compiler/aslcompiler.h> 45 #include "aslcompiler.y.h" 46 47 #include <contrib/dev/acpica/include/acparser.h> 48 #include <contrib/dev/acpica/include/amlcode.h> 49 #include <contrib/dev/acpica/include/acnamesp.h> 50 51 52 #define _COMPONENT ACPI_COMPILER 53 ACPI_MODULE_NAME ("aslopt") 54 55 56 static UINT32 OptTotal = 0; 57 58 /* Local prototypes */ 59 60 static ACPI_STATUS 61 OptSearchToRoot ( 62 ACPI_PARSE_OBJECT *Op, 63 ACPI_WALK_STATE *WalkState, 64 ACPI_NAMESPACE_NODE *CurrentNode, 65 ACPI_NAMESPACE_NODE *TargetNode, 66 ACPI_BUFFER *TargetPath, 67 char **NewPath); 68 69 static ACPI_STATUS 70 OptBuildShortestPath ( 71 ACPI_PARSE_OBJECT *Op, 72 ACPI_WALK_STATE *WalkState, 73 ACPI_NAMESPACE_NODE *CurrentNode, 74 ACPI_NAMESPACE_NODE *TargetNode, 75 ACPI_BUFFER *CurrentPath, 76 ACPI_BUFFER *TargetPath, 77 ACPI_SIZE AmlNameStringLength, 78 UINT8 IsDeclaration, 79 char **ReturnNewPath); 80 81 static ACPI_STATUS 82 OptOptimizeNameDeclaration ( 83 ACPI_PARSE_OBJECT *Op, 84 ACPI_WALK_STATE *WalkState, 85 ACPI_NAMESPACE_NODE *CurrentNode, 86 ACPI_NAMESPACE_NODE *TargetNode, 87 char *AmlNameString, 88 char **NewPath); 89 90 91 /******************************************************************************* 92 * 93 * FUNCTION: OptSearchToRoot 94 * 95 * PARAMETERS: Op - Current parser op 96 * WalkState - Current state 97 * CurrentNode - Where we are in the namespace 98 * TargetNode - Node to which we are referring 99 * TargetPath - External full path to the target node 100 * NewPath - Where the optimized path is returned 101 * 102 * RETURN: Status 103 * 104 * DESCRIPTION: Attempt to optimize a reference to a single 4-character ACPI 105 * name utilizing the search-to-root name resolution algorithm 106 * that is used by AML interpreters. 107 * 108 ******************************************************************************/ 109 110 static ACPI_STATUS 111 OptSearchToRoot ( 112 ACPI_PARSE_OBJECT *Op, 113 ACPI_WALK_STATE *WalkState, 114 ACPI_NAMESPACE_NODE *CurrentNode, 115 ACPI_NAMESPACE_NODE *TargetNode, 116 ACPI_BUFFER *TargetPath, 117 char **NewPath) 118 { 119 ACPI_NAMESPACE_NODE *Node; 120 ACPI_GENERIC_STATE ScopeInfo; 121 ACPI_STATUS Status; 122 char *Path; 123 124 125 ACPI_FUNCTION_NAME (OptSearchToRoot); 126 127 128 /* 129 * Check if search-to-root can be utilized. Use the last NameSeg of 130 * the NamePath and 1) See if can be found and 2) If found, make 131 * sure that it is the same node that we want. If there is another 132 * name in the search path before the one we want, the nodes will 133 * not match, and we cannot use this optimization. 134 */ 135 Path = &(((char *) TargetPath->Pointer)[ 136 TargetPath->Length - ACPI_NAME_SIZE]); 137 ScopeInfo.Scope.Node = CurrentNode; 138 139 /* Lookup the NameSeg using SEARCH_PARENT (search-to-root) */ 140 141 Status = AcpiNsLookup (&ScopeInfo, Path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 142 ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE, 143 WalkState, &(Node)); 144 if (ACPI_FAILURE (Status)) 145 { 146 return (Status); 147 } 148 149 /* 150 * We found the name, but we must check to make sure that the node 151 * matches. Otherwise, there is another identical name in the search 152 * path that precludes the use of this optimization. 153 */ 154 if (Node != TargetNode) 155 { 156 /* 157 * This means that another object with the same name was found first, 158 * and we cannot use this optimization. 159 */ 160 return (AE_NOT_FOUND); 161 } 162 163 /* Found the node, we can use this optimization */ 164 165 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 166 "NAMESEG: %-24s", Path)); 167 168 /* We must allocate a new string for the name (TargetPath gets deleted) */ 169 170 *NewPath = UtStringCacheCalloc (ACPI_NAME_SIZE + 1); 171 strcpy (*NewPath, Path); 172 173 if (strncmp (*NewPath, "_T_", 3)) 174 { 175 AslError (ASL_OPTIMIZATION, ASL_MSG_SINGLE_NAME_OPTIMIZATION, 176 Op, *NewPath); 177 } 178 179 return (AE_OK); 180 } 181 182 183 /******************************************************************************* 184 * 185 * FUNCTION: OptBuildShortestPath 186 * 187 * PARAMETERS: Op - Current parser op 188 * WalkState - Current state 189 * CurrentNode - Where we are in the namespace 190 * TargetNode - Node to which we are referring 191 * CurrentPath - External full path to the current node 192 * TargetPath - External full path to the target node 193 * AmlNameStringLength - Length of the original namepath 194 * IsDeclaration - TRUE for declaration, FALSE for reference 195 * ReturnNewPath - Where the optimized path is returned 196 * 197 * RETURN: Status 198 * 199 * DESCRIPTION: Build an optimal NamePath using carats 200 * 201 ******************************************************************************/ 202 203 static ACPI_STATUS 204 OptBuildShortestPath ( 205 ACPI_PARSE_OBJECT *Op, 206 ACPI_WALK_STATE *WalkState, 207 ACPI_NAMESPACE_NODE *CurrentNode, 208 ACPI_NAMESPACE_NODE *TargetNode, 209 ACPI_BUFFER *CurrentPath, 210 ACPI_BUFFER *TargetPath, 211 ACPI_SIZE AmlNameStringLength, 212 UINT8 IsDeclaration, 213 char **ReturnNewPath) 214 { 215 UINT32 NumCommonSegments; 216 UINT32 MaxCommonSegments; 217 UINT32 Index; 218 UINT32 NumCarats; 219 UINT32 i; 220 char *NewPathInternal; 221 char *NewPathExternal; 222 ACPI_NAMESPACE_NODE *Node; 223 ACPI_GENERIC_STATE ScopeInfo; 224 ACPI_STATUS Status; 225 BOOLEAN SubPath = FALSE; 226 227 228 ACPI_FUNCTION_NAME (OptBuildShortestPath); 229 230 231 ScopeInfo.Scope.Node = CurrentNode; 232 233 /* 234 * Determine the maximum number of NameSegs that the Target and Current paths 235 * can possibly have in common. (To optimize, we have to have at least 1) 236 * 237 * Note: The external NamePath string lengths are always a multiple of 5 238 * (ACPI_NAME_SIZE + separator) 239 */ 240 MaxCommonSegments = TargetPath->Length / ACPI_PATH_SEGMENT_LENGTH; 241 if (CurrentPath->Length < TargetPath->Length) 242 { 243 MaxCommonSegments = CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH; 244 } 245 246 /* 247 * Determine how many NameSegs the two paths have in common. 248 * (Starting from the root) 249 */ 250 for (NumCommonSegments = 0; 251 NumCommonSegments < MaxCommonSegments; 252 NumCommonSegments++) 253 { 254 /* Compare two single NameSegs */ 255 256 Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1; 257 258 if (!ACPI_COMPARE_NAME ( 259 &(ACPI_CAST_PTR (char, TargetPath->Pointer)) [Index], 260 &(ACPI_CAST_PTR (char, CurrentPath->Pointer)) [Index])) 261 { 262 /* Mismatch */ 263 264 break; 265 } 266 } 267 268 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " COMMON: %u", 269 NumCommonSegments)); 270 271 /* There must be at least 1 common NameSeg in order to optimize */ 272 273 if (NumCommonSegments == 0) 274 { 275 return (AE_NOT_FOUND); 276 } 277 278 if (NumCommonSegments == MaxCommonSegments) 279 { 280 if (CurrentPath->Length == TargetPath->Length) 281 { 282 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SAME PATH")); 283 return (AE_NOT_FOUND); 284 } 285 else 286 { 287 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SUBPATH")); 288 SubPath = TRUE; 289 } 290 } 291 292 /* Determine how many prefix Carats are required */ 293 294 NumCarats = (CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH) - 295 NumCommonSegments; 296 297 /* 298 * Construct a new target string 299 */ 300 NewPathExternal = 301 ACPI_ALLOCATE_ZEROED (TargetPath->Length + NumCarats + 1); 302 303 /* Insert the Carats into the Target string */ 304 305 for (i = 0; i < NumCarats; i++) 306 { 307 NewPathExternal[i] = AML_PARENT_PREFIX; 308 } 309 310 /* 311 * Copy only the necessary (optimal) segments from the original 312 * target string 313 */ 314 Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1; 315 316 /* Special handling for exact subpath in a name declaration */ 317 318 if (IsDeclaration && SubPath && 319 (CurrentPath->Length > TargetPath->Length)) 320 { 321 /* 322 * The current path is longer than the target, and the target is a 323 * subpath of the current path. We must include one more NameSeg of 324 * the target path 325 */ 326 Index -= ACPI_PATH_SEGMENT_LENGTH; 327 328 /* Special handling for Scope() operator */ 329 330 if (Op->Asl.AmlOpcode == AML_SCOPE_OP) 331 { 332 NewPathExternal[i] = AML_PARENT_PREFIX; 333 i++; 334 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "(EXTRA ^)")); 335 } 336 } 337 338 /* Make sure we haven't gone off the end of the target path */ 339 340 if (Index > TargetPath->Length) 341 { 342 Index = TargetPath->Length; 343 } 344 345 strcpy (&NewPathExternal[i], 346 &(ACPI_CAST_PTR (char, TargetPath->Pointer))[Index]); 347 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " %-24s", NewPathExternal)); 348 349 /* 350 * Internalize the new target string and check it against the original 351 * string to make sure that this is in fact an optimization. If the 352 * original string is already optimal, there is no point in continuing. 353 */ 354 Status = AcpiNsInternalizeName (NewPathExternal, &NewPathInternal); 355 if (ACPI_FAILURE (Status)) 356 { 357 AslCoreSubsystemError (Op, Status, "Internalizing new NamePath", 358 ASL_NO_ABORT); 359 goto Cleanup; 360 } 361 362 if (strlen (NewPathInternal) >= AmlNameStringLength) 363 { 364 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 365 " NOT SHORTER (New %u old %u)", 366 (UINT32) strlen (NewPathInternal), 367 (UINT32) AmlNameStringLength)); 368 369 ACPI_FREE (NewPathInternal); 370 Status = AE_NOT_FOUND; 371 goto Cleanup; 372 } 373 374 /* 375 * Check to make sure that the optimization finds the node we are 376 * looking for. This is simply a sanity check on the new 377 * path that has been created. 378 */ 379 Status = AcpiNsLookup (&ScopeInfo, NewPathInternal, 380 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 381 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 382 if (ACPI_SUCCESS (Status)) 383 { 384 /* Found the namepath, but make sure the node is correct */ 385 386 if (Node == TargetNode) 387 { 388 /* The lookup matched the node, accept this optimization */ 389 390 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 391 Op, NewPathExternal); 392 *ReturnNewPath = NewPathInternal; 393 } 394 else 395 { 396 /* Node is not correct, do not use this optimization */ 397 398 Status = AE_NOT_FOUND; 399 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** WRONG NODE")); 400 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 401 "Not using optimized name - found wrong node"); 402 } 403 } 404 else 405 { 406 /* The lookup failed, we obviously cannot use this optimization */ 407 408 ACPI_FREE (NewPathInternal); 409 410 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** NOT FOUND")); 411 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 412 "Not using optimized name - did not find node"); 413 } 414 415 Cleanup: 416 417 ACPI_FREE (NewPathExternal); 418 return (Status); 419 } 420 421 422 /******************************************************************************* 423 * 424 * FUNCTION: OptOptimizeNameDeclaration 425 * 426 * PARAMETERS: Op - Current parser op 427 * WalkState - Current state 428 * CurrentNode - Where we are in the namespace 429 * AmlNameString - Unoptimized namepath 430 * NewPath - Where the optimized path is returned 431 * 432 * RETURN: Status. AE_OK If path is optimized 433 * 434 * DESCRIPTION: Perform a simple optimization of removing an extraneous 435 * backslash prefix if we are already at the root scope. 436 * 437 ******************************************************************************/ 438 439 static ACPI_STATUS 440 OptOptimizeNameDeclaration ( 441 ACPI_PARSE_OBJECT *Op, 442 ACPI_WALK_STATE *WalkState, 443 ACPI_NAMESPACE_NODE *CurrentNode, 444 ACPI_NAMESPACE_NODE *TargetNode, 445 char *AmlNameString, 446 char **NewPath) 447 { 448 ACPI_STATUS Status; 449 char *NewPathExternal; 450 ACPI_NAMESPACE_NODE *Node; 451 452 453 ACPI_FUNCTION_TRACE (OptOptimizeNameDeclaration); 454 455 456 if (((CurrentNode == AcpiGbl_RootNode) || 457 (Op->Common.Parent->Asl.ParseOpcode == PARSEOP_DEFINITION_BLOCK)) && 458 (ACPI_IS_ROOT_PREFIX (AmlNameString[0]))) 459 { 460 /* 461 * The current scope is the root, and the namepath has a root prefix 462 * that is therefore extraneous. Remove it. 463 */ 464 *NewPath = &AmlNameString[1]; 465 466 /* Debug output */ 467 468 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, *NewPath, 469 NULL, &NewPathExternal); 470 if (ACPI_FAILURE (Status)) 471 { 472 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", 473 ASL_NO_ABORT); 474 return (Status); 475 } 476 477 /* 478 * Check to make sure that the optimization finds the node we are 479 * looking for. This is simply a sanity check on the new 480 * path that has been created. 481 * 482 * We know that we are at the root, so NULL is used for the scope. 483 */ 484 Status = AcpiNsLookup (NULL, *NewPath, 485 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 486 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 487 if (ACPI_SUCCESS (Status)) 488 { 489 /* Found the namepath, but make sure the node is correct */ 490 491 if (Node == TargetNode) 492 { 493 /* The lookup matched the node, accept this optimization */ 494 495 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 496 Op, NewPathExternal); 497 498 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 499 "AT ROOT: %-24s", NewPathExternal)); 500 } 501 else 502 { 503 /* Node is not correct, do not use this optimization */ 504 505 Status = AE_NOT_FOUND; 506 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 507 " ***** WRONG NODE")); 508 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 509 "Not using optimized name - found wrong node"); 510 } 511 } 512 else 513 { 514 /* The lookup failed, we obviously cannot use this optimization */ 515 516 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 517 " ***** NOT FOUND")); 518 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 519 "Not using optimized name - did not find node"); 520 } 521 522 ACPI_FREE (NewPathExternal); 523 return (Status); 524 } 525 526 /* Could not optimize */ 527 528 return (AE_NOT_FOUND); 529 } 530 531 532 /******************************************************************************* 533 * 534 * FUNCTION: OptOptimizeNamePath 535 * 536 * PARAMETERS: Op - Current parser op 537 * Flags - Opcode info flags 538 * WalkState - Current state 539 * AmlNameString - Unoptimized namepath 540 * TargetNode - Node to which AmlNameString refers 541 * 542 * RETURN: None. If path is optimized, the Op is updated with new path 543 * 544 * DESCRIPTION: Optimize a Named Declaration or Reference to the minimal length. 545 * Must take into account both the current location in the 546 * namespace and the actual reference path. 547 * 548 ******************************************************************************/ 549 550 void 551 OptOptimizeNamePath ( 552 ACPI_PARSE_OBJECT *Op, 553 UINT32 Flags, 554 ACPI_WALK_STATE *WalkState, 555 char *AmlNameString, 556 ACPI_NAMESPACE_NODE *TargetNode) 557 { 558 ACPI_STATUS Status; 559 ACPI_BUFFER TargetPath; 560 ACPI_BUFFER CurrentPath; 561 ACPI_SIZE AmlNameStringLength; 562 ACPI_NAMESPACE_NODE *CurrentNode; 563 char *ExternalNameString; 564 char *NewPath = NULL; 565 ACPI_SIZE HowMuchShorter; 566 ACPI_PARSE_OBJECT *NextOp; 567 568 569 ACPI_FUNCTION_TRACE (OptOptimizeNamePath); 570 571 572 /* This is an optional optimization */ 573 574 if (!Gbl_ReferenceOptimizationFlag) 575 { 576 return_VOID; 577 } 578 579 /* Various required items */ 580 581 if (!TargetNode || !WalkState || !AmlNameString || !Op->Common.Parent) 582 { 583 return_VOID; 584 } 585 586 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 587 "PATH OPTIMIZE: Line %5d ParentOp [%12.12s] ThisOp [%12.12s] ", 588 Op->Asl.LogicalLineNumber, 589 AcpiPsGetOpcodeName (Op->Common.Parent->Common.AmlOpcode), 590 AcpiPsGetOpcodeName (Op->Common.AmlOpcode))); 591 592 if (!(Flags & (AML_NAMED | AML_CREATE))) 593 { 594 if (Op->Asl.CompileFlags & NODE_IS_NAME_DECLARATION) 595 { 596 /* We don't want to fuss with actual name declaration nodes here */ 597 598 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 599 "******* NAME DECLARATION\n")); 600 return_VOID; 601 } 602 } 603 604 /* 605 * The original path must be longer than one NameSeg (4 chars) for there 606 * to be any possibility that it can be optimized to a shorter string 607 */ 608 AmlNameStringLength = strlen (AmlNameString); 609 if (AmlNameStringLength <= ACPI_NAME_SIZE) 610 { 611 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 612 "NAMESEG %4.4s\n", AmlNameString)); 613 return_VOID; 614 } 615 616 /* 617 * We need to obtain the node that represents the current scope -- where 618 * we are right now in the namespace. We will compare this path 619 * against the Namepath, looking for commonality. 620 */ 621 CurrentNode = AcpiGbl_RootNode; 622 if (WalkState->ScopeInfo) 623 { 624 CurrentNode = WalkState->ScopeInfo->Scope.Node; 625 } 626 627 if (Flags & (AML_NAMED | AML_CREATE)) 628 { 629 /* This is the declaration of a new name */ 630 631 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "NAME\n")); 632 633 /* 634 * The node of interest is the parent of this node (the containing 635 * scope). The actual namespace node may be up more than one level 636 * of parse op or it may not exist at all (if we traverse back 637 * up to the root.) 638 */ 639 NextOp = Op->Asl.Parent; 640 while (NextOp && (!NextOp->Asl.Node)) 641 { 642 NextOp = NextOp->Asl.Parent; 643 } 644 645 if (NextOp && NextOp->Asl.Node) 646 { 647 CurrentNode = NextOp->Asl.Node; 648 } 649 else 650 { 651 CurrentNode = AcpiGbl_RootNode; 652 } 653 } 654 else 655 { 656 /* This is a reference to an existing named object */ 657 658 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "REFERENCE\n")); 659 } 660 661 /* 662 * Obtain the full paths to the two nodes that we are interested in 663 * (Target and current namespace location) in external 664 * format -- something we can easily manipulate 665 */ 666 TargetPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 667 Status = AcpiNsHandleToPathname (TargetNode, &TargetPath, FALSE); 668 if (ACPI_FAILURE (Status)) 669 { 670 AslCoreSubsystemError (Op, Status, "Getting Target NamePath", 671 ASL_NO_ABORT); 672 return_VOID; 673 } 674 675 TargetPath.Length--; /* Subtract one for null terminator */ 676 677 /* CurrentPath is the path to this scope (where we are in the namespace) */ 678 679 CurrentPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 680 Status = AcpiNsHandleToPathname (CurrentNode, &CurrentPath, FALSE); 681 if (ACPI_FAILURE (Status)) 682 { 683 AslCoreSubsystemError (Op, Status, "Getting Current NamePath", 684 ASL_NO_ABORT); 685 return_VOID; 686 } 687 688 CurrentPath.Length--; /* Subtract one for null terminator */ 689 690 /* Debug output only */ 691 692 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, AmlNameString, 693 NULL, &ExternalNameString); 694 if (ACPI_FAILURE (Status)) 695 { 696 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", 697 ASL_NO_ABORT); 698 return_VOID; 699 } 700 701 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 702 "CURRENT SCOPE: (%2u) %-37s FULL PATH TO NAME: (%2u) %-32s ACTUAL AML:%-32s\n", 703 (UINT32) CurrentPath.Length, (char *) CurrentPath.Pointer, 704 (UINT32) TargetPath.Length, (char *) TargetPath.Pointer, 705 ExternalNameString)); 706 707 ACPI_FREE (ExternalNameString); 708 709 /* 710 * Attempt an optmization depending on the type of namepath 711 */ 712 if (Flags & (AML_NAMED | AML_CREATE)) 713 { 714 /* 715 * This is a named opcode and the namepath is a name declaration, not 716 * a reference. 717 */ 718 Status = OptOptimizeNameDeclaration (Op, WalkState, CurrentNode, 719 TargetNode, AmlNameString, &NewPath); 720 if (ACPI_FAILURE (Status)) 721 { 722 /* 723 * 2) now attempt to 724 * optimize the namestring with carats (up-arrow) 725 */ 726 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 727 TargetNode, &CurrentPath, &TargetPath, 728 AmlNameStringLength, 1, &NewPath); 729 } 730 } 731 else 732 { 733 /* 734 * This is a reference to an existing named object 735 * 736 * 1) Check if search-to-root can be utilized using the last 737 * NameSeg of the NamePath 738 */ 739 Status = OptSearchToRoot (Op, WalkState, CurrentNode, 740 TargetNode, &TargetPath, &NewPath); 741 if (ACPI_FAILURE (Status)) 742 { 743 /* 744 * 2) Search-to-root could not be used, now attempt to 745 * optimize the namestring with carats (up-arrow) 746 */ 747 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 748 TargetNode, &CurrentPath, &TargetPath, 749 AmlNameStringLength, 0, &NewPath); 750 } 751 } 752 753 /* 754 * Success from above indicates that the NamePath was successfully 755 * optimized. We need to update the parse op with the new name 756 */ 757 if (ACPI_SUCCESS (Status)) 758 { 759 HowMuchShorter = (AmlNameStringLength - strlen (NewPath)); 760 OptTotal += HowMuchShorter; 761 762 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 763 " REDUCED BY %2u (TOTAL SAVED %2u)", 764 (UINT32) HowMuchShorter, OptTotal)); 765 766 if (Flags & AML_NAMED) 767 { 768 if (Op->Asl.AmlOpcode == AML_ALIAS_OP) 769 { 770 /* 771 * ALIAS is the only oddball opcode, the name declaration 772 * (alias name) is the second operand 773 */ 774 Op->Asl.Child->Asl.Next->Asl.Value.String = NewPath; 775 Op->Asl.Child->Asl.Next->Asl.AmlLength = strlen (NewPath); 776 } 777 else 778 { 779 Op->Asl.Child->Asl.Value.String = NewPath; 780 Op->Asl.Child->Asl.AmlLength = strlen (NewPath); 781 } 782 } 783 else if (Flags & AML_CREATE) 784 { 785 /* Name must appear as the last parameter */ 786 787 NextOp = Op->Asl.Child; 788 while (!(NextOp->Asl.CompileFlags & NODE_IS_NAME_DECLARATION)) 789 { 790 NextOp = NextOp->Asl.Next; 791 } 792 /* Update the parse node with the new NamePath */ 793 794 NextOp->Asl.Value.String = NewPath; 795 NextOp->Asl.AmlLength = strlen (NewPath); 796 } 797 else 798 { 799 /* Update the parse node with the new NamePath */ 800 801 Op->Asl.Value.String = NewPath; 802 Op->Asl.AmlLength = strlen (NewPath); 803 } 804 } 805 else 806 { 807 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ALREADY OPTIMAL")); 808 } 809 810 /* Cleanup path buffers */ 811 812 ACPI_FREE (TargetPath.Pointer); 813 ACPI_FREE (CurrentPath.Pointer); 814 815 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "\n")); 816 return_VOID; 817 } 818