1 /****************************************************************************** 2 * 3 * Module Name: aslopt- Compiler optimizations 4 * $Revision: 1.26 $ 5 * 6 *****************************************************************************/ 7 8 /****************************************************************************** 9 * 10 * 1. Copyright Notice 11 * 12 * Some or all of this work - Copyright (c) 1999 - 2007, Intel Corp. 13 * All rights reserved. 14 * 15 * 2. License 16 * 17 * 2.1. This is your license from Intel Corp. under its intellectual property 18 * rights. You may have additional license terms from the party that provided 19 * you this software, covering your right to use that party's intellectual 20 * property rights. 21 * 22 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 23 * copy of the source code appearing in this file ("Covered Code") an 24 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 25 * base code distributed originally by Intel ("Original Intel Code") to copy, 26 * make derivatives, distribute, use and display any portion of the Covered 27 * Code in any form, with the right to sublicense such rights; and 28 * 29 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 30 * license (with the right to sublicense), under only those claims of Intel 31 * patents that are infringed by the Original Intel Code, to make, use, sell, 32 * offer to sell, and import the Covered Code and derivative works thereof 33 * solely to the minimum extent necessary to exercise the above copyright 34 * license, and in no event shall the patent license extend to any additions 35 * to or modifications of the Original Intel Code. No other license or right 36 * is granted directly or by implication, estoppel or otherwise; 37 * 38 * The above copyright and patent license is granted only if the following 39 * conditions are met: 40 * 41 * 3. Conditions 42 * 43 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 44 * Redistribution of source code of any substantial portion of the Covered 45 * Code or modification with rights to further distribute source must include 46 * the above Copyright Notice, the above License, this list of Conditions, 47 * and the following Disclaimer and Export Compliance provision. In addition, 48 * Licensee must cause all Covered Code to which Licensee contributes to 49 * contain a file documenting the changes Licensee made to create that Covered 50 * Code and the date of any change. Licensee must include in that file the 51 * documentation of any changes made by any predecessor Licensee. Licensee 52 * must include a prominent statement that the modification is derived, 53 * directly or indirectly, from Original Intel Code. 54 * 55 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 56 * Redistribution of source code of any substantial portion of the Covered 57 * Code or modification without rights to further distribute source must 58 * include the following Disclaimer and Export Compliance provision in the 59 * documentation and/or other materials provided with distribution. In 60 * addition, Licensee may not authorize further sublicense of source of any 61 * portion of the Covered Code, and must include terms to the effect that the 62 * license from Licensee to its licensee is limited to the intellectual 63 * property embodied in the software Licensee provides to its licensee, and 64 * not to intellectual property embodied in modifications its licensee may 65 * make. 66 * 67 * 3.3. Redistribution of Executable. Redistribution in executable form of any 68 * substantial portion of the Covered Code or modification must reproduce the 69 * above Copyright Notice, and the following Disclaimer and Export Compliance 70 * provision in the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3.4. Intel retains all right, title, and interest in and to the Original 74 * Intel Code. 75 * 76 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 77 * Intel shall be used in advertising or otherwise to promote the sale, use or 78 * other dealings in products derived from or relating to the Covered Code 79 * without prior written authorization from Intel. 80 * 81 * 4. Disclaimer and Export Compliance 82 * 83 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 84 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 85 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 86 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 87 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 88 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 89 * PARTICULAR PURPOSE. 90 * 91 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 92 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 93 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 94 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 95 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 96 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 97 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 98 * LIMITED REMEDY. 99 * 100 * 4.3. Licensee shall not export, either directly or indirectly, any of this 101 * software or system incorporating such software without first obtaining any 102 * required license or other approval from the U. S. Department of Commerce or 103 * any other agency or department of the United States Government. In the 104 * event Licensee exports any such software from the United States or 105 * re-exports any such software from a foreign destination, Licensee shall 106 * ensure that the distribution and export/re-export of the software is in 107 * compliance with all laws, regulations, orders, or other restrictions of the 108 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 109 * any of its subsidiaries will export/re-export any technical data, process, 110 * software, or service, directly or indirectly, to any country for which the 111 * United States government or any agency thereof requires an export license, 112 * other governmental approval, or letter of assurance, without first obtaining 113 * such license, approval or letter. 114 * 115 *****************************************************************************/ 116 117 118 #include <contrib/dev/acpica/compiler/aslcompiler.h> 119 #include "aslcompiler.y.h" 120 121 #include <contrib/dev/acpica/acparser.h> 122 #include <contrib/dev/acpica/amlcode.h> 123 #include <contrib/dev/acpica/acnamesp.h> 124 125 126 #define _COMPONENT ACPI_COMPILER 127 ACPI_MODULE_NAME ("aslopt") 128 129 130 static UINT32 OptTotal = 0; 131 132 /* Local prototypes */ 133 134 static ACPI_STATUS 135 OptSearchToRoot ( 136 ACPI_PARSE_OBJECT *Op, 137 ACPI_WALK_STATE *WalkState, 138 ACPI_NAMESPACE_NODE *CurrentNode, 139 ACPI_NAMESPACE_NODE *TargetNode, 140 ACPI_BUFFER *TargetPath, 141 char **NewPath); 142 143 static ACPI_STATUS 144 OptBuildShortestPath ( 145 ACPI_PARSE_OBJECT *Op, 146 ACPI_WALK_STATE *WalkState, 147 ACPI_NAMESPACE_NODE *CurrentNode, 148 ACPI_NAMESPACE_NODE *TargetNode, 149 ACPI_BUFFER *CurrentPath, 150 ACPI_BUFFER *TargetPath, 151 ACPI_SIZE AmlNameStringLength, 152 UINT8 IsDeclaration, 153 char **ReturnNewPath); 154 155 static ACPI_STATUS 156 OptOptimizeNameDeclaration ( 157 ACPI_PARSE_OBJECT *Op, 158 ACPI_WALK_STATE *WalkState, 159 ACPI_NAMESPACE_NODE *CurrentNode, 160 ACPI_NAMESPACE_NODE *TargetNode, 161 char *AmlNameString, 162 char **NewPath); 163 164 165 /******************************************************************************* 166 * 167 * FUNCTION: OptSearchToRoot 168 * 169 * PARAMETERS: Op - Current parser op 170 * WalkState - Current state 171 * CurrentNode - Where we are in the namespace 172 * TargetNode - Node to which we are referring 173 * TargetPath - External full path to the target node 174 * NewPath - Where the optimized path is returned 175 * 176 * RETURN: Status 177 * 178 * DESCRIPTION: Attempt to optimize a reference to a single 4-character ACPI 179 * name utilizing the search-to-root name resolution algorithm 180 * that is used by AML interpreters. 181 * 182 ******************************************************************************/ 183 184 static ACPI_STATUS 185 OptSearchToRoot ( 186 ACPI_PARSE_OBJECT *Op, 187 ACPI_WALK_STATE *WalkState, 188 ACPI_NAMESPACE_NODE *CurrentNode, 189 ACPI_NAMESPACE_NODE *TargetNode, 190 ACPI_BUFFER *TargetPath, 191 char **NewPath) 192 { 193 ACPI_NAMESPACE_NODE *Node; 194 ACPI_GENERIC_STATE ScopeInfo; 195 ACPI_STATUS Status; 196 char *Path; 197 198 199 ACPI_FUNCTION_NAME (OptSearchToRoot); 200 201 202 /* 203 * Check if search-to-root can be utilized. Use the last NameSeg of 204 * the NamePath and 1) See if can be found and 2) If found, make 205 * sure that it is the same node that we want. If there is another 206 * name in the search path before the one we want, the nodes will 207 * not match, and we cannot use this optimization. 208 */ 209 Path = &(((char *) TargetPath->Pointer)[TargetPath->Length - 210 ACPI_NAME_SIZE]), 211 ScopeInfo.Scope.Node = CurrentNode; 212 213 /* Lookup the NameSeg using SEARCH_PARENT (search-to-root) */ 214 215 Status = AcpiNsLookup (&ScopeInfo, Path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 216 ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE, 217 WalkState, &(Node)); 218 if (ACPI_FAILURE (Status)) 219 { 220 return (Status); 221 } 222 223 /* 224 * We found the name, but we must check to make sure that the node 225 * matches. Otherwise, there is another identical name in the search 226 * path that precludes the use of this optimization. 227 */ 228 if (Node != TargetNode) 229 { 230 /* 231 * This means that another object with the same name was found first, 232 * and we cannot use this optimization. 233 */ 234 return (AE_NOT_FOUND); 235 } 236 237 /* Found the node, we can use this optimization */ 238 239 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 240 "NAMESEG: %-24s", Path)); 241 242 /* We must allocate a new string for the name (TargetPath gets deleted) */ 243 244 *NewPath = ACPI_ALLOCATE_ZEROED (ACPI_NAME_SIZE + 1); 245 ACPI_STRCPY (*NewPath, Path); 246 247 if (ACPI_STRNCMP (*NewPath, "_T_", 3)) 248 { 249 AslError (ASL_OPTIMIZATION, ASL_MSG_SINGLE_NAME_OPTIMIZATION, Op, 250 *NewPath); 251 } 252 253 return (AE_OK); 254 } 255 256 257 /******************************************************************************* 258 * 259 * FUNCTION: OptBuildShortestPath 260 * 261 * PARAMETERS: Op - Current parser op 262 * WalkState - Current state 263 * CurrentNode - Where we are in the namespace 264 * TargetNode - Node to which we are referring 265 * CurrentPath - External full path to the current node 266 * TargetPath - External full path to the target node 267 * AmlNameStringLength - Length of the original namepath 268 * IsDeclaration - TRUE for declaration, FALSE for reference 269 * ReturnNewPath - Where the optimized path is returned 270 * 271 * RETURN: Status 272 * 273 * DESCRIPTION: Build an optimal NamePath using carats 274 * 275 ******************************************************************************/ 276 277 static ACPI_STATUS 278 OptBuildShortestPath ( 279 ACPI_PARSE_OBJECT *Op, 280 ACPI_WALK_STATE *WalkState, 281 ACPI_NAMESPACE_NODE *CurrentNode, 282 ACPI_NAMESPACE_NODE *TargetNode, 283 ACPI_BUFFER *CurrentPath, 284 ACPI_BUFFER *TargetPath, 285 ACPI_SIZE AmlNameStringLength, 286 UINT8 IsDeclaration, 287 char **ReturnNewPath) 288 { 289 UINT32 NumCommonSegments; 290 UINT32 MaxCommonSegments; 291 ACPI_NATIVE_UINT Index; 292 UINT32 NumCarats; 293 ACPI_NATIVE_UINT i; 294 char *NewPath; 295 char *NewPathExternal; 296 ACPI_NAMESPACE_NODE *Node; 297 ACPI_GENERIC_STATE ScopeInfo; 298 ACPI_STATUS Status; 299 BOOLEAN SubPath = FALSE; 300 301 302 ACPI_FUNCTION_NAME (OptBuildShortestPath); 303 304 305 ScopeInfo.Scope.Node = CurrentNode; 306 307 /* 308 * Determine the maximum number of NameSegs that the Target and Current paths 309 * can possibly have in common. (To optimize, we have to have at least 1) 310 * 311 * Note: The external NamePath string lengths are always a multiple of 5 312 * (ACPI_NAME_SIZE + separator) 313 */ 314 MaxCommonSegments = TargetPath->Length / ACPI_PATH_SEGMENT_LENGTH; 315 if (CurrentPath->Length < TargetPath->Length) 316 { 317 MaxCommonSegments = CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH; 318 } 319 320 /* 321 * Determine how many NameSegs the two paths have in common. 322 * (Starting from the root) 323 */ 324 for (NumCommonSegments = 0; 325 NumCommonSegments < MaxCommonSegments; 326 NumCommonSegments++) 327 { 328 /* Compare two single NameSegs */ 329 330 if (ACPI_STRNCMP ( 331 &((char *) TargetPath->Pointer)[(NumCommonSegments * 332 ACPI_PATH_SEGMENT_LENGTH) + 1], 333 &((char *) CurrentPath->Pointer)[(NumCommonSegments * 334 ACPI_PATH_SEGMENT_LENGTH) + 1], 335 ACPI_NAME_SIZE)) 336 { 337 /* Mismatch */ 338 339 break; 340 } 341 } 342 343 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " COMMON: %d", 344 NumCommonSegments)); 345 346 /* There must be at least 1 common NameSeg in order to optimize */ 347 348 if (NumCommonSegments == 0) 349 { 350 return (AE_NOT_FOUND); 351 } 352 353 if (NumCommonSegments == MaxCommonSegments) 354 { 355 if (CurrentPath->Length == TargetPath->Length) 356 { 357 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SAME PATH")); 358 return (AE_NOT_FOUND); 359 } 360 else 361 { 362 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SUBPATH")); 363 SubPath = TRUE; 364 } 365 } 366 367 /* Determine how many prefix Carats are required */ 368 369 NumCarats = (CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH) - 370 NumCommonSegments; 371 372 /* 373 * Construct a new target string 374 */ 375 NewPathExternal = ACPI_ALLOCATE_ZEROED ( 376 TargetPath->Length + NumCarats + 1); 377 378 /* Insert the Carats into the Target string */ 379 380 for (i = 0; i < NumCarats; i++) 381 { 382 NewPathExternal[i] = '^'; 383 } 384 385 /* 386 * Copy only the necessary (optimal) segments from the original 387 * target string 388 */ 389 Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1; 390 391 /* Special handling for exact subpath in a name declaration */ 392 393 if (IsDeclaration && SubPath && (CurrentPath->Length > TargetPath->Length)) 394 { 395 /* 396 * The current path is longer than the target, and the target is a 397 * subpath of the current path. We must include one more NameSeg of 398 * the target path 399 */ 400 Index -= ACPI_PATH_SEGMENT_LENGTH; 401 402 /* Special handling for Scope() operator */ 403 404 if (Op->Asl.AmlOpcode == AML_SCOPE_OP) 405 { 406 NewPathExternal[i] = '^'; 407 i++; 408 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "(EXTRA ^)")); 409 } 410 } 411 412 /* Make sure we haven't gone off the end of the target path */ 413 414 if (Index > TargetPath->Length) 415 { 416 Index = TargetPath->Length; 417 } 418 419 ACPI_STRCPY (&NewPathExternal[i], &((char *) TargetPath->Pointer)[Index]); 420 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " %-24s", NewPathExternal)); 421 422 /* 423 * Internalize the new target string and check it against the original 424 * string to make sure that this is in fact an optimization. If the 425 * original string is already optimal, there is no point in continuing. 426 */ 427 Status = AcpiNsInternalizeName (NewPathExternal, &NewPath); 428 if (ACPI_FAILURE (Status)) 429 { 430 AslCoreSubsystemError (Op, Status, "Internalizing new NamePath", 431 ASL_NO_ABORT); 432 ACPI_FREE (NewPathExternal); 433 return (Status); 434 } 435 436 if (ACPI_STRLEN (NewPath) >= AmlNameStringLength) 437 { 438 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 439 " NOT SHORTER (New %u old %u)", 440 ACPI_STRLEN (NewPath), AmlNameStringLength)); 441 ACPI_FREE (NewPathExternal); 442 return (AE_NOT_FOUND); 443 } 444 445 /* 446 * Check to make sure that the optimization finds the node we are 447 * looking for. This is simply a sanity check on the new 448 * path that has been created. 449 */ 450 Status = AcpiNsLookup (&ScopeInfo, NewPath, 451 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 452 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 453 if (ACPI_SUCCESS (Status)) 454 { 455 /* Found the namepath, but make sure the node is correct */ 456 457 if (Node == TargetNode) 458 { 459 /* The lookup matched the node, accept this optimization */ 460 461 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 462 Op, NewPathExternal); 463 *ReturnNewPath = NewPath; 464 } 465 else 466 { 467 /* Node is not correct, do not use this optimization */ 468 469 Status = AE_NOT_FOUND; 470 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** WRONG NODE")); 471 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 472 "Not using optimized name - found wrong node"); 473 } 474 } 475 else 476 { 477 /* The lookup failed, we obviously cannot use this optimization */ 478 479 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** NOT FOUND")); 480 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 481 "Not using optimized name - did not find node"); 482 } 483 484 ACPI_FREE (NewPathExternal); 485 return (Status); 486 } 487 488 489 /******************************************************************************* 490 * 491 * FUNCTION: OptOptimizeNameDeclaration 492 * 493 * PARAMETERS: Op - Current parser op 494 * WalkState - Current state 495 * CurrentNode - Where we are in the namespace 496 * AmlNameString - Unoptimized namepath 497 * NewPath - Where the optimized path is returned 498 * 499 * RETURN: Status. AE_OK If path is optimized 500 * 501 * DESCRIPTION: Perform a simple optimization of removing an extraneous 502 * backslash prefix if we are already at the root scope. 503 * 504 ******************************************************************************/ 505 506 static ACPI_STATUS 507 OptOptimizeNameDeclaration ( 508 ACPI_PARSE_OBJECT *Op, 509 ACPI_WALK_STATE *WalkState, 510 ACPI_NAMESPACE_NODE *CurrentNode, 511 ACPI_NAMESPACE_NODE *TargetNode, 512 char *AmlNameString, 513 char **NewPath) 514 { 515 ACPI_STATUS Status; 516 char *NewPathExternal; 517 ACPI_GENERIC_STATE ScopeInfo; 518 ACPI_NAMESPACE_NODE *Node; 519 520 521 ACPI_FUNCTION_TRACE (OptOptimizeNameDeclaration); 522 523 524 if (((CurrentNode == AcpiGbl_RootNode) || 525 (Op->Common.Parent->Asl.ParseOpcode == PARSEOP_DEFINITIONBLOCK)) && 526 (AmlNameString[0] == '\\')) 527 { 528 /* 529 * The current scope is the root, and the namepath has a root prefix 530 * that is therefore extraneous. Remove it. 531 */ 532 *NewPath = &AmlNameString[1]; 533 534 /* Debug output */ 535 536 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, *NewPath, 537 NULL, &NewPathExternal); 538 if (ACPI_FAILURE (Status)) 539 { 540 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", 541 ASL_NO_ABORT); 542 return (Status); 543 } 544 545 /* 546 * Check to make sure that the optimization finds the node we are 547 * looking for. This is simply a sanity check on the new 548 * path that has been created. 549 */ 550 ScopeInfo.Scope.Node = CurrentNode; 551 Status = AcpiNsLookup (&ScopeInfo, *NewPath, 552 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 553 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 554 if (ACPI_SUCCESS (Status)) 555 { 556 /* Found the namepath, but make sure the node is correct */ 557 558 if (Node == TargetNode) 559 { 560 /* The lookup matched the node, accept this optimization */ 561 562 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 563 Op, NewPathExternal); 564 565 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 566 "AT ROOT: %-24s", NewPathExternal)); 567 } 568 else 569 { 570 /* Node is not correct, do not use this optimization */ 571 572 Status = AE_NOT_FOUND; 573 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 574 " ***** WRONG NODE")); 575 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 576 "Not using optimized name - found wrong node"); 577 } 578 } 579 else 580 { 581 /* The lookup failed, we obviously cannot use this optimization */ 582 583 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 584 " ***** NOT FOUND")); 585 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 586 "Not using optimized name - did not find node"); 587 } 588 589 ACPI_FREE (NewPathExternal); 590 return (Status); 591 } 592 593 /* Could not optimize */ 594 595 return (AE_NOT_FOUND); 596 } 597 598 599 /******************************************************************************* 600 * 601 * FUNCTION: OptOptimizeNamePath 602 * 603 * PARAMETERS: Op - Current parser op 604 * Flags - Opcode info flags 605 * WalkState - Current state 606 * AmlNameString - Unoptimized namepath 607 * TargetNode - Node to which AmlNameString refers 608 * 609 * RETURN: None. If path is optimized, the Op is updated with new path 610 * 611 * DESCRIPTION: Optimize a Named Declaration or Reference to the minimal length. 612 * Must take into account both the current location in the 613 * namespace and the actual reference path. 614 * 615 ******************************************************************************/ 616 617 void 618 OptOptimizeNamePath ( 619 ACPI_PARSE_OBJECT *Op, 620 UINT32 Flags, 621 ACPI_WALK_STATE *WalkState, 622 char *AmlNameString, 623 ACPI_NAMESPACE_NODE *TargetNode) 624 { 625 ACPI_STATUS Status; 626 ACPI_BUFFER TargetPath; 627 ACPI_BUFFER CurrentPath; 628 ACPI_SIZE AmlNameStringLength; 629 ACPI_NAMESPACE_NODE *CurrentNode; 630 char *ExternalNameString; 631 char *NewPath = NULL; 632 ACPI_SIZE HowMuchShorter; 633 ACPI_PARSE_OBJECT *NextOp; 634 635 636 ACPI_FUNCTION_TRACE (OptOptimizeNamePath); 637 638 639 /* This is an optional optimization */ 640 641 if (!Gbl_ReferenceOptimizationFlag) 642 { 643 return_VOID; 644 } 645 646 /* Various required items */ 647 648 if (!TargetNode || !WalkState || !AmlNameString || !Op->Common.Parent) 649 { 650 return_VOID; 651 } 652 653 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "%5d [%12.12s] [%12.12s] ", 654 Op->Asl.LogicalLineNumber, 655 AcpiPsGetOpcodeName (Op->Common.Parent->Common.AmlOpcode), 656 AcpiPsGetOpcodeName (Op->Common.AmlOpcode))); 657 658 if (!(Flags & (AML_NAMED | AML_CREATE))) 659 { 660 if (Op->Asl.CompileFlags & NODE_IS_NAME_DECLARATION) 661 { 662 /* We don't want to fuss with actual name declaration nodes here */ 663 664 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 665 "******* NAME DECLARATION\n")); 666 return_VOID; 667 } 668 } 669 670 /* 671 * The original path must be longer than one NameSeg (4 chars) for there 672 * to be any possibility that it can be optimized to a shorter string 673 */ 674 AmlNameStringLength = ACPI_STRLEN (AmlNameString); 675 if (AmlNameStringLength <= ACPI_NAME_SIZE) 676 { 677 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 678 "NAMESEG %4.4s\n", AmlNameString)); 679 return_VOID; 680 } 681 682 /* 683 * We need to obtain the node that represents the current scope -- where 684 * we are right now in the namespace. We will compare this path 685 * against the Namepath, looking for commonality. 686 */ 687 CurrentNode = AcpiGbl_RootNode; 688 if (WalkState->ScopeInfo) 689 { 690 CurrentNode = WalkState->ScopeInfo->Scope.Node; 691 } 692 693 if (Flags & (AML_NAMED | AML_CREATE)) 694 { 695 /* This is the declaration of a new name */ 696 697 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "NAME")); 698 699 /* 700 * The node of interest is the parent of this node 701 * (the containing scope) 702 */ 703 CurrentNode = Op->Asl.Parent->Asl.Node; 704 if (!CurrentNode) 705 { 706 CurrentNode = AcpiGbl_RootNode; 707 } 708 } 709 else 710 { 711 /* This is a reference to an existing named object */ 712 713 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "REF ")); 714 } 715 716 /* 717 * Obtain the full paths to the two nodes that we are interested in 718 * (Target and current namespace location) in external 719 * format -- something we can easily manipulate 720 */ 721 TargetPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 722 Status = AcpiNsHandleToPathname (TargetNode, &TargetPath); 723 if (ACPI_FAILURE (Status)) 724 { 725 AslCoreSubsystemError (Op, Status, "Getting Target NamePath", 726 ASL_NO_ABORT); 727 return_VOID; 728 } 729 TargetPath.Length--; /* Subtract one for null terminator */ 730 731 /* CurrentPath is the path to this scope (where we are in the namespace) */ 732 733 CurrentPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 734 Status = AcpiNsHandleToPathname (CurrentNode, &CurrentPath); 735 if (ACPI_FAILURE (Status)) 736 { 737 AslCoreSubsystemError (Op, Status, "Getting Current NamePath", 738 ASL_NO_ABORT); 739 return_VOID; 740 } 741 CurrentPath.Length--; /* Subtract one for null terminator */ 742 743 /* Debug output only */ 744 745 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, AmlNameString, 746 NULL, &ExternalNameString); 747 if (ACPI_FAILURE (Status)) 748 { 749 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", 750 ASL_NO_ABORT); 751 return_VOID; 752 } 753 754 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 755 "%37s (%2u) ==> %-32s(%2u) %-32s", 756 (char *) CurrentPath.Pointer, CurrentPath.Length, 757 (char *) TargetPath.Pointer, TargetPath.Length, ExternalNameString)); 758 759 ACPI_FREE (ExternalNameString); 760 761 /* 762 * Attempt an optmization depending on the type of namepath 763 */ 764 if (Flags & (AML_NAMED | AML_CREATE)) 765 { 766 /* 767 * This is a named opcode and the namepath is a name declaration, not 768 * a reference. 769 */ 770 Status = OptOptimizeNameDeclaration (Op, WalkState, CurrentNode, 771 TargetNode, AmlNameString, &NewPath); 772 if (ACPI_FAILURE (Status)) 773 { 774 /* 775 * 2) now attempt to 776 * optimize the namestring with carats (up-arrow) 777 */ 778 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 779 TargetNode, &CurrentPath, &TargetPath, 780 AmlNameStringLength, 1, &NewPath); 781 } 782 } 783 else 784 { 785 /* 786 * This is a reference to an existing named object 787 * 788 * 1) Check if search-to-root can be utilized using the last 789 * NameSeg of the NamePath 790 */ 791 Status = OptSearchToRoot (Op, WalkState, CurrentNode, 792 TargetNode, &TargetPath, &NewPath); 793 if (ACPI_FAILURE (Status)) 794 { 795 /* 796 * 2) Search-to-root could not be used, now attempt to 797 * optimize the namestring with carats (up-arrow) 798 */ 799 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 800 TargetNode, &CurrentPath, &TargetPath, 801 AmlNameStringLength, 0, &NewPath); 802 } 803 } 804 805 /* 806 * Success from above indicates that the NamePath was successfully 807 * optimized. We need to update the parse op with the new name 808 */ 809 if (ACPI_SUCCESS (Status)) 810 { 811 HowMuchShorter = (AmlNameStringLength - ACPI_STRLEN (NewPath)); 812 OptTotal += HowMuchShorter; 813 814 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " REDUCED %2u (%u)", 815 HowMuchShorter, OptTotal)); 816 817 if (Flags & AML_NAMED) 818 { 819 if (Op->Asl.AmlOpcode == AML_ALIAS_OP) 820 { 821 /* 822 * ALIAS is the only oddball opcode, the name declaration 823 * (alias name) is the second operand 824 */ 825 Op->Asl.Child->Asl.Next->Asl.Value.String = NewPath; 826 Op->Asl.Child->Asl.Next->Asl.AmlLength = ACPI_STRLEN (NewPath); 827 } 828 else 829 { 830 Op->Asl.Child->Asl.Value.String = NewPath; 831 Op->Asl.Child->Asl.AmlLength = ACPI_STRLEN (NewPath); 832 } 833 } 834 else if (Flags & AML_CREATE) 835 { 836 /* Name must appear as the last parameter */ 837 838 NextOp = Op->Asl.Child; 839 while (!(NextOp->Asl.CompileFlags & NODE_IS_NAME_DECLARATION)) 840 { 841 NextOp = NextOp->Asl.Next; 842 } 843 /* Update the parse node with the new NamePath */ 844 845 NextOp->Asl.Value.String = NewPath; 846 NextOp->Asl.AmlLength = ACPI_STRLEN (NewPath); 847 } 848 else 849 { 850 /* Update the parse node with the new NamePath */ 851 852 Op->Asl.Value.String = NewPath; 853 Op->Asl.AmlLength = ACPI_STRLEN (NewPath); 854 } 855 } 856 else 857 { 858 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ALREADY OPTIMAL")); 859 } 860 861 /* Cleanup path buffers */ 862 863 ACPI_FREE (TargetPath.Pointer); 864 ACPI_FREE (CurrentPath.Pointer); 865 866 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "\n")); 867 return_VOID; 868 } 869 870