1 /****************************************************************************** 2 * 3 * Module Name: aslopt- Compiler optimizations 4 * $Revision: 16 $ 5 * 6 *****************************************************************************/ 7 8 /****************************************************************************** 9 * 10 * 1. Copyright Notice 11 * 12 * Some or all of this work - Copyright (c) 1999 - 2004, 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 "aslcompiler.h" 119 #include "aslcompiler.y.h" 120 121 #include "acparser.h" 122 #include "amlcode.h" 123 #include "acnamesp.h" 124 125 126 #define _COMPONENT ACPI_COMPILER 127 ACPI_MODULE_NAME ("aslopt") 128 129 130 UINT32 OptTotal = 0; 131 132 133 /******************************************************************************* 134 * 135 * FUNCTION: OptSearchToRoot 136 * 137 * PARAMETERS: Op - Current parser op 138 * WalkState - Current state 139 * CurrentNode - Where we are in the namespace 140 * TargetNode - Node to which we are referring 141 * TargetPath - External full path to the target node 142 * NewPath - Where the optimized path is returned 143 * 144 * RETURN: Status 145 * 146 * DESCRIPTION: Attempt to optimize a reference to a single 4-character ACPI 147 * name utilizing the search-to-root name resolution algorithm 148 * that is used by AML interpreters. 149 * 150 ******************************************************************************/ 151 152 ACPI_STATUS 153 OptSearchToRoot ( 154 ACPI_PARSE_OBJECT *Op, 155 ACPI_WALK_STATE *WalkState, 156 ACPI_NAMESPACE_NODE *CurrentNode, 157 ACPI_NAMESPACE_NODE *TargetNode, 158 ACPI_BUFFER *TargetPath, 159 char **NewPath) 160 { 161 ACPI_NAMESPACE_NODE *Node; 162 ACPI_GENERIC_STATE ScopeInfo; 163 ACPI_STATUS Status; 164 char *Path; 165 166 167 ACPI_FUNCTION_NAME ("OptSearchToRoot"); 168 169 170 /* 171 * Check if search-to-root can be utilized. Use the last NameSeg of 172 * the NamePath and 1) See if can be found and 2) If found, make 173 * sure that it is the same node that we want. If there is another 174 * name in the search path before the one we want, the nodes will 175 * not match, and we cannot use this optimization. 176 */ 177 Path = &(((char *) TargetPath->Pointer)[TargetPath->Length - ACPI_NAME_SIZE]), 178 ScopeInfo.Scope.Node = CurrentNode; 179 180 /* Lookup the NameSeg using SEARCH_PARENT (search-to-root) */ 181 182 Status = AcpiNsLookup (&ScopeInfo, Path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 183 ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE, 184 WalkState, &(Node)); 185 if (ACPI_FAILURE (Status)) 186 { 187 return (Status); 188 } 189 190 /* 191 * We found the name, but we must check to make sure that the node 192 * matches. Otherwise, there is another identical name in the search 193 * path that precludes the use of this optimization. 194 */ 195 if (Node != TargetNode) 196 { 197 /* 198 * This means that another object with the same name was found first, 199 * and we cannot use this optimization. 200 */ 201 return (AE_NOT_FOUND); 202 } 203 204 /* Found the node, we can use this optimization */ 205 206 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 207 "NAMESEG: %-24s", Path)); 208 209 /* We must allocate a new string for the name (TargetPath gets deleted) */ 210 211 *NewPath = ACPI_MEM_CALLOCATE (ACPI_NAME_SIZE + 1); 212 ACPI_STRCPY (*NewPath, Path); 213 214 if (ACPI_STRNCMP (*NewPath, "_T_", 3)) 215 { 216 AslError (ASL_OPTIMIZATION, ASL_MSG_SINGLE_NAME_OPTIMIZATION, Op, 217 *NewPath); 218 } 219 220 return (AE_OK); 221 } 222 223 224 /******************************************************************************* 225 * 226 * FUNCTION: OptBuildShortestPath 227 * 228 * PARAMETERS: Op - Current parser op 229 * WalkState - Current state 230 * CurrentNode - Where we are in the namespace 231 * TargetNode - Node to which we are referring 232 * CurrentPath - External full path to the current node 233 * TargetPath - External full path to the target node 234 * AmlNameStringLength - Length of the original namepath 235 * IsDeclaration - TRUE for declaration, FALSE for reference 236 * ReturnNewPath - Where the optimized path is returned 237 * 238 * RETURN: Status 239 * 240 * DESCRIPTION: Build an optimal NamePath using carats 241 * 242 ******************************************************************************/ 243 244 ACPI_STATUS 245 OptBuildShortestPath ( 246 ACPI_PARSE_OBJECT *Op, 247 ACPI_WALK_STATE *WalkState, 248 ACPI_NAMESPACE_NODE *CurrentNode, 249 ACPI_NAMESPACE_NODE *TargetNode, 250 ACPI_BUFFER *CurrentPath, 251 ACPI_BUFFER *TargetPath, 252 ACPI_SIZE AmlNameStringLength, 253 UINT8 IsDeclaration, 254 char **ReturnNewPath) 255 { 256 UINT32 NumCommonSegments; 257 UINT32 MaxCommonSegments; 258 ACPI_NATIVE_UINT Index; 259 UINT32 NumCarats; 260 ACPI_NATIVE_UINT i; 261 char *NewPath; 262 char *NewPathExternal; 263 ACPI_NAMESPACE_NODE *Node; 264 ACPI_GENERIC_STATE ScopeInfo; 265 ACPI_STATUS Status; 266 BOOLEAN SubPath = FALSE; 267 268 269 ACPI_FUNCTION_NAME ("OptBuildShortestPath"); 270 271 272 ScopeInfo.Scope.Node = CurrentNode; 273 274 /* 275 * Determine the maximum number of NameSegs that the Target and Current paths 276 * can possibly have in common. (To optimize, we have to have at least 1) 277 * 278 * Note: The external NamePath string lengths are always a multiple of 5 279 * (ACPI_NAME_SIZE + separator) 280 */ 281 MaxCommonSegments = TargetPath->Length / ACPI_PATH_SEGMENT_LENGTH; 282 if (CurrentPath->Length < TargetPath->Length) 283 { 284 MaxCommonSegments = CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH; 285 } 286 287 /* 288 * Determine how many NameSegs the two paths have in common. 289 * (Starting from the root) 290 */ 291 for (NumCommonSegments = 0; 292 NumCommonSegments < MaxCommonSegments; 293 NumCommonSegments++) 294 { 295 /* Compare two single NameSegs */ 296 297 if (ACPI_STRNCMP ( 298 &((char *) TargetPath->Pointer)[(NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1], 299 &((char *) CurrentPath->Pointer)[(NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1], 300 ACPI_NAME_SIZE)) 301 { 302 /* Mismatch */ 303 304 break; 305 } 306 } 307 308 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " COMMON: %d", NumCommonSegments)); 309 310 /* There must be at least 1 common NameSeg in order to optimize */ 311 312 if (NumCommonSegments == 0) 313 { 314 return (AE_NOT_FOUND); 315 } 316 317 if (NumCommonSegments == MaxCommonSegments) 318 { 319 if (CurrentPath->Length == TargetPath->Length) 320 { 321 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SAME PATH")); 322 return (AE_NOT_FOUND); 323 } 324 else 325 { 326 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SUBPATH")); 327 SubPath = TRUE; 328 } 329 } 330 331 /* Determine how many prefix Carats are required */ 332 333 NumCarats = (CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH) - NumCommonSegments; 334 335 /* 336 * Construct a new target string 337 */ 338 NewPathExternal = ACPI_MEM_CALLOCATE (TargetPath->Length + NumCarats); 339 340 /* Insert the Carats into the Target string */ 341 342 for (i = 0; i < NumCarats; i++) 343 { 344 NewPathExternal[i] = '^'; 345 } 346 347 /* Copy only the necessary (optimal) segments from the original target string */ 348 349 Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1; 350 351 /* Special handling for exact subpath in a name declaration */ 352 353 if (IsDeclaration && SubPath && (CurrentPath->Length > TargetPath->Length)) 354 { 355 /* 356 * The current path is longer than the target, and the target is a subpath 357 * of the current path. We must include one more NameSeg of the target path 358 */ 359 Index -= ACPI_PATH_SEGMENT_LENGTH; 360 361 /* Special handling for Scope() operator */ 362 363 if (Op->Asl.AmlOpcode == AML_SCOPE_OP) 364 { 365 NewPathExternal[i] = '^'; 366 i++; 367 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "(EXTRA ^)")); 368 } 369 } 370 371 ACPI_STRCPY (&NewPathExternal[i], &((char *) TargetPath->Pointer)[Index]); 372 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " %-24s", NewPathExternal)); 373 374 /* 375 * Internalize the new target string and check it against the original string 376 * to make sure that this is in fact an optimization. If the original string 377 * is already optimal, there is no point in continuing. 378 */ 379 Status = AcpiNsInternalizeName (NewPathExternal, &NewPath); 380 381 if (ACPI_FAILURE (Status)) 382 { 383 AslCoreSubsystemError (Op, Status, "Internalizing new NamePath", ASL_NO_ABORT); 384 ACPI_MEM_FREE (NewPathExternal); 385 return (Status); 386 } 387 388 if (ACPI_STRLEN (NewPath) >= AmlNameStringLength) 389 { 390 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " NOT SHORTER (New %d old %d)", 391 ACPI_STRLEN (NewPath), AmlNameStringLength)); 392 ACPI_MEM_FREE (NewPathExternal); 393 return (AE_NOT_FOUND); 394 } 395 396 /* 397 * Check to make sure that the optimization finds the node we are 398 * looking for. This is simply a sanity check on the new 399 * path that has been created. 400 */ 401 Status = AcpiNsLookup (&ScopeInfo, NewPath, 402 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 403 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 404 if (ACPI_SUCCESS (Status)) 405 { 406 /* Found the namepath, but make sure the node is correct */ 407 408 if (Node == TargetNode) 409 { 410 /* The lookup matched the node, accept this optimization */ 411 412 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 413 Op, NewPathExternal); 414 *ReturnNewPath = NewPath; 415 } 416 else 417 { 418 /* Node is not correct, do not use this optimization */ 419 420 Status = AE_NOT_FOUND; 421 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** WRONG NODE")); 422 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 423 "Not using optimized name - found wrong node"); 424 } 425 } 426 else 427 { 428 /* The lookup failed, we obviously cannot use this optimization */ 429 430 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** NOT FOUND")); 431 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 432 "Not using optimized name - did not find node"); 433 } 434 435 ACPI_MEM_FREE (NewPathExternal); 436 return (Status); 437 } 438 439 440 /******************************************************************************* 441 * 442 * FUNCTION: OptOptimizeNameDeclaration 443 * 444 * PARAMETERS: Op - Current parser op 445 * WalkState - Current state 446 * CurrentNode - Where we are in the namespace 447 * AmlNameString - Unoptimized namepath 448 * NewPath - Where the optimized path is returned 449 * 450 * RETURN: Status. AE_OK If path is optimized 451 * 452 * DESCRIPTION: Perform a simple optimization of removing an extraneous 453 * backslash prefix if we are already at the root scope. 454 * 455 ******************************************************************************/ 456 457 ACPI_STATUS 458 OptOptimizeNameDeclaration ( 459 ACPI_PARSE_OBJECT *Op, 460 ACPI_WALK_STATE *WalkState, 461 ACPI_NAMESPACE_NODE *CurrentNode, 462 ACPI_NAMESPACE_NODE *TargetNode, 463 char *AmlNameString, 464 char **NewPath) 465 { 466 ACPI_STATUS Status; 467 char *NewPathExternal; 468 ACPI_GENERIC_STATE ScopeInfo; 469 ACPI_NAMESPACE_NODE *Node; 470 471 472 ACPI_FUNCTION_TRACE ("OptOptimizeNameDeclaration"); 473 474 475 if (((CurrentNode == AcpiGbl_RootNode) || 476 (Op->Common.Parent->Asl.ParseOpcode == PARSEOP_DEFINITIONBLOCK)) && 477 (AmlNameString[0] == '\\')) 478 { 479 /* 480 * The current scope is the root, and the namepath has a root prefix 481 * that is therefore extraneous. Remove it. 482 */ 483 *NewPath = &AmlNameString[1]; 484 485 /* Debug output */ 486 487 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, *NewPath, 488 NULL, &NewPathExternal); 489 if (ACPI_FAILURE (Status)) 490 { 491 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", ASL_NO_ABORT); 492 return (Status); 493 } 494 495 /* 496 * Check to make sure that the optimization finds the node we are 497 * looking for. This is simply a sanity check on the new 498 * path that has been created. 499 */ 500 ScopeInfo.Scope.Node = CurrentNode; 501 Status = AcpiNsLookup (&ScopeInfo, *NewPath, 502 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE, 503 ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node)); 504 if (ACPI_SUCCESS (Status)) 505 { 506 /* Found the namepath, but make sure the node is correct */ 507 508 if (Node == TargetNode) 509 { 510 /* The lookup matched the node, accept this optimization */ 511 512 AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION, 513 Op, NewPathExternal); 514 515 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 516 "AT ROOT: %-24s", NewPathExternal)); 517 } 518 else 519 { 520 /* Node is not correct, do not use this optimization */ 521 522 Status = AE_NOT_FOUND; 523 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** WRONG NODE")); 524 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 525 "Not using optimized name - found wrong node"); 526 } 527 } 528 else 529 { 530 /* The lookup failed, we obviously cannot use this optimization */ 531 532 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** NOT FOUND")); 533 AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op, 534 "Not using optimized name - did not find node"); 535 } 536 537 ACPI_MEM_FREE (NewPathExternal); 538 return (Status); 539 } 540 541 /* Could not optimize */ 542 543 return (AE_NOT_FOUND); 544 } 545 546 547 /******************************************************************************* 548 * 549 * FUNCTION: OptOptimizeNamePath 550 * 551 * PARAMETERS: Op - Current parser op 552 * Flags - Opcode info flags 553 * WalkState - Current state 554 * AmlNameString - Unoptimized namepath 555 * TargetNode - Node to which AmlNameString refers 556 * 557 * RETURN: None. If path is optimized, the Op is updated with new path 558 * 559 * DESCRIPTION: Optimize a Named Declaration or Reference to the minimal length. 560 * Must take into account both the current location in the 561 * namespace and the actual reference path. 562 * 563 ******************************************************************************/ 564 565 void 566 OptOptimizeNamePath ( 567 ACPI_PARSE_OBJECT *Op, 568 UINT32 Flags, 569 ACPI_WALK_STATE *WalkState, 570 char *AmlNameString, 571 ACPI_NAMESPACE_NODE *TargetNode) 572 { 573 ACPI_STATUS Status; 574 ACPI_BUFFER TargetPath; 575 ACPI_BUFFER CurrentPath; 576 ACPI_SIZE AmlNameStringLength; 577 ACPI_NAMESPACE_NODE *CurrentNode; 578 char *ExternalNameString; 579 char *NewPath = NULL; 580 ACPI_SIZE HowMuchShorter; 581 ACPI_PARSE_OBJECT *NextOp; 582 583 584 ACPI_FUNCTION_TRACE ("OptOptimizeNamePath"); 585 586 587 /* This is an optional optimization */ 588 589 if (!Gbl_ReferenceOptimizationFlag) 590 { 591 return_VOID; 592 } 593 594 /* Various required items */ 595 596 if (!TargetNode || !WalkState || !AmlNameString || !Op->Common.Parent) 597 { 598 return_VOID; 599 } 600 601 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "%5d [%12.12s] [%12.12s] ", 602 Op->Asl.LogicalLineNumber, 603 AcpiPsGetOpcodeName (Op->Common.Parent->Common.AmlOpcode), 604 AcpiPsGetOpcodeName (Op->Common.AmlOpcode))); 605 606 if (!(Flags & (AML_NAMED | AML_CREATE))) 607 { 608 if (Op->Asl.CompileFlags & NODE_IS_NAME_DECLARATION) 609 { 610 /* We don't want to fuss with actual name declaration nodes here */ 611 612 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 613 "******* NAME DECLARATION\n")); 614 return_VOID; 615 } 616 } 617 618 /* 619 * The original path must be longer than one NameSeg (4 chars) for there 620 * to be any possibility that it can be optimized to a shorter string 621 */ 622 AmlNameStringLength = ACPI_STRLEN (AmlNameString); 623 if (AmlNameStringLength <= ACPI_NAME_SIZE) 624 { 625 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 626 "NAMESEG %4.4s\n", AmlNameString)); 627 return_VOID; 628 } 629 630 /* 631 * We need to obtain the node that represents the current scope -- where 632 * we are right now in the namespace. We will compare this path 633 * against the Namepath, looking for commonality. 634 */ 635 CurrentNode = AcpiGbl_RootNode; 636 if (WalkState->ScopeInfo) 637 { 638 CurrentNode = WalkState->ScopeInfo->Scope.Node; 639 } 640 641 if (Flags & (AML_NAMED | AML_CREATE)) 642 { 643 /* This is the declaration of a new name */ 644 645 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "NAME")); 646 647 /* The node of interest is the parent of this node (the containing scope) */ 648 649 CurrentNode = Op->Asl.Parent->Asl.Node; 650 if (!CurrentNode) 651 { 652 CurrentNode = AcpiGbl_RootNode; 653 } 654 } 655 else 656 { 657 /* This is a reference to an existing named object */ 658 659 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "REF ")); 660 } 661 662 /* 663 * Obtain the full paths to the two nodes that we are interested in 664 * (Target and current namespace location) in external 665 * format -- something we can easily manipulate 666 */ 667 TargetPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 668 Status = AcpiNsHandleToPathname (TargetNode, &TargetPath); 669 if (ACPI_FAILURE (Status)) 670 { 671 AslCoreSubsystemError (Op, Status, "Getting Target NamePath", ASL_NO_ABORT); 672 return_VOID; 673 } 674 TargetPath.Length--; /* Subtract one for null terminator */ 675 676 /* CurrentPath is the path to this scope (where we are in the namespace) */ 677 678 CurrentPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER; 679 Status = AcpiNsHandleToPathname (CurrentNode, &CurrentPath); 680 if (ACPI_FAILURE (Status)) 681 { 682 AslCoreSubsystemError (Op, Status, "Getting Current NamePath", ASL_NO_ABORT); 683 return_VOID; 684 } 685 CurrentPath.Length--; /* Subtract one for null terminator */ 686 687 /* Debug output only */ 688 689 Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, AmlNameString, 690 NULL, &ExternalNameString); 691 if (ACPI_FAILURE (Status)) 692 { 693 AslCoreSubsystemError (Op, Status, "Externalizing NamePath", ASL_NO_ABORT); 694 return_VOID; 695 } 696 697 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, 698 "%37s (%2d) ==> %-32s(%2d) %-32s", 699 (char *) CurrentPath.Pointer, CurrentPath.Length, 700 (char *) TargetPath.Pointer, TargetPath.Length, ExternalNameString)); 701 702 ACPI_MEM_FREE (ExternalNameString); 703 704 /* 705 * Attempt an optmization depending on the type of namepath 706 */ 707 if (Flags & (AML_NAMED | AML_CREATE)) 708 { 709 /* 710 * This is a named opcode and the namepath is a name declaration, not 711 * a reference. 712 */ 713 Status = OptOptimizeNameDeclaration (Op, WalkState, CurrentNode, 714 TargetNode, AmlNameString, &NewPath); 715 if (ACPI_FAILURE (Status)) 716 { 717 /* 718 * 2) now attempt to 719 * optimize the namestring with carats (up-arrow) 720 */ 721 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 722 TargetNode, &CurrentPath, &TargetPath, 723 AmlNameStringLength, 1, &NewPath); 724 } 725 } 726 else 727 { 728 /* 729 * This is a reference to an existing named object 730 * 731 * 1) Check if search-to-root can be utilized using the last 732 * NameSeg of the NamePath 733 */ 734 Status = OptSearchToRoot (Op, WalkState, CurrentNode, 735 TargetNode, &TargetPath, &NewPath); 736 if (ACPI_FAILURE (Status)) 737 { 738 /* 739 * 2) Search-to-root could not be used, now attempt to 740 * optimize the namestring with carats (up-arrow) 741 */ 742 Status = OptBuildShortestPath (Op, WalkState, CurrentNode, 743 TargetNode, &CurrentPath, &TargetPath, 744 AmlNameStringLength, 0, &NewPath); 745 } 746 } 747 748 /* 749 * Success from above indicates that the NamePath was successfully 750 * optimized. We need to update the parse op with the new name 751 */ 752 if (ACPI_SUCCESS (Status)) 753 { 754 HowMuchShorter = (AmlNameStringLength - ACPI_STRLEN (NewPath)); 755 OptTotal += HowMuchShorter; 756 757 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " REDUCED %2d (%d)", 758 HowMuchShorter, OptTotal)); 759 760 if (Flags & AML_NAMED) 761 { 762 if (Op->Asl.AmlOpcode == AML_ALIAS_OP) 763 { 764 /* 765 * ALIAS is the only oddball opcode, the name declaration 766 * (alias name) is the second operand 767 */ 768 Op->Asl.Child->Asl.Next->Asl.Value.String = NewPath; 769 Op->Asl.Child->Asl.Next->Asl.AmlLength = ACPI_STRLEN (NewPath); 770 } 771 else 772 { 773 Op->Asl.Child->Asl.Value.String = NewPath; 774 Op->Asl.Child->Asl.AmlLength = ACPI_STRLEN (NewPath); 775 } 776 } 777 else if (Flags & AML_CREATE) 778 { 779 /* Name must appear as the last parameter */ 780 781 NextOp = Op->Asl.Child; 782 while (!(NextOp->Asl.CompileFlags & NODE_IS_NAME_DECLARATION)) 783 { 784 NextOp = NextOp->Asl.Next; 785 } 786 /* Update the parse node with the new NamePath */ 787 788 NextOp->Asl.Value.String = NewPath; 789 NextOp->Asl.AmlLength = ACPI_STRLEN (NewPath); 790 } 791 else 792 { 793 /* Update the parse node with the new NamePath */ 794 795 Op->Asl.Value.String = NewPath; 796 Op->Asl.AmlLength = ACPI_STRLEN (NewPath); 797 } 798 } 799 else 800 { 801 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ALREADY OPTIMAL")); 802 } 803 804 /* Cleanup path buffers */ 805 806 ACPI_MEM_FREE (TargetPath.Pointer); 807 ACPI_MEM_FREE (CurrentPath.Pointer); 808 809 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "\n")); 810 return_VOID; 811 } 812 813