reactos/drivers/bus/acpi/acpica/namespace/nsinit.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsinit - namespace initialization
   4  *
   5  *****************************************************************************/
   6
   7 /******************************************************************************
   8  *
   9  * 1. Copyright Notice
  10  *
  11  * Some or all of this work - Copyright (c) 1999 - 2014, 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 #include "acpi.h"
 117 #include "accommon.h"
 118 #include "acnamesp.h"
 119 #include "acdispat.h"
 120 #include "acinterp.h"
 121
 122 #define _COMPONENT          ACPI_NAMESPACE
 123         ACPI_MODULE_NAME    ("nsinit")
 124
 125 /* Local prototypes */
 126
 127 static ACPI_STATUS
 128 AcpiNsInitOneObject (
 129     ACPI_HANDLE             ObjHandle,
 130     UINT32                  Level,
 131     void                    *Context,
 132     void                    **ReturnValue);
 133
 134 static ACPI_STATUS
 135 AcpiNsInitOneDevice (
 136     ACPI_HANDLE             ObjHandle,
 137     UINT32                  NestingLevel,
 138     void                    *Context,
 139     void                    **ReturnValue);
 140
 141 static ACPI_STATUS
 142 AcpiNsFindIniMethods (
 143     ACPI_HANDLE             ObjHandle,
 144     UINT32                  NestingLevel,
 145     void                    *Context,
 146     void                    **ReturnValue);
 147
 148
 149 /*******************************************************************************
 150  *
 151  * FUNCTION:    AcpiNsInitializeObjects
 152  *
 153  * PARAMETERS:  None
 154  *
 155  * RETURN:      Status
 156  *
 157  * DESCRIPTION: Walk the entire namespace and perform any necessary
 158  *              initialization on the objects found therein
 159  *
 160  ******************************************************************************/
 161
 162 ACPI_STATUS
 163 AcpiNsInitializeObjects (
 164     void)
 165 {
 166     ACPI_STATUS             Status;
 167     ACPI_INIT_WALK_INFO     Info;
 168
 169
 170     ACPI_FUNCTION_TRACE (NsInitializeObjects);
 171
 172
 173     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 174         "**** Starting initialization of namespace objects ****\n"));
 175     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INIT,
 176         "Completing Region/Field/Buffer/Package initialization:\n"));
 177
 178     /* Set all init info to zero */
 179
 180     ACPI_MEMSET (&Info, 0, sizeof (ACPI_INIT_WALK_INFO));
 181
 182     /* Walk entire namespace from the supplied root */
 183
 184     Status = AcpiWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
 185                 ACPI_UINT32_MAX, AcpiNsInitOneObject, NULL,
 186                 &Info, NULL);
 187     if (ACPI_FAILURE (Status))
 188     {
 189         ACPI_EXCEPTION ((AE_INFO, Status, "During WalkNamespace"));
 190     }
 191
 192     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INIT,
 193         "    Initialized %u/%u Regions %u/%u Fields %u/%u "
 194         "Buffers %u/%u Packages (%u nodes)\n",
 195         Info.OpRegionInit,  Info.OpRegionCount,
 196         Info.FieldInit,     Info.FieldCount,
 197         Info.BufferInit,    Info.BufferCount,
 198         Info.PackageInit,   Info.PackageCount, Info.ObjectCount));
 199
 200     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 201         "%u Control Methods found\n%u Op Regions found\n",
 202         Info.MethodCount, Info.OpRegionCount));
 203
 204     return_ACPI_STATUS (AE_OK);
 205 }
 206
 207
 208 /*******************************************************************************
 209  *
 210  * FUNCTION:    AcpiNsInitializeDevices
 211  *
 212  * PARAMETERS:  None
 213  *
 214  * RETURN:      ACPI_STATUS
 215  *
 216  * DESCRIPTION: Walk the entire namespace and initialize all ACPI devices.
 217  *              This means running _INI on all present devices.
 218  *
 219  *              Note: We install PCI config space handler on region access,
 220  *              not here.
 221  *
 222  ******************************************************************************/
 223
 224 ACPI_STATUS
 225 AcpiNsInitializeDevices (
 226     void)
 227 {
 228     ACPI_STATUS             Status;
 229     ACPI_DEVICE_WALK_INFO   Info;
 230
 231
 232     ACPI_FUNCTION_TRACE (NsInitializeDevices);
 233
 234
 235     /* Init counters */
 236
 237     Info.DeviceCount = 0;
 238     Info.Num_STA = 0;
 239     Info.Num_INI = 0;
 240
 241     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INIT,
 242         "Initializing Device/Processor/Thermal objects "
 243         "and executing _INI/_STA methods:\n"));
 244
 245     /* Tree analysis: find all subtrees that contain _INI methods */
 246
 247     Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
 248                 ACPI_UINT32_MAX, FALSE, AcpiNsFindIniMethods, NULL, &Info, NULL);
 249     if (ACPI_FAILURE (Status))
 250     {
 251         goto ErrorExit;
 252     }
 253
 254     /* Allocate the evaluation information block */
 255
 256     Info.EvaluateInfo = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
 257     if (!Info.EvaluateInfo)
 258     {
 259         Status = AE_NO_MEMORY;
 260         goto ErrorExit;
 261     }
 262
 263     /*
 264      * Execute the "global" _INI method that may appear at the root. This
 265      * support is provided for Windows compatibility (Vista+) and is not
 266      * part of the ACPI specification.
 267      */
 268     Info.EvaluateInfo->PrefixNode = AcpiGbl_RootNode;
 269     Info.EvaluateInfo->RelativePathname = METHOD_NAME__INI;
 270     Info.EvaluateInfo->Parameters = NULL;
 271     Info.EvaluateInfo->Flags = ACPI_IGNORE_RETURN_VALUE;
 272
 273     Status = AcpiNsEvaluate (Info.EvaluateInfo);
 274     if (ACPI_SUCCESS (Status))
 275     {
 276         Info.Num_INI++;
 277     }
 278
 279     /* Walk namespace to execute all _INIs on present devices */
 280
 281     Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
 282                 ACPI_UINT32_MAX, FALSE, AcpiNsInitOneDevice, NULL, &Info, NULL);
 283
 284     /*
 285      * Any _OSI requests should be completed by now. If the BIOS has
 286      * requested any Windows OSI strings, we will always truncate
 287      * I/O addresses to 16 bits -- for Windows compatibility.
 288      */
 289     if (AcpiGbl_OsiData >= ACPI_OSI_WIN_2000)
 290     {
 291         AcpiGbl_TruncateIoAddresses = TRUE;
 292     }
 293
 294     ACPI_FREE (Info.EvaluateInfo);
 295     if (ACPI_FAILURE (Status))
 296     {
 297         goto ErrorExit;
 298     }
 299
 300     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INIT,
 301         "    Executed %u _INI methods requiring %u _STA executions "
 302         "(examined %u objects)\n",
 303         Info.Num_INI, Info.Num_STA, Info.DeviceCount));
 304
 305     return_ACPI_STATUS (Status);
 306
 307
 308 ErrorExit:
 309     ACPI_EXCEPTION ((AE_INFO, Status, "During device initialization"));
 310     return_ACPI_STATUS (Status);
 311 }
 312
 313
 314 /*******************************************************************************
 315  *
 316  * FUNCTION:    AcpiNsInitOneObject
 317  *
 318  * PARAMETERS:  ObjHandle       - Node
 319  *              Level           - Current nesting level
 320  *              Context         - Points to a init info struct
 321  *              ReturnValue     - Not used
 322  *
 323  * RETURN:      Status
 324  *
 325  * DESCRIPTION: Callback from AcpiWalkNamespace. Invoked for every object
 326  *              within the  namespace.
 327  *
 328  *              Currently, the only objects that require initialization are:
 329  *              1) Methods
 330  *              2) Op Regions
 331  *
 332  ******************************************************************************/
 333
 334 static ACPI_STATUS
 335 AcpiNsInitOneObject (
 336     ACPI_HANDLE             ObjHandle,
 337     UINT32                  Level,
 338     void                    *Context,
 339     void                    **ReturnValue)
 340 {
 341     ACPI_OBJECT_TYPE        Type;
 342     ACPI_STATUS             Status = AE_OK;
 343     ACPI_INIT_WALK_INFO     *Info = (ACPI_INIT_WALK_INFO *) Context;
 344     ACPI_NAMESPACE_NODE     *Node = (ACPI_NAMESPACE_NODE *) ObjHandle;
 345     ACPI_OPERAND_OBJECT     *ObjDesc;
 346
 347
 348     ACPI_FUNCTION_NAME (NsInitOneObject);
 349
 350
 351     Info->ObjectCount++;
 352
 353     /* And even then, we are only interested in a few object types */
 354
 355     Type = AcpiNsGetType (ObjHandle);
 356     ObjDesc = AcpiNsGetAttachedObject (Node);
 357     if (!ObjDesc)
 358     {
 359         return (AE_OK);
 360     }
 361
 362     /* Increment counters for object types we are looking for */
 363
 364     switch (Type)
 365     {
 366     case ACPI_TYPE_REGION:
 367
 368         Info->OpRegionCount++;
 369         break;
 370
 371     case ACPI_TYPE_BUFFER_FIELD:
 372
 373         Info->FieldCount++;
 374         break;
 375
 376     case ACPI_TYPE_LOCAL_BANK_FIELD:
 377
 378         Info->FieldCount++;
 379         break;
 380
 381     case ACPI_TYPE_BUFFER:
 382
 383         Info->BufferCount++;
 384         break;
 385
 386     case ACPI_TYPE_PACKAGE:
 387
 388         Info->PackageCount++;
 389         break;
 390
 391     default:
 392
 393         /* No init required, just exit now */
 394
 395         return (AE_OK);
 396     }
 397
 398     /* If the object is already initialized, nothing else to do */
 399
 400     if (ObjDesc->Common.Flags & AOPOBJ_DATA_VALID)
 401     {
 402         return (AE_OK);
 403     }
 404
 405     /* Must lock the interpreter before executing AML code */
 406
 407     AcpiExEnterInterpreter ();
 408
 409     /*
 410      * Each of these types can contain executable AML code within the
 411      * declaration.
 412      */
 413     switch (Type)
 414     {
 415     case ACPI_TYPE_REGION:
 416
 417         Info->OpRegionInit++;
 418         Status = AcpiDsGetRegionArguments (ObjDesc);
 419         break;
 420
 421     case ACPI_TYPE_BUFFER_FIELD:
 422
 423         Info->FieldInit++;
 424         Status = AcpiDsGetBufferFieldArguments (ObjDesc);
 425         break;
 426
 427     case ACPI_TYPE_LOCAL_BANK_FIELD:
 428
 429         Info->FieldInit++;
 430         Status = AcpiDsGetBankFieldArguments (ObjDesc);
 431         break;
 432
 433     case ACPI_TYPE_BUFFER:
 434
 435         Info->BufferInit++;
 436         Status = AcpiDsGetBufferArguments (ObjDesc);
 437         break;
 438
 439     case ACPI_TYPE_PACKAGE:
 440
 441         Info->PackageInit++;
 442         Status = AcpiDsGetPackageArguments (ObjDesc);
 443         break;
 444
 445     default:
 446
 447         /* No other types can get here */
 448
 449         break;
 450     }
 451
 452     if (ACPI_FAILURE (Status))
 453     {
 454         ACPI_EXCEPTION ((AE_INFO, Status,
 455             "Could not execute arguments for [%4.4s] (%s)",
 456             AcpiUtGetNodeName (Node), AcpiUtGetTypeName (Type)));
 457     }
 458
 459     /*
 460      * We ignore errors from above, and always return OK, since we don't want
 461      * to abort the walk on any single error.
 462      */
 463     AcpiExExitInterpreter ();
 464     return (AE_OK);
 465 }
 466
 467
 468 /*******************************************************************************
 469  *
 470  * FUNCTION:    AcpiNsFindIniMethods
 471  *
 472  * PARAMETERS:  ACPI_WALK_CALLBACK
 473  *
 474  * RETURN:      ACPI_STATUS
 475  *
 476  * DESCRIPTION: Called during namespace walk. Finds objects named _INI under
 477  *              device/processor/thermal objects, and marks the entire subtree
 478  *              with a SUBTREE_HAS_INI flag. This flag is used during the
 479  *              subsequent device initialization walk to avoid entire subtrees
 480  *              that do not contain an _INI.
 481  *
 482  ******************************************************************************/
 483
 484 static ACPI_STATUS
 485 AcpiNsFindIniMethods (
 486     ACPI_HANDLE             ObjHandle,
 487     UINT32                  NestingLevel,
 488     void                    *Context,
 489     void                    **ReturnValue)
 490 {
 491     ACPI_DEVICE_WALK_INFO   *Info = ACPI_CAST_PTR (ACPI_DEVICE_WALK_INFO, Context);
 492     ACPI_NAMESPACE_NODE     *Node;
 493     ACPI_NAMESPACE_NODE     *ParentNode;
 494
 495
 496     /* Keep count of device/processor/thermal objects */
 497
 498     Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);
 499     if ((Node->Type == ACPI_TYPE_DEVICE)    ||
 500         (Node->Type == ACPI_TYPE_PROCESSOR) ||
 501         (Node->Type == ACPI_TYPE_THERMAL))
 502     {
 503         Info->DeviceCount++;
 504         return (AE_OK);
 505     }
 506
 507     /* We are only looking for methods named _INI */
 508
 509     if (!ACPI_COMPARE_NAME (Node->Name.Ascii, METHOD_NAME__INI))
 510     {
 511         return (AE_OK);
 512     }
 513
 514     /*
 515      * The only _INI methods that we care about are those that are
 516      * present under Device, Processor, and Thermal objects.
 517      */
 518     ParentNode = Node->Parent;
 519     switch (ParentNode->Type)
 520     {
 521     case ACPI_TYPE_DEVICE:
 522     case ACPI_TYPE_PROCESSOR:
 523     case ACPI_TYPE_THERMAL:
 524
 525         /* Mark parent and bubble up the INI present flag to the root */
 526
 527         while (ParentNode)
 528         {
 529             ParentNode->Flags |= ANOBJ_SUBTREE_HAS_INI;
 530             ParentNode = ParentNode->Parent;
 531         }
 532         break;
 533
 534     default:
 535
 536         break;
 537     }
 538
 539     return (AE_OK);
 540 }
 541
 542
 543 /*******************************************************************************
 544  *
 545  * FUNCTION:    AcpiNsInitOneDevice
 546  *
 547  * PARAMETERS:  ACPI_WALK_CALLBACK
 548  *
 549  * RETURN:      ACPI_STATUS
 550  *
 551  * DESCRIPTION: This is called once per device soon after ACPI is enabled
 552  *              to initialize each device. It determines if the device is
 553  *              present, and if so, calls _INI.
 554  *
 555  ******************************************************************************/
 556
 557 static ACPI_STATUS
 558 AcpiNsInitOneDevice (
 559     ACPI_HANDLE             ObjHandle,
 560     UINT32                  NestingLevel,
 561     void                    *Context,
 562     void                    **ReturnValue)
 563 {
 564     ACPI_DEVICE_WALK_INFO   *WalkInfo = ACPI_CAST_PTR (ACPI_DEVICE_WALK_INFO, Context);
 565     ACPI_EVALUATE_INFO      *Info = WalkInfo->EvaluateInfo;
 566     UINT32                  Flags;
 567     ACPI_STATUS             Status;
 568     ACPI_NAMESPACE_NODE     *DeviceNode;
 569
 570
 571     ACPI_FUNCTION_TRACE (NsInitOneDevice);
 572
 573
 574     /* We are interested in Devices, Processors and ThermalZones only */
 575
 576     DeviceNode = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);
 577     if ((DeviceNode->Type != ACPI_TYPE_DEVICE)    &&
 578         (DeviceNode->Type != ACPI_TYPE_PROCESSOR) &&
 579         (DeviceNode->Type != ACPI_TYPE_THERMAL))
 580     {
 581         return_ACPI_STATUS (AE_OK);
 582     }
 583
 584     /*
 585      * Because of an earlier namespace analysis, all subtrees that contain an
 586      * _INI method are tagged.
 587      *
 588      * If this device subtree does not contain any _INI methods, we
 589      * can exit now and stop traversing this entire subtree.
 590      */
 591     if (!(DeviceNode->Flags & ANOBJ_SUBTREE_HAS_INI))
 592     {
 593         return_ACPI_STATUS (AE_CTRL_DEPTH);
 594     }
 595
 596     /*
 597      * Run _STA to determine if this device is present and functioning. We
 598      * must know this information for two important reasons (from ACPI spec):
 599      *
 600      * 1) We can only run _INI if the device is present.
 601      * 2) We must abort the device tree walk on this subtree if the device is
 602      *    not present and is not functional (we will not examine the children)
 603      *
 604      * The _STA method is not required to be present under the device, we
 605      * assume the device is present if _STA does not exist.
 606      */
 607     ACPI_DEBUG_EXEC (AcpiUtDisplayInitPathname (
 608         ACPI_TYPE_METHOD, DeviceNode, METHOD_NAME__STA));
 609
 610     Status = AcpiUtExecute_STA (DeviceNode, &Flags);
 611     if (ACPI_FAILURE (Status))
 612     {
 613         /* Ignore error and move on to next device */
 614
 615         return_ACPI_STATUS (AE_OK);
 616     }
 617
 618     /*
 619      * Flags == -1 means that _STA was not found. In this case, we assume that
 620      * the device is both present and functional.
 621      *
 622      * From the ACPI spec, description of _STA:
 623      *
 624      * "If a device object (including the processor object) does not have an
 625      * _STA object, then OSPM assumes that all of the above bits are set (in
 626      * other words, the device is present, ..., and functioning)"
 627      */
 628     if (Flags != ACPI_UINT32_MAX)
 629     {
 630         WalkInfo->Num_STA++;
 631     }
 632
 633     /*
 634      * Examine the PRESENT and FUNCTIONING status bits
 635      *
 636      * Note: ACPI spec does not seem to specify behavior for the present but
 637      * not functioning case, so we assume functioning if present.
 638      */
 639     if (!(Flags & ACPI_STA_DEVICE_PRESENT))
 640     {
 641         /* Device is not present, we must examine the Functioning bit */
 642
 643         if (Flags & ACPI_STA_DEVICE_FUNCTIONING)
 644         {
 645             /*
 646              * Device is not present but is "functioning". In this case,
 647              * we will not run _INI, but we continue to examine the children
 648              * of this device.
 649              *
 650              * From the ACPI spec, description of _STA: (Note - no mention
 651              * of whether to run _INI or not on the device in question)
 652              *
 653              * "_STA may return bit 0 clear (not present) with bit 3 set
 654              * (device is functional). This case is used to indicate a valid
 655              * device for which no device driver should be loaded (for example,
 656              * a bridge device.) Children of this device may be present and
 657              * valid. OSPM should continue enumeration below a device whose
 658              * _STA returns this bit combination"
 659              */
 660             return_ACPI_STATUS (AE_OK);
 661         }
 662         else
 663         {
 664             /*
 665              * Device is not present and is not functioning. We must abort the
 666              * walk of this subtree immediately -- don't look at the children
 667              * of such a device.
 668              *
 669              * From the ACPI spec, description of _INI:
 670              *
 671              * "If the _STA method indicates that the device is not present,
 672              * OSPM will not run the _INI and will not examine the children
 673              * of the device for _INI methods"
 674              */
 675             return_ACPI_STATUS (AE_CTRL_DEPTH);
 676         }
 677     }
 678
 679     /*
 680      * The device is present or is assumed present if no _STA exists.
 681      * Run the _INI if it exists (not required to exist)
 682      *
 683      * Note: We know there is an _INI within this subtree, but it may not be
 684      * under this particular device, it may be lower in the branch.
 685      */
 686     ACPI_DEBUG_EXEC (AcpiUtDisplayInitPathname (
 687         ACPI_TYPE_METHOD, DeviceNode, METHOD_NAME__INI));
 688
 689     ACPI_MEMSET (Info, 0, sizeof (ACPI_EVALUATE_INFO));
 690     Info->PrefixNode = DeviceNode;
 691     Info->RelativePathname = METHOD_NAME__INI;
 692     Info->Parameters = NULL;
 693     Info->Flags = ACPI_IGNORE_RETURN_VALUE;
 694
 695     Status = AcpiNsEvaluate (Info);
 696     if (ACPI_SUCCESS (Status))
 697     {
 698         WalkInfo->Num_INI++;
 699     }
 700
 701 #ifdef ACPI_DEBUG_OUTPUT
 702     else if (Status != AE_NOT_FOUND)
 703     {
 704         /* Ignore error and move on to next device */
 705
 706         char *ScopeName = AcpiNsGetExternalPathname (Info->Node);
 707
 708         ACPI_EXCEPTION ((AE_INFO, Status, "during %s._INI execution",
 709             ScopeName));
 710         ACPI_FREE (ScopeName);
 711     }
 712 #endif
 713
 714     /* Ignore errors from above */
 715
 716     Status = AE_OK;
 717
 718     /*
 719      * The _INI method has been run if present; call the Global Initialization
 720      * Handler for this device.
 721      */
 722     if (AcpiGbl_InitHandler)
 723     {
 724         Status = AcpiGbl_InitHandler (DeviceNode, ACPI_INIT_DEVICE_INI);
 725     }
 726
 727     return_ACPI_STATUS (Status);
 728 }