drivers/bus/acpi/acpica/namespace/nswalk.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nswalk - Functions for walking the ACPI namespace
   4  *
   5  *****************************************************************************/
   6
   7 /******************************************************************************
   8  *
   9  * 1. Copyright Notice
  10  *
  11  * Some or all of this work - Copyright (c) 1999 - 2009, Intel Corp.
  12  * All rights reserved.
  13  *
  14  * 2. License
  15  *
  16  * 2.1. This is your license from Intel Corp. under its intellectual property
  17  * rights.  You may have additional license terms from the party that provided
  18  * you this software, covering your right to use that party's intellectual
  19  * property rights.
  20  *
  21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
  22  * copy of the source code appearing in this file ("Covered Code") an
  23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
  24  * base code distributed originally by Intel ("Original Intel Code") to copy,
  25  * make derivatives, distribute, use and display any portion of the Covered
  26  * Code in any form, with the right to sublicense such rights; and
  27  *
  28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
  29  * license (with the right to sublicense), under only those claims of Intel
  30  * patents that are infringed by the Original Intel Code, to make, use, sell,
  31  * offer to sell, and import the Covered Code and derivative works thereof
  32  * solely to the minimum extent necessary to exercise the above copyright
  33  * license, and in no event shall the patent license extend to any additions
  34  * to or modifications of the Original Intel Code.  No other license or right
  35  * is granted directly or by implication, estoppel or otherwise;
  36  *
  37  * The above copyright and patent license is granted only if the following
  38  * conditions are met:
  39  *
  40  * 3. Conditions
  41  *
  42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
  43  * Redistribution of source code of any substantial portion of the Covered
  44  * Code or modification with rights to further distribute source must include
  45  * the above Copyright Notice, the above License, this list of Conditions,
  46  * and the following Disclaimer and Export Compliance provision.  In addition,
  47  * Licensee must cause all Covered Code to which Licensee contributes to
  48  * contain a file documenting the changes Licensee made to create that Covered
  49  * Code and the date of any change.  Licensee must include in that file the
  50  * documentation of any changes made by any predecessor Licensee.  Licensee
  51  * must include a prominent statement that the modification is derived,
  52  * directly or indirectly, from Original Intel Code.
  53  *
  54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
  55  * Redistribution of source code of any substantial portion of the Covered
  56  * Code or modification without rights to further distribute source must
  57  * include the following Disclaimer and Export Compliance provision in the
  58  * documentation and/or other materials provided with distribution.  In
  59  * addition, Licensee may not authorize further sublicense of source of any
  60  * portion of the Covered Code, and must include terms to the effect that the
  61  * license from Licensee to its licensee is limited to the intellectual
  62  * property embodied in the software Licensee provides to its licensee, and
  63  * not to intellectual property embodied in modifications its licensee may
  64  * make.
  65  *
  66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
  67  * substantial portion of the Covered Code or modification must reproduce the
  68  * above Copyright Notice, and the following Disclaimer and Export Compliance
  69  * provision in the documentation and/or other materials provided with the
  70  * distribution.
  71  *
  72  * 3.4. Intel retains all right, title, and interest in and to the Original
  73  * Intel Code.
  74  *
  75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
  76  * Intel shall be used in advertising or otherwise to promote the sale, use or
  77  * other dealings in products derived from or relating to the Covered Code
  78  * without prior written authorization from Intel.
  79  *
  80  * 4. Disclaimer and Export Compliance
  81  *
  82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
  83  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
  84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
  85  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
  86  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
  87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
  88  * PARTICULAR PURPOSE.
  89  *
  90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
  91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
  92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
  93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
  94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
  95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
  96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
  97  * LIMITED REMEDY.
  98  *
  99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
 100  * software or system incorporating such software without first obtaining any
 101  * required license or other approval from the U. S. Department of Commerce or
 102  * any other agency or department of the United States Government.  In the
 103  * event Licensee exports any such software from the United States or
 104  * re-exports any such software from a foreign destination, Licensee shall
 105  * ensure that the distribution and export/re-export of the software is in
 106  * compliance with all laws, regulations, orders, or other restrictions of the
 107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
 108  * any of its subsidiaries will export/re-export any technical data, process,
 109  * software, or service, directly or indirectly, to any country for which the
 110  * United States government or any agency thereof requires an export license,
 111  * other governmental approval, or letter of assurance, without first obtaining
 112  * such license, approval or letter.
 113  *
 114  *****************************************************************************/
 115
 116
 117 #define __NSWALK_C__
 118
 119 #include "acpi.h"
 120 #include "accommon.h"
 121 #include "acnamesp.h"
 122
 123
 124 #define _COMPONENT          ACPI_NAMESPACE
 125         ACPI_MODULE_NAME    ("nswalk")
 126
 127
 128 /*******************************************************************************
 129  *
 130  * FUNCTION:    AcpiNsGetNextNode
 131  *
 132  * PARAMETERS:  ParentNode          - Parent node whose children we are
 133  *                                    getting
 134  *              ChildNode           - Previous child that was found.
 135  *                                    The NEXT child will be returned
 136  *
 137  * RETURN:      ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
 138  *                                    none is found.
 139  *
 140  * DESCRIPTION: Return the next peer node within the namespace.  If Handle
 141  *              is valid, Scope is ignored.  Otherwise, the first node
 142  *              within Scope is returned.
 143  *
 144  ******************************************************************************/
 145
 146 ACPI_NAMESPACE_NODE *
 147 AcpiNsGetNextNode (
 148     ACPI_NAMESPACE_NODE     *ParentNode,
 149     ACPI_NAMESPACE_NODE     *ChildNode)
 150 {
 151     ACPI_FUNCTION_ENTRY ();
 152
 153
 154     if (!ChildNode)
 155     {
 156         /* It's really the parent's _scope_ that we want */
 157
 158         return (ParentNode->Child);
 159     }
 160
 161     /*
 162      * Get the next node.
 163      *
 164      * If we are at the end of this peer list, return NULL
 165      */
 166     if (ChildNode->Flags & ANOBJ_END_OF_PEER_LIST)
 167     {
 168         return NULL;
 169     }
 170
 171     /* Otherwise just return the next peer */
 172
 173     return (ChildNode->Peer);
 174 }
 175
 176
 177 /*******************************************************************************
 178  *
 179  * FUNCTION:    AcpiNsGetNextNodeTyped
 180  *
 181  * PARAMETERS:  Type                - Type of node to be searched for
 182  *              ParentNode          - Parent node whose children we are
 183  *                                    getting
 184  *              ChildNode           - Previous child that was found.
 185  *                                    The NEXT child will be returned
 186  *
 187  * RETURN:      ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
 188  *                                    none is found.
 189  *
 190  * DESCRIPTION: Return the next peer node within the namespace.  If Handle
 191  *              is valid, Scope is ignored.  Otherwise, the first node
 192  *              within Scope is returned.
 193  *
 194  ******************************************************************************/
 195
 196 ACPI_NAMESPACE_NODE *
 197 AcpiNsGetNextNodeTyped (
 198     ACPI_OBJECT_TYPE        Type,
 199     ACPI_NAMESPACE_NODE     *ParentNode,
 200     ACPI_NAMESPACE_NODE     *ChildNode)
 201 {
 202     ACPI_NAMESPACE_NODE     *NextNode = NULL;
 203
 204
 205     ACPI_FUNCTION_ENTRY ();
 206
 207
 208     NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
 209
 210     /* If any type is OK, we are done */
 211
 212     if (Type == ACPI_TYPE_ANY)
 213     {
 214         /* NextNode is NULL if we are at the end-of-list */
 215
 216         return (NextNode);
 217     }
 218
 219     /* Must search for the node -- but within this scope only */
 220
 221     while (NextNode)
 222     {
 223         /* If type matches, we are done */
 224
 225         if (NextNode->Type == Type)
 226         {
 227             return (NextNode);
 228         }
 229
 230         /* Otherwise, move on to the next node */
 231
 232         NextNode = AcpiNsGetNextValidNode (NextNode);
 233     }
 234
 235     /* Not found */
 236
 237     return (NULL);
 238 }
 239
 240
 241 /*******************************************************************************
 242  *
 243  * FUNCTION:    AcpiNsWalkNamespace
 244  *
 245  * PARAMETERS:  Type                - ACPI_OBJECT_TYPE to search for
 246  *              StartNode           - Handle in namespace where search begins
 247  *              MaxDepth            - Depth to which search is to reach
 248  *              Flags               - Whether to unlock the NS before invoking
 249  *                                    the callback routine
 250  *              PreOrderVisit       - Called during tree pre-order visit
 251  *                                    when an object of "Type" is found
 252  *              PostOrderVisit      - Called during tree post-order visit
 253  *                                    when an object of "Type" is found
 254  *              Context             - Passed to user function(s) above
 255  *              ReturnValue         - from the UserFunction if terminated
 256  *                                    early. Otherwise, returns NULL.
 257  * RETURNS:     Status
 258  *
 259  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 260  *              starting (and ending) at the node specified by StartHandle.
 261  *              The callback function is called whenever a node that matches
 262  *              the type parameter is found. If the callback function returns
 263  *              a non-zero value, the search is terminated immediately and
 264  *              this value is returned to the caller.
 265  *
 266  *              The point of this procedure is to provide a generic namespace
 267  *              walk routine that can be called from multiple places to
 268  *              provide multiple services; the callback function(s) can be
 269  *              tailored to each task, whether it is a print function,
 270  *              a compare function, etc.
 271  *
 272  ******************************************************************************/
 273
 274 ACPI_STATUS
 275 AcpiNsWalkNamespace (
 276     ACPI_OBJECT_TYPE        Type,
 277     ACPI_HANDLE             StartNode,
 278     UINT32                  MaxDepth,
 279     UINT32                  Flags,
 280     ACPI_WALK_CALLBACK      PreOrderVisit,
 281     ACPI_WALK_CALLBACK      PostOrderVisit,
 282     void                    *Context,
 283     void                    **ReturnValue)
 284 {
 285     ACPI_STATUS             Status;
 286     ACPI_STATUS             MutexStatus;
 287     ACPI_NAMESPACE_NODE     *ChildNode;
 288     ACPI_NAMESPACE_NODE     *ParentNode;
 289     ACPI_OBJECT_TYPE        ChildType;
 290     UINT32                  Level;
 291     BOOLEAN                 NodePreviouslyVisited = FALSE;
 292
 293
 294     ACPI_FUNCTION_TRACE (NsWalkNamespace);
 295
 296
 297     /* Special case for the namespace Root Node */
 298
 299     if (StartNode == ACPI_ROOT_OBJECT)
 300     {
 301         StartNode = AcpiGbl_RootNode;
 302     }
 303
 304     /* Null child means "get first node" */
 305
 306     ParentNode  = StartNode;
 307     ChildNode   = AcpiNsGetNextNode (ParentNode, NULL);
 308     ChildType   = ACPI_TYPE_ANY;
 309     Level       = 1;
 310
 311     /*
 312      * Traverse the tree of nodes until we bubble back up to where we
 313      * started. When Level is zero, the loop is done because we have
 314      * bubbled up to (and passed) the original parent handle (StartEntry)
 315      */
 316     while (Level > 0 && ChildNode)
 317     {
 318         Status = AE_OK;
 319
 320         /* Found next child, get the type if we are not searching for ANY */
 321
 322         if (Type != ACPI_TYPE_ANY)
 323         {
 324             ChildType = ChildNode->Type;
 325         }
 326
 327         /*
 328          * Ignore all temporary namespace nodes (created during control
 329          * method execution) unless told otherwise. These temporary nodes
 330          * can cause a race condition because they can be deleted during
 331          * the execution of the user function (if the namespace is
 332          * unlocked before invocation of the user function.) Only the
 333          * debugger namespace dump will examine the temporary nodes.
 334          */
 335         if ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
 336             !(Flags & ACPI_NS_WALK_TEMP_NODES))
 337         {
 338             Status = AE_CTRL_DEPTH;
 339         }
 340
 341         /* Type must match requested type */
 342
 343         else if (ChildType == Type)
 344         {
 345             /*
 346              * Found a matching node, invoke the user callback function.
 347              * Unlock the namespace if flag is set.
 348              */
 349             if (Flags & ACPI_NS_WALK_UNLOCK)
 350             {
 351                 MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
 352                 if (ACPI_FAILURE (MutexStatus))
 353                 {
 354                     return_ACPI_STATUS (MutexStatus);
 355                 }
 356             }
 357
 358             /*
 359              * Invoke the user function, either pre-order or post-order
 360              * or both.
 361              */
 362             if (!NodePreviouslyVisited)
 363             {
 364                 if (PreOrderVisit)
 365                 {
 366                     Status = PreOrderVisit (ChildNode, Level,
 367                                 Context, ReturnValue);
 368                 }
 369             }
 370             else
 371             {
 372                 if (PostOrderVisit)
 373                 {
 374                     Status = PostOrderVisit (ChildNode, Level,
 375                                 Context, ReturnValue);
 376                 }
 377             }
 378
 379             if (Flags & ACPI_NS_WALK_UNLOCK)
 380             {
 381                 MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
 382                 if (ACPI_FAILURE (MutexStatus))
 383                 {
 384                     return_ACPI_STATUS (MutexStatus);
 385                 }
 386             }
 387
 388             switch (Status)
 389             {
 390             case AE_OK:
 391             case AE_CTRL_DEPTH:
 392
 393                 /* Just keep going */
 394                 break;
 395
 396             case AE_CTRL_TERMINATE:
 397
 398                 /* Exit now, with OK status */
 399
 400                 return_ACPI_STATUS (AE_OK);
 401
 402             default:
 403
 404                 /* All others are valid exceptions */
 405
 406                 return_ACPI_STATUS (Status);
 407             }
 408         }
 409
 410         /*
 411          * Depth first search: Attempt to go down another level in the
 412          * namespace if we are allowed to.  Don't go any further if we have
 413          * reached the caller specified maximum depth or if the user
 414          * function has specified that the maximum depth has been reached.
 415          */
 416         if (!NodePreviouslyVisited &&
 417             (Level < MaxDepth) &&
 418             (Status != AE_CTRL_DEPTH))
 419         {
 420             if (ChildNode->Child)
 421             {
 422                 /* There is at least one child of this node, visit it */
 423
 424                 Level++;
 425                 ParentNode = ChildNode;
 426                 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
 427                 continue;
 428             }
 429         }
 430
 431         /* No more children, re-visit this node */
 432
 433         if (!NodePreviouslyVisited)
 434         {
 435             NodePreviouslyVisited = TRUE;
 436             continue;
 437         }
 438
 439         /* No more children, visit peers */
 440
 441         ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
 442         if (ChildNode)
 443         {
 444             NodePreviouslyVisited = FALSE;
 445         }
 446
 447         /* No peers, re-visit parent */
 448
 449         else
 450         {
 451             /*
 452              * No more children of this node (AcpiNsGetNextNode failed), go
 453              * back upwards in the namespace tree to the node's parent.
 454              */
 455             Level--;
 456             ChildNode = ParentNode;
 457             ParentNode = AcpiNsGetParentNode (ParentNode);
 458
 459             NodePreviouslyVisited = TRUE;
 460         }
 461     }
 462
 463     /* Complete walk, not terminated by user function */
 464
 465     return_ACPI_STATUS (AE_OK);
 466 }
 467
 468