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

   1 /*******************************************************************************
   2  *
   3  * Module Name: nssearch - Namespace search
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46 #include "acnamesp.h"
  47
  48 #ifdef ACPI_ASL_COMPILER
  49 #include "amlcode.h"
  50 #endif
  51
  52 #define _COMPONENT          ACPI_NAMESPACE
  53         ACPI_MODULE_NAME    ("nssearch")
  54
  55 /* Local prototypes */
  56
  57 static ACPI_STATUS
  58 AcpiNsSearchParentTree (
  59     UINT32                  TargetName,
  60     ACPI_NAMESPACE_NODE     *Node,
  61     ACPI_OBJECT_TYPE        Type,
  62     ACPI_NAMESPACE_NODE     **ReturnNode);
  63
  64
  65 /*******************************************************************************
  66  *
  67  * FUNCTION:    AcpiNsSearchOneScope
  68  *
  69  * PARAMETERS:  TargetName      - Ascii ACPI name to search for
  70  *              ParentNode      - Starting node where search will begin
  71  *              Type            - Object type to match
  72  *              ReturnNode      - Where the matched Named obj is returned
  73  *
  74  * RETURN:      Status
  75  *
  76  * DESCRIPTION: Search a single level of the namespace. Performs a
  77  *              simple search of the specified level, and does not add
  78  *              entries or search parents.
  79  *
  80  *
  81  *      Named object lists are built (and subsequently dumped) in the
  82  *      order in which the names are encountered during the namespace load;
  83  *
  84  *      All namespace searching is linear in this implementation, but
  85  *      could be easily modified to support any improved search
  86  *      algorithm. However, the linear search was chosen for simplicity
  87  *      and because the trees are small and the other interpreter
  88  *      execution overhead is relatively high.
  89  *
  90  *      Note: CPU execution analysis has shown that the AML interpreter spends
  91  *      a very small percentage of its time searching the namespace. Therefore,
  92  *      the linear search seems to be sufficient, as there would seem to be
  93  *      little value in improving the search.
  94  *
  95  ******************************************************************************/
  96
  97 ACPI_STATUS
  98 AcpiNsSearchOneScope (
  99     UINT32                  TargetName,
 100     ACPI_NAMESPACE_NODE     *ParentNode,
 101     ACPI_OBJECT_TYPE        Type,
 102     ACPI_NAMESPACE_NODE     **ReturnNode)
 103 {
 104     ACPI_NAMESPACE_NODE     *Node;
 105
 106
 107     ACPI_FUNCTION_TRACE (NsSearchOneScope);
 108
 109
 110 #ifdef ACPI_DEBUG_OUTPUT
 111     if (ACPI_LV_NAMES & AcpiDbgLevel)
 112     {
 113         char                *ScopeName;
 114
 115         ScopeName = AcpiNsGetNormalizedPathname (ParentNode, TRUE);
 116         if (ScopeName)
 117         {
 118             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 119                 "Searching %s (%p) For [%4.4s] (%s)\n",
 120                 ScopeName, ParentNode, ACPI_CAST_PTR (char, &TargetName),
 121                 AcpiUtGetTypeName (Type)));
 122
 123             ACPI_FREE (ScopeName);
 124         }
 125     }
 126 #endif
 127
 128     /*
 129      * Search for name at this namespace level, which is to say that we
 130      * must search for the name among the children of this object
 131      */
 132     Node = ParentNode->Child;
 133     while (Node)
 134     {
 135         /* Check for match against the name */
 136
 137         if (Node->Name.Integer == TargetName)
 138         {
 139             /* Resolve a control method alias if any */
 140
 141             if (AcpiNsGetType (Node) == ACPI_TYPE_LOCAL_METHOD_ALIAS)
 142             {
 143                 Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, Node->Object);
 144             }
 145
 146             /* Found matching entry */
 147
 148             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 149                 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
 150                 ACPI_CAST_PTR (char, &TargetName),
 151                 AcpiUtGetTypeName (Node->Type),
 152                 Node, AcpiUtGetNodeName (ParentNode), ParentNode));
 153
 154             *ReturnNode = Node;
 155             return_ACPI_STATUS (AE_OK);
 156         }
 157
 158         /* Didn't match name, move on to the next peer object */
 159
 160         Node = Node->Peer;
 161     }
 162
 163     /* Searched entire namespace level, not found */
 164
 165     ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 166         "Name [%4.4s] (%s) not found in search in scope [%4.4s] "
 167         "%p first child %p\n",
 168         ACPI_CAST_PTR (char, &TargetName), AcpiUtGetTypeName (Type),
 169         AcpiUtGetNodeName (ParentNode), ParentNode, ParentNode->Child));
 170
 171     return_ACPI_STATUS (AE_NOT_FOUND);
 172 }
 173
 174
 175 /*******************************************************************************
 176  *
 177  * FUNCTION:    AcpiNsSearchParentTree
 178  *
 179  * PARAMETERS:  TargetName      - Ascii ACPI name to search for
 180  *              Node            - Starting node where search will begin
 181  *              Type            - Object type to match
 182  *              ReturnNode      - Where the matched Node is returned
 183  *
 184  * RETURN:      Status
 185  *
 186  * DESCRIPTION: Called when a name has not been found in the current namespace
 187  *              level. Before adding it or giving up, ACPI scope rules require
 188  *              searching enclosing scopes in cases identified by AcpiNsLocal().
 189  *
 190  *              "A name is located by finding the matching name in the current
 191  *              name space, and then in the parent name space. If the parent
 192  *              name space does not contain the name, the search continues
 193  *              recursively until either the name is found or the name space
 194  *              does not have a parent (the root of the name space). This
 195  *              indicates that the name is not found" (From ACPI Specification,
 196  *              section 5.3)
 197  *
 198  ******************************************************************************/
 199
 200 static ACPI_STATUS
 201 AcpiNsSearchParentTree (
 202     UINT32                  TargetName,
 203     ACPI_NAMESPACE_NODE     *Node,
 204     ACPI_OBJECT_TYPE        Type,
 205     ACPI_NAMESPACE_NODE     **ReturnNode)
 206 {
 207     ACPI_STATUS             Status;
 208     ACPI_NAMESPACE_NODE     *ParentNode;
 209
 210
 211     ACPI_FUNCTION_TRACE (NsSearchParentTree);
 212
 213
 214     ParentNode = Node->Parent;
 215
 216     /*
 217      * If there is no parent (i.e., we are at the root) or type is "local",
 218      * we won't be searching the parent tree.
 219      */
 220     if (!ParentNode)
 221     {
 222         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
 223             ACPI_CAST_PTR (char, &TargetName)));
 224         return_ACPI_STATUS (AE_NOT_FOUND);
 225     }
 226
 227     if (AcpiNsLocal (Type))
 228     {
 229         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 230             "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
 231             ACPI_CAST_PTR (char, &TargetName), AcpiUtGetTypeName (Type)));
 232         return_ACPI_STATUS (AE_NOT_FOUND);
 233     }
 234
 235     /* Search the parent tree */
 236
 237     ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 238         "Searching parent [%4.4s] for [%4.4s]\n",
 239         AcpiUtGetNodeName (ParentNode), ACPI_CAST_PTR (char, &TargetName)));
 240
 241     /* Search parents until target is found or we have backed up to the root */
 242
 243     while (ParentNode)
 244     {
 245         /*
 246          * Search parent scope. Use TYPE_ANY because we don't care about the
 247          * object type at this point, we only care about the existence of
 248          * the actual name we are searching for. Typechecking comes later.
 249          */
 250         Status = AcpiNsSearchOneScope (
 251             TargetName, ParentNode, ACPI_TYPE_ANY, ReturnNode);
 252         if (ACPI_SUCCESS (Status))
 253         {
 254             return_ACPI_STATUS (Status);
 255         }
 256
 257         /* Not found here, go up another level (until we reach the root) */
 258
 259         ParentNode = ParentNode->Parent;
 260     }
 261
 262     /* Not found in parent tree */
 263
 264     return_ACPI_STATUS (AE_NOT_FOUND);
 265 }
 266
 267
 268 /*******************************************************************************
 269  *
 270  * FUNCTION:    AcpiNsSearchAndEnter
 271  *
 272  * PARAMETERS:  TargetName          - Ascii ACPI name to search for (4 chars)
 273  *              WalkState           - Current state of the walk
 274  *              Node                - Starting node where search will begin
 275  *              InterpreterMode     - Add names only in ACPI_MODE_LOAD_PASS_x.
 276  *                                    Otherwise,search only.
 277  *              Type                - Object type to match
 278  *              Flags               - Flags describing the search restrictions
 279  *              ReturnNode          - Where the Node is returned
 280  *
 281  * RETURN:      Status
 282  *
 283  * DESCRIPTION: Search for a name segment in a single namespace level,
 284  *              optionally adding it if it is not found. If the passed
 285  *              Type is not Any and the type previously stored in the
 286  *              entry was Any (i.e. unknown), update the stored type.
 287  *
 288  *              In ACPI_IMODE_EXECUTE, search only.
 289  *              In other modes, search and add if not found.
 290  *
 291  ******************************************************************************/
 292
 293 ACPI_STATUS
 294 AcpiNsSearchAndEnter (
 295     UINT32                  TargetName,
 296     ACPI_WALK_STATE         *WalkState,
 297     ACPI_NAMESPACE_NODE     *Node,
 298     ACPI_INTERPRETER_MODE   InterpreterMode,
 299     ACPI_OBJECT_TYPE        Type,
 300     UINT32                  Flags,
 301     ACPI_NAMESPACE_NODE     **ReturnNode)
 302 {
 303     ACPI_STATUS             Status;
 304     ACPI_NAMESPACE_NODE     *NewNode;
 305
 306
 307     ACPI_FUNCTION_TRACE (NsSearchAndEnter);
 308
 309
 310     /* Parameter validation */
 311
 312     if (!Node || !TargetName || !ReturnNode)
 313     {
 314         ACPI_ERROR ((AE_INFO,
 315             "Null parameter: Node %p Name 0x%X ReturnNode %p",
 316             Node, TargetName, ReturnNode));
 317         return_ACPI_STATUS (AE_BAD_PARAMETER);
 318     }
 319
 320     /*
 321      * Name must consist of valid ACPI characters. We will repair the name if
 322      * necessary because we don't want to abort because of this, but we want
 323      * all namespace names to be printable. A warning message is appropriate.
 324      *
 325      * This issue came up because there are in fact machines that exhibit
 326      * this problem, and we want to be able to enable ACPI support for them,
 327      * even though there are a few bad names.
 328      */
 329     AcpiUtRepairName (ACPI_CAST_PTR (char, &TargetName));
 330
 331     /* Try to find the name in the namespace level specified by the caller */
 332
 333     *ReturnNode = ACPI_ENTRY_NOT_FOUND;
 334     Status = AcpiNsSearchOneScope (TargetName, Node, Type, ReturnNode);
 335     if (Status != AE_NOT_FOUND)
 336     {
 337         /*
 338          * If we found it AND the request specifies that a find is an error,
 339          * return the error
 340          */
 341         if (Status == AE_OK)
 342         {
 343             /* The node was found in the namespace */
 344
 345             /*
 346              * If the namespace override feature is enabled for this node,
 347              * delete any existing attached sub-object and make the node
 348              * look like a new node that is owned by the override table.
 349              */
 350             if (Flags & ACPI_NS_OVERRIDE_IF_FOUND)
 351             {
 352                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 353                     "Namespace override: %4.4s pass %u type %X Owner %X\n",
 354                     ACPI_CAST_PTR(char, &TargetName), InterpreterMode,
 355                     (*ReturnNode)->Type, WalkState->OwnerId));
 356
 357                 AcpiNsDeleteChildren (*ReturnNode);
 358                 if (AcpiGbl_RuntimeNamespaceOverride)
 359                 {
 360                     AcpiUtRemoveReference ((*ReturnNode)->Object);
 361                     (*ReturnNode)->Object = NULL;
 362                     (*ReturnNode)->OwnerId = WalkState->OwnerId;
 363                 }
 364                 else
 365                 {
 366                     AcpiNsRemoveNode (*ReturnNode);
 367                     *ReturnNode = ACPI_ENTRY_NOT_FOUND;
 368                 }
 369             }
 370
 371             /* Return an error if we don't expect to find the object */
 372
 373             else if (Flags & ACPI_NS_ERROR_IF_FOUND)
 374             {
 375                 Status = AE_ALREADY_EXISTS;
 376             }
 377         }
 378
 379 #ifdef ACPI_ASL_COMPILER
 380         if (*ReturnNode && (*ReturnNode)->Type == ACPI_TYPE_ANY)
 381         {
 382             (*ReturnNode)->Flags |= ANOBJ_IS_EXTERNAL;
 383         }
 384 #endif
 385
 386         /* Either found it or there was an error: finished either way */
 387
 388         return_ACPI_STATUS (Status);
 389     }
 390
 391     /*
 392      * The name was not found. If we are NOT performing the first pass
 393      * (name entry) of loading the namespace, search the parent tree (all the
 394      * way to the root if necessary.) We don't want to perform the parent
 395      * search when the namespace is actually being loaded. We want to perform
 396      * the search when namespace references are being resolved (load pass 2)
 397      * and during the execution phase.
 398      */
 399     if ((InterpreterMode != ACPI_IMODE_LOAD_PASS1) &&
 400         (Flags & ACPI_NS_SEARCH_PARENT))
 401     {
 402         /*
 403          * Not found at this level - search parent tree according to the
 404          * ACPI specification
 405          */
 406         Status = AcpiNsSearchParentTree (TargetName, Node, Type, ReturnNode);
 407         if (ACPI_SUCCESS (Status))
 408         {
 409             return_ACPI_STATUS (Status);
 410         }
 411     }
 412
 413     /* In execute mode, just search, never add names. Exit now */
 414
 415     if (InterpreterMode == ACPI_IMODE_EXECUTE)
 416     {
 417         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 418             "%4.4s Not found in %p [Not adding]\n",
 419             ACPI_CAST_PTR (char, &TargetName), Node));
 420
 421         return_ACPI_STATUS (AE_NOT_FOUND);
 422     }
 423
 424     /* Create the new named object */
 425
 426     NewNode = AcpiNsCreateNode (TargetName);
 427     if (!NewNode)
 428     {
 429         return_ACPI_STATUS (AE_NO_MEMORY);
 430     }
 431
 432 #ifdef ACPI_ASL_COMPILER
 433
 434     /* Node is an object defined by an External() statement */
 435
 436     if (Flags & ACPI_NS_EXTERNAL ||
 437         (WalkState && WalkState->Opcode == AML_SCOPE_OP))
 438     {
 439         NewNode->Flags |= ANOBJ_IS_EXTERNAL;
 440         NewNode->Flags |= IMPLICIT_EXTERNAL;
 441     }
 442 #endif
 443
 444     if (Flags & ACPI_NS_TEMPORARY)
 445     {
 446         NewNode->Flags |= ANOBJ_TEMPORARY;
 447     }
 448
 449     /* Install the new object into the parent's list of children */
 450
 451     AcpiNsInstallNode (WalkState, Node, NewNode, Type);
 452     *ReturnNode = NewNode;
 453     return_ACPI_STATUS (AE_OK);
 454 }