/*******************************************************************************

 *

 * Module Name: nssearch - Namespace search

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2018, Intel Corp.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions, and the following disclaimer,

 *    without modification.

 * 2. Redistributions in binary form must reproduce at minimum a disclaimer

 *    substantially similar to the "NO WARRANTY" disclaimer below

 *    ("Disclaimer") and any redistribution must be conditioned upon

 *    including a substantially similar Disclaimer requirement for further

 *    binary redistribution.

 * 3. Neither the names of the above-listed copyright holders nor the names

 *    of any contributors may be used to endorse or promote products derived

 *    from this software without specific prior written permission.

 *

 * Alternatively, this software may be distributed under the terms of the

 * GNU General Public License ("GPL") version 2 as published by the Free

 * Software Foundation.

 *

 * NO WARRANTY

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGES.

 */

#include "acpi.h"

#include "accommon.h"

#include "acnamesp.h"

#ifdef ACPI_ASL_COMPILER

#include "amlcode.h"

#endif

#define _COMPONENT          ACPI_NAMESPACE

        ACPI_MODULE_NAME    ("nssearch")

/* Local prototypes */

static ACPI_STATUS

AcpiNsSearchParentTree (

    UINT32                  TargetName,

    ACPI_NAMESPACE_NODE     *Node,

    ACPI_OBJECT_TYPE        Type,

    ACPI_NAMESPACE_NODE     **ReturnNode);

/*******************************************************************************

 *

 * FUNCTION:    AcpiNsSearchOneScope

 *

 * PARAMETERS:  TargetName      - Ascii ACPI name to search for

 *              ParentNode      - Starting node where search will begin

 *              Type            - Object type to match

 *              ReturnNode      - Where the matched Named obj is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Search a single level of the namespace. Performs a

 *              simple search of the specified level, and does not add

 *              entries or search parents.

 *

 *

 *      Named object lists are built (and subsequently dumped) in the

 *      order in which the names are encountered during the namespace load;

 *

 *      All namespace searching is linear in this implementation, but

 *      could be easily modified to support any improved search

 *      algorithm. However, the linear search was chosen for simplicity

 *      and because the trees are small and the other interpreter

 *      execution overhead is relatively high.

 *

 *      Note: CPU execution analysis has shown that the AML interpreter spends

 *      a very small percentage of its time searching the namespace. Therefore,

 *      the linear search seems to be sufficient, as there would seem to be

 *      little value in improving the search.

 *

 ******************************************************************************/

ACPI_STATUS

AcpiNsSearchOneScope (

    UINT32                  TargetName,

    ACPI_NAMESPACE_NODE     *ParentNode,

    ACPI_OBJECT_TYPE        Type,

    ACPI_NAMESPACE_NODE     **ReturnNode)

{

    ACPI_NAMESPACE_NODE     *Node;

    ACPI_FUNCTION_TRACE (NsSearchOneScope);

#ifdef ACPI_DEBUG_OUTPUT

    if (ACPI_LV_NAMES & AcpiDbgLevel)

    {

        char                *ScopeName;

        ScopeName = AcpiNsGetNormalizedPathname (ParentNode, TRUE);

        if (ScopeName)

        {

            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

                "Searching %s (%p) For [%4.4s] (%s)\n",

                ScopeName, ParentNode, ACPI_CAST_PTR (char, &TargetName),

                AcpiUtGetTypeName (Type)));

            ACPI_FREE (ScopeName);

        }

    }

#endif

    /*

     * Search for name at this namespace level, which is to say that we

     * must search for the name among the children of this object

     */

    Node = ParentNode->Child;

    while (Node)

    {

        /* Check for match against the name */

        if (Node->Name.Integer == TargetName)

        {

            /* Resolve a control method alias if any */

            if (AcpiNsGetType (Node) == ACPI_TYPE_LOCAL_METHOD_ALIAS)

            {

                Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, Node->Object);

            }

            /* Found matching entry */

            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

                "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",

                ACPI_CAST_PTR (char, &TargetName),

                AcpiUtGetTypeName (Node->Type),

                Node, AcpiUtGetNodeName (ParentNode), ParentNode));

            *ReturnNode = Node;

            return_ACPI_STATUS (AE_OK);

        }

        /* Didn't match name, move on to the next peer object */

        Node = Node->Peer;

    }

    /* Searched entire namespace level, not found */

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

        "Name [%4.4s] (%s) not found in search in scope [%4.4s] "

        "%p first child %p\n",

        ACPI_CAST_PTR (char, &TargetName), AcpiUtGetTypeName (Type),

        AcpiUtGetNodeName (ParentNode), ParentNode, ParentNode->Child));

    return_ACPI_STATUS (AE_NOT_FOUND);

}

/*******************************************************************************

 *

 * FUNCTION:    AcpiNsSearchParentTree

 *

 * PARAMETERS:  TargetName      - Ascii ACPI name to search for

 *              Node            - Starting node where search will begin

 *              Type            - Object type to match

 *              ReturnNode      - Where the matched Node is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Called when a name has not been found in the current namespace

 *              level. Before adding it or giving up, ACPI scope rules require

 *              searching enclosing scopes in cases identified by AcpiNsLocal().

 *

 *              "A name is located by finding the matching name in the current

 *              name space, and then in the parent name space. If the parent

 *              name space does not contain the name, the search continues

 *              recursively until either the name is found or the name space

 *              does not have a parent (the root of the name space). This

 *              indicates that the name is not found" (From ACPI Specification,

 *              section 5.3)

 *

 ******************************************************************************/

static ACPI_STATUS

AcpiNsSearchParentTree (

    UINT32                  TargetName,

    ACPI_NAMESPACE_NODE     *Node,

    ACPI_OBJECT_TYPE        Type,

    ACPI_NAMESPACE_NODE     **ReturnNode)

{

    ACPI_STATUS             Status;

    ACPI_NAMESPACE_NODE     *ParentNode;

    ACPI_FUNCTION_TRACE (NsSearchParentTree);

    ParentNode = Node->Parent;

    /*

     * If there is no parent (i.e., we are at the root) or type is "local",

     * we won't be searching the parent tree.

     */

    if (!ParentNode)

    {

        ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "[%4.4s] has no parent\n",

            ACPI_CAST_PTR (char, &TargetName)));

        return_ACPI_STATUS (AE_NOT_FOUND);

    }

    if (AcpiNsLocal (Type))

    {

        ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

            "[%4.4s] type [%s] must be local to this scope (no parent search)\n",

            ACPI_CAST_PTR (char, &TargetName), AcpiUtGetTypeName (Type)));

        return_ACPI_STATUS (AE_NOT_FOUND);

    }

    /* Search the parent tree */

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

        "Searching parent [%4.4s] for [%4.4s]\n",

        AcpiUtGetNodeName (ParentNode), ACPI_CAST_PTR (char, &TargetName)));

    /* Search parents until target is found or we have backed up to the root */

    while (ParentNode)

    {

        /*

         * Search parent scope. Use TYPE_ANY because we don't care about the

         * object type at this point, we only care about the existence of

         * the actual name we are searching for. Typechecking comes later.

         */

        Status = AcpiNsSearchOneScope (

            TargetName, ParentNode, ACPI_TYPE_ANY, ReturnNode);

        if (ACPI_SUCCESS (Status))

        {

            return_ACPI_STATUS (Status);

        }

        /* Not found here, go up another level (until we reach the root) */

        ParentNode = ParentNode->Parent;

    }

    /* Not found in parent tree */

    return_ACPI_STATUS (AE_NOT_FOUND);

}

/*******************************************************************************

 *

 * FUNCTION:    AcpiNsSearchAndEnter

 *

 * PARAMETERS:  TargetName          - Ascii ACPI name to search for (4 chars)

 *              WalkState           - Current state of the walk

 *              Node                - Starting node where search will begin

 *              InterpreterMode     - Add names only in ACPI_MODE_LOAD_PASS_x.

 *                                    Otherwise,search only.

 *              Type                - Object type to match

 *              Flags               - Flags describing the search restrictions

 *              ReturnNode          - Where the Node is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Search for a name segment in a single namespace level,

 *              optionally adding it if it is not found. If the passed

 *              Type is not Any and the type previously stored in the

 *              entry was Any (i.e. unknown), update the stored type.

 *

 *              In ACPI_IMODE_EXECUTE, search only.

 *              In other modes, search and add if not found.

 *

 ******************************************************************************/

ACPI_STATUS

AcpiNsSearchAndEnter (

    UINT32                  TargetName,

    ACPI_WALK_STATE         *WalkState,

    ACPI_NAMESPACE_NODE     *Node,

    ACPI_INTERPRETER_MODE   InterpreterMode,

    ACPI_OBJECT_TYPE        Type,

    UINT32                  Flags,

    ACPI_NAMESPACE_NODE     **ReturnNode)

{

    ACPI_STATUS             Status;

    ACPI_NAMESPACE_NODE     *NewNode;

    ACPI_FUNCTION_TRACE (NsSearchAndEnter);

    /* Parameter validation */

    if (!Node || !TargetName || !ReturnNode)

    {

        ACPI_ERROR ((AE_INFO,

            "Null parameter: Node %p Name 0x%X ReturnNode %p",

            Node, TargetName, ReturnNode));

        return_ACPI_STATUS (AE_BAD_PARAMETER);

    }

    /*

     * Name must consist of valid ACPI characters. We will repair the name if

     * necessary because we don't want to abort because of this, but we want

     * all namespace names to be printable. A warning message is appropriate.

     *

     * This issue came up because there are in fact machines that exhibit

     * this problem, and we want to be able to enable ACPI support for them,

     * even though there are a few bad names.

     */

    AcpiUtRepairName (ACPI_CAST_PTR (char, &TargetName));

    /* Try to find the name in the namespace level specified by the caller */

    *ReturnNode = ACPI_ENTRY_NOT_FOUND;

    Status = AcpiNsSearchOneScope (TargetName, Node, Type, ReturnNode);

    if (Status != AE_NOT_FOUND)

    {

        /*

         * If we found it AND the request specifies that a find is an error,

         * return the error

         */

        if (Status == AE_OK)

        {

            /* The node was found in the namespace */

            /*

             * If the namespace override feature is enabled for this node,

             * delete any existing attached sub-object and make the node

             * look like a new node that is owned by the override table.

             */

            if (Flags & ACPI_NS_OVERRIDE_IF_FOUND)

            {

                ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

                    "Namespace override: %4.4s pass %u type %X Owner %X\n",

                    ACPI_CAST_PTR(char, &TargetName), InterpreterMode,

                    (*ReturnNode)->Type, WalkState->OwnerId));

                AcpiNsDeleteChildren (*ReturnNode);

                if (AcpiGbl_RuntimeNamespaceOverride)

                {

                    AcpiUtRemoveReference ((*ReturnNode)->Object);

                    (*ReturnNode)->Object = NULL;

                    (*ReturnNode)->OwnerId = WalkState->OwnerId;

                }

                else

                {

                    AcpiNsRemoveNode (*ReturnNode);

                    *ReturnNode = ACPI_ENTRY_NOT_FOUND;

                }

            }

            /* Return an error if we don't expect to find the object */

            else if (Flags & ACPI_NS_ERROR_IF_FOUND)

            {

                Status = AE_ALREADY_EXISTS;

            }

        }

#ifdef ACPI_ASL_COMPILER

        if (*ReturnNode && (*ReturnNode)->Type == ACPI_TYPE_ANY)

        {

            (*ReturnNode)->Flags |= ANOBJ_IS_EXTERNAL;

        }

#endif

        /* Either found it or there was an error: finished either way */

        return_ACPI_STATUS (Status);

    }

    /*

     * The name was not found. If we are NOT performing the first pass

     * (name entry) of loading the namespace, search the parent tree (all the

     * way to the root if necessary.) We don't want to perform the parent

     * search when the namespace is actually being loaded. We want to perform

     * the search when namespace references are being resolved (load pass 2)

     * and during the execution phase.

     */

    if ((InterpreterMode != ACPI_IMODE_LOAD_PASS1) &&

        (Flags & ACPI_NS_SEARCH_PARENT))

    {

        /*

         * Not found at this level - search parent tree according to the

         * ACPI specification

         */

        Status = AcpiNsSearchParentTree (TargetName, Node, Type, ReturnNode);

        if (ACPI_SUCCESS (Status))

        {

            return_ACPI_STATUS (Status);

        }

    }

    /* In execute mode, just search, never add names. Exit now */

    if (InterpreterMode == ACPI_IMODE_EXECUTE)

    {

        ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,

            "%4.4s Not found in %p [Not adding]\n",

            ACPI_CAST_PTR (char, &TargetName), Node));

        return_ACPI_STATUS (AE_NOT_FOUND);

    }

    /* Create the new named object */

    NewNode = AcpiNsCreateNode (TargetName);

    if (!NewNode)

    {

        return_ACPI_STATUS (AE_NO_MEMORY);

    }

#ifdef ACPI_ASL_COMPILER

    /* Node is an object defined by an External() statement */

    if (Flags & ACPI_NS_EXTERNAL ||

        (WalkState && WalkState->Opcode == AML_SCOPE_OP))

    {

        NewNode->Flags |= ANOBJ_IS_EXTERNAL;

    }

#endif

    if (Flags & ACPI_NS_TEMPORARY)

    {

        NewNode->Flags |= ANOBJ_TEMPORARY;

    }

    /* Install the new object into the parent's list of children */

    AcpiNsInstallNode (WalkState, Node, NewNode, Type);

    *ReturnNode = NewNode;

    return_ACPI_STATUS (AE_OK);

}