nssearch.c

acpi tools for linux include acpiexec and acpixtract

 *
 * 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 = AcpiNsGetParentNode (Node);

    /*
     * 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 = AcpiNsGetParentNode (ParentNode);
    }

    /* 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 %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.
     */
    if (!AcpiUtValidAcpiName (TargetName))
    {
        TargetName = AcpiUtRepairName (ACPI_CAST_PTR (char, &TargetName));

        /* Report warning only if in strict mode or debug mode */

        if (!AcpiGbl_EnableInterpreterSlack)
        {
            ACPI_WARNING ((AE_INFO,
                "Found bad character(s) in name, repaired: [%4.4s]\n",
                ACPI_CAST_PTR (char, &TargetName)));
        }
        else
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_WARN,
                "Found bad character(s) in name, repaired: [%4.4s]\n",
                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) &&
            (Flags & ACPI_NS_ERROR_IF_FOUND))
        {
            Status = AE_ALREADY_EXISTS;
        }

        /* 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)
    {
        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);
}