async_tx: avoid the async xor_zero_sum path when src_cnt > device->max_xor

[wrt350n-kernel.git] / drivers / acpi / namespace / nsutils.c

/******************************************************************************
 *
 * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
 *                        parents and siblings and Scope manipulation
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * 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/acpi.h>
#include <acpi/acnamesp.h>
#include <acpi/amlcode.h>
#include <acpi/actables.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsutils")

/* Local prototypes */
static u8 acpi_ns_valid_path_separator(char sep);

#ifdef ACPI_OBSOLETE_FUNCTIONS
acpi_name acpi_ns_find_parent_name(struct acpi_namespace_node *node_to_search);
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_report_error
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *              internal_name       - Name or path of the namespace node
 *              lookup_status       - Exception code from NS lookup
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print warning message with full pathname
 *
 ******************************************************************************/

void
acpi_ns_report_error(char *module_name,
                     u32 line_number,
                     char *internal_name, acpi_status lookup_status)
{
        acpi_status status;
        u32 bad_name;
        char *name = NULL;

        acpi_os_printf("ACPI Error (%s-%04d): ", module_name, line_number);

        if (lookup_status == AE_BAD_CHARACTER) {

                /* There is a non-ascii character in the name */

                ACPI_MOVE_32_TO_32(&bad_name, internal_name);
                acpi_os_printf("[0x%4.4X] (NON-ASCII)", bad_name);
        } else {
                /* Convert path to external format */

                status = acpi_ns_externalize_name(ACPI_UINT32_MAX,
                                                  internal_name, NULL, &name);

                /* Print target name */

                if (ACPI_SUCCESS(status)) {
                        acpi_os_printf("[%s]", name);
                } else {
                        acpi_os_printf("[COULD NOT EXTERNALIZE NAME]");
                }

                if (name) {
                        ACPI_FREE(name);
                }
        }

        acpi_os_printf(" Namespace lookup failure, %s\n",
                       acpi_format_exception(lookup_status));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_report_method_error
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *              Message             - Error message to use on failure
 *              prefix_node         - Prefix relative to the path
 *              Path                - Path to the node (optional)
 *              method_status       - Execution status
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print warning message with full pathname
 *
 ******************************************************************************/

void
acpi_ns_report_method_error(char *module_name,
                            u32 line_number,
                            char *message,
                            struct acpi_namespace_node *prefix_node,
                            char *path, acpi_status method_status)
{
        acpi_status status;
        struct acpi_namespace_node *node = prefix_node;

        acpi_os_printf("ACPI Error (%s-%04d): ", module_name, line_number);

        if (path) {
                status =
                    acpi_ns_get_node(prefix_node, path, ACPI_NS_NO_UPSEARCH,
                                     &node);
                if (ACPI_FAILURE(status)) {
                        acpi_os_printf("[Could not get node by pathname]");
                }
        }

        acpi_ns_print_node_pathname(node, message);
        acpi_os_printf(", %s\n", acpi_format_exception(method_status));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_print_node_pathname
 *
 * PARAMETERS:  Node            - Object
 *              Message         - Prefix message
 *
 * DESCRIPTION: Print an object's full namespace pathname
 *              Manages allocation/freeing of a pathname buffer
 *
 ******************************************************************************/

void
acpi_ns_print_node_pathname(struct acpi_namespace_node *node, char *message)
{
        struct acpi_buffer buffer;
        acpi_status status;

        if (!node) {
                acpi_os_printf("[NULL NAME]");
                return;
        }

        /* Convert handle to full pathname and print it (with supplied message) */

        buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;

        status = acpi_ns_handle_to_pathname(node, &buffer);
        if (ACPI_SUCCESS(status)) {
                if (message) {
                        acpi_os_printf("%s ", message);
                }

                acpi_os_printf("[%s] (Node %p)", (char *)buffer.pointer, node);
                ACPI_FREE(buffer.pointer);
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_valid_root_prefix
 *
 * PARAMETERS:  Prefix          - Character to be checked
 *
 * RETURN:      TRUE if a valid prefix
 *
 * DESCRIPTION: Check if a character is a valid ACPI Root prefix
 *
 ******************************************************************************/

u8 acpi_ns_valid_root_prefix(char prefix)
{

        return ((u8) (prefix == '\\'));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_valid_path_separator
 *
 * PARAMETERS:  Sep         - Character to be checked
 *
 * RETURN:      TRUE if a valid path separator
 *
 * DESCRIPTION: Check if a character is a valid ACPI path separator
 *
 ******************************************************************************/

static u8 acpi_ns_valid_path_separator(char sep)
{

        return ((u8) (sep == '.'));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_type
 *
 * PARAMETERS:  Node        - Parent Node to be examined
 *
 * RETURN:      Type field from Node whose handle is passed
 *
 * DESCRIPTION: Return the type of a Namespace node
 *
 ******************************************************************************/

acpi_object_type acpi_ns_get_type(struct acpi_namespace_node * node)
{
        ACPI_FUNCTION_TRACE(ns_get_type);

        if (!node) {
                ACPI_WARNING((AE_INFO, "Null Node parameter"));
                return_UINT32(ACPI_TYPE_ANY);
        }

        return_UINT32((acpi_object_type) node->type);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_local
 *
 * PARAMETERS:  Type        - A namespace object type
 *
 * RETURN:      LOCAL if names must be found locally in objects of the
 *              passed type, 0 if enclosing scopes should be searched
 *
 * DESCRIPTION: Returns scope rule for the given object type.
 *
 ******************************************************************************/

u32 acpi_ns_local(acpi_object_type type)
{
        ACPI_FUNCTION_TRACE(ns_local);

        if (!acpi_ut_valid_object_type(type)) {

                /* Type code out of range  */

                ACPI_WARNING((AE_INFO, "Invalid Object Type %X", type));
                return_UINT32(ACPI_NS_NORMAL);
        }

        return_UINT32((u32) acpi_gbl_ns_properties[type] & ACPI_NS_LOCAL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_internal_name_length
 *
 * PARAMETERS:  Info            - Info struct initialized with the
 *                                external name pointer.
 *
 * RETURN:      None
 *
 * DESCRIPTION: Calculate the length of the internal (AML) namestring
 *              corresponding to the external (ASL) namestring.
 *
 ******************************************************************************/

void acpi_ns_get_internal_name_length(struct acpi_namestring_info *info)
{
        char *next_external_char;
        u32 i;

        ACPI_FUNCTION_ENTRY();

        next_external_char = info->external_name;
        info->num_carats = 0;
        info->num_segments = 0;
        info->fully_qualified = FALSE;

        /*
         * For the internal name, the required length is 4 bytes per segment, plus
         * 1 each for root_prefix, multi_name_prefix_op, segment count, trailing null
         * (which is not really needed, but no there's harm in putting it there)
         *
         * strlen() + 1 covers the first name_seg, which has no path separator
         */
        if (acpi_ns_valid_root_prefix(next_external_char[0])) {
                info->fully_qualified = TRUE;
                next_external_char++;
        } else {
                /*
                 * Handle Carat prefixes
                 */
                while (*next_external_char == '^') {
                        info->num_carats++;
                        next_external_char++;
                }
        }

        /*
         * Determine the number of ACPI name "segments" by counting the number of
         * path separators within the string. Start with one segment since the
         * segment count is [(# separators) + 1], and zero separators is ok.
         */
        if (*next_external_char) {
                info->num_segments = 1;
                for (i = 0; next_external_char[i]; i++) {
                        if (acpi_ns_valid_path_separator(next_external_char[i])) {
                                info->num_segments++;
                        }
                }
        }

        info->length = (ACPI_NAME_SIZE * info->num_segments) +
            4 + info->num_carats;

        info->next_external_char = next_external_char;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_build_internal_name
 *
 * PARAMETERS:  Info            - Info struct fully initialized
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Construct the internal (AML) namestring
 *              corresponding to the external (ASL) namestring.
 *
 ******************************************************************************/

acpi_status acpi_ns_build_internal_name(struct acpi_namestring_info *info)
{
        u32 num_segments = info->num_segments;
        char *internal_name = info->internal_name;
        char *external_name = info->next_external_char;
        char *result = NULL;
        acpi_native_uint i;

        ACPI_FUNCTION_TRACE(ns_build_internal_name);

        /* Setup the correct prefixes, counts, and pointers */

        if (info->fully_qualified) {
                internal_name[0] = '\\';

                if (num_segments <= 1) {
                        result = &internal_name[1];
                } else if (num_segments == 2) {
                        internal_name[1] = AML_DUAL_NAME_PREFIX;
                        result = &internal_name[2];
                } else {
                        internal_name[1] = AML_MULTI_NAME_PREFIX_OP;
                        internal_name[2] = (char)num_segments;
                        result = &internal_name[3];
                }
        } else {
                /*
                 * Not fully qualified.
                 * Handle Carats first, then append the name segments
                 */
                i = 0;
                if (info->num_carats) {
                        for (i = 0; i < info->num_carats; i++) {
                                internal_name[i] = '^';
                        }
                }

                if (num_segments <= 1) {
                        result = &internal_name[i];
                } else if (num_segments == 2) {
                        internal_name[i] = AML_DUAL_NAME_PREFIX;
                        result = &internal_name[(acpi_native_uint) (i + 1)];
                } else {
                        internal_name[i] = AML_MULTI_NAME_PREFIX_OP;
                        internal_name[(acpi_native_uint) (i + 1)] =
                            (char)num_segments;
                        result = &internal_name[(acpi_native_uint) (i + 2)];
                }
        }

        /* Build the name (minus path separators) */

        for (; num_segments; num_segments--) {
                for (i = 0; i < ACPI_NAME_SIZE; i++) {
                        if (acpi_ns_valid_path_separator(*external_name) ||
                            (*external_name == 0)) {

                                /* Pad the segment with underscore(s) if segment is short */

                                result[i] = '_';
                        } else {
                                /* Convert the character to uppercase and save it */

                                result[i] =
                                    (char)ACPI_TOUPPER((int)*external_name);
                                external_name++;
                        }
                }

                /* Now we must have a path separator, or the pathname is bad */

                if (!acpi_ns_valid_path_separator(*external_name) &&
                    (*external_name != 0)) {
                        return_ACPI_STATUS(AE_BAD_PARAMETER);
                }

                /* Move on the next segment */

                external_name++;
                result += ACPI_NAME_SIZE;
        }

        /* Terminate the string */

        *result = 0;

        if (info->fully_qualified) {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "Returning [%p] (abs) \"\\%s\"\n",
                                  internal_name, internal_name));
        } else {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Returning [%p] (rel) \"%s\"\n",
                                  internal_name, internal_name));
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_internalize_name
 *
 * PARAMETERS:  *external_name          - External representation of name
 *              **Converted Name        - Where to return the resulting
 *                                        internal represention of the name
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
 *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *
 *******************************************************************************/

acpi_status acpi_ns_internalize_name(char *external_name, char **converted_name)
{
        char *internal_name;
        struct acpi_namestring_info info;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_internalize_name);

        if ((!external_name) || (*external_name == 0) || (!converted_name)) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /* Get the length of the new internal name */

        info.external_name = external_name;
        acpi_ns_get_internal_name_length(&info);

        /* We need a segment to store the internal  name */

        internal_name = ACPI_ALLOCATE_ZEROED(info.length);
        if (!internal_name) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Build the name */

        info.internal_name = internal_name;
        status = acpi_ns_build_internal_name(&info);
        if (ACPI_FAILURE(status)) {
                ACPI_FREE(internal_name);
                return_ACPI_STATUS(status);
        }

        *converted_name = internal_name;
        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_externalize_name
 *
 * PARAMETERS:  internal_name_length - Lenth of the internal name below
 *              internal_name       - Internal representation of name
 *              converted_name_length - Where the length is returned
 *              converted_name      - Where the resulting external name
 *                                    is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *              to its external (printable) form (e.g. "\_PR_.CPU0")
 *
 ******************************************************************************/

acpi_status
acpi_ns_externalize_name(u32 internal_name_length,
                         char *internal_name,
                         u32 * converted_name_length, char **converted_name)
{
        acpi_native_uint names_index = 0;
        acpi_native_uint num_segments = 0;
        acpi_native_uint required_length;
        acpi_native_uint prefix_length = 0;
        acpi_native_uint i = 0;
        acpi_native_uint j = 0;

        ACPI_FUNCTION_TRACE(ns_externalize_name);

        if (!internal_name_length || !internal_name || !converted_name) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /*
         * Check for a prefix (one '\' | one or more '^').
         */
        switch (internal_name[0]) {
        case '\\':
                prefix_length = 1;
                break;

        case '^':
                for (i = 0; i < internal_name_length; i++) {
                        if (internal_name[i] == '^') {
                                prefix_length = i + 1;
                        } else {
                                break;
                        }
                }

                if (i == internal_name_length) {
                        prefix_length = i;
                }

                break;

        default:
                break;
        }

        /*
         * Check for object names.  Note that there could be 0-255 of these
         * 4-byte elements.
         */
        if (prefix_length < internal_name_length) {
                switch (internal_name[prefix_length]) {
                case AML_MULTI_NAME_PREFIX_OP:

                        /* <count> 4-byte names */

                        names_index = prefix_length + 2;
                        num_segments = (acpi_native_uint) (u8)
                            internal_name[(acpi_native_uint)
                                          (prefix_length + 1)];
                        break;

                case AML_DUAL_NAME_PREFIX:

                        /* Two 4-byte names */

                        names_index = prefix_length + 1;
                        num_segments = 2;
                        break;

                case 0:

                        /* null_name */

                        names_index = 0;
                        num_segments = 0;
                        break;

                default:

                        /* one 4-byte name */

                        names_index = prefix_length;
                        num_segments = 1;
                        break;
                }
        }

        /*
         * Calculate the length of converted_name, which equals the length
         * of the prefix, length of all object names, length of any required
         * punctuation ('.') between object names, plus the NULL terminator.
         */
        required_length = prefix_length + (4 * num_segments) +
            ((num_segments > 0) ? (num_segments - 1) : 0) + 1;

        /*
         * Check to see if we're still in bounds.  If not, there's a problem
         * with internal_name (invalid format).
         */
        if (required_length > internal_name_length) {
                ACPI_ERROR((AE_INFO, "Invalid internal name"));
                return_ACPI_STATUS(AE_BAD_PATHNAME);
        }

        /*
         * Build converted_name
         */
        *converted_name = ACPI_ALLOCATE_ZEROED(required_length);
        if (!(*converted_name)) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        j = 0;

        for (i = 0; i < prefix_length; i++) {
                (*converted_name)[j++] = internal_name[i];
        }

        if (num_segments > 0) {
                for (i = 0; i < num_segments; i++) {
                        if (i > 0) {
                                (*converted_name)[j++] = '.';
                        }

                        (*converted_name)[j++] = internal_name[names_index++];
                        (*converted_name)[j++] = internal_name[names_index++];
                        (*converted_name)[j++] = internal_name[names_index++];
                        (*converted_name)[j++] = internal_name[names_index++];
                }
        }

        if (converted_name_length) {
                *converted_name_length = (u32) required_length;
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_map_handle_to_node
 *
 * PARAMETERS:  Handle          - Handle to be converted to an Node
 *
 * RETURN:      A Name table entry pointer
 *
 * DESCRIPTION: Convert a namespace handle to a real Node
 *
 * Note: Real integer handles would allow for more verification
 *       and keep all pointers within this subsystem - however this introduces
 *       more (and perhaps unnecessary) overhead.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_map_handle_to_node(acpi_handle handle)
{

        ACPI_FUNCTION_ENTRY();

        /*
         * Simple implementation
         */
        if ((!handle) || (handle == ACPI_ROOT_OBJECT)) {
                return (acpi_gbl_root_node);
        }

        /* We can at least attempt to verify the handle */

        if (ACPI_GET_DESCRIPTOR_TYPE(handle) != ACPI_DESC_TYPE_NAMED) {
                return (NULL);
        }

        return (ACPI_CAST_PTR(struct acpi_namespace_node, handle));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_convert_entry_to_handle
 *
 * PARAMETERS:  Node          - Node to be converted to a Handle
 *
 * RETURN:      A user handle
 *
 * DESCRIPTION: Convert a real Node to a namespace handle
 *
 ******************************************************************************/

acpi_handle acpi_ns_convert_entry_to_handle(struct acpi_namespace_node *node)
{

        /*
         * Simple implementation for now;
         */
        return ((acpi_handle) node);

/* Example future implementation ---------------------

        if (!Node)
        {
                return (NULL);
        }

        if (Node == acpi_gbl_root_node)
        {
                return (ACPI_ROOT_OBJECT);
        }

        return ((acpi_handle) Node);
------------------------------------------------------*/
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: free memory allocated for namespace and ACPI table storage.
 *
 ******************************************************************************/

void acpi_ns_terminate(void)
{
        union acpi_operand_object *obj_desc;

        ACPI_FUNCTION_TRACE(ns_terminate);

        /*
         * 1) Free the entire namespace -- all nodes and objects
         *
         * Delete all object descriptors attached to namepsace nodes
         */
        acpi_ns_delete_namespace_subtree(acpi_gbl_root_node);

        /* Detach any objects attached to the root */

        obj_desc = acpi_ns_get_attached_object(acpi_gbl_root_node);
        if (obj_desc) {
                acpi_ns_detach_object(acpi_gbl_root_node);
        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace freed\n"));
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_opens_scope
 *
 * PARAMETERS:  Type        - A valid namespace type
 *
 * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
 *              to the ACPI specification, else 0
 *
 ******************************************************************************/

u32 acpi_ns_opens_scope(acpi_object_type type)
{
        ACPI_FUNCTION_TRACE_STR(ns_opens_scope, acpi_ut_get_type_name(type));

        if (!acpi_ut_valid_object_type(type)) {

                /* type code out of range  */

                ACPI_WARNING((AE_INFO, "Invalid Object Type %X", type));
                return_UINT32(ACPI_NS_NORMAL);
        }

        return_UINT32(((u32) acpi_gbl_ns_properties[type]) & ACPI_NS_NEWSCOPE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_node
 *
 * PARAMETERS:  *Pathname   - Name to be found, in external (ASL) format. The
 *                            \ (backslash) and ^ (carat) prefixes, and the
 *                            . (period) to separate segments are supported.
 *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
 *                            root of the name space.  If Name is fully
 *                            qualified (first s8 is '\'), the passed value
 *                            of Scope will not be accessed.
 *              Flags       - Used to indicate whether to perform upsearch or
 *                            not.
 *              return_node - Where the Node is returned
 *
 * DESCRIPTION: Look up a name relative to a given scope and return the
 *              corresponding Node.  NOTE: Scope can be null.
 *
 * MUTEX:       Locks namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
                 char *pathname,
                 u32 flags, struct acpi_namespace_node **return_node)
{
        union acpi_generic_state scope_info;
        acpi_status status;
        char *internal_path;

        ACPI_FUNCTION_TRACE_PTR(ns_get_node, pathname);

        if (!pathname) {
                *return_node = prefix_node;
                if (!prefix_node) {
                        *return_node = acpi_gbl_root_node;
                }
                return_ACPI_STATUS(AE_OK);
        }

        /* Convert path to internal representation */

        status = acpi_ns_internalize_name(pathname, &internal_path);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

        /* Must lock namespace during lookup */

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        if (ACPI_FAILURE(status)) {
                goto cleanup;
        }

        /* Setup lookup scope (search starting point) */

        scope_info.scope.node = prefix_node;

        /* Lookup the name in the namespace */

        status = acpi_ns_lookup(&scope_info, internal_path, ACPI_TYPE_ANY,
                                ACPI_IMODE_EXECUTE,
                                (flags | ACPI_NS_DONT_OPEN_SCOPE), NULL,
                                return_node);
        if (ACPI_FAILURE(status)) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s, %s\n",
                                  pathname, acpi_format_exception(status)));
        }

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

      cleanup:
        ACPI_FREE(internal_path);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_parent_node
 *
 * PARAMETERS:  Node       - Current table entry
 *
 * RETURN:      Parent entry of the given entry
 *
 * DESCRIPTION: Obtain the parent entry for a given entry in the namespace.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_get_parent_node(struct acpi_namespace_node
                                                    *node)
{
        ACPI_FUNCTION_ENTRY();

        if (!node) {
                return (NULL);
        }

        /*
         * Walk to the end of this peer list. The last entry is marked with a flag
         * and the peer pointer is really a pointer back to the parent. This saves
         * putting a parent back pointer in each and every named object!
         */
        while (!(node->flags & ANOBJ_END_OF_PEER_LIST)) {
                node = node->peer;
        }

        return (node->peer);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_next_valid_node
 *
 * PARAMETERS:  Node       - Current table entry
 *
 * RETURN:      Next valid Node in the linked node list. NULL if no more valid
 *              nodes.
 *
 * DESCRIPTION: Find the next valid node within a name table.
 *              Useful for implementing NULL-end-of-list loops.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_get_next_valid_node(struct
                                                        acpi_namespace_node
                                                        *node)
{

        /* If we are at the end of this peer list, return NULL */

        if (node->flags & ANOBJ_END_OF_PEER_LIST) {
                return NULL;
        }

        /* Otherwise just return the next peer */

        return (node->peer);
}

#ifdef ACPI_OBSOLETE_FUNCTIONS
/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_find_parent_name
 *
 * PARAMETERS:  *child_node            - Named Obj whose name is to be found
 *
 * RETURN:      The ACPI name
 *
 * DESCRIPTION: Search for the given obj in its parent scope and return the
 *              name segment, or "????" if the parent name can't be found
 *              (which "should not happen").
 *
 ******************************************************************************/

acpi_name acpi_ns_find_parent_name(struct acpi_namespace_node * child_node)
{
        struct acpi_namespace_node *parent_node;

        ACPI_FUNCTION_TRACE(ns_find_parent_name);

        if (child_node) {

                /* Valid entry.  Get the parent Node */

                parent_node = acpi_ns_get_parent_node(child_node);
                if (parent_node) {
                        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                          "Parent of %p [%4.4s] is %p [%4.4s]\n",
                                          child_node,
                                          acpi_ut_get_node_name(child_node),
                                          parent_node,
                                          acpi_ut_get_node_name(parent_node)));

                        if (parent_node->name.integer) {
                                return_VALUE((acpi_name) parent_node->name.
                                             integer);
                        }
                }

                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "Unable to find parent of %p (%4.4s)\n",
                                  child_node,
                                  acpi_ut_get_node_name(child_node)));
        }

        return_VALUE(ACPI_UNKNOWN_NAME);
}
#endif