nsutils.c

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

/*
 * Copyright (C) 2000 - 2012, 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/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "amlcode.h"
#include "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_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,
                const 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 0x%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)
{
    const 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)) {
        info->fully_qualified = TRUE;
        next_external_char++;

        /* Skip redundant root_prefix, like \\_SB.PCI0.SBRG.EC0 */

        while (acpi_ns_valid_root_prefix(*next_external_char)) {
            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;
    const char *external_name = info->next_external_char;
    char *result = NULL;
    u32 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_size) i + 1];
        } else {
            internal_name[i] = AML_MULTI_NAME_PREFIX_OP;
            internal_name[(acpi_size) i + 1] = (char)num_segments;
            result = &internal_name[(acpi_size) 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_PATHNAME);
        }

        /* 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(const 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,
             const char *internal_name,
             u32 * converted_name_length, char **converted_name)
{
    u32 names_index = 0;
    u32 num_segments = 0;
    u32 required_length;
    u32 prefix_length = 0;
    u32 i = 0;
    u32 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 = (u8)
                internal_name[(acpi_size) 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 the 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_validate_handle
 *
 * PARAMETERS:  handle          - Handle to be validated and typecast to a
 *                                namespace node.
 *
 * RETURN:      A pointer to a namespace node
 *
 * DESCRIPTION: Convert a namespace handle to a namespace node. Handles special
 *              cases for the root node.
 *
 * NOTE: Real integer handles would allow for more verification
 *       and keep all pointers within this subsystem - however this introduces
 *       more overhead and has not been necessary to this point. Drivers
 *       holding handles are typically notified before a node becomes invalid
 *       due to a table unload.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_validate_handle(acpi_handle handle)
{

    ACPI_FUNCTION_ENTRY();

    /* Parameter validation */

    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_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 0x%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,
         const 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, ACPI_CAST_PTR(char, 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_EXEC, "%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);
}