/******************************************************************************
 *
 * Module Name: nsrepair2 - Repair for objects returned by specific
 *                          predefined methods
 *
 *****************************************************************************/

/*
 * 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"

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsrepair2")

/*
 * Information structure and handler for ACPI predefined names that can
 * be repaired on a per-name basis.
 */
typedef
acpi_status(*acpi_repair_function) (struct acpi_predefined_data *data,
                                    union acpi_operand_object **return_object_ptr);

typedef struct acpi_repair_info {
        char name[ACPI_NAME_SIZE];
        acpi_repair_function repair_function;

} acpi_repair_info;

/* Local prototypes */

static const struct acpi_repair_info *acpi_ns_match_repairable_name(struct
                                                                    acpi_namespace_node
                                                                    *node);

static acpi_status
acpi_ns_repair_ALR(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_repair_CID(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_repair_FDE(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_repair_HID(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_repair_PSS(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_repair_TSS(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr);

static acpi_status
acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
                          union acpi_operand_object *return_object,
                          u32 expected_count,
                          u32 sort_index,
                          u8 sort_direction, char *sort_key_name);

static void
acpi_ns_sort_list(union acpi_operand_object **elements,
                  u32 count, u32 index, u8 sort_direction);

/* Values for sort_direction above */

#define ACPI_SORT_ASCENDING     0
#define ACPI_SORT_DESCENDING    1

/*
 * This table contains the names of the predefined methods for which we can
 * perform more complex repairs.
 *
 * As necessary:
 *
 * _ALR: Sort the list ascending by ambient_illuminance
 * _CID: Strings: uppercase all, remove any leading asterisk
 * _FDE: Convert Buffer of BYTEs to a Buffer of DWORDs
 * _GTM: Convert Buffer of BYTEs to a Buffer of DWORDs
 * _HID: Strings: uppercase all, remove any leading asterisk
 * _PSS: Sort the list descending by Power
 * _TSS: Sort the list descending by Power
 *
 * Names that must be packages, but cannot be sorted:
 *
 * _BCL: Values are tied to the Package index where they appear, and cannot
 * be moved or sorted. These index values are used for _BQC and _BCM.
 * However, we can fix the case where a buffer is returned, by converting
 * it to a Package of integers.
 */
static const struct acpi_repair_info acpi_ns_repairable_names[] = {
        {"_ALR", acpi_ns_repair_ALR},
        {"_CID", acpi_ns_repair_CID},
        {"_FDE", acpi_ns_repair_FDE},
        {"_GTM", acpi_ns_repair_FDE},   /* _GTM has same repair as _FDE */
        {"_HID", acpi_ns_repair_HID},
        {"_PSS", acpi_ns_repair_PSS},
        {"_TSS", acpi_ns_repair_TSS},
        {{0, 0, 0, 0}, NULL}    /* Table terminator */
};

#define ACPI_FDE_FIELD_COUNT        5
#define ACPI_FDE_BYTE_BUFFER_SIZE   5
#define ACPI_FDE_DWORD_BUFFER_SIZE  (ACPI_FDE_FIELD_COUNT * sizeof (u32))

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_complex_repairs
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              Node                - Namespace node for the method/object
 *              validate_status     - Original status of earlier validation
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if repair was successful. If name is not
 *              matched, validate_status is returned.
 *
 * DESCRIPTION: Attempt to repair/convert a return object of a type that was
 *              not expected.
 *
 *****************************************************************************/

acpi_status
acpi_ns_complex_repairs(struct acpi_predefined_data *data,
                        struct acpi_namespace_node *node,
                        acpi_status validate_status,
                        union acpi_operand_object **return_object_ptr)
{
        const struct acpi_repair_info *predefined;
        acpi_status status;

        /* Check if this name is in the list of repairable names */

        predefined = acpi_ns_match_repairable_name(node);
        if (!predefined) {
                return (validate_status);
        }

        status = predefined->repair_function(data, return_object_ptr);
        return (status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_match_repairable_name
 *
 * PARAMETERS:  Node                - Namespace node for the method/object
 *
 * RETURN:      Pointer to entry in repair table. NULL indicates not found.
 *
 * DESCRIPTION: Check an object name against the repairable object list.
 *
 *****************************************************************************/

static const struct acpi_repair_info *acpi_ns_match_repairable_name(struct
                                                                    acpi_namespace_node
                                                                    *node)
{
        const struct acpi_repair_info *this_name;

        /* Search info table for a repairable predefined method/object name */

        this_name = acpi_ns_repairable_names;
        while (this_name->repair_function) {
                if (ACPI_COMPARE_NAME(node->name.ascii, this_name->name)) {
                        return (this_name);
                }
                this_name++;
        }

        return (NULL);          /* Not found */
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_ALR
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _ALR object. If necessary, sort the object list
 *              ascending by the ambient illuminance values.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_ALR(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        union acpi_operand_object *return_object = *return_object_ptr;
        acpi_status status;

        status = acpi_ns_check_sorted_list(data, return_object, 2, 1,
                                           ACPI_SORT_ASCENDING,
                                           "AmbientIlluminance");

        return (status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_FDE
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _FDE and _GTM objects. The expected return
 *              value is a Buffer of 5 DWORDs. This function repairs a common
 *              problem where the return value is a Buffer of BYTEs, not
 *              DWORDs.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_FDE(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        union acpi_operand_object *return_object = *return_object_ptr;
        union acpi_operand_object *buffer_object;
        u8 *byte_buffer;
        u32 *dword_buffer;
        u32 i;

        ACPI_FUNCTION_NAME(ns_repair_FDE);

        switch (return_object->common.type) {
        case ACPI_TYPE_BUFFER:

                /* This is the expected type. Length should be (at least) 5 DWORDs */

                if (return_object->buffer.length >= ACPI_FDE_DWORD_BUFFER_SIZE) {
                        return (AE_OK);
                }

                /* We can only repair if we have exactly 5 BYTEs */

                if (return_object->buffer.length != ACPI_FDE_BYTE_BUFFER_SIZE) {
                        ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
                                              data->node_flags,
                                              "Incorrect return buffer length %u, expected %u",
                                              return_object->buffer.length,
                                              ACPI_FDE_DWORD_BUFFER_SIZE));

                        return (AE_AML_OPERAND_TYPE);
                }

                /* Create the new (larger) buffer object */

                buffer_object =
                    acpi_ut_create_buffer_object(ACPI_FDE_DWORD_BUFFER_SIZE);
                if (!buffer_object) {
                        return (AE_NO_MEMORY);
                }

                /* Expand each byte to a DWORD */

                byte_buffer = return_object->buffer.pointer;
                dword_buffer =
                    ACPI_CAST_PTR(u32, buffer_object->buffer.pointer);

                for (i = 0; i < ACPI_FDE_FIELD_COUNT; i++) {
                        *dword_buffer = (u32) *byte_buffer;
                        dword_buffer++;
                        byte_buffer++;
                }

                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
                                  "%s Expanded Byte Buffer to expected DWord Buffer\n",
                                  data->pathname));
                break;

        default:
                return (AE_AML_OPERAND_TYPE);
        }

        /* Delete the original return object, return the new buffer object */

        acpi_ut_remove_reference(return_object);
        *return_object_ptr = buffer_object;

        data->flags |= ACPI_OBJECT_REPAIRED;
        return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_CID
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _CID object. If a string, ensure that all
 *              letters are uppercase and that there is no leading asterisk.
 *              If a Package, ensure same for all string elements.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_CID(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        acpi_status status;
        union acpi_operand_object *return_object = *return_object_ptr;
        union acpi_operand_object **element_ptr;
        union acpi_operand_object *original_element;
        u16 original_ref_count;
        u32 i;

        /* Check for _CID as a simple string */

        if (return_object->common.type == ACPI_TYPE_STRING) {
                status = acpi_ns_repair_HID(data, return_object_ptr);
                return (status);
        }

        /* Exit if not a Package */

        if (return_object->common.type != ACPI_TYPE_PACKAGE) {
                return (AE_OK);
        }

        /* Examine each element of the _CID package */

        element_ptr = return_object->package.elements;
        for (i = 0; i < return_object->package.count; i++) {
                original_element = *element_ptr;
                original_ref_count = original_element->common.reference_count;

                status = acpi_ns_repair_HID(data, element_ptr);
                if (ACPI_FAILURE(status)) {
                        return (status);
                }

                /* Take care with reference counts */

                if (original_element != *element_ptr) {

                        /* Element was replaced */

                        (*element_ptr)->common.reference_count =
                            original_ref_count;

                        acpi_ut_remove_reference(original_element);
                }

                element_ptr++;
        }

        return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_HID
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _HID object. If a string, ensure that all
 *              letters are uppercase and that there is no leading asterisk.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_HID(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        union acpi_operand_object *return_object = *return_object_ptr;
        union acpi_operand_object *new_string;
        char *source;
        char *dest;

        ACPI_FUNCTION_NAME(ns_repair_HID);

        /* We only care about string _HID objects (not integers) */

        if (return_object->common.type != ACPI_TYPE_STRING) {
                return (AE_OK);
        }

        if (return_object->string.length == 0) {
                ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
                                      "Invalid zero-length _HID or _CID string"));

                /* Return AE_OK anyway, let driver handle it */

                data->flags |= ACPI_OBJECT_REPAIRED;
                return (AE_OK);
        }

        /* It is simplest to always create a new string object */

        new_string = acpi_ut_create_string_object(return_object->string.length);
        if (!new_string) {
                return (AE_NO_MEMORY);
        }

        /*
         * Remove a leading asterisk if present. For some unknown reason, there
         * are many machines in the field that contains IDs like this.
         *
         * Examples: "*PNP0C03", "*ACPI0003"
         */
        source = return_object->string.pointer;
        if (*source == '*') {
                source++;
                new_string->string.length--;

                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
                                  "%s: Removed invalid leading asterisk\n",
                                  data->pathname));
        }

        /*
         * Copy and uppercase the string. From the ACPI 5.0 specification:
         *
         * A valid PNP ID must be of the form "AAA####" where A is an uppercase
         * letter and # is a hex digit. A valid ACPI ID must be of the form
         * "NNNN####" where N is an uppercase letter or decimal digit, and
         * # is a hex digit.
         */
        for (dest = new_string->string.pointer; *source; dest++, source++) {
                *dest = (char)ACPI_TOUPPER(*source);
        }

        acpi_ut_remove_reference(return_object);
        *return_object_ptr = new_string;
        return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_TSS
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _TSS object. If necessary, sort the object list
 *              descending by the power dissipation values.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_TSS(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        union acpi_operand_object *return_object = *return_object_ptr;
        acpi_status status;
        struct acpi_namespace_node *node;

        /*
         * We can only sort the _TSS return package if there is no _PSS in the
         * same scope. This is because if _PSS is present, the ACPI specification
         * dictates that the _TSS Power Dissipation field is to be ignored, and
         * therefore some BIOSs leave garbage values in the _TSS Power field(s).
         * In this case, it is best to just return the _TSS package as-is.
         * (May, 2011)
         */
        status =
            acpi_ns_get_node(data->node, "^_PSS", ACPI_NS_NO_UPSEARCH, &node);
        if (ACPI_SUCCESS(status)) {
                return (AE_OK);
        }

        status = acpi_ns_check_sorted_list(data, return_object, 5, 1,
                                           ACPI_SORT_DESCENDING,
                                           "PowerDissipation");

        return (status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_repair_PSS
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object_ptr   - Pointer to the object returned from the
 *                                    evaluation of a method or object
 *
 * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 *
 * DESCRIPTION: Repair for the _PSS object. If necessary, sort the object list
 *              by the CPU frequencies. Check that the power dissipation values
 *              are all proportional to CPU frequency (i.e., sorting by
 *              frequency should be the same as sorting by power.)
 *
 *****************************************************************************/

static acpi_status
acpi_ns_repair_PSS(struct acpi_predefined_data *data,
                   union acpi_operand_object **return_object_ptr)
{
        union acpi_operand_object *return_object = *return_object_ptr;
        union acpi_operand_object **outer_elements;
        u32 outer_element_count;
        union acpi_operand_object **elements;
        union acpi_operand_object *obj_desc;
        u32 previous_value;
        acpi_status status;
        u32 i;

        /*
         * Entries (sub-packages) in the _PSS Package must be sorted by power
         * dissipation, in descending order. If it appears that the list is
         * incorrectly sorted, sort it. We sort by cpu_frequency, since this
         * should be proportional to the power.
         */
        status = acpi_ns_check_sorted_list(data, return_object, 6, 0,
                                           ACPI_SORT_DESCENDING,
                                           "CpuFrequency");
        if (ACPI_FAILURE(status)) {
                return (status);
        }

        /*
         * We now know the list is correctly sorted by CPU frequency. Check if
         * the power dissipation values are proportional.
         */
        previous_value = ACPI_UINT32_MAX;
        outer_elements = return_object->package.elements;
        outer_element_count = return_object->package.count;

        for (i = 0; i < outer_element_count; i++) {
                elements = (*outer_elements)->package.elements;
                obj_desc = elements[1]; /* Index1 = power_dissipation */

                if ((u32) obj_desc->integer.value > previous_value) {
                        ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
                                              data->node_flags,
                                              "SubPackage[%u,%u] - suspicious power dissipation values",
                                              i - 1, i));
                }

                previous_value = (u32) obj_desc->integer.value;
                outer_elements++;
        }

        return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_check_sorted_list
 *
 * PARAMETERS:  Data                - Pointer to validation data structure
 *              return_object       - Pointer to the top-level returned object
 *              expected_count      - Minimum length of each sub-package
 *              sort_index          - Sub-package entry to sort on
 *              sort_direction      - Ascending or descending
 *              sort_key_name       - Name of the sort_index field
 *
 * RETURN:      Status. AE_OK if the list is valid and is sorted correctly or
 *              has been repaired by sorting the list.
 *
 * DESCRIPTION: Check if the package list is valid and sorted correctly by the
 *              sort_index. If not, then sort the list.
 *
 *****************************************************************************/

static acpi_status
acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
                          union acpi_operand_object *return_object,
                          u32 expected_count,
                          u32 sort_index,
                          u8 sort_direction, char *sort_key_name)
{
        u32 outer_element_count;
        union acpi_operand_object **outer_elements;
        union acpi_operand_object **elements;
        union acpi_operand_object *obj_desc;
        u32 i;
        u32 previous_value;

        ACPI_FUNCTION_NAME(ns_check_sorted_list);

        /* The top-level object must be a package */

        if (return_object->common.type != ACPI_TYPE_PACKAGE) {
                return (AE_AML_OPERAND_TYPE);
        }

        /*
         * NOTE: assumes list of sub-packages contains no NULL elements.
         * Any NULL elements should have been removed by earlier call
         * to acpi_ns_remove_null_elements.
         */
        outer_elements = return_object->package.elements;
        outer_element_count = return_object->package.count;
        if (!outer_element_count) {
                return (AE_AML_PACKAGE_LIMIT);
        }

        previous_value = 0;
        if (sort_direction == ACPI_SORT_DESCENDING) {
                previous_value = ACPI_UINT32_MAX;
        }

        /* Examine each subpackage */

        for (i = 0; i < outer_element_count; i++) {

                /* Each element of the top-level package must also be a package */

                if ((*outer_elements)->common.type != ACPI_TYPE_PACKAGE) {
                        return (AE_AML_OPERAND_TYPE);
                }

                /* Each sub-package must have the minimum length */

                if ((*outer_elements)->package.count < expected_count) {
                        return (AE_AML_PACKAGE_LIMIT);
                }

                elements = (*outer_elements)->package.elements;
                obj_desc = elements[sort_index];

                if (obj_desc->common.type != ACPI_TYPE_INTEGER) {
                        return (AE_AML_OPERAND_TYPE);
                }

                /*
                 * The list must be sorted in the specified order. If we detect a
                 * discrepancy, sort the entire list.
                 */
                if (((sort_direction == ACPI_SORT_ASCENDING) &&
                     (obj_desc->integer.value < previous_value)) ||
                    ((sort_direction == ACPI_SORT_DESCENDING) &&
                     (obj_desc->integer.value > previous_value))) {
                        acpi_ns_sort_list(return_object->package.elements,
                                          outer_element_count, sort_index,
                                          sort_direction);

                        data->flags |= ACPI_OBJECT_REPAIRED;

                        ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
                                          "%s: Repaired unsorted list - now sorted by %s\n",
                                          data->pathname, sort_key_name));
                        return (AE_OK);
                }

                previous_value = (u32) obj_desc->integer.value;
                outer_elements++;
        }

        return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ns_sort_list
 *
 * PARAMETERS:  Elements            - Package object element list
 *              Count               - Element count for above
 *              Index               - Sort by which package element
 *              sort_direction      - Ascending or Descending sort
 *
 * RETURN:      None
 *
 * DESCRIPTION: Sort the objects that are in a package element list.
 *
 * NOTE: Assumes that all NULL elements have been removed from the package,
 *       and that all elements have been verified to be of type Integer.
 *
 *****************************************************************************/

static void
acpi_ns_sort_list(union acpi_operand_object **elements,
                  u32 count, u32 index, u8 sort_direction)
{
        union acpi_operand_object *obj_desc1;
        union acpi_operand_object *obj_desc2;
        union acpi_operand_object *temp_obj;
        u32 i;
        u32 j;

        /* Simple bubble sort */

        for (i = 1; i < count; i++) {
                for (j = (count - 1); j >= i; j--) {
                        obj_desc1 = elements[j - 1]->package.elements[index];
                        obj_desc2 = elements[j]->package.elements[index];

                        if (((sort_direction == ACPI_SORT_ASCENDING) &&
                             (obj_desc1->integer.value >
                              obj_desc2->integer.value))
                            || ((sort_direction == ACPI_SORT_DESCENDING)
                                && (obj_desc1->integer.value <
                                    obj_desc2->integer.value))) {
                                temp_obj = elements[j - 1];
                                elements[j - 1] = elements[j];
                                elements[j] = temp_obj;
                        }
                }
        }
}