exconvrt.c

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/******************************************************************************
 *
 * Module Name: exconvrt - Object conversion routines
 *
 *****************************************************************************/

/*
 * 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 "acinterp.h"
#include "amlcode.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exconvrt")

/* Local prototypes */
static u32
acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 max_length);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_convert_to_integer
 *
 * PARAMETERS:  obj_desc        - Object to be converted. Must be an
 *                                Integer, Buffer, or String
 *              result_desc     - Where the new Integer object is returned
 *              flags           - Used for string conversion
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an ACPI Object to an integer.
 *
 ******************************************************************************/

acpi_status
acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
               union acpi_operand_object **result_desc, u32 flags)
{
    union acpi_operand_object *return_desc;
    u8 *pointer;
    u64 result;
    u32 i;
    u32 count;
    acpi_status status;

    ACPI_FUNCTION_TRACE_PTR(ex_convert_to_integer, obj_desc);

    switch (obj_desc->common.type) {
    case ACPI_TYPE_INTEGER:

        /* No conversion necessary */

        *result_desc = obj_desc;
        return_ACPI_STATUS(AE_OK);

    case ACPI_TYPE_BUFFER:
    case ACPI_TYPE_STRING:

        /* Note: Takes advantage of common buffer/string fields */

        pointer = obj_desc->buffer.pointer;
        count = obj_desc->buffer.length;
        break;

    default:
        return_ACPI_STATUS(AE_TYPE);
    }

    /*
     * Convert the buffer/string to an integer. Note that both buffers and
     * strings are treated as raw data - we don't convert ascii to hex for
     * strings.
     *
     * There are two terminating conditions for the loop:
     * 1) The size of an integer has been reached, or
     * 2) The end of the buffer or string has been reached
     */
    result = 0;

    /* String conversion is different than Buffer conversion */

    switch (obj_desc->common.type) {
    case ACPI_TYPE_STRING:

        /*
         * Convert string to an integer - for most cases, the string must be
         * hexadecimal as per the ACPI specification. The only exception (as
         * of ACPI 3.0) is that the to_integer() operator allows both decimal
         * and hexadecimal strings (hex prefixed with "0x").
         */
        status = acpi_ut_strtoul64((char *)pointer, flags, &result);
        if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
        }
        break;

    case ACPI_TYPE_BUFFER:

        /* Check for zero-length buffer */

        if (!count) {
            return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
        }

        /* Transfer no more than an integer's worth of data */

        if (count > acpi_gbl_integer_byte_width) {
            count = acpi_gbl_integer_byte_width;
        }

        /*
         * Convert buffer to an integer - we simply grab enough raw data
         * from the buffer to fill an integer
         */
        for (i = 0; i < count; i++) {
            /*
             * Get next byte and shift it into the Result.
             * Little endian is used, meaning that the first byte of the buffer
             * is the LSB of the integer
             */
            result |= (((u64) pointer[i]) << (i * 8));
        }
        break;

    default:

        /* No other types can get here */
        break;
    }

    /* Create a new integer */

    return_desc = acpi_ut_create_integer_object(result);
    if (!return_desc) {
        return_ACPI_STATUS(AE_NO_MEMORY);
    }

    ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
              ACPI_FORMAT_UINT64(result)));

    /* Save the Result */

    acpi_ex_truncate_for32bit_table(return_desc);
    *result_desc = return_desc;
    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_convert_to_buffer
 *
 * PARAMETERS:  obj_desc        - Object to be converted. Must be an
 *                                Integer, Buffer, or String
 *              result_desc     - Where the new buffer object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an ACPI Object to a Buffer
 *
 ******************************************************************************/

acpi_status
acpi_ex_convert_to_buffer(union acpi_operand_object *obj_desc,
              union acpi_operand_object **result_desc)
{
    union acpi_operand_object *return_desc;
    u8 *new_buf;

    ACPI_FUNCTION_TRACE_PTR(ex_convert_to_buffer, obj_desc);

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

        /* No conversion necessary */

        *result_desc = obj_desc;
        return_ACPI_STATUS(AE_OK);

    case ACPI_TYPE_INTEGER:

        /*
         * Create a new Buffer object.
         * Need enough space for one integer
         */
        return_desc =
            acpi_ut_create_buffer_object(acpi_gbl_integer_byte_width);
        if (!return_desc) {
            return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Copy the integer to the buffer, LSB first */

        new_buf = return_desc->buffer.pointer;
        ACPI_MEMCPY(new_buf,
                &obj_desc->integer.value,
                acpi_gbl_integer_byte_width);
        break;

    case ACPI_TYPE_STRING:

        /*
         * Create a new Buffer object
         * Size will be the string length
         *
         * NOTE: Add one to the string length to include the null terminator.
         * The ACPI spec is unclear on this subject, but there is existing
         * ASL/AML code that depends on the null being transferred to the new
         * buffer.
         */
        return_desc = acpi_ut_create_buffer_object((acpi_size)
                               obj_desc->string.
                               length + 1);
        if (!return_desc) {
            return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Copy the string to the buffer */

        new_buf = return_desc->buffer.pointer;
        ACPI_STRNCPY((char *)new_buf, (char *)obj_desc->string.pointer,
                 obj_desc->string.length);
        break;

    default:
        return_ACPI_STATUS(AE_TYPE);
    }

    /* Mark buffer initialized */

    return_desc->common.flags |= AOPOBJ_DATA_VALID;
    *result_desc = return_desc;
    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_convert_to_ascii
 *
 * PARAMETERS:  integer         - Value to be converted
 *              base            - ACPI_STRING_DECIMAL or ACPI_STRING_HEX
 *              string          - Where the string is returned
 *              data_width      - Size of data item to be converted, in bytes
 *
 * RETURN:      Actual string length
 *
 * DESCRIPTION: Convert an ACPI Integer to a hex or decimal string
 *
 ******************************************************************************/

static u32
acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 data_width)
{
    u64 digit;
    u32 i;
    u32 j;
    u32 k = 0;
    u32 hex_length;
    u32 decimal_length;
    u32 remainder;
    u8 supress_zeros;

    ACPI_FUNCTION_ENTRY();

    switch (base) {
    case 10:

        /* Setup max length for the decimal number */

        switch (data_width) {
        case 1:
            decimal_length = ACPI_MAX8_DECIMAL_DIGITS;
            break;

        case 4:
            decimal_length = ACPI_MAX32_DECIMAL_DIGITS;
            break;

        case 8:
        default:
            decimal_length = ACPI_MAX64_DECIMAL_DIGITS;
            break;
        }

        supress_zeros = TRUE;   /* No leading zeros */
        remainder = 0;

        for (i = decimal_length; i > 0; i--) {

            /* Divide by nth factor of 10 */

            digit = integer;
            for (j = 0; j < i; j++) {
                (void)acpi_ut_short_divide(digit, 10, &digit,
                               &remainder);
            }

            /* Handle leading zeros */

            if (remainder != 0) {
                supress_zeros = FALSE;
            }

            if (!supress_zeros) {
                string[k] = (u8) (ACPI_ASCII_ZERO + remainder);
                k++;
            }
        }
        break;

    case 16:

        /* hex_length: 2 ascii hex chars per data byte */

        hex_length = ACPI_MUL_2(data_width);
        for (i = 0, j = (hex_length - 1); i < hex_length; i++, j--) {

            /* Get one hex digit, most significant digits first */

            string[k] =
                (u8) acpi_ut_hex_to_ascii_char(integer,
                               ACPI_MUL_4(j));
            k++;
        }
        break;

    default:
        return (0);
    }

    /*
     * Since leading zeros are suppressed, we must check for the case where
     * the integer equals 0
     *
     * Finally, null terminate the string and return the length
     */
    if (!k) {
        string[0] = ACPI_ASCII_ZERO;
        k = 1;
    }

    string[k] = 0;
    return ((u32) k);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_convert_to_string
 *
 * PARAMETERS:  obj_desc        - Object to be converted. Must be an
 *                                Integer, Buffer, or String
 *              result_desc     - Where the string object is returned
 *              type            - String flags (base and conversion type)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an ACPI Object to a string
 *
 ******************************************************************************/

acpi_status
acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
              union acpi_operand_object ** result_desc, u32 type)
{
    union acpi_operand_object *return_desc;
    u8 *new_buf;
    u32 i;
    u32 string_length = 0;
    u16 base = 16;
    u8 separator = ',';

    ACPI_FUNCTION_TRACE_PTR(ex_convert_to_string, obj_desc);

    switch (obj_desc->common.type) {
    case ACPI_TYPE_STRING:

        /* No conversion necessary */

        *result_desc = obj_desc;
        return_ACPI_STATUS(AE_OK);

    case ACPI_TYPE_INTEGER:

        switch (type) {
        case ACPI_EXPLICIT_CONVERT_DECIMAL:

            /* Make room for maximum decimal number */

            string_length = ACPI_MAX_DECIMAL_DIGITS;
            base = 10;
            break;

        default:

            /* Two hex string characters for each integer byte */

            string_length = ACPI_MUL_2(acpi_gbl_integer_byte_width);
            break;
        }

        /*
         * Create a new String
         * Need enough space for one ASCII integer (plus null terminator)
         */
        return_desc =
            acpi_ut_create_string_object((acpi_size) string_length);
        if (!return_desc) {
            return_ACPI_STATUS(AE_NO_MEMORY);
        }

        new_buf = return_desc->buffer.pointer;

        /* Convert integer to string */

        string_length =
            acpi_ex_convert_to_ascii(obj_desc->integer.value, base,
                         new_buf,
                         acpi_gbl_integer_byte_width);

        /* Null terminate at the correct place */

        return_desc->string.length = string_length;
        new_buf[string_length] = 0;
        break;

    case ACPI_TYPE_BUFFER:

        /* Setup string length, base, and separator */

        switch (type) {
        case ACPI_EXPLICIT_CONVERT_DECIMAL: /* Used by to_decimal_string */
            /*
             * From ACPI: "If Data is a buffer, it is converted to a string of
             * decimal values separated by commas."
             */
            base = 10;

            /*
             * Calculate the final string length. Individual string values
             * are variable length (include separator for each)
             */
            for (i = 0; i < obj_desc->buffer.length; i++) {
                if (obj_desc->buffer.pointer[i] >= 100) {
                    string_length += 4;
                } else if (obj_desc->buffer.pointer[i] >= 10) {
                    string_length += 3;
                } else {
                    string_length += 2;
                }
            }
            break;

        case ACPI_IMPLICIT_CONVERT_HEX:
            /*
             * From the ACPI spec:
             *"The entire contents of the buffer are converted to a string of
             * two-character hexadecimal numbers, each separated by a space."
             */
            separator = ' ';
            string_length = (obj_desc->buffer.length * 3);
            break;

        case ACPI_EXPLICIT_CONVERT_HEX: /* Used by to_hex_string */
            /*
             * From ACPI: "If Data is a buffer, it is converted to a string of
             * hexadecimal values separated by commas."
             */
            string_length = (obj_desc->buffer.length * 3);
            break;

        default:
            return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /*
         * Create a new string object and string buffer
         * (-1 because of extra separator included in string_length from above)
         * Allow creation of zero-length strings from zero-length buffers.
         */
        if (string_length) {
            string_length--;
        }

        return_desc = acpi_ut_create_string_object((acpi_size)
                               string_length);
        if (!return_desc) {
            return_ACPI_STATUS(AE_NO_MEMORY);
        }

        new_buf = return_desc->buffer.pointer;

        /*
         * Convert buffer bytes to hex or decimal values
         * (separated by commas or spaces)
         */
        for (i = 0; i < obj_desc->buffer.length; i++) {
            new_buf += acpi_ex_convert_to_ascii((u64) obj_desc->
                                buffer.pointer[i],
                                base, new_buf, 1);
            *new_buf++ = separator; /* each separated by a comma or space */
        }

        /*
         * Null terminate the string
         * (overwrites final comma/space from above)
         */
        if (obj_desc->buffer.length) {
            new_buf--;
        }
        *new_buf = 0;
        break;

    default:
        return_ACPI_STATUS(AE_TYPE);
    }

    *result_desc = return_desc;
    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_convert_to_target_type
 *
 * PARAMETERS:  destination_type    - Current type of the destination
 *              source_desc         - Source object to be converted.
 *              result_desc         - Where the converted object is returned
 *              walk_state          - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Implements "implicit conversion" rules for storing an object.
 *
 ******************************************************************************/

acpi_status
acpi_ex_convert_to_target_type(acpi_object_type destination_type,
                   union acpi_operand_object *source_desc,
                   union acpi_operand_object **result_desc,
                   struct acpi_walk_state *walk_state)
{
    acpi_status status = AE_OK;

    ACPI_FUNCTION_TRACE(ex_convert_to_target_type);

    /* Default behavior */

    *result_desc = source_desc;

    /*
     * If required by the target,
     * perform implicit conversion on the source before we store it.
     */
    switch (GET_CURRENT_ARG_TYPE(walk_state->op_info->runtime_args)) {
    case ARGI_SIMPLE_TARGET:
    case ARGI_FIXED_TARGET:
    case ARGI_INTEGER_REF:  /* Handles Increment, Decrement cases */

        switch (destination_type) {
        case ACPI_TYPE_LOCAL_REGION_FIELD:
            /*
             * Named field can always handle conversions
             */
            break;

        default:
            /* No conversion allowed for these types */

            if (destination_type != source_desc->common.type) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Explicit operator, will store (%s) over existing type (%s)\n",
                          acpi_ut_get_object_type_name
                          (source_desc),
                          acpi_ut_get_type_name
                          (destination_type)));
                status = AE_TYPE;
            }
        }
        break;

    case ARGI_TARGETREF:

        switch (destination_type) {
        case ACPI_TYPE_INTEGER:
        case ACPI_TYPE_BUFFER_FIELD:
        case ACPI_TYPE_LOCAL_BANK_FIELD:
        case ACPI_TYPE_LOCAL_INDEX_FIELD:
            /*
             * These types require an Integer operand. We can convert
             * a Buffer or a String to an Integer if necessary.
             */
            status =
                acpi_ex_convert_to_integer(source_desc, result_desc,
                               16);
            break;

        case ACPI_TYPE_STRING:
            /*
             * The operand must be a String. We can convert an
             * Integer or Buffer if necessary
             */
            status =
                acpi_ex_convert_to_string(source_desc, result_desc,
                              ACPI_IMPLICIT_CONVERT_HEX);
            break;

        case ACPI_TYPE_BUFFER:
            /*
             * The operand must be a Buffer. We can convert an
             * Integer or String if necessary
             */
            status =
                acpi_ex_convert_to_buffer(source_desc, result_desc);
            break;

        default:
            ACPI_ERROR((AE_INFO,
                    "Bad destination type during conversion: 0x%X",
                    destination_type));
            status = AE_AML_INTERNAL;
            break;
        }
        break;

    case ARGI_REFERENCE:
        /*
         * create_xxxx_field cases - we are storing the field object into the name
         */
        break;

    default:
        ACPI_ERROR((AE_INFO,
                "Unknown Target type ID 0x%X AmlOpcode 0x%X DestType %s",
                GET_CURRENT_ARG_TYPE(walk_state->op_info->
                         runtime_args),
                walk_state->opcode,
                acpi_ut_get_type_name(destination_type)));
        status = AE_AML_INTERNAL;
    }

    /*
     * Source-to-Target conversion semantics:
     *
     * If conversion to the target type cannot be performed, then simply
     * overwrite the target with the new object and type.
     */
    if (status == AE_TYPE) {
        status = AE_OK;
    }

    return_ACPI_STATUS(status);
}