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exconvrt.c

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

/*
 * 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/acinterp.h>
#include <acpi/amlcode.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exconvrt")

/* Local prototypes */
static u32
acpi_ex_convert_to_ascii(acpi_integer 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;
      acpi_integer result;
      u32 i;
      u32 count;
      acpi_status status;

      ACPI_FUNCTION_TRACE_PTR(ex_convert_to_integer, obj_desc);

      switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
      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 (ACPI_GET_OBJECT_TYPE(obj_desc)) {
      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 |= (((acpi_integer) pointer[i]) << (i * 8));
            }
            break;

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

      /* Create a new integer */

      return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
      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 */

      return_desc->integer.value = 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 (ACPI_GET_OBJECT_TYPE(obj_desc)) {
      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(acpi_integer integer,
                   u16 base, u8 * string, u8 data_width)
{
      acpi_integer digit;
      acpi_native_uint i;
      acpi_native_uint j;
      acpi_native_uint k = 0;
      acpi_native_uint hex_length;
      acpi_native_uint 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_native_uint) 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 supressed, 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 (ACPI_GET_OBJECT_TYPE(obj_desc)) {
      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)
             */
            return_desc = acpi_ut_create_string_object((acpi_size)
                                             (string_length - 1));
            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((acpi_integer)
                                              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)
             */
            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 !=
                      ACPI_GET_OBJECT_TYPE(source_desc)) {
                        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: %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 %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);
}

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