drivers/bus/acpi/acpica/utilities/utstrtoul64.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utstrtoul64 - String-to-integer conversion support for both
   4  *                            64-bit and 32-bit integers
   5  *
   6  ******************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2018, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include "acpi.h"
  46 #include "accommon.h"
  47
  48 #define _COMPONENT          ACPI_UTILITIES
  49         ACPI_MODULE_NAME    ("utstrtoul64")
  50
  51
  52 /*******************************************************************************
  53  *
  54  * This module contains the top-level string to 64/32-bit unsigned integer
  55  * conversion functions:
  56  *
  57  *  1) A standard strtoul() function that supports 64-bit integers, base
  58  *     8/10/16, with integer overflow support. This is used mainly by the
  59  *     iASL compiler, which implements tighter constraints on integer
  60  *     constants than the runtime (interpreter) integer-to-string conversions.
  61  *  2) Runtime "Explicit conversion" as defined in the ACPI specification.
  62  *  3) Runtime "Implicit conversion" as defined in the ACPI specification.
  63  *
  64  * Current users of this module:
  65  *
  66  *  iASL        - Preprocessor (constants and math expressions)
  67  *  iASL        - Main parser, conversion of constants to integers
  68  *  iASL        - Data Table Compiler parser (constants and math expressions)
  69  *  Interpreter - Implicit and explicit conversions, GPE method names
  70  *  Interpreter - Repair code for return values from predefined names
  71  *  Debugger    - Command line input string conversion
  72  *  AcpiDump    - ACPI table physical addresses
  73  *  AcpiExec    - Support for namespace overrides
  74  *
  75  * Notes concerning users of these interfaces:
  76  *
  77  * AcpiGbl_IntegerByteWidth is used to set the 32/64 bit limit for explicit
  78  * and implicit conversions. This global must be set to the proper width.
  79  * For the core ACPICA code, the width depends on the DSDT version. For the
  80  * AcpiUtStrtoul64 interface, all conversions are 64 bits. This interface is
  81  * used primarily for iASL, where the default width is 64 bits for all parsers,
  82  * but error checking is performed later to flag cases where a 64-bit constant
  83  * is wrongly defined in a 32-bit DSDT/SSDT.
  84  *
  85  * In ACPI, the only place where octal numbers are supported is within
  86  * the ASL language itself. This is implemented via the main AcpiUtStrtoul64
  87  * interface. According the ACPI specification, there is no ACPI runtime
  88  * support (explicit/implicit) for octal string conversions.
  89  *
  90  ******************************************************************************/
  91
  92
  93 /*******************************************************************************
  94  *
  95  * FUNCTION:    AcpiUtStrtoul64
  96  *
  97  * PARAMETERS:  String                  - Null terminated input string,
  98  *                                        must be a valid pointer
  99  *              ReturnValue             - Where the converted integer is
 100  *                                        returned. Must be a valid pointer
 101  *
 102  * RETURN:      Status and converted integer. Returns an exception on a
 103  *              64-bit numeric overflow
 104  *
 105  * DESCRIPTION: Convert a string into an unsigned integer. Always performs a
 106  *              full 64-bit conversion, regardless of the current global
 107  *              integer width. Supports Decimal, Hex, and Octal strings.
 108  *
 109  * Current users of this function:
 110  *
 111  *  iASL        - Preprocessor (constants and math expressions)
 112  *  iASL        - Main ASL parser, conversion of ASL constants to integers
 113  *  iASL        - Data Table Compiler parser (constants and math expressions)
 114  *  Interpreter - Repair code for return values from predefined names
 115  *  AcpiDump    - ACPI table physical addresses
 116  *  AcpiExec    - Support for namespace overrides
 117  *
 118  ******************************************************************************/
 119
 120 ACPI_STATUS
 121 AcpiUtStrtoul64 (
 122     char                    *String,
 123     UINT64                  *ReturnValue)
 124 {
 125     ACPI_STATUS             Status = AE_OK;
 126     UINT8                   OriginalBitWidth;
 127     UINT32                  Base = 10;          /* Default is decimal */
 128
 129
 130     ACPI_FUNCTION_TRACE_STR (UtStrtoul64, String);
 131
 132
 133     *ReturnValue = 0;
 134
 135     /* A NULL return string returns a value of zero */
 136
 137     if (*String == 0)
 138     {
 139         return_ACPI_STATUS (AE_OK);
 140     }
 141
 142     if (!AcpiUtRemoveWhitespace (&String))
 143     {
 144         return_ACPI_STATUS (AE_OK);
 145     }
 146
 147     /*
 148      * 1) Check for a hex constant. A "0x" prefix indicates base 16.
 149      */
 150     if (AcpiUtDetectHexPrefix (&String))
 151     {
 152         Base = 16;
 153     }
 154
 155     /*
 156      * 2) Check for an octal constant, defined to be a leading zero
 157      * followed by sequence of octal digits (0-7)
 158      */
 159     else if (AcpiUtDetectOctalPrefix (&String))
 160     {
 161         Base = 8;
 162     }
 163
 164     if (!AcpiUtRemoveLeadingZeros (&String))
 165     {
 166         return_ACPI_STATUS (AE_OK);     /* Return value 0 */
 167     }
 168
 169     /*
 170      * Force a full 64-bit conversion. The caller (usually iASL) must
 171      * check for a 32-bit overflow later as necessary (If current mode
 172      * is 32-bit, meaning a 32-bit DSDT).
 173      */
 174     OriginalBitWidth = AcpiGbl_IntegerBitWidth;
 175     AcpiGbl_IntegerBitWidth = 64;
 176
 177     /*
 178      * Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow
 179      * will return an exception (to allow iASL to flag the statement).
 180      */
 181     switch (Base)
 182     {
 183     case 8:
 184         Status = AcpiUtConvertOctalString (String, ReturnValue);
 185         break;
 186
 187     case 10:
 188         Status = AcpiUtConvertDecimalString (String, ReturnValue);
 189         break;
 190
 191     case 16:
 192     default:
 193         Status = AcpiUtConvertHexString (String, ReturnValue);
 194         break;
 195     }
 196
 197     /* Only possible exception from above is a 64-bit overflow */
 198
 199     AcpiGbl_IntegerBitWidth = OriginalBitWidth;
 200     return_ACPI_STATUS (Status);
 201 }
 202
 203
 204 /*******************************************************************************
 205  *
 206  * FUNCTION:    AcpiUtImplicitStrtoul64
 207  *
 208  * PARAMETERS:  String                  - Null terminated input string,
 209  *                                        must be a valid pointer
 210  *
 211  * RETURN:      Converted integer
 212  *
 213  * DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon
 214  *              an "implicit conversion" by the ACPI specification. Used by
 215  *              many ASL operators that require an integer operand, and support
 216  *              an automatic (implicit) conversion from a string operand
 217  *              to the final integer operand. The major restriction is that
 218  *              only hex strings are supported.
 219  *
 220  * -----------------------------------------------------------------------------
 221  *
 222  * Base is always 16, either with or without the 0x prefix. Decimal and
 223  * Octal strings are not supported, as per the ACPI specification.
 224  *
 225  * Examples (both are hex values):
 226  *      Add ("BA98", Arg0, Local0)
 227  *      Subtract ("0x12345678", Arg1, Local1)
 228  *
 229  * Conversion rules as extracted from the ACPI specification:
 230  *
 231  *  The converted integer is initialized to the value zero.
 232  *  The ASCII string is always interpreted as a hexadecimal constant.
 233  *
 234  *  1)  According to the ACPI specification, a "0x" prefix is not allowed.
 235  *      However, ACPICA allows this as an ACPI extension on general
 236  *      principle. (NO ERROR)
 237  *
 238  *  2)  The conversion terminates when the size of an integer is reached
 239  *      (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR)
 240  *
 241  *  3)  The first non-hex character terminates the conversion and returns
 242  *      the current accumulated value of the converted integer (NO ERROR).
 243  *
 244  *  4)  Conversion of a null (zero-length) string to an integer is
 245  *      technically not allowed. However, ACPICA allows this as an ACPI
 246  *      extension. The conversion returns the value 0. (NO ERROR)
 247  *
 248  * NOTE: There are no error conditions returned by this function. At
 249  * the minimum, a value of zero is returned.
 250  *
 251  * Current users of this function:
 252  *
 253  *  Interpreter - All runtime implicit conversions, as per ACPI specification
 254  *  iASL        - Data Table Compiler parser (constants and math expressions)
 255  *
 256  ******************************************************************************/
 257
 258 UINT64
 259 AcpiUtImplicitStrtoul64 (
 260     char                    *String)
 261 {
 262     UINT64                  ConvertedInteger = 0;
 263
 264
 265     ACPI_FUNCTION_TRACE_STR (UtImplicitStrtoul64, String);
 266
 267
 268     if (!AcpiUtRemoveWhitespace (&String))
 269     {
 270         return_VALUE (0);
 271     }
 272
 273     /*
 274      * Per the ACPI specification, only hexadecimal is supported for
 275      * implicit conversions, and the "0x" prefix is "not allowed".
 276      * However, allow a "0x" prefix as an ACPI extension.
 277      */
 278     AcpiUtDetectHexPrefix (&String);
 279
 280     if (!AcpiUtRemoveLeadingZeros (&String))
 281     {
 282         return_VALUE (0);
 283     }
 284
 285     /*
 286      * Ignore overflow as per the ACPI specification. This is implemented by
 287      * ignoring the return status from the conversion function called below.
 288      * On overflow, the input string is simply truncated.
 289      */
 290     AcpiUtConvertHexString (String, &ConvertedInteger);
 291     return_VALUE (ConvertedInteger);
 292 }
 293
 294
 295 /*******************************************************************************
 296  *
 297  * FUNCTION:    AcpiUtExplicitStrtoul64
 298  *
 299  * PARAMETERS:  String                  - Null terminated input string,
 300  *                                        must be a valid pointer
 301  *
 302  * RETURN:      Converted integer
 303  *
 304  * DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon
 305  *              an "explicit conversion" by the ACPI specification. The
 306  *              main restriction is that only hex and decimal are supported.
 307  *
 308  * -----------------------------------------------------------------------------
 309  *
 310  * Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings
 311  * are not supported, as per the ACPI specification.
 312  *
 313  * Examples:
 314  *      ToInteger ("1000")      Decimal
 315  *      ToInteger ("0xABCD")    Hex
 316  *
 317  * Conversion rules as extracted from the ACPI specification:
 318  *
 319  *  1)  The input string is either a decimal or hexadecimal numeric string.
 320  *      A hex value must be prefixed by "0x" or it is interpreted as decimal.
 321  *
 322  *  2)  The value must not exceed the maximum of an integer value
 323  *      (32 or 64 bits). The ACPI specification states the behavior is
 324  *      "unpredictable", so ACPICA matches the behavior of the implicit
 325  *      conversion case. There are no numeric overflow conditions. (NO ERROR)
 326  *
 327  *  3)  Behavior on the first non-hex character is not defined by the ACPI
 328  *      specification (for the ToInteger operator), so ACPICA matches the
 329  *      behavior of the implicit conversion case. It terminates the
 330  *      conversion and returns the current accumulated value of the converted
 331  *      integer. (NO ERROR)
 332  *
 333  *  4)  Conversion of a null (zero-length) string to an integer is
 334  *      technically not allowed. However, ACPICA allows this as an ACPI
 335  *      extension. The conversion returns the value 0. (NO ERROR)
 336  *
 337  * NOTE: There are no error conditions returned by this function. At the
 338  * minimum, a value of zero is returned.
 339  *
 340  * Current users of this function:
 341  *
 342  *  Interpreter - Runtime ASL ToInteger operator, as per the ACPI specification
 343  *
 344  ******************************************************************************/
 345
 346 UINT64
 347 AcpiUtExplicitStrtoul64 (
 348     char                    *String)
 349 {
 350     UINT64                  ConvertedInteger = 0;
 351     UINT32                  Base = 10;          /* Default is decimal */
 352
 353
 354     ACPI_FUNCTION_TRACE_STR (UtExplicitStrtoul64, String);
 355
 356
 357     if (!AcpiUtRemoveWhitespace (&String))
 358     {
 359         return_VALUE (0);
 360     }
 361
 362     /*
 363      * Only Hex and Decimal are supported, as per the ACPI specification.
 364      * A "0x" prefix indicates hex; otherwise decimal is assumed.
 365      */
 366     if (AcpiUtDetectHexPrefix (&String))
 367     {
 368         Base = 16;
 369     }
 370
 371     if (!AcpiUtRemoveLeadingZeros (&String))
 372     {
 373         return_VALUE (0);
 374     }
 375
 376     /*
 377      * Ignore overflow as per the ACPI specification. This is implemented by
 378      * ignoring the return status from the conversion functions called below.
 379      * On overflow, the input string is simply truncated.
 380      */
 381     switch (Base)
 382     {
 383     case 10:
 384     default:
 385         AcpiUtConvertDecimalString (String, &ConvertedInteger);
 386         break;
 387
 388     case 16:
 389         AcpiUtConvertHexString (String, &ConvertedInteger);
 390         break;
 391     }
 392
 393     return_VALUE (ConvertedInteger);
 394 }