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

   1 /*******************************************************************************
   2  *
   3  * Module Name: utstrsuppt - Support functions for string-to-integer conversion
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2019, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46
  47 #define _COMPONENT          ACPI_UTILITIES
  48         ACPI_MODULE_NAME    ("utstrsuppt")
  49
  50
  51 /* Local prototypes */
  52
  53 static ACPI_STATUS
  54 AcpiUtInsertDigit (
  55     UINT64                  *AccumulatedValue,
  56     UINT32                  Base,
  57     int                     AsciiDigit);
  58
  59 static ACPI_STATUS
  60 AcpiUtStrtoulMultiply64 (
  61     UINT64                  Multiplicand,
  62     UINT32                  Base,
  63     UINT64                  *OutProduct);
  64
  65 static ACPI_STATUS
  66 AcpiUtStrtoulAdd64 (
  67     UINT64                  Addend1,
  68     UINT32                  Digit,
  69     UINT64                  *OutSum);
  70
  71
  72 /*******************************************************************************
  73  *
  74  * FUNCTION:    AcpiUtConvertOctalString
  75  *
  76  * PARAMETERS:  String                  - Null terminated input string
  77  *              ReturnValuePtr          - Where the converted value is returned
  78  *
  79  * RETURN:      Status and 64-bit converted integer
  80  *
  81  * DESCRIPTION: Performs a base 8 conversion of the input string to an
  82  *              integer value, either 32 or 64 bits.
  83  *
  84  * NOTE:        Maximum 64-bit unsigned octal value is 01777777777777777777777
  85  *              Maximum 32-bit unsigned octal value is 037777777777
  86  *
  87  ******************************************************************************/
  88
  89 ACPI_STATUS
  90 AcpiUtConvertOctalString (
  91     char                    *String,
  92     UINT64                  *ReturnValuePtr)
  93 {
  94     UINT64                  AccumulatedValue = 0;
  95     ACPI_STATUS             Status = AE_OK;
  96
  97
  98     /* Convert each ASCII byte in the input string */
  99
 100     while (*String)
 101     {
 102         /* Character must be ASCII 0-7, otherwise terminate with no error */
 103
 104         if (!(ACPI_IS_OCTAL_DIGIT (*String)))
 105         {
 106             break;
 107         }
 108
 109         /* Convert and insert this octal digit into the accumulator */
 110
 111         Status = AcpiUtInsertDigit (&AccumulatedValue, 8, *String);
 112         if (ACPI_FAILURE (Status))
 113         {
 114             Status = AE_OCTAL_OVERFLOW;
 115             break;
 116         }
 117
 118         String++;
 119     }
 120
 121     /* Always return the value that has been accumulated */
 122
 123     *ReturnValuePtr = AccumulatedValue;
 124     return (Status);
 125 }
 126
 127
 128 /*******************************************************************************
 129  *
 130  * FUNCTION:    AcpiUtConvertDecimalString
 131  *
 132  * PARAMETERS:  String                  - Null terminated input string
 133  *              ReturnValuePtr          - Where the converted value is returned
 134  *
 135  * RETURN:      Status and 64-bit converted integer
 136  *
 137  * DESCRIPTION: Performs a base 10 conversion of the input string to an
 138  *              integer value, either 32 or 64 bits.
 139  *
 140  * NOTE:        Maximum 64-bit unsigned decimal value is 18446744073709551615
 141  *              Maximum 32-bit unsigned decimal value is 4294967295
 142  *
 143  ******************************************************************************/
 144
 145 ACPI_STATUS
 146 AcpiUtConvertDecimalString (
 147     char                    *String,
 148     UINT64                  *ReturnValuePtr)
 149 {
 150     UINT64                  AccumulatedValue = 0;
 151     ACPI_STATUS             Status = AE_OK;
 152
 153
 154     /* Convert each ASCII byte in the input string */
 155
 156     while (*String)
 157     {
 158         /* Character must be ASCII 0-9, otherwise terminate with no error */
 159
 160         if (!isdigit (*String))
 161         {
 162            break;
 163         }
 164
 165         /* Convert and insert this decimal digit into the accumulator */
 166
 167         Status = AcpiUtInsertDigit (&AccumulatedValue, 10, *String);
 168         if (ACPI_FAILURE (Status))
 169         {
 170             Status = AE_DECIMAL_OVERFLOW;
 171             break;
 172         }
 173
 174         String++;
 175     }
 176
 177     /* Always return the value that has been accumulated */
 178
 179     *ReturnValuePtr = AccumulatedValue;
 180     return (Status);
 181 }
 182
 183
 184 /*******************************************************************************
 185  *
 186  * FUNCTION:    AcpiUtConvertHexString
 187  *
 188  * PARAMETERS:  String                  - Null terminated input string
 189  *              ReturnValuePtr          - Where the converted value is returned
 190  *
 191  * RETURN:      Status and 64-bit converted integer
 192  *
 193  * DESCRIPTION: Performs a base 16 conversion of the input string to an
 194  *              integer value, either 32 or 64 bits.
 195  *
 196  * NOTE:        Maximum 64-bit unsigned hex value is 0xFFFFFFFFFFFFFFFF
 197  *              Maximum 32-bit unsigned hex value is 0xFFFFFFFF
 198  *
 199  ******************************************************************************/
 200
 201 ACPI_STATUS
 202 AcpiUtConvertHexString (
 203     char                    *String,
 204     UINT64                  *ReturnValuePtr)
 205 {
 206     UINT64                  AccumulatedValue = 0;
 207     ACPI_STATUS             Status = AE_OK;
 208
 209
 210     /* Convert each ASCII byte in the input string */
 211
 212     while (*String)
 213     {
 214         /* Must be ASCII A-F, a-f, or 0-9, otherwise terminate with no error */
 215
 216         if (!isxdigit (*String))
 217         {
 218             break;
 219         }
 220
 221         /* Convert and insert this hex digit into the accumulator */
 222
 223         Status = AcpiUtInsertDigit (&AccumulatedValue, 16, *String);
 224         if (ACPI_FAILURE (Status))
 225         {
 226             Status = AE_HEX_OVERFLOW;
 227             break;
 228         }
 229
 230         String++;
 231     }
 232
 233     /* Always return the value that has been accumulated */
 234
 235     *ReturnValuePtr = AccumulatedValue;
 236     return (Status);
 237 }
 238
 239
 240 /*******************************************************************************
 241  *
 242  * FUNCTION:    AcpiUtRemoveLeadingZeros
 243  *
 244  * PARAMETERS:  String                  - Pointer to input ASCII string
 245  *
 246  * RETURN:      Next character after any leading zeros. This character may be
 247  *              used by the caller to detect end-of-string.
 248  *
 249  * DESCRIPTION: Remove any leading zeros in the input string. Return the
 250  *              next character after the final ASCII zero to enable the caller
 251  *              to check for the end of the string (NULL terminator).
 252  *
 253  ******************************************************************************/
 254
 255 char
 256 AcpiUtRemoveLeadingZeros (
 257     char                    **String)
 258 {
 259
 260     while (**String == ACPI_ASCII_ZERO)
 261     {
 262         *String += 1;
 263     }
 264
 265     return (**String);
 266 }
 267
 268
 269 /*******************************************************************************
 270  *
 271  * FUNCTION:    AcpiUtRemoveWhitespace
 272  *
 273  * PARAMETERS:  String                  - Pointer to input ASCII string
 274  *
 275  * RETURN:      Next character after any whitespace. This character may be
 276  *              used by the caller to detect end-of-string.
 277  *
 278  * DESCRIPTION: Remove any leading whitespace in the input string. Return the
 279  *              next character after the final ASCII zero to enable the caller
 280  *              to check for the end of the string (NULL terminator).
 281  *
 282  ******************************************************************************/
 283
 284 char
 285 AcpiUtRemoveWhitespace (
 286     char                    **String)
 287 {
 288
 289     while (isspace ((UINT8) **String))
 290     {
 291         *String += 1;
 292     }
 293
 294     return (**String);
 295 }
 296
 297
 298 /*******************************************************************************
 299  *
 300  * FUNCTION:    AcpiUtDetectHexPrefix
 301  *
 302  * PARAMETERS:  String                  - Pointer to input ASCII string
 303  *
 304  * RETURN:      TRUE if a "0x" prefix was found at the start of the string
 305  *
 306  * DESCRIPTION: Detect and remove a hex "0x" prefix
 307  *
 308  ******************************************************************************/
 309
 310 BOOLEAN
 311 AcpiUtDetectHexPrefix (
 312     char                    **String)
 313 {
 314     char                    *InitialPosition = *String;
 315
 316     AcpiUtRemoveHexPrefix (String);
 317     if (*String != InitialPosition)
 318     {
 319         return (TRUE); /* String is past leading 0x */
 320     }
 321
 322     return (FALSE);     /* Not a hex string */
 323 }
 324
 325
 326 /*******************************************************************************
 327  *
 328  * FUNCTION:    AcpiUtRemoveHexPrefix
 329  *
 330  * PARAMETERS:  String                  - Pointer to input ASCII string
 331  *
 332  * RETURN:      none
 333  *
 334  * DESCRIPTION: Remove a hex "0x" prefix
 335  *
 336  ******************************************************************************/
 337
 338 void
 339 AcpiUtRemoveHexPrefix (
 340     char                    **String)
 341 {
 342     if ((**String == ACPI_ASCII_ZERO) &&
 343         (tolower ((int) *(*String + 1)) == 'x'))
 344     {
 345         *String += 2;        /* Go past the leading 0x */
 346     }
 347 }
 348
 349
 350 /*******************************************************************************
 351  *
 352  * FUNCTION:    AcpiUtDetectOctalPrefix
 353  *
 354  * PARAMETERS:  String                  - Pointer to input ASCII string
 355  *
 356  * RETURN:      True if an octal "0" prefix was found at the start of the
 357  *              string
 358  *
 359  * DESCRIPTION: Detect and remove an octal prefix (zero)
 360  *
 361  ******************************************************************************/
 362
 363 BOOLEAN
 364 AcpiUtDetectOctalPrefix (
 365     char                    **String)
 366 {
 367
 368     if (**String == ACPI_ASCII_ZERO)
 369     {
 370         *String += 1;       /* Go past the leading 0 */
 371         return (TRUE);
 372     }
 373
 374     return (FALSE);     /* Not an octal string */
 375 }
 376
 377
 378 /*******************************************************************************
 379  *
 380  * FUNCTION:    AcpiUtInsertDigit
 381  *
 382  * PARAMETERS:  AccumulatedValue        - Current value of the integer value
 383  *                                        accumulator. The new value is
 384  *                                        returned here.
 385  *              Base                    - Radix, either 8/10/16
 386  *              AsciiDigit              - ASCII single digit to be inserted
 387  *
 388  * RETURN:      Status and result of the convert/insert operation. The only
 389  *              possible returned exception code is numeric overflow of
 390  *              either the multiply or add conversion operations.
 391  *
 392  * DESCRIPTION: Generic conversion and insertion function for all bases:
 393  *
 394  *              1) Multiply the current accumulated/converted value by the
 395  *              base in order to make room for the new character.
 396  *
 397  *              2) Convert the new character to binary and add it to the
 398  *              current accumulated value.
 399  *
 400  *              Note: The only possible exception indicates an integer
 401  *              overflow (AE_NUMERIC_OVERFLOW)
 402  *
 403  ******************************************************************************/
 404
 405 static ACPI_STATUS
 406 AcpiUtInsertDigit (
 407     UINT64                  *AccumulatedValue,
 408     UINT32                  Base,
 409     int                     AsciiDigit)
 410 {
 411     ACPI_STATUS             Status;
 412     UINT64                  Product;
 413
 414
 415      /* Make room in the accumulated value for the incoming digit */
 416
 417     Status = AcpiUtStrtoulMultiply64 (*AccumulatedValue, Base, &Product);
 418     if (ACPI_FAILURE (Status))
 419     {
 420         return (Status);
 421     }
 422
 423     /* Add in the new digit, and store the sum to the accumulated value */
 424
 425     Status = AcpiUtStrtoulAdd64 (Product, AcpiUtAsciiCharToHex (AsciiDigit),
 426         AccumulatedValue);
 427
 428     return (Status);
 429 }
 430
 431
 432 /*******************************************************************************
 433  *
 434  * FUNCTION:    AcpiUtStrtoulMultiply64
 435  *
 436  * PARAMETERS:  Multiplicand            - Current accumulated converted integer
 437  *              Base                    - Base/Radix
 438  *              OutProduct              - Where the product is returned
 439  *
 440  * RETURN:      Status and 64-bit product
 441  *
 442  * DESCRIPTION: Multiply two 64-bit values, with checking for 64-bit overflow as
 443  *              well as 32-bit overflow if necessary (if the current global
 444  *              integer width is 32).
 445  *
 446  ******************************************************************************/
 447
 448 static ACPI_STATUS
 449 AcpiUtStrtoulMultiply64 (
 450     UINT64                  Multiplicand,
 451     UINT32                  Base,
 452     UINT64                  *OutProduct)
 453 {
 454     UINT64                  Product;
 455     UINT64                  Quotient;
 456
 457
 458     /* Exit if either operand is zero */
 459
 460     *OutProduct = 0;
 461     if (!Multiplicand || !Base)
 462     {
 463         return (AE_OK);
 464     }
 465
 466     /*
 467      * Check for 64-bit overflow before the actual multiplication.
 468      *
 469      * Notes: 64-bit division is often not supported on 32-bit platforms
 470      * (it requires a library function), Therefore ACPICA has a local
 471      * 64-bit divide function. Also, Multiplier is currently only used
 472      * as the radix (8/10/16), to the 64/32 divide will always work.
 473      */
 474     AcpiUtShortDivide (ACPI_UINT64_MAX, Base, &Quotient, NULL);
 475     if (Multiplicand > Quotient)
 476     {
 477         return (AE_NUMERIC_OVERFLOW);
 478     }
 479
 480     Product = Multiplicand * Base;
 481
 482     /* Check for 32-bit overflow if necessary */
 483
 484     if ((AcpiGbl_IntegerBitWidth == 32) && (Product > ACPI_UINT32_MAX))
 485     {
 486         return (AE_NUMERIC_OVERFLOW);
 487     }
 488
 489     *OutProduct = Product;
 490     return (AE_OK);
 491 }
 492
 493
 494 /*******************************************************************************
 495  *
 496  * FUNCTION:    AcpiUtStrtoulAdd64
 497  *
 498  * PARAMETERS:  Addend1                 - Current accumulated converted integer
 499  *              Digit                   - New hex value/char
 500  *              OutSum                  - Where sum is returned (Accumulator)
 501  *
 502  * RETURN:      Status and 64-bit sum
 503  *
 504  * DESCRIPTION: Add two 64-bit values, with checking for 64-bit overflow as
 505  *              well as 32-bit overflow if necessary (if the current global
 506  *              integer width is 32).
 507  *
 508  ******************************************************************************/
 509
 510 static ACPI_STATUS
 511 AcpiUtStrtoulAdd64 (
 512     UINT64                  Addend1,
 513     UINT32                  Digit,
 514     UINT64                  *OutSum)
 515 {
 516     UINT64                  Sum;
 517
 518
 519     /* Check for 64-bit overflow before the actual addition */
 520
 521     if ((Addend1 > 0) && (Digit > (ACPI_UINT64_MAX - Addend1)))
 522     {
 523         return (AE_NUMERIC_OVERFLOW);
 524     }
 525
 526     Sum = Addend1 + Digit;
 527
 528     /* Check for 32-bit overflow if necessary */
 529
 530     if ((AcpiGbl_IntegerBitWidth == 32) && (Sum > ACPI_UINT32_MAX))
 531     {
 532         return (AE_NUMERIC_OVERFLOW);
 533     }
 534
 535     *OutSum = Sum;
 536     return (AE_OK);
 537 }