drivers/acpi/acpica/exconvrt.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: exconvrt - Object conversion routines
   5  *
   6  * Copyright (C) 2000 - 2023, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acinterp.h"
  13 #include "amlcode.h"
  14
  15 #define _COMPONENT          ACPI_EXECUTER
  16 ACPI_MODULE_NAME("exconvrt")
  17
  18 /* Local prototypes */
  19 static u32
  20 acpi_ex_convert_to_ascii(u64 integer,
  21                          u16 base, u8 *string, u8 max_length, u8 leading_zeros);
  22
  23 /*******************************************************************************
  24  *
  25  * FUNCTION:    acpi_ex_convert_to_integer
  26  *
  27  * PARAMETERS:  obj_desc            - Object to be converted. Must be an
  28  *                                    Integer, Buffer, or String
  29  *              result_desc         - Where the new Integer object is returned
  30  *              implicit_conversion - Used for string conversion
  31  *
  32  * RETURN:      Status
  33  *
  34  * DESCRIPTION: Convert an ACPI Object to an integer.
  35  *
  36  ******************************************************************************/
  37
  38 acpi_status
  39 acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
  40                            union acpi_operand_object **result_desc,
  41                            u32 implicit_conversion)
  42 {
  43         union acpi_operand_object *return_desc;
  44         u8 *pointer;
  45         u64 result;
  46         u32 i;
  47         u32 count;
  48
  49         ACPI_FUNCTION_TRACE_PTR(ex_convert_to_integer, obj_desc);
  50
  51         switch (obj_desc->common.type) {
  52         case ACPI_TYPE_INTEGER:
  53
  54                 /* No conversion necessary */
  55
  56                 *result_desc = obj_desc;
  57                 return_ACPI_STATUS(AE_OK);
  58
  59         case ACPI_TYPE_BUFFER:
  60         case ACPI_TYPE_STRING:
  61
  62                 /* Note: Takes advantage of common buffer/string fields */
  63
  64                 pointer = obj_desc->buffer.pointer;
  65                 count = obj_desc->buffer.length;
  66                 break;
  67
  68         default:
  69
  70                 return_ACPI_STATUS(AE_TYPE);
  71         }
  72
  73         /*
  74          * Convert the buffer/string to an integer. Note that both buffers and
  75          * strings are treated as raw data - we don't convert ascii to hex for
  76          * strings.
  77          *
  78          * There are two terminating conditions for the loop:
  79          * 1) The size of an integer has been reached, or
  80          * 2) The end of the buffer or string has been reached
  81          */
  82         result = 0;
  83
  84         /* String conversion is different than Buffer conversion */
  85
  86         switch (obj_desc->common.type) {
  87         case ACPI_TYPE_STRING:
  88                 /*
  89                  * Convert string to an integer - for most cases, the string must be
  90                  * hexadecimal as per the ACPI specification. The only exception (as
  91                  * of ACPI 3.0) is that the to_integer() operator allows both decimal
  92                  * and hexadecimal strings (hex prefixed with "0x").
  93                  *
  94                  * Explicit conversion is used only by to_integer.
  95                  * All other string-to-integer conversions are implicit conversions.
  96                  */
  97                 if (implicit_conversion) {
  98                         result =
  99                             acpi_ut_implicit_strtoul64(ACPI_CAST_PTR
 100                                                        (char, pointer));
 101                 } else {
 102                         result =
 103                             acpi_ut_explicit_strtoul64(ACPI_CAST_PTR
 104                                                        (char, pointer));
 105                 }
 106                 break;
 107
 108         case ACPI_TYPE_BUFFER:
 109
 110                 /* Check for zero-length buffer */
 111
 112                 if (!count) {
 113                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
 114                 }
 115
 116                 /* Transfer no more than an integer's worth of data */
 117
 118                 if (count > acpi_gbl_integer_byte_width) {
 119                         count = acpi_gbl_integer_byte_width;
 120                 }
 121
 122                 /*
 123                  * Convert buffer to an integer - we simply grab enough raw data
 124                  * from the buffer to fill an integer
 125                  */
 126                 for (i = 0; i < count; i++) {
 127                         /*
 128                          * Get next byte and shift it into the Result.
 129                          * Little endian is used, meaning that the first byte of the buffer
 130                          * is the LSB of the integer
 131                          */
 132                         result |= (((u64) pointer[i]) << (i * 8));
 133                 }
 134                 break;
 135
 136         default:
 137
 138                 /* No other types can get here */
 139
 140                 break;
 141         }
 142
 143         /* Create a new integer */
 144
 145         return_desc = acpi_ut_create_integer_object(result);
 146         if (!return_desc) {
 147                 return_ACPI_STATUS(AE_NO_MEMORY);
 148         }
 149
 150         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
 151                           ACPI_FORMAT_UINT64(result)));
 152
 153         /* Save the Result */
 154
 155         (void)acpi_ex_truncate_for32bit_table(return_desc);
 156         *result_desc = return_desc;
 157         return_ACPI_STATUS(AE_OK);
 158 }
 159
 160 /*******************************************************************************
 161  *
 162  * FUNCTION:    acpi_ex_convert_to_buffer
 163  *
 164  * PARAMETERS:  obj_desc        - Object to be converted. Must be an
 165  *                                Integer, Buffer, or String
 166  *              result_desc     - Where the new buffer object is returned
 167  *
 168  * RETURN:      Status
 169  *
 170  * DESCRIPTION: Convert an ACPI Object to a Buffer
 171  *
 172  ******************************************************************************/
 173
 174 acpi_status
 175 acpi_ex_convert_to_buffer(union acpi_operand_object *obj_desc,
 176                           union acpi_operand_object **result_desc)
 177 {
 178         union acpi_operand_object *return_desc;
 179         u8 *new_buf;
 180
 181         ACPI_FUNCTION_TRACE_PTR(ex_convert_to_buffer, obj_desc);
 182
 183         switch (obj_desc->common.type) {
 184         case ACPI_TYPE_BUFFER:
 185
 186                 /* No conversion necessary */
 187
 188                 *result_desc = obj_desc;
 189                 return_ACPI_STATUS(AE_OK);
 190
 191         case ACPI_TYPE_INTEGER:
 192                 /*
 193                  * Create a new Buffer object.
 194                  * Need enough space for one integer
 195                  */
 196                 return_desc =
 197                     acpi_ut_create_buffer_object(acpi_gbl_integer_byte_width);
 198                 if (!return_desc) {
 199                         return_ACPI_STATUS(AE_NO_MEMORY);
 200                 }
 201
 202                 /* Copy the integer to the buffer, LSB first */
 203
 204                 new_buf = return_desc->buffer.pointer;
 205                 memcpy(new_buf, &obj_desc->integer.value,
 206                        acpi_gbl_integer_byte_width);
 207                 break;
 208
 209         case ACPI_TYPE_STRING:
 210                 /*
 211                  * Create a new Buffer object
 212                  * Size will be the string length
 213                  *
 214                  * NOTE: Add one to the string length to include the null terminator.
 215                  * The ACPI spec is unclear on this subject, but there is existing
 216                  * ASL/AML code that depends on the null being transferred to the new
 217                  * buffer.
 218                  */
 219                 return_desc = acpi_ut_create_buffer_object((acpi_size)
 220                                                            obj_desc->string.
 221                                                            length + 1);
 222                 if (!return_desc) {
 223                         return_ACPI_STATUS(AE_NO_MEMORY);
 224                 }
 225
 226                 /* Copy the string to the buffer */
 227
 228                 new_buf = return_desc->buffer.pointer;
 229                 strncpy((char *)new_buf, (char *)obj_desc->string.pointer,
 230                         obj_desc->string.length);
 231                 break;
 232
 233         default:
 234
 235                 return_ACPI_STATUS(AE_TYPE);
 236         }
 237
 238         /* Mark buffer initialized */
 239
 240         return_desc->common.flags |= AOPOBJ_DATA_VALID;
 241         *result_desc = return_desc;
 242         return_ACPI_STATUS(AE_OK);
 243 }
 244
 245 /*******************************************************************************
 246  *
 247  * FUNCTION:    acpi_ex_convert_to_ascii
 248  *
 249  * PARAMETERS:  integer         - Value to be converted
 250  *              base            - ACPI_STRING_DECIMAL or ACPI_STRING_HEX
 251  *              string          - Where the string is returned
 252  *              data_width      - Size of data item to be converted, in bytes
 253  *              leading_zeros   - Allow leading zeros
 254  *
 255  * RETURN:      Actual string length
 256  *
 257  * DESCRIPTION: Convert an ACPI Integer to a hex or decimal string
 258  *
 259  ******************************************************************************/
 260
 261 static u32
 262 acpi_ex_convert_to_ascii(u64 integer,
 263                          u16 base, u8 *string, u8 data_width, u8 leading_zeros)
 264 {
 265         u64 digit;
 266         u32 i;
 267         u32 j;
 268         u32 k = 0;
 269         u32 hex_length;
 270         u32 decimal_length;
 271         u32 remainder;
 272         u8 supress_zeros = !leading_zeros;
 273         u8 hex_char;
 274
 275         ACPI_FUNCTION_ENTRY();
 276
 277         switch (base) {
 278         case 10:
 279
 280                 /* Setup max length for the decimal number */
 281
 282                 switch (data_width) {
 283                 case 1:
 284
 285                         decimal_length = ACPI_MAX8_DECIMAL_DIGITS;
 286                         break;
 287
 288                 case 4:
 289
 290                         decimal_length = ACPI_MAX32_DECIMAL_DIGITS;
 291                         break;
 292
 293                 case 8:
 294                 default:
 295
 296                         decimal_length = ACPI_MAX64_DECIMAL_DIGITS;
 297                         break;
 298                 }
 299
 300                 remainder = 0;
 301
 302                 for (i = decimal_length; i > 0; i--) {
 303
 304                         /* Divide by nth factor of 10 */
 305
 306                         digit = integer;
 307                         for (j = 0; j < i; j++) {
 308                                 (void)acpi_ut_short_divide(digit, 10, &digit,
 309                                                            &remainder);
 310                         }
 311
 312                         /* Handle leading zeros */
 313
 314                         if (remainder != 0) {
 315                                 supress_zeros = FALSE;
 316                         }
 317
 318                         if (!supress_zeros) {
 319                                 string[k] = (u8) (ACPI_ASCII_ZERO + remainder);
 320                                 k++;
 321                         }
 322                 }
 323                 break;
 324
 325         case 16:
 326
 327                 /* hex_length: 2 ascii hex chars per data byte */
 328
 329                 hex_length = (data_width * 2);
 330                 for (i = 0, j = (hex_length - 1); i < hex_length; i++, j--) {
 331
 332                         /* Get one hex digit, most significant digits first */
 333
 334                         hex_char = (u8)
 335                             acpi_ut_hex_to_ascii_char(integer, ACPI_MUL_4(j));
 336
 337                         /* Supress leading zeros until the first non-zero character */
 338
 339                         if (hex_char == ACPI_ASCII_ZERO && supress_zeros) {
 340                                 continue;
 341                         }
 342
 343                         supress_zeros = FALSE;
 344                         string[k] = hex_char;
 345                         k++;
 346                 }
 347                 break;
 348
 349         default:
 350                 return (0);
 351         }
 352
 353         /*
 354          * Since leading zeros are suppressed, we must check for the case where
 355          * the integer equals 0
 356          *
 357          * Finally, null terminate the string and return the length
 358          */
 359         if (!k) {
 360                 string[0] = ACPI_ASCII_ZERO;
 361                 k = 1;
 362         }
 363
 364         string[k] = 0;
 365         return ((u32) k);
 366 }
 367
 368 /*******************************************************************************
 369  *
 370  * FUNCTION:    acpi_ex_convert_to_string
 371  *
 372  * PARAMETERS:  obj_desc        - Object to be converted. Must be an
 373  *                                Integer, Buffer, or String
 374  *              result_desc     - Where the string object is returned
 375  *              type            - String flags (base and conversion type)
 376  *
 377  * RETURN:      Status
 378  *
 379  * DESCRIPTION: Convert an ACPI Object to a string. Supports both implicit
 380  *              and explicit conversions and related rules.
 381  *
 382  ******************************************************************************/
 383
 384 acpi_status
 385 acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
 386                           union acpi_operand_object ** result_desc, u32 type)
 387 {
 388         union acpi_operand_object *return_desc;
 389         u8 *new_buf;
 390         u32 i;
 391         u32 string_length = 0;
 392         u16 base = 16;
 393         u8 separator = ',';
 394         u8 leading_zeros;
 395
 396         ACPI_FUNCTION_TRACE_PTR(ex_convert_to_string, obj_desc);
 397
 398         switch (obj_desc->common.type) {
 399         case ACPI_TYPE_STRING:
 400
 401                 /* No conversion necessary */
 402
 403                 *result_desc = obj_desc;
 404                 return_ACPI_STATUS(AE_OK);
 405
 406         case ACPI_TYPE_INTEGER:
 407
 408                 switch (type) {
 409                 case ACPI_EXPLICIT_CONVERT_DECIMAL:
 410                         /*
 411                          * From to_decimal_string, integer source.
 412                          *
 413                          * Make room for the maximum decimal number size
 414                          */
 415                         string_length = ACPI_MAX_DECIMAL_DIGITS;
 416                         leading_zeros = FALSE;
 417                         base = 10;
 418                         break;
 419
 420                 case ACPI_EXPLICIT_CONVERT_HEX:
 421                         /*
 422                          * From to_hex_string.
 423                          *
 424                          * Supress leading zeros and append "0x"
 425                          */
 426                         string_length =
 427                             ACPI_MUL_2(acpi_gbl_integer_byte_width) + 2;
 428                         leading_zeros = FALSE;
 429                         break;
 430                 default:
 431
 432                         /* Two hex string characters for each integer byte */
 433
 434                         string_length = ACPI_MUL_2(acpi_gbl_integer_byte_width);
 435                         leading_zeros = TRUE;
 436                         break;
 437                 }
 438
 439                 /*
 440                  * Create a new String
 441                  * Need enough space for one ASCII integer (plus null terminator)
 442                  */
 443                 return_desc =
 444                     acpi_ut_create_string_object((acpi_size)string_length);
 445                 if (!return_desc) {
 446                         return_ACPI_STATUS(AE_NO_MEMORY);
 447                 }
 448
 449                 new_buf = return_desc->buffer.pointer;
 450                 if (type == ACPI_EXPLICIT_CONVERT_HEX) {
 451
 452                         /* Append "0x" prefix for explicit hex conversion */
 453
 454                         *new_buf++ = '0';
 455                         *new_buf++ = 'x';
 456                 }
 457
 458                 /* Convert integer to string */
 459
 460                 string_length =
 461                     acpi_ex_convert_to_ascii(obj_desc->integer.value, base,
 462                                              new_buf,
 463                                              acpi_gbl_integer_byte_width,
 464                                              leading_zeros);
 465
 466                 /* Null terminate at the correct place */
 467
 468                 return_desc->string.length = string_length;
 469                 if (type == ACPI_EXPLICIT_CONVERT_HEX) {
 470
 471                         /* Take "0x" prefix into account */
 472
 473                         return_desc->string.length += 2;
 474                 }
 475
 476                 new_buf[string_length] = 0;
 477                 break;
 478
 479         case ACPI_TYPE_BUFFER:
 480
 481                 /* Setup string length, base, and separator */
 482
 483                 switch (type) {
 484                 case ACPI_EXPLICIT_CONVERT_DECIMAL:     /* Used by to_decimal_string */
 485                         /*
 486                          * Explicit conversion from the to_decimal_string ASL operator.
 487                          *
 488                          * From ACPI: "If the input is a buffer, it is converted to a
 489                          * a string of decimal values separated by commas."
 490                          */
 491                         leading_zeros = FALSE;
 492                         base = 10;
 493
 494                         /*
 495                          * Calculate the final string length. Individual string values
 496                          * are variable length (include separator for each)
 497                          */
 498                         for (i = 0; i < obj_desc->buffer.length; i++) {
 499                                 if (obj_desc->buffer.pointer[i] >= 100) {
 500                                         string_length += 4;
 501                                 } else if (obj_desc->buffer.pointer[i] >= 10) {
 502                                         string_length += 3;
 503                                 } else {
 504                                         string_length += 2;
 505                                 }
 506                         }
 507                         break;
 508
 509                 case ACPI_IMPLICIT_CONVERT_HEX:
 510                         /*
 511                          * Implicit buffer-to-string conversion
 512                          *
 513                          * From the ACPI spec:
 514                          * "The entire contents of the buffer are converted to a string of
 515                          * two-character hexadecimal numbers, each separated by a space."
 516                          *
 517                          * Each hex number is prefixed with 0x (11/2018)
 518                          */
 519                         leading_zeros = TRUE;
 520                         separator = ' ';
 521                         string_length = (obj_desc->buffer.length * 5);
 522                         break;
 523
 524                 case ACPI_EXPLICIT_CONVERT_HEX:
 525                         /*
 526                          * Explicit conversion from the to_hex_string ASL operator.
 527                          *
 528                          * From ACPI: "If Data is a buffer, it is converted to a string of
 529                          * hexadecimal values separated by commas."
 530                          *
 531                          * Each hex number is prefixed with 0x (11/2018)
 532                          */
 533                         leading_zeros = TRUE;
 534                         separator = ',';
 535                         string_length = (obj_desc->buffer.length * 5);
 536                         break;
 537
 538                 default:
 539                         return_ACPI_STATUS(AE_BAD_PARAMETER);
 540                 }
 541
 542                 /*
 543                  * Create a new string object and string buffer
 544                  * (-1 because of extra separator included in string_length from above)
 545                  * Allow creation of zero-length strings from zero-length buffers.
 546                  */
 547                 if (string_length) {
 548                         string_length--;
 549                 }
 550
 551                 return_desc =
 552                     acpi_ut_create_string_object((acpi_size)string_length);
 553                 if (!return_desc) {
 554                         return_ACPI_STATUS(AE_NO_MEMORY);
 555                 }
 556
 557                 new_buf = return_desc->buffer.pointer;
 558
 559                 /*
 560                  * Convert buffer bytes to hex or decimal values
 561                  * (separated by commas or spaces)
 562                  */
 563                 for (i = 0; i < obj_desc->buffer.length; i++) {
 564                         if (base == 16) {
 565
 566                                 /* Emit 0x prefix for explicit/implicit hex conversion */
 567
 568                                 *new_buf++ = '0';
 569                                 *new_buf++ = 'x';
 570                         }
 571
 572                         new_buf += acpi_ex_convert_to_ascii((u64) obj_desc->
 573                                                             buffer.pointer[i],
 574                                                             base, new_buf, 1,
 575                                                             leading_zeros);
 576
 577                         /* Each digit is separated by either a comma or space */
 578
 579                         *new_buf++ = separator;
 580                 }
 581
 582                 /*
 583                  * Null terminate the string
 584                  * (overwrites final comma/space from above)
 585                  */
 586                 if (obj_desc->buffer.length) {
 587                         new_buf--;
 588                 }
 589                 *new_buf = 0;
 590                 break;
 591
 592         default:
 593
 594                 return_ACPI_STATUS(AE_TYPE);
 595         }
 596
 597         *result_desc = return_desc;
 598         return_ACPI_STATUS(AE_OK);
 599 }
 600
 601 /*******************************************************************************
 602  *
 603  * FUNCTION:    acpi_ex_convert_to_target_type
 604  *
 605  * PARAMETERS:  destination_type    - Current type of the destination
 606  *              source_desc         - Source object to be converted.
 607  *              result_desc         - Where the converted object is returned
 608  *              walk_state          - Current method state
 609  *
 610  * RETURN:      Status
 611  *
 612  * DESCRIPTION: Implements "implicit conversion" rules for storing an object.
 613  *
 614  ******************************************************************************/
 615
 616 acpi_status
 617 acpi_ex_convert_to_target_type(acpi_object_type destination_type,
 618                                union acpi_operand_object *source_desc,
 619                                union acpi_operand_object **result_desc,
 620                                struct acpi_walk_state *walk_state)
 621 {
 622         acpi_status status = AE_OK;
 623
 624         ACPI_FUNCTION_TRACE(ex_convert_to_target_type);
 625
 626         /* Default behavior */
 627
 628         *result_desc = source_desc;
 629
 630         /*
 631          * If required by the target,
 632          * perform implicit conversion on the source before we store it.
 633          */
 634         switch (GET_CURRENT_ARG_TYPE(walk_state->op_info->runtime_args)) {
 635         case ARGI_SIMPLE_TARGET:
 636         case ARGI_FIXED_TARGET:
 637         case ARGI_INTEGER_REF:  /* Handles Increment, Decrement cases */
 638
 639                 switch (destination_type) {
 640                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 641                         /*
 642                          * Named field can always handle conversions
 643                          */
 644                         break;
 645
 646                 default:
 647
 648                         /* No conversion allowed for these types */
 649
 650                         if (destination_type != source_desc->common.type) {
 651                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 652                                                   "Explicit operator, will store (%s) over existing type (%s)\n",
 653                                                   acpi_ut_get_object_type_name
 654                                                   (source_desc),
 655                                                   acpi_ut_get_type_name
 656                                                   (destination_type)));
 657                                 status = AE_TYPE;
 658                         }
 659                 }
 660                 break;
 661
 662         case ARGI_TARGETREF:
 663         case ARGI_STORE_TARGET:
 664
 665                 switch (destination_type) {
 666                 case ACPI_TYPE_INTEGER:
 667                 case ACPI_TYPE_BUFFER_FIELD:
 668                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 669                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 670                         /*
 671                          * These types require an Integer operand. We can convert
 672                          * a Buffer or a String to an Integer if necessary.
 673                          */
 674                         status =
 675                             acpi_ex_convert_to_integer(source_desc, result_desc,
 676                                                        ACPI_IMPLICIT_CONVERSION);
 677                         break;
 678
 679                 case ACPI_TYPE_STRING:
 680                         /*
 681                          * The operand must be a String. We can convert an
 682                          * Integer or Buffer if necessary
 683                          */
 684                         status =
 685                             acpi_ex_convert_to_string(source_desc, result_desc,
 686                                                       ACPI_IMPLICIT_CONVERT_HEX);
 687                         break;
 688
 689                 case ACPI_TYPE_BUFFER:
 690                         /*
 691                          * The operand must be a Buffer. We can convert an
 692                          * Integer or String if necessary
 693                          */
 694                         status =
 695                             acpi_ex_convert_to_buffer(source_desc, result_desc);
 696                         break;
 697
 698                 default:
 699
 700                         ACPI_ERROR((AE_INFO,
 701                                     "Bad destination type during conversion: 0x%X",
 702                                     destination_type));
 703                         status = AE_AML_INTERNAL;
 704                         break;
 705                 }
 706                 break;
 707
 708         case ARGI_REFERENCE:
 709                 /*
 710                  * create_xxxx_field cases - we are storing the field object into the name
 711                  */
 712                 break;
 713
 714         default:
 715
 716                 ACPI_ERROR((AE_INFO,
 717                             "Unknown Target type ID 0x%X AmlOpcode 0x%X DestType %s",
 718                             GET_CURRENT_ARG_TYPE(walk_state->op_info->
 719                                                  runtime_args),
 720                             walk_state->opcode,
 721                             acpi_ut_get_type_name(destination_type)));
 722                 status = AE_AML_INTERNAL;
 723         }
 724
 725         /*
 726          * Source-to-Target conversion semantics:
 727          *
 728          * If conversion to the target type cannot be performed, then simply
 729          * overwrite the target with the new object and type.
 730          */
 731         if (status == AE_TYPE) {
 732                 status = AE_OK;
 733         }
 734
 735         return_ACPI_STATUS(status);
 736 }