drivers/acpi/acpica/tbfadt.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbfadt   - FADT table utilities
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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/acpi.h>
  45 #include <acpi/accommon.h>
  46 #include <acpi/actables.h>
  47
  48 #define _COMPONENT          ACPI_TABLES
  49 ACPI_MODULE_NAME("tbfadt")
  50
  51 /* Local prototypes */
  52 static inline void
  53 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
  54                              u8 space_id, u8 byte_width, u64 address);
  55
  56 static void acpi_tb_convert_fadt(void);
  57
  58 static void acpi_tb_validate_fadt(void);
  59
  60 /* Table for conversion of FADT to common internal format and FADT validation */
  61
  62 typedef struct acpi_fadt_info {
  63         char *name;
  64         u8 address64;
  65         u8 address32;
  66         u8 length;
  67         u8 default_length;
  68         u8 type;
  69
  70 } acpi_fadt_info;
  71
  72 #define ACPI_FADT_REQUIRED          1
  73 #define ACPI_FADT_SEPARATE_LENGTH   2
  74
  75 static struct acpi_fadt_info fadt_info_table[] = {
  76         {"Pm1aEventBlock",
  77          ACPI_FADT_OFFSET(xpm1a_event_block),
  78          ACPI_FADT_OFFSET(pm1a_event_block),
  79          ACPI_FADT_OFFSET(pm1_event_length),
  80          ACPI_PM1_REGISTER_WIDTH * 2,   /* Enable + Status register */
  81          ACPI_FADT_REQUIRED},
  82
  83         {"Pm1bEventBlock",
  84          ACPI_FADT_OFFSET(xpm1b_event_block),
  85          ACPI_FADT_OFFSET(pm1b_event_block),
  86          ACPI_FADT_OFFSET(pm1_event_length),
  87          ACPI_PM1_REGISTER_WIDTH * 2,   /* Enable + Status register */
  88          0},
  89
  90         {"Pm1aControlBlock",
  91          ACPI_FADT_OFFSET(xpm1a_control_block),
  92          ACPI_FADT_OFFSET(pm1a_control_block),
  93          ACPI_FADT_OFFSET(pm1_control_length),
  94          ACPI_PM1_REGISTER_WIDTH,
  95          ACPI_FADT_REQUIRED},
  96
  97         {"Pm1bControlBlock",
  98          ACPI_FADT_OFFSET(xpm1b_control_block),
  99          ACPI_FADT_OFFSET(pm1b_control_block),
 100          ACPI_FADT_OFFSET(pm1_control_length),
 101          ACPI_PM1_REGISTER_WIDTH,
 102          0},
 103
 104         {"Pm2ControlBlock",
 105          ACPI_FADT_OFFSET(xpm2_control_block),
 106          ACPI_FADT_OFFSET(pm2_control_block),
 107          ACPI_FADT_OFFSET(pm2_control_length),
 108          ACPI_PM2_REGISTER_WIDTH,
 109          ACPI_FADT_SEPARATE_LENGTH},
 110
 111         {"PmTimerBlock",
 112          ACPI_FADT_OFFSET(xpm_timer_block),
 113          ACPI_FADT_OFFSET(pm_timer_block),
 114          ACPI_FADT_OFFSET(pm_timer_length),
 115          ACPI_PM_TIMER_WIDTH,
 116          ACPI_FADT_REQUIRED},
 117
 118         {"Gpe0Block",
 119          ACPI_FADT_OFFSET(xgpe0_block),
 120          ACPI_FADT_OFFSET(gpe0_block),
 121          ACPI_FADT_OFFSET(gpe0_block_length),
 122          0,
 123          ACPI_FADT_SEPARATE_LENGTH},
 124
 125         {"Gpe1Block",
 126          ACPI_FADT_OFFSET(xgpe1_block),
 127          ACPI_FADT_OFFSET(gpe1_block),
 128          ACPI_FADT_OFFSET(gpe1_block_length),
 129          0,
 130          ACPI_FADT_SEPARATE_LENGTH}
 131 };
 132
 133 #define ACPI_FADT_INFO_ENTRIES        (sizeof (fadt_info_table) / sizeof (struct acpi_fadt_info))
 134
 135 /*******************************************************************************
 136  *
 137  * FUNCTION:    acpi_tb_init_generic_address
 138  *
 139  * PARAMETERS:  generic_address     - GAS struct to be initialized
 140  *              byte_width          - Width of this register
 141  *              Address             - Address of the register
 142  *
 143  * RETURN:      None
 144  *
 145  * DESCRIPTION: Initialize a Generic Address Structure (GAS)
 146  *              See the ACPI specification for a full description and
 147  *              definition of this structure.
 148  *
 149  ******************************************************************************/
 150
 151 static inline void
 152 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
 153                              u8 space_id, u8 byte_width, u64 address)
 154 {
 155
 156         /*
 157          * The 64-bit Address field is non-aligned in the byte packed
 158          * GAS struct.
 159          */
 160         ACPI_MOVE_64_TO_64(&generic_address->address, &address);
 161
 162         /* All other fields are byte-wide */
 163
 164         generic_address->space_id = space_id;
 165         generic_address->bit_width = (u8)ACPI_MUL_8(byte_width);
 166         generic_address->bit_offset = 0;
 167         generic_address->access_width = 0;      /* Access width ANY */
 168 }
 169
 170 /*******************************************************************************
 171  *
 172  * FUNCTION:    acpi_tb_parse_fadt
 173  *
 174  * PARAMETERS:  table_index         - Index for the FADT
 175  *              Flags               - Flags
 176  *
 177  * RETURN:      None
 178  *
 179  * DESCRIPTION: Initialize the FADT, DSDT and FACS tables
 180  *              (FADT contains the addresses of the DSDT and FACS)
 181  *
 182  ******************************************************************************/
 183
 184 void acpi_tb_parse_fadt(u32 table_index, u8 flags)
 185 {
 186         u32 length;
 187         struct acpi_table_header *table;
 188
 189         /*
 190          * The FADT has multiple versions with different lengths,
 191          * and it contains pointers to both the DSDT and FACS tables.
 192          *
 193          * Get a local copy of the FADT and convert it to a common format
 194          * Map entire FADT, assumed to be smaller than one page.
 195          */
 196         length = acpi_gbl_root_table_list.tables[table_index].length;
 197
 198         table =
 199             acpi_os_map_memory(acpi_gbl_root_table_list.tables[table_index].
 200                                address, length);
 201         if (!table) {
 202                 return;
 203         }
 204
 205         /*
 206          * Validate the FADT checksum before we copy the table. Ignore
 207          * checksum error as we want to try to get the DSDT and FACS.
 208          */
 209         (void)acpi_tb_verify_checksum(table, length);
 210
 211         /* Obtain a local copy of the FADT in common ACPI 2.0+ format */
 212
 213         acpi_tb_create_local_fadt(table, length);
 214
 215         /* All done with the real FADT, unmap it */
 216
 217         acpi_os_unmap_memory(table, length);
 218
 219         /* Obtain the DSDT and FACS tables via their addresses within the FADT */
 220
 221         acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.Xdsdt,
 222                               flags, ACPI_SIG_DSDT, ACPI_TABLE_INDEX_DSDT);
 223
 224         acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.Xfacs,
 225                               flags, ACPI_SIG_FACS, ACPI_TABLE_INDEX_FACS);
 226 }
 227
 228 /*******************************************************************************
 229  *
 230  * FUNCTION:    acpi_tb_create_local_fadt
 231  *
 232  * PARAMETERS:  Table               - Pointer to BIOS FADT
 233  *              Length              - Length of the table
 234  *
 235  * RETURN:      None
 236  *
 237  * DESCRIPTION: Get a local copy of the FADT and convert it to a common format.
 238  *              Performs validation on some important FADT fields.
 239  *
 240  * NOTE:        We create a local copy of the FADT regardless of the version.
 241  *
 242  ******************************************************************************/
 243
 244 void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
 245 {
 246
 247         /*
 248          * Check if the FADT is larger than the largest table that we expect
 249          * (the ACPI 2.0/3.0 version). If so, truncate the table, and issue
 250          * a warning.
 251          */
 252         if (length > sizeof(struct acpi_table_fadt)) {
 253                 ACPI_WARNING((AE_INFO,
 254                               "FADT (revision %u) is longer than ACPI 2.0 version, "
 255                               "truncating length 0x%X to 0x%zX",
 256                               table->revision, (unsigned)length,
 257                               sizeof(struct acpi_table_fadt)));
 258         }
 259
 260         /* Clear the entire local FADT */
 261
 262         ACPI_MEMSET(&acpi_gbl_FADT, 0, sizeof(struct acpi_table_fadt));
 263
 264         /* Copy the original FADT, up to sizeof (struct acpi_table_fadt) */
 265
 266         ACPI_MEMCPY(&acpi_gbl_FADT, table,
 267                     ACPI_MIN(length, sizeof(struct acpi_table_fadt)));
 268
 269         /*
 270          * 1) Convert the local copy of the FADT to the common internal format
 271          * 2) Validate some of the important values within the FADT
 272          */
 273         acpi_tb_convert_fadt();
 274 }
 275
 276 /*******************************************************************************
 277  *
 278  * FUNCTION:    acpi_tb_convert_fadt
 279  *
 280  * PARAMETERS:  None, uses acpi_gbl_FADT
 281  *
 282  * RETURN:      None
 283  *
 284  * DESCRIPTION: Converts all versions of the FADT to a common internal format.
 285  *              Expand all 32-bit addresses to 64-bit.
 286  *
 287  * NOTE:        acpi_gbl_FADT must be of size (struct acpi_table_fadt),
 288  *              and must contain a copy of the actual FADT.
 289  *
 290  * ACPICA will use the "X" fields of the FADT for all addresses.
 291  *
 292  * "X" fields are optional extensions to the original V1.0 fields. Even if
 293  * they are present in the structure, they can be optionally not used by
 294  * setting them to zero. Therefore, we must selectively expand V1.0 fields
 295  * if the corresponding X field is zero.
 296  *
 297  * For ACPI 1.0 FADTs, all address fields are expanded to the corresponding
 298  * "X" fields.
 299  *
 300  * For ACPI 2.0 FADTs, any "X" fields that are NULL are filled in by
 301  * expanding the corresponding ACPI 1.0 field.
 302  *
 303  ******************************************************************************/
 304
 305 static void acpi_tb_convert_fadt(void)
 306 {
 307         u8 pm1_register_bit_width;
 308         u8 pm1_register_byte_width;
 309         struct acpi_generic_address *target64;
 310         u32 i;
 311
 312         /* Update the local FADT table header length */
 313
 314         acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
 315
 316         /*
 317          * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
 318          * Later code will always use the X 64-bit field. Also, check for an
 319          * address mismatch between the 32-bit and 64-bit address fields
 320          * (FIRMWARE_CTRL/X_FIRMWARE_CTRL, DSDT/X_DSDT) which would indicate
 321          * the presence of two FACS or two DSDT tables.
 322          */
 323         if (!acpi_gbl_FADT.Xfacs) {
 324                 acpi_gbl_FADT.Xfacs = (u64) acpi_gbl_FADT.facs;
 325         } else if (acpi_gbl_FADT.facs &&
 326                    (acpi_gbl_FADT.Xfacs != (u64) acpi_gbl_FADT.facs)) {
 327                 ACPI_WARNING((AE_INFO,
 328                     "32/64 FACS address mismatch in FADT - two FACS tables!"));
 329         }
 330
 331         if (!acpi_gbl_FADT.Xdsdt) {
 332                 acpi_gbl_FADT.Xdsdt = (u64) acpi_gbl_FADT.dsdt;
 333         } else if (acpi_gbl_FADT.dsdt &&
 334                    (acpi_gbl_FADT.Xdsdt != (u64) acpi_gbl_FADT.dsdt)) {
 335                 ACPI_WARNING((AE_INFO,
 336                     "32/64 DSDT address mismatch in FADT - two DSDT tables!"));
 337         }
 338
 339         /*
 340          * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
 341          * should be zero are indeed zero. This will workaround BIOSs that
 342          * inadvertently place values in these fields.
 343          *
 344          * The ACPI 1.0 reserved fields that will be zeroed are the bytes located at
 345          * offset 45, 55, 95, and the word located at offset 109, 110.
 346          */
 347         if (acpi_gbl_FADT.header.revision < FADT2_REVISION_ID) {
 348                 acpi_gbl_FADT.preferred_profile = 0;
 349                 acpi_gbl_FADT.pstate_control = 0;
 350                 acpi_gbl_FADT.cst_control = 0;
 351                 acpi_gbl_FADT.boot_flags = 0;
 352         }
 353
 354         /*
 355          * Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X"
 356          * generic address structures as necessary. Later code will always use
 357          * the 64-bit address structures.
 358          */
 359         for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 360                 target64 =
 361                     ACPI_ADD_PTR(struct acpi_generic_address, &acpi_gbl_FADT,
 362                                  fadt_info_table[i].address64);
 363
 364                 /* Expand only if the 64-bit X target is null */
 365
 366                 if (!target64->address) {
 367
 368                         /* The space_id is always I/O for the 32-bit legacy address fields */
 369
 370                         acpi_tb_init_generic_address(target64,
 371                                                      ACPI_ADR_SPACE_SYSTEM_IO,
 372                                                      *ACPI_ADD_PTR(u8,
 373                                                                    &acpi_gbl_FADT,
 374                                                                    fadt_info_table
 375                                                                    [i].length),
 376                                                      (u64) * ACPI_ADD_PTR(u32,
 377                                                                           &acpi_gbl_FADT,
 378                                                                           fadt_info_table
 379                                                                           [i].
 380                                                                           address32));
 381                 }
 382         }
 383
 384         /* Validate FADT values now, before we make any changes */
 385
 386         acpi_tb_validate_fadt();
 387
 388         /*
 389          * Optionally check all register lengths against the default values and
 390          * update them if they are incorrect.
 391          */
 392         if (acpi_gbl_use_default_register_widths) {
 393                 for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 394                         target64 =
 395                             ACPI_ADD_PTR(struct acpi_generic_address,
 396                                          &acpi_gbl_FADT,
 397                                          fadt_info_table[i].address64);
 398
 399                         /*
 400                          * If a valid register (Address != 0) and the (default_length > 0)
 401                          * (Not a GPE register), then check the width against the default.
 402                          */
 403                         if ((target64->address) &&
 404                             (fadt_info_table[i].default_length > 0) &&
 405                             (fadt_info_table[i].default_length !=
 406                              target64->bit_width)) {
 407                                 ACPI_WARNING((AE_INFO,
 408                                               "Invalid length for %s: %d, using default %d",
 409                                               fadt_info_table[i].name,
 410                                               target64->bit_width,
 411                                               fadt_info_table[i].
 412                                               default_length));
 413
 414                                 /* Incorrect size, set width to the default */
 415
 416                                 target64->bit_width =
 417                                     fadt_info_table[i].default_length;
 418                         }
 419                 }
 420         }
 421
 422         /*
 423          * Get the length of the individual PM1 registers (enable and status).
 424          * Each register is defined to be (event block length / 2).
 425          */
 426         pm1_register_bit_width =
 427             (u8)ACPI_DIV_2(acpi_gbl_FADT.xpm1a_event_block.bit_width);
 428         pm1_register_byte_width = (u8)ACPI_DIV_8(pm1_register_bit_width);
 429
 430         /*
 431          * Adjust the lengths of the PM1 Event Blocks so that they can be used to
 432          * access the PM1 status register(s). Use (width / 2)
 433          */
 434         acpi_gbl_FADT.xpm1a_event_block.bit_width = pm1_register_bit_width;
 435         acpi_gbl_FADT.xpm1b_event_block.bit_width = pm1_register_bit_width;
 436
 437         /*
 438          * Calculate separate GAS structs for the PM1 Enable registers.
 439          * These addresses do not appear (directly) in the FADT, so it is
 440          * useful to calculate them once, here.
 441          *
 442          * The PM event blocks are split into two register blocks, first is the
 443          * PM Status Register block, followed immediately by the PM Enable
 444          * Register block. Each is of length (xpm1x_event_block.bit_width/2).
 445          *
 446          * On various systems the v2 fields (and particularly the bit widths)
 447          * cannot be relied upon, though. Hence resort to using the v1 length
 448          * here (and warn about the inconsistency).
 449          */
 450         if (acpi_gbl_FADT.xpm1a_event_block.bit_width
 451             != acpi_gbl_FADT.pm1_event_length * 8)
 452                 printk(KERN_WARNING "FADT: "
 453                        "X_PM1a_EVT_BLK.bit_width (%u) does not match"
 454                        " PM1_EVT_LEN (%u)\n",
 455                        acpi_gbl_FADT.xpm1a_event_block.bit_width,
 456                        acpi_gbl_FADT.pm1_event_length);
 457
 458         /* The PM1A register block is required */
 459
 460         acpi_tb_init_generic_address(&acpi_gbl_xpm1a_enable,
 461                                      acpi_gbl_FADT.xpm1a_event_block.space_id,
 462                                      pm1_register_byte_width,
 463                                      (acpi_gbl_FADT.xpm1a_event_block.address +
 464                                       pm1_register_byte_width));
 465         /* Don't forget to copy space_id of the GAS */
 466         acpi_gbl_xpm1a_enable.space_id =
 467             acpi_gbl_FADT.xpm1a_event_block.space_id;
 468
 469         /* The PM1B register block is optional, ignore if not present */
 470
 471         if (acpi_gbl_FADT.xpm1b_event_block.address) {
 472                 if (acpi_gbl_FADT.xpm1b_event_block.bit_width
 473                     != acpi_gbl_FADT.pm1_event_length * 8)
 474                         printk(KERN_WARNING "FADT: "
 475                                "X_PM1b_EVT_BLK.bit_width (%u) does not match"
 476                                " PM1_EVT_LEN (%u)\n",
 477                                acpi_gbl_FADT.xpm1b_event_block.bit_width,
 478                                acpi_gbl_FADT.pm1_event_length);
 479                 acpi_tb_init_generic_address(&acpi_gbl_xpm1b_enable,
 480                                              acpi_gbl_FADT.xpm1b_event_block.space_id,
 481                                              pm1_register_byte_width,
 482                                              (acpi_gbl_FADT.xpm1b_event_block.
 483                                               address + pm1_register_byte_width));
 484                 /* Don't forget to copy space_id of the GAS */
 485                 acpi_gbl_xpm1b_enable.space_id =
 486                     acpi_gbl_FADT.xpm1b_event_block.space_id;
 487
 488         }
 489 }
 490
 491 /******************************************************************************
 492  *
 493  * FUNCTION:    acpi_tb_validate_fadt
 494  *
 495  * PARAMETERS:  Table           - Pointer to the FADT to be validated
 496  *
 497  * RETURN:      None
 498  *
 499  * DESCRIPTION: Validate various important fields within the FADT. If a problem
 500  *              is found, issue a message, but no status is returned.
 501  *              Used by both the table manager and the disassembler.
 502  *
 503  * Possible additional checks:
 504  * (acpi_gbl_FADT.pm1_event_length >= 4)
 505  * (acpi_gbl_FADT.pm1_control_length >= 2)
 506  * (acpi_gbl_FADT.pm_timer_length >= 4)
 507  * Gpe block lengths must be multiple of 2
 508  *
 509  ******************************************************************************/
 510
 511 static void acpi_tb_validate_fadt(void)
 512 {
 513         char *name;
 514         u32 *address32;
 515         struct acpi_generic_address *address64;
 516         u8 length;
 517         u32 i;
 518
 519         /*
 520          * Check for FACS and DSDT address mismatches. An address mismatch between
 521          * the 32-bit and 64-bit address fields (FIRMWARE_CTRL/X_FIRMWARE_CTRL and
 522          * DSDT/X_DSDT) would indicate the presence of two FACS or two DSDT tables.
 523          */
 524         if (acpi_gbl_FADT.facs &&
 525             (acpi_gbl_FADT.Xfacs != (u64) acpi_gbl_FADT.facs)) {
 526                 ACPI_WARNING((AE_INFO,
 527                               "32/64X FACS address mismatch in FADT - "
 528                               "two FACS tables! %8.8X/%8.8X%8.8X",
 529                               acpi_gbl_FADT.facs,
 530                               ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xfacs)));
 531         }
 532
 533         if (acpi_gbl_FADT.dsdt &&
 534             (acpi_gbl_FADT.Xdsdt != (u64) acpi_gbl_FADT.dsdt)) {
 535                 ACPI_WARNING((AE_INFO,
 536                               "32/64X DSDT address mismatch in FADT - "
 537                               "two DSDT tables! %8.8X/%8.8X%8.8X",
 538                               acpi_gbl_FADT.dsdt,
 539                               ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xdsdt)));
 540         }
 541
 542         /* Examine all of the 64-bit extended address fields (X fields) */
 543
 544         for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 545                 /*
 546                  * Generate pointers to the 32-bit and 64-bit addresses, get the
 547                  * register length (width), and the register name
 548                  */
 549                 address64 = ACPI_ADD_PTR(struct acpi_generic_address,
 550                                          &acpi_gbl_FADT,
 551                                          fadt_info_table[i].address64);
 552                 address32 =
 553                     ACPI_ADD_PTR(u32, &acpi_gbl_FADT,
 554                                  fadt_info_table[i].address32);
 555                 length =
 556                     *ACPI_ADD_PTR(u8, &acpi_gbl_FADT,
 557                                   fadt_info_table[i].length);
 558                 name = fadt_info_table[i].name;
 559
 560                 /*
 561                  * For each extended field, check for length mismatch between the
 562                  * legacy length field and the corresponding 64-bit X length field.
 563                  */
 564                 if (address64 && (address64->bit_width != ACPI_MUL_8(length))) {
 565                         ACPI_WARNING((AE_INFO,
 566                                       "32/64X length mismatch in %s: %d/%d",
 567                                       name, ACPI_MUL_8(length),
 568                                       address64->bit_width));
 569                 }
 570
 571                 if (fadt_info_table[i].type & ACPI_FADT_REQUIRED) {
 572                         /*
 573                          * Field is required (Pm1a_event, Pm1a_control, pm_timer).
 574                          * Both the address and length must be non-zero.
 575                          */
 576                         if (!address64->address || !length) {
 577                                 ACPI_ERROR((AE_INFO,
 578                                             "Required field %s has zero address and/or length: %8.8X%8.8X/%X",
 579                                             name,
 580                                             ACPI_FORMAT_UINT64(address64->
 581                                                                address),
 582                                             length));
 583                         }
 584                 } else if (fadt_info_table[i].type & ACPI_FADT_SEPARATE_LENGTH) {
 585                         /*
 586                          * Field is optional (PM2Control, GPE0, GPE1) AND has its own
 587                          * length field. If present, both the address and length must be valid.
 588                          */
 589                         if ((address64->address && !length)
 590                             || (!address64->address && length)) {
 591                                 ACPI_WARNING((AE_INFO,
 592                                               "Optional field %s has zero address or length: %8.8X%8.8X/%X",
 593                                               name,
 594                                               ACPI_FORMAT_UINT64(address64->
 595                                                                  address),
 596                                               length));
 597                         }
 598                 }
 599
 600                 /* If both 32- and 64-bit addresses are valid (non-zero), they must match */
 601
 602                 if (address64->address && *address32 &&
 603                     (address64->address != (u64) * address32)) {
 604                         ACPI_ERROR((AE_INFO,
 605                                     "32/64X address mismatch in %s: %8.8X/%8.8X%8.8X, using 64X",
 606                                     name, *address32,
 607                                     ACPI_FORMAT_UINT64(address64->address)));
 608                 }
 609         }
 610 }