drivers/acpi/acpica/tbfadt.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbfadt   - FADT table utilities
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, 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 "accommon.h"
  46 #include "actables.h"
  47
  48 #define _COMPONENT          ACPI_TABLES
  49 ACPI_MODULE_NAME("tbfadt")
  50
  51 /* Local prototypes */
  52 static void
  53 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
  54                              u8 space_id,
  55                              u8 byte_width, u64 address, char *register_name);
  56
  57 static void acpi_tb_convert_fadt(void);
  58
  59 static void acpi_tb_validate_fadt(void);
  60
  61 static void acpi_tb_setup_fadt_registers(void);
  62
  63 /* Table for conversion of FADT to common internal format and FADT validation */
  64
  65 typedef struct acpi_fadt_info {
  66         char *name;
  67         u16 address64;
  68         u16 address32;
  69         u16 length;
  70         u8 default_length;
  71         u8 type;
  72
  73 } acpi_fadt_info;
  74
  75 #define ACPI_FADT_OPTIONAL          0
  76 #define ACPI_FADT_REQUIRED          1
  77 #define ACPI_FADT_SEPARATE_LENGTH   2
  78
  79 static struct acpi_fadt_info fadt_info_table[] = {
  80         {"Pm1aEventBlock",
  81          ACPI_FADT_OFFSET(xpm1a_event_block),
  82          ACPI_FADT_OFFSET(pm1a_event_block),
  83          ACPI_FADT_OFFSET(pm1_event_length),
  84          ACPI_PM1_REGISTER_WIDTH * 2,   /* Enable + Status register */
  85          ACPI_FADT_REQUIRED},
  86
  87         {"Pm1bEventBlock",
  88          ACPI_FADT_OFFSET(xpm1b_event_block),
  89          ACPI_FADT_OFFSET(pm1b_event_block),
  90          ACPI_FADT_OFFSET(pm1_event_length),
  91          ACPI_PM1_REGISTER_WIDTH * 2,   /* Enable + Status register */
  92          ACPI_FADT_OPTIONAL},
  93
  94         {"Pm1aControlBlock",
  95          ACPI_FADT_OFFSET(xpm1a_control_block),
  96          ACPI_FADT_OFFSET(pm1a_control_block),
  97          ACPI_FADT_OFFSET(pm1_control_length),
  98          ACPI_PM1_REGISTER_WIDTH,
  99          ACPI_FADT_REQUIRED},
 100
 101         {"Pm1bControlBlock",
 102          ACPI_FADT_OFFSET(xpm1b_control_block),
 103          ACPI_FADT_OFFSET(pm1b_control_block),
 104          ACPI_FADT_OFFSET(pm1_control_length),
 105          ACPI_PM1_REGISTER_WIDTH,
 106          ACPI_FADT_OPTIONAL},
 107
 108         {"Pm2ControlBlock",
 109          ACPI_FADT_OFFSET(xpm2_control_block),
 110          ACPI_FADT_OFFSET(pm2_control_block),
 111          ACPI_FADT_OFFSET(pm2_control_length),
 112          ACPI_PM2_REGISTER_WIDTH,
 113          ACPI_FADT_SEPARATE_LENGTH},
 114
 115         {"PmTimerBlock",
 116          ACPI_FADT_OFFSET(xpm_timer_block),
 117          ACPI_FADT_OFFSET(pm_timer_block),
 118          ACPI_FADT_OFFSET(pm_timer_length),
 119          ACPI_PM_TIMER_WIDTH,
 120          ACPI_FADT_REQUIRED},
 121
 122         {"Gpe0Block",
 123          ACPI_FADT_OFFSET(xgpe0_block),
 124          ACPI_FADT_OFFSET(gpe0_block),
 125          ACPI_FADT_OFFSET(gpe0_block_length),
 126          0,
 127          ACPI_FADT_SEPARATE_LENGTH},
 128
 129         {"Gpe1Block",
 130          ACPI_FADT_OFFSET(xgpe1_block),
 131          ACPI_FADT_OFFSET(gpe1_block),
 132          ACPI_FADT_OFFSET(gpe1_block_length),
 133          0,
 134          ACPI_FADT_SEPARATE_LENGTH}
 135 };
 136
 137 #define ACPI_FADT_INFO_ENTRIES \
 138                         (sizeof (fadt_info_table) / sizeof (struct acpi_fadt_info))
 139
 140 /* Table used to split Event Blocks into separate status/enable registers */
 141
 142 typedef struct acpi_fadt_pm_info {
 143         struct acpi_generic_address *target;
 144         u16 source;
 145         u8 register_num;
 146
 147 } acpi_fadt_pm_info;
 148
 149 static struct acpi_fadt_pm_info fadt_pm_info_table[] = {
 150         {&acpi_gbl_xpm1a_status,
 151          ACPI_FADT_OFFSET(xpm1a_event_block),
 152          0},
 153
 154         {&acpi_gbl_xpm1a_enable,
 155          ACPI_FADT_OFFSET(xpm1a_event_block),
 156          1},
 157
 158         {&acpi_gbl_xpm1b_status,
 159          ACPI_FADT_OFFSET(xpm1b_event_block),
 160          0},
 161
 162         {&acpi_gbl_xpm1b_enable,
 163          ACPI_FADT_OFFSET(xpm1b_event_block),
 164          1}
 165 };
 166
 167 #define ACPI_FADT_PM_INFO_ENTRIES \
 168                         (sizeof (fadt_pm_info_table) / sizeof (struct acpi_fadt_pm_info))
 169
 170 /*******************************************************************************
 171  *
 172  * FUNCTION:    acpi_tb_init_generic_address
 173  *
 174  * PARAMETERS:  generic_address     - GAS struct to be initialized
 175  *              byte_width          - Width of this register
 176  *              address             - Address of the register
 177  *
 178  * RETURN:      None
 179  *
 180  * DESCRIPTION: Initialize a Generic Address Structure (GAS)
 181  *              See the ACPI specification for a full description and
 182  *              definition of this structure.
 183  *
 184  ******************************************************************************/
 185
 186 static void
 187 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
 188                              u8 space_id,
 189                              u8 byte_width, u64 address, char *register_name)
 190 {
 191         u8 bit_width;
 192
 193         /* Bit width field in the GAS is only one byte long, 255 max */
 194
 195         bit_width = (u8)(byte_width * 8);
 196
 197         if (byte_width > 31) {  /* (31*8)=248 */
 198                 ACPI_ERROR((AE_INFO,
 199                             "%s - 32-bit FADT register is too long (%u bytes, %u bits) "
 200                             "to convert to GAS struct - 255 bits max, truncating",
 201                             register_name, byte_width, (byte_width * 8)));
 202
 203                 bit_width = 255;
 204         }
 205
 206         /*
 207          * The 64-bit Address field is non-aligned in the byte packed
 208          * GAS struct.
 209          */
 210         ACPI_MOVE_64_TO_64(&generic_address->address, &address);
 211
 212         /* All other fields are byte-wide */
 213
 214         generic_address->space_id = space_id;
 215         generic_address->bit_width = bit_width;
 216         generic_address->bit_offset = 0;
 217         generic_address->access_width = 0;      /* Access width ANY */
 218 }
 219
 220 /*******************************************************************************
 221  *
 222  * FUNCTION:    acpi_tb_parse_fadt
 223  *
 224  * PARAMETERS:  table_index         - Index for the FADT
 225  *
 226  * RETURN:      None
 227  *
 228  * DESCRIPTION: Initialize the FADT, DSDT and FACS tables
 229  *              (FADT contains the addresses of the DSDT and FACS)
 230  *
 231  ******************************************************************************/
 232
 233 void acpi_tb_parse_fadt(u32 table_index)
 234 {
 235         u32 length;
 236         struct acpi_table_header *table;
 237
 238         /*
 239          * The FADT has multiple versions with different lengths,
 240          * and it contains pointers to both the DSDT and FACS tables.
 241          *
 242          * Get a local copy of the FADT and convert it to a common format
 243          * Map entire FADT, assumed to be smaller than one page.
 244          */
 245         length = acpi_gbl_root_table_list.tables[table_index].length;
 246
 247         table =
 248             acpi_os_map_memory(acpi_gbl_root_table_list.tables[table_index].
 249                                address, length);
 250         if (!table) {
 251                 return;
 252         }
 253
 254         /*
 255          * Validate the FADT checksum before we copy the table. Ignore
 256          * checksum error as we want to try to get the DSDT and FACS.
 257          */
 258         (void)acpi_tb_verify_checksum(table, length);
 259
 260         /* Create a local copy of the FADT in common ACPI 2.0+ format */
 261
 262         acpi_tb_create_local_fadt(table, length);
 263
 264         /* All done with the real FADT, unmap it */
 265
 266         acpi_os_unmap_memory(table, length);
 267
 268         /* Obtain the DSDT and FACS tables via their addresses within the FADT */
 269
 270         acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.Xdsdt,
 271                               ACPI_SIG_DSDT, ACPI_TABLE_INDEX_DSDT);
 272
 273         /* If Hardware Reduced flag is set, there is no FACS */
 274
 275         if (!acpi_gbl_reduced_hardware) {
 276                 acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.
 277                                       Xfacs, ACPI_SIG_FACS,
 278                                       ACPI_TABLE_INDEX_FACS);
 279         }
 280 }
 281
 282 /*******************************************************************************
 283  *
 284  * FUNCTION:    acpi_tb_create_local_fadt
 285  *
 286  * PARAMETERS:  table               - Pointer to BIOS FADT
 287  *              length              - Length of the table
 288  *
 289  * RETURN:      None
 290  *
 291  * DESCRIPTION: Get a local copy of the FADT and convert it to a common format.
 292  *              Performs validation on some important FADT fields.
 293  *
 294  * NOTE:        We create a local copy of the FADT regardless of the version.
 295  *
 296  ******************************************************************************/
 297
 298 void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
 299 {
 300         /*
 301          * Check if the FADT is larger than the largest table that we expect
 302          * (the ACPI 5.0 version). If so, truncate the table, and issue
 303          * a warning.
 304          */
 305         if (length > sizeof(struct acpi_table_fadt)) {
 306                 ACPI_BIOS_WARNING((AE_INFO,
 307                                    "FADT (revision %u) is longer than ACPI 5.0 version, "
 308                                    "truncating length %u to %u",
 309                                    table->revision, length,
 310                                    (u32)sizeof(struct acpi_table_fadt)));
 311         }
 312
 313         /* Clear the entire local FADT */
 314
 315         ACPI_MEMSET(&acpi_gbl_FADT, 0, sizeof(struct acpi_table_fadt));
 316
 317         /* Copy the original FADT, up to sizeof (struct acpi_table_fadt) */
 318
 319         ACPI_MEMCPY(&acpi_gbl_FADT, table,
 320                     ACPI_MIN(length, sizeof(struct acpi_table_fadt)));
 321
 322         /* Take a copy of the Hardware Reduced flag */
 323
 324         acpi_gbl_reduced_hardware = FALSE;
 325         if (acpi_gbl_FADT.flags & ACPI_FADT_HW_REDUCED) {
 326                 acpi_gbl_reduced_hardware = TRUE;
 327         }
 328
 329         /* Convert the local copy of the FADT to the common internal format */
 330
 331         acpi_tb_convert_fadt();
 332
 333         /* Validate FADT values now, before we make any changes */
 334
 335         acpi_tb_validate_fadt();
 336
 337         /* Initialize the global ACPI register structures */
 338
 339         acpi_tb_setup_fadt_registers();
 340 }
 341
 342 /*******************************************************************************
 343  *
 344  * FUNCTION:    acpi_tb_convert_fadt
 345  *
 346  * PARAMETERS:  None, uses acpi_gbl_FADT
 347  *
 348  * RETURN:      None
 349  *
 350  * DESCRIPTION: Converts all versions of the FADT to a common internal format.
 351  *              Expand 32-bit addresses to 64-bit as necessary.
 352  *
 353  * NOTE:        acpi_gbl_FADT must be of size (struct acpi_table_fadt),
 354  *              and must contain a copy of the actual FADT.
 355  *
 356  * Notes on 64-bit register addresses:
 357  *
 358  * After this FADT conversion, later ACPICA code will only use the 64-bit "X"
 359  * fields of the FADT for all ACPI register addresses.
 360  *
 361  * The 64-bit "X" fields are optional extensions to the original 32-bit FADT
 362  * V1.0 fields. Even if they are present in the FADT, they are optional and
 363  * are unused if the BIOS sets them to zero. Therefore, we must copy/expand
 364  * 32-bit V1.0 fields if the corresponding X field is zero.
 365  *
 366  * For ACPI 1.0 FADTs, all 32-bit address fields are expanded to the
 367  * corresponding "X" fields in the internal FADT.
 368  *
 369  * For ACPI 2.0+ FADTs, all valid (non-zero) 32-bit address fields are expanded
 370  * to the corresponding 64-bit X fields. For compatibility with other ACPI
 371  * implementations, we ignore the 64-bit field if the 32-bit field is valid,
 372  * regardless of whether the host OS is 32-bit or 64-bit.
 373  *
 374  ******************************************************************************/
 375
 376 static void acpi_tb_convert_fadt(void)
 377 {
 378         struct acpi_generic_address *address64;
 379         u32 address32;
 380         u32 i;
 381
 382         /*
 383          * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
 384          * Later code will always use the X 64-bit field. Also, check for an
 385          * address mismatch between the 32-bit and 64-bit address fields
 386          * (FIRMWARE_CTRL/X_FIRMWARE_CTRL, DSDT/X_DSDT) which would indicate
 387          * the presence of two FACS or two DSDT tables.
 388          */
 389         if (!acpi_gbl_FADT.Xfacs) {
 390                 acpi_gbl_FADT.Xfacs = (u64) acpi_gbl_FADT.facs;
 391         } else if (acpi_gbl_FADT.facs &&
 392                    (acpi_gbl_FADT.Xfacs != (u64) acpi_gbl_FADT.facs)) {
 393                 ACPI_WARNING((AE_INFO,
 394                     "32/64 FACS address mismatch in FADT - two FACS tables!"));
 395         }
 396
 397         if (!acpi_gbl_FADT.Xdsdt) {
 398                 acpi_gbl_FADT.Xdsdt = (u64) acpi_gbl_FADT.dsdt;
 399         } else if (acpi_gbl_FADT.dsdt &&
 400                    (acpi_gbl_FADT.Xdsdt != (u64) acpi_gbl_FADT.dsdt)) {
 401                 ACPI_WARNING((AE_INFO,
 402                     "32/64 DSDT address mismatch in FADT - two DSDT tables!"));
 403         }
 404
 405         /*
 406          * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
 407          * should be zero are indeed zero. This will workaround BIOSs that
 408          * inadvertently place values in these fields.
 409          *
 410          * The ACPI 1.0 reserved fields that will be zeroed are the bytes located at
 411          * offset 45, 55, 95, and the word located at offset 109, 110.
 412          *
 413          * Note: The FADT revision value is unreliable. Only the length can be
 414          * trusted.
 415          */
 416         if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {
 417                 acpi_gbl_FADT.preferred_profile = 0;
 418                 acpi_gbl_FADT.pstate_control = 0;
 419                 acpi_gbl_FADT.cst_control = 0;
 420                 acpi_gbl_FADT.boot_flags = 0;
 421         }
 422
 423         /* Update the local FADT table header length */
 424
 425         acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
 426
 427         /*
 428          * Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X"
 429          * generic address structures as necessary. Later code will always use
 430          * the 64-bit address structures.
 431          *
 432          * March 2009:
 433          * We now always use the 32-bit address if it is valid (non-null). This
 434          * is not in accordance with the ACPI specification which states that
 435          * the 64-bit address supersedes the 32-bit version, but we do this for
 436          * compatibility with other ACPI implementations. Most notably, in the
 437          * case where both the 32 and 64 versions are non-null, we use the 32-bit
 438          * version. This is the only address that is guaranteed to have been
 439          * tested by the BIOS manufacturer.
 440          */
 441         for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 442                 address32 = *ACPI_ADD_PTR(u32,
 443                                           &acpi_gbl_FADT,
 444                                           fadt_info_table[i].address32);
 445
 446                 address64 = ACPI_ADD_PTR(struct acpi_generic_address,
 447                                          &acpi_gbl_FADT,
 448                                          fadt_info_table[i].address64);
 449
 450                 /*
 451                  * If both 32- and 64-bit addresses are valid (non-zero),
 452                  * they must match.
 453                  */
 454                 if (address64->address && address32 &&
 455                     (address64->address != (u64)address32)) {
 456                         ACPI_BIOS_ERROR((AE_INFO,
 457                                          "32/64X address mismatch in FADT/%s: "
 458                                          "0x%8.8X/0x%8.8X%8.8X, using 32",
 459                                          fadt_info_table[i].name, address32,
 460                                          ACPI_FORMAT_UINT64(address64->
 461                                                             address)));
 462                 }
 463
 464                 /* Always use 32-bit address if it is valid (non-null) */
 465
 466                 if (address32) {
 467                         /*
 468                          * Copy the 32-bit address to the 64-bit GAS structure. The
 469                          * Space ID is always I/O for 32-bit legacy address fields
 470                         */
 471                         acpi_tb_init_generic_address(address64,
 472                                                      ACPI_ADR_SPACE_SYSTEM_IO,
 473                                                      *ACPI_ADD_PTR(u8,
 474                                                                    &acpi_gbl_FADT,
 475                                                                    fadt_info_table
 476                                                                    [i].length),
 477                                                      (u64) address32,
 478                                                      fadt_info_table[i].name);
 479                 }
 480         }
 481 }
 482
 483 /*******************************************************************************
 484  *
 485  * FUNCTION:    acpi_tb_validate_fadt
 486  *
 487  * PARAMETERS:  table           - Pointer to the FADT to be validated
 488  *
 489  * RETURN:      None
 490  *
 491  * DESCRIPTION: Validate various important fields within the FADT. If a problem
 492  *              is found, issue a message, but no status is returned.
 493  *              Used by both the table manager and the disassembler.
 494  *
 495  * Possible additional checks:
 496  * (acpi_gbl_FADT.pm1_event_length >= 4)
 497  * (acpi_gbl_FADT.pm1_control_length >= 2)
 498  * (acpi_gbl_FADT.pm_timer_length >= 4)
 499  * Gpe block lengths must be multiple of 2
 500  *
 501  ******************************************************************************/
 502
 503 static void acpi_tb_validate_fadt(void)
 504 {
 505         char *name;
 506         struct acpi_generic_address *address64;
 507         u8 length;
 508         u32 i;
 509
 510         /*
 511          * Check for FACS and DSDT address mismatches. An address mismatch between
 512          * the 32-bit and 64-bit address fields (FIRMWARE_CTRL/X_FIRMWARE_CTRL and
 513          * DSDT/X_DSDT) would indicate the presence of two FACS or two DSDT tables.
 514          */
 515         if (acpi_gbl_FADT.facs &&
 516             (acpi_gbl_FADT.Xfacs != (u64)acpi_gbl_FADT.facs)) {
 517                 ACPI_BIOS_WARNING((AE_INFO,
 518                                    "32/64X FACS address mismatch in FADT - "
 519                                    "0x%8.8X/0x%8.8X%8.8X, using 32",
 520                                    acpi_gbl_FADT.facs,
 521                                    ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xfacs)));
 522
 523                 acpi_gbl_FADT.Xfacs = (u64)acpi_gbl_FADT.facs;
 524         }
 525
 526         if (acpi_gbl_FADT.dsdt &&
 527             (acpi_gbl_FADT.Xdsdt != (u64)acpi_gbl_FADT.dsdt)) {
 528                 ACPI_BIOS_WARNING((AE_INFO,
 529                                    "32/64X DSDT address mismatch in FADT - "
 530                                    "0x%8.8X/0x%8.8X%8.8X, using 32",
 531                                    acpi_gbl_FADT.dsdt,
 532                                    ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xdsdt)));
 533
 534                 acpi_gbl_FADT.Xdsdt = (u64)acpi_gbl_FADT.dsdt;
 535         }
 536
 537         /* If Hardware Reduced flag is set, we are all done */
 538
 539         if (acpi_gbl_reduced_hardware) {
 540                 return;
 541         }
 542
 543         /* Examine all of the 64-bit extended address fields (X fields) */
 544
 545         for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 546                 /*
 547                  * Generate pointer to the 64-bit address, get the register
 548                  * length (width) and the register name
 549                  */
 550                 address64 = ACPI_ADD_PTR(struct acpi_generic_address,
 551                                          &acpi_gbl_FADT,
 552                                          fadt_info_table[i].address64);
 553                 length =
 554                     *ACPI_ADD_PTR(u8, &acpi_gbl_FADT,
 555                                   fadt_info_table[i].length);
 556                 name = fadt_info_table[i].name;
 557
 558                 /*
 559                  * For each extended field, check for length mismatch between the
 560                  * legacy length field and the corresponding 64-bit X length field.
 561                  */
 562                 if (address64->address &&
 563                     (address64->bit_width != ACPI_MUL_8(length))) {
 564                         ACPI_BIOS_WARNING((AE_INFO,
 565                                            "32/64X length mismatch in FADT/%s: %u/%u",
 566                                            name, ACPI_MUL_8(length),
 567                                            address64->bit_width));
 568                 }
 569
 570                 if (fadt_info_table[i].type & ACPI_FADT_REQUIRED) {
 571                         /*
 572                          * Field is required (Pm1a_event, Pm1a_control, pm_timer).
 573                          * Both the address and length must be non-zero.
 574                          */
 575                         if (!address64->address || !length) {
 576                                 ACPI_BIOS_ERROR((AE_INFO,
 577                                                  "Required FADT field %s has zero address and/or length: "
 578                                                  "0x%8.8X%8.8X/0x%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 (Pm2_control, GPE0, GPE1) AND has its own
 587                          * length field. If present, both the address and length must
 588                          * be valid.
 589                          */
 590                         if ((address64->address && !length) ||
 591                             (!address64->address && length)) {
 592                                 ACPI_BIOS_WARNING((AE_INFO,
 593                                                    "Optional FADT field %s has zero address or length: "
 594                                                    "0x%8.8X%8.8X/0x%X",
 595                                                    name,
 596                                                    ACPI_FORMAT_UINT64
 597                                                    (address64->address),
 598                                                    length));
 599                         }
 600                 }
 601         }
 602 }
 603
 604 /*******************************************************************************
 605  *
 606  * FUNCTION:    acpi_tb_setup_fadt_registers
 607  *
 608  * PARAMETERS:  None, uses acpi_gbl_FADT.
 609  *
 610  * RETURN:      None
 611  *
 612  * DESCRIPTION: Initialize global ACPI PM1 register definitions. Optionally,
 613  *              force FADT register definitions to their default lengths.
 614  *
 615  ******************************************************************************/
 616
 617 static void acpi_tb_setup_fadt_registers(void)
 618 {
 619         struct acpi_generic_address *target64;
 620         struct acpi_generic_address *source64;
 621         u8 pm1_register_byte_width;
 622         u32 i;
 623
 624         /*
 625          * Optionally check all register lengths against the default values and
 626          * update them if they are incorrect.
 627          */
 628         if (acpi_gbl_use_default_register_widths) {
 629                 for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 630                         target64 =
 631                             ACPI_ADD_PTR(struct acpi_generic_address,
 632                                          &acpi_gbl_FADT,
 633                                          fadt_info_table[i].address64);
 634
 635                         /*
 636                          * If a valid register (Address != 0) and the (default_length > 0)
 637                          * (Not a GPE register), then check the width against the default.
 638                          */
 639                         if ((target64->address) &&
 640                             (fadt_info_table[i].default_length > 0) &&
 641                             (fadt_info_table[i].default_length !=
 642                              target64->bit_width)) {
 643                                 ACPI_BIOS_WARNING((AE_INFO,
 644                                                    "Invalid length for FADT/%s: %u, using default %u",
 645                                                    fadt_info_table[i].name,
 646                                                    target64->bit_width,
 647                                                    fadt_info_table[i].
 648                                                    default_length));
 649
 650                                 /* Incorrect size, set width to the default */
 651
 652                                 target64->bit_width =
 653                                     fadt_info_table[i].default_length;
 654                         }
 655                 }
 656         }
 657
 658         /*
 659          * Get the length of the individual PM1 registers (enable and status).
 660          * Each register is defined to be (event block length / 2). Extra divide
 661          * by 8 converts bits to bytes.
 662          */
 663         pm1_register_byte_width = (u8)
 664             ACPI_DIV_16(acpi_gbl_FADT.xpm1a_event_block.bit_width);
 665
 666         /*
 667          * Calculate separate GAS structs for the PM1x (A/B) Status and Enable
 668          * registers. These addresses do not appear (directly) in the FADT, so it
 669          * is useful to pre-calculate them from the PM1 Event Block definitions.
 670          *
 671          * The PM event blocks are split into two register blocks, first is the
 672          * PM Status Register block, followed immediately by the PM Enable
 673          * Register block. Each is of length (pm1_event_length/2)
 674          *
 675          * Note: The PM1A event block is required by the ACPI specification.
 676          * However, the PM1B event block is optional and is rarely, if ever,
 677          * used.
 678          */
 679
 680         for (i = 0; i < ACPI_FADT_PM_INFO_ENTRIES; i++) {
 681                 source64 =
 682                     ACPI_ADD_PTR(struct acpi_generic_address, &acpi_gbl_FADT,
 683                                  fadt_pm_info_table[i].source);
 684
 685                 if (source64->address) {
 686                         acpi_tb_init_generic_address(fadt_pm_info_table[i].
 687                                                      target, source64->space_id,
 688                                                      pm1_register_byte_width,
 689                                                      source64->address +
 690                                                      (fadt_pm_info_table[i].
 691                                                       register_num *
 692                                                       pm1_register_byte_width),
 693                                                      "PmRegisters");
 694                 }
 695         }
 696 }