drivers/acpi/tables/tbxfroot.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbxfroot - Find the root ACPI table (RSDT)
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2004, R. Byron Moore
   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 <linux/module.h>
  45
  46 #include <acpi/acpi.h>
  47 #include <acpi/actables.h>
  48
  49
  50 #define _COMPONENT          ACPI_TABLES
  51          ACPI_MODULE_NAME    ("tbxfroot")
  52
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_tb_find_table
  57  *
  58  * PARAMETERS:  Signature           - String with ACPI table signature
  59  *              oem_id              - String with the table OEM ID
  60  *              oem_table_id        - String with the OEM Table ID.
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
  65  *              Signature, OEM ID and OEM Table ID.
  66  *
  67  ******************************************************************************/
  68
  69 acpi_status
  70 acpi_tb_find_table (
  71         char                            *signature,
  72         char                            *oem_id,
  73         char                            *oem_table_id,
  74         struct acpi_table_header        **table_ptr)
  75 {
  76         acpi_status                     status;
  77         struct acpi_table_header        *table;
  78
  79
  80         ACPI_FUNCTION_TRACE ("tb_find_table");
  81
  82
  83         /* Validate string lengths */
  84
  85         if ((ACPI_STRLEN (signature)  > ACPI_NAME_SIZE) ||
  86                 (ACPI_STRLEN (oem_id)     > sizeof (table->oem_id)) ||
  87                 (ACPI_STRLEN (oem_table_id) > sizeof (table->oem_table_id))) {
  88                 return_ACPI_STATUS (AE_AML_STRING_LIMIT);
  89         }
  90
  91         if (!ACPI_STRNCMP (signature, DSDT_SIG, ACPI_NAME_SIZE)) {
  92                 /*
  93                  * The DSDT pointer is contained in the FADT, not the RSDT.
  94                  * This code should suffice, because the only code that would perform
  95                  * a "find" on the DSDT is the data_table_region() AML opcode -- in
  96                  * which case, the DSDT is guaranteed to be already loaded.
  97                  * If this becomes insufficient, the FADT will have to be found first.
  98                  */
  99                 if (!acpi_gbl_DSDT) {
 100                         return_ACPI_STATUS (AE_NO_ACPI_TABLES);
 101                 }
 102
 103                 table = acpi_gbl_DSDT;
 104         }
 105         else {
 106                 /* Find the table */
 107
 108                 status = acpi_get_firmware_table (signature, 1,
 109                                    ACPI_LOGICAL_ADDRESSING, &table);
 110                 if (ACPI_FAILURE (status)) {
 111                         return_ACPI_STATUS (status);
 112                 }
 113         }
 114
 115         /* Check oem_id and oem_table_id */
 116
 117         if ((oem_id[0]     && ACPI_STRCMP (oem_id, table->oem_id)) ||
 118                 (oem_table_id[0] && ACPI_STRCMP (oem_table_id, table->oem_table_id))) {
 119                 return_ACPI_STATUS (AE_AML_NAME_NOT_FOUND);
 120         }
 121
 122         ACPI_DEBUG_PRINT ((ACPI_DB_TABLES, "Found table [%4.4s]\n", table->signature));
 123         *table_ptr = table;
 124         return_ACPI_STATUS (AE_OK);
 125 }
 126
 127
 128 /*******************************************************************************
 129  *
 130  * FUNCTION:    acpi_get_firmware_table
 131  *
 132  * PARAMETERS:  Signature       - Any ACPI table signature
 133  *              Instance        - the non zero instance of the table, allows
 134  *                                support for multiple tables of the same type
 135  *              Flags           - Physical/Virtual support
 136  *              table_pointer   - Where a buffer containing the table is
 137  *                                returned
 138  *
 139  * RETURN:      Status
 140  *
 141  * DESCRIPTION: This function is called to get an ACPI table. A buffer is
 142  *              allocated for the table and returned in table_pointer.
 143  *              This table will be a complete table including the header.
 144  *
 145  ******************************************************************************/
 146
 147 acpi_status
 148 acpi_get_firmware_table (
 149         acpi_string                     signature,
 150         u32                             instance,
 151         u32                             flags,
 152         struct acpi_table_header        **table_pointer)
 153 {
 154         acpi_status                     status;
 155         struct acpi_pointer             address;
 156         struct acpi_table_header        *header = NULL;
 157         struct acpi_table_desc          *table_info = NULL;
 158         struct acpi_table_desc          *rsdt_info;
 159         u32                             table_count;
 160         u32                             i;
 161         u32                             j;
 162
 163
 164         ACPI_FUNCTION_TRACE ("acpi_get_firmware_table");
 165
 166
 167         /*
 168          * Ensure that at least the table manager is initialized.  We don't
 169          * require that the entire ACPI subsystem is up for this interface.
 170          * If we have a buffer, we must have a length too
 171          */
 172         if ((instance == 0)     ||
 173                 (!signature)        ||
 174                 (!table_pointer)) {
 175                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 176         }
 177
 178         /* Ensure that we have a RSDP */
 179
 180         if (!acpi_gbl_RSDP) {
 181                 /* Get the RSDP */
 182
 183                 status = acpi_os_get_root_pointer (flags, &address);
 184                 if (ACPI_FAILURE (status)) {
 185                         ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "RSDP not found\n"));
 186                         return_ACPI_STATUS (AE_NO_ACPI_TABLES);
 187                 }
 188
 189                 /* Map and validate the RSDP */
 190
 191                 if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
 192                         status = acpi_os_map_memory (address.pointer.physical, sizeof (struct rsdp_descriptor),
 193                                           (void *) &acpi_gbl_RSDP);
 194                         if (ACPI_FAILURE (status)) {
 195                                 return_ACPI_STATUS (status);
 196                         }
 197                 }
 198                 else {
 199                         acpi_gbl_RSDP = address.pointer.logical;
 200                 }
 201
 202                 /* The signature and checksum must both be correct */
 203
 204                 if (ACPI_STRNCMP ((char *) acpi_gbl_RSDP, RSDP_SIG, sizeof (RSDP_SIG)-1) != 0) {
 205                         /* Nope, BAD Signature */
 206
 207                         return_ACPI_STATUS (AE_BAD_SIGNATURE);
 208                 }
 209
 210                 if (acpi_tb_checksum (acpi_gbl_RSDP, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
 211                         /* Nope, BAD Checksum */
 212
 213                         return_ACPI_STATUS (AE_BAD_CHECKSUM);
 214                 }
 215         }
 216
 217         /* Get the RSDT address via the RSDP */
 218
 219         acpi_tb_get_rsdt_address (&address);
 220         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 221                 "RSDP located at %p, RSDT physical=%8.8X%8.8X \n",
 222                 acpi_gbl_RSDP,
 223                 ACPI_FORMAT_UINT64 (address.pointer.value)));
 224
 225         /* Insert processor_mode flags */
 226
 227         address.pointer_type |= flags;
 228
 229         /* Get and validate the RSDT */
 230
 231         rsdt_info = ACPI_MEM_CALLOCATE (sizeof (struct acpi_table_desc));
 232         if (!rsdt_info) {
 233                 return_ACPI_STATUS (AE_NO_MEMORY);
 234         }
 235
 236         status = acpi_tb_get_table (&address, rsdt_info);
 237         if (ACPI_FAILURE (status)) {
 238                 goto cleanup;
 239         }
 240
 241         status = acpi_tb_validate_rsdt (rsdt_info->pointer);
 242         if (ACPI_FAILURE (status)) {
 243                 goto cleanup;
 244         }
 245
 246         /* Allocate a scratch table header and table descriptor */
 247
 248         header = ACPI_MEM_ALLOCATE (sizeof (struct acpi_table_header));
 249         if (!header) {
 250                 status = AE_NO_MEMORY;
 251                 goto cleanup;
 252         }
 253
 254         table_info = ACPI_MEM_ALLOCATE (sizeof (struct acpi_table_desc));
 255         if (!table_info) {
 256                 status = AE_NO_MEMORY;
 257                 goto cleanup;
 258         }
 259
 260         /* Get the number of table pointers within the RSDT */
 261
 262         table_count = acpi_tb_get_table_count (acpi_gbl_RSDP, rsdt_info->pointer);
 263         address.pointer_type = acpi_gbl_table_flags | flags;
 264
 265         /*
 266          * Search the RSDT/XSDT for the correct instance of the
 267          * requested table
 268          */
 269         for (i = 0, j = 0; i < table_count; i++) {
 270                 /* Get the next table pointer, handle RSDT vs. XSDT */
 271
 272                 if (acpi_gbl_RSDP->revision < 2) {
 273                         address.pointer.value = (ACPI_CAST_PTR (
 274                                 RSDT_DESCRIPTOR, rsdt_info->pointer))->table_offset_entry[i];
 275                 }
 276                 else {
 277                         address.pointer.value = (ACPI_CAST_PTR (
 278                                 XSDT_DESCRIPTOR, rsdt_info->pointer))->table_offset_entry[i];
 279                 }
 280
 281                 /* Get the table header */
 282
 283                 status = acpi_tb_get_table_header (&address, header);
 284                 if (ACPI_FAILURE (status)) {
 285                         goto cleanup;
 286                 }
 287
 288                 /* Compare table signatures and table instance */
 289
 290                 if (!ACPI_STRNCMP (header->signature, signature, ACPI_NAME_SIZE)) {
 291                         /* An instance of the table was found */
 292
 293                         j++;
 294                         if (j >= instance) {
 295                                 /* Found the correct instance, get the entire table */
 296
 297                                 status = acpi_tb_get_table_body (&address, header, table_info);
 298                                 if (ACPI_FAILURE (status)) {
 299                                         goto cleanup;
 300                                 }
 301
 302                                 *table_pointer = table_info->pointer;
 303                                 goto cleanup;
 304                         }
 305                 }
 306         }
 307
 308         /* Did not find the table */
 309
 310         status = AE_NOT_EXIST;
 311
 312
 313 cleanup:
 314         acpi_os_unmap_memory (rsdt_info->pointer, (acpi_size) rsdt_info->pointer->length);
 315         ACPI_MEM_FREE (rsdt_info);
 316
 317         if (header) {
 318                 ACPI_MEM_FREE (header);
 319         }
 320         if (table_info) {
 321                 ACPI_MEM_FREE (table_info);
 322         }
 323         return_ACPI_STATUS (status);
 324 }
 325 EXPORT_SYMBOL(acpi_get_firmware_table);
 326
 327
 328 /* TBD: Move to a new file */
 329
 330 #if ACPI_MACHINE_WIDTH != 16
 331
 332 /*******************************************************************************
 333  *
 334  * FUNCTION:    acpi_find_root_pointer
 335  *
 336  * PARAMETERS:  **rsdp_address          - Where to place the RSDP address
 337  *              Flags                   - Logical/Physical addressing
 338  *
 339  * RETURN:      Status, Physical address of the RSDP
 340  *
 341  * DESCRIPTION: Find the RSDP
 342  *
 343  ******************************************************************************/
 344
 345 acpi_status
 346 acpi_find_root_pointer (
 347         u32                             flags,
 348         struct acpi_pointer             *rsdp_address)
 349 {
 350         struct acpi_table_desc          table_info;
 351         acpi_status                     status;
 352
 353
 354         ACPI_FUNCTION_TRACE ("acpi_find_root_pointer");
 355
 356
 357         /* Get the RSDP */
 358
 359         status = acpi_tb_find_rsdp (&table_info, flags);
 360         if (ACPI_FAILURE (status)) {
 361                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "RSDP structure not found, %s Flags=%X\n",
 362                         acpi_format_exception (status), flags));
 363                 return_ACPI_STATUS (AE_NO_ACPI_TABLES);
 364         }
 365
 366         rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
 367         rsdp_address->pointer.physical = table_info.physical_address;
 368         return_ACPI_STATUS (AE_OK);
 369 }
 370
 371
 372 /*******************************************************************************
 373  *
 374  * FUNCTION:    acpi_tb_scan_memory_for_rsdp
 375  *
 376  * PARAMETERS:  start_address       - Starting pointer for search
 377  *              Length              - Maximum length to search
 378  *
 379  * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 380  *
 381  * DESCRIPTION: Search a block of memory for the RSDP signature
 382  *
 383  ******************************************************************************/
 384
 385 u8 *
 386 acpi_tb_scan_memory_for_rsdp (
 387         u8                              *start_address,
 388         u32                             length)
 389 {
 390         u32                             offset;
 391         u8                              *mem_rover;
 392
 393
 394         ACPI_FUNCTION_TRACE ("tb_scan_memory_for_rsdp");
 395
 396
 397         /* Search from given start addr for the requested length  */
 398
 399         for (offset = 0, mem_rover = start_address;
 400                  offset < length;
 401                  offset += ACPI_RSDP_SCAN_STEP, mem_rover += ACPI_RSDP_SCAN_STEP) {
 402
 403                 /* The signature and checksum must both be correct */
 404
 405                 if (ACPI_STRNCMP ((char *) mem_rover,
 406                                 RSDP_SIG, sizeof (RSDP_SIG)-1) == 0 &&
 407                         acpi_tb_checksum (mem_rover, ACPI_RSDP_CHECKSUM_LENGTH) == 0) {
 408                         /* If so, we have found the RSDP */
 409
 410                         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 411                                 "RSDP located at physical address %p\n",mem_rover));
 412                         return_PTR (mem_rover);
 413                 }
 414         }
 415
 416         /* Searched entire block, no RSDP was found */
 417
 418         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,"Searched entire block, no RSDP was found.\n"));
 419         return_PTR (NULL);
 420 }
 421
 422
 423 /*******************************************************************************
 424  *
 425  * FUNCTION:    acpi_tb_find_rsdp
 426  *
 427  * PARAMETERS:  *table_info             - Where the table info is returned
 428  *              Flags                   - Current memory mode (logical vs.
 429  *                                        physical addressing)
 430  *
 431  * RETURN:      Status, RSDP physical address
 432  *
 433  * DESCRIPTION: search lower 1_mbyte of memory for the root system descriptor
 434  *              pointer structure.  If it is found, set *RSDP to point to it.
 435  *
 436  *              NOTE1: The RSDp must be either in the first 1_k of the Extended
 437  *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 438  *              Only a 32-bit physical address is necessary.
 439  *
 440  *              NOTE2: This function is always available, regardless of the
 441  *              initialization state of the rest of ACPI.
 442  *
 443  ******************************************************************************/
 444
 445 acpi_status
 446 acpi_tb_find_rsdp (
 447         struct acpi_table_desc          *table_info,
 448         u32                             flags)
 449 {
 450         u8                              *table_ptr;
 451         u8                              *mem_rover;
 452         u32                             physical_address;
 453         acpi_status                     status;
 454
 455
 456         ACPI_FUNCTION_TRACE ("tb_find_rsdp");
 457
 458
 459         /*
 460          * Scan supports either 1) Logical addressing or 2) Physical addressing
 461          */
 462         if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
 463                 /*
 464                  * 1a) Get the location of the EBDA
 465                  */
 466                 status = acpi_os_map_memory ((acpi_physical_address) ACPI_EBDA_PTR_LOCATION,
 467                                   ACPI_EBDA_PTR_LENGTH,
 468                                   (void *) &table_ptr);
 469                 if (ACPI_FAILURE (status)) {
 470                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
 471                                 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
 472                         return_ACPI_STATUS (status);
 473                 }
 474
 475                 ACPI_MOVE_16_TO_32 (&physical_address, table_ptr);
 476                 physical_address <<= 4;                 /* Convert segment to physical address */
 477                 acpi_os_unmap_memory (table_ptr, ACPI_EBDA_PTR_LENGTH);
 478
 479                 /* EBDA present? */
 480
 481                 if (physical_address > 0x400) {
 482                         /*
 483                          * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of 1_k length)
 484                          */
 485                         status = acpi_os_map_memory ((acpi_physical_address) physical_address,
 486                                           ACPI_EBDA_WINDOW_SIZE,
 487                                           (void *) &table_ptr);
 488                         if (ACPI_FAILURE (status)) {
 489                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
 490                                         physical_address, ACPI_EBDA_WINDOW_SIZE));
 491                                 return_ACPI_STATUS (status);
 492                         }
 493
 494                         mem_rover = acpi_tb_scan_memory_for_rsdp (table_ptr, ACPI_EBDA_WINDOW_SIZE);
 495                         acpi_os_unmap_memory (table_ptr, ACPI_EBDA_WINDOW_SIZE);
 496
 497                         if (mem_rover) {
 498                                 /* Found it, return the physical address */
 499
 500                                 physical_address += ACPI_PTR_DIFF (mem_rover, table_ptr);
 501
 502                                 table_info->physical_address = (acpi_physical_address) physical_address;
 503                                 return_ACPI_STATUS (AE_OK);
 504                         }
 505                 }
 506
 507                 /*
 508                  * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
 509                  */
 510                 status = acpi_os_map_memory ((acpi_physical_address) ACPI_HI_RSDP_WINDOW_BASE,
 511                                   ACPI_HI_RSDP_WINDOW_SIZE,
 512                                   (void *) &table_ptr);
 513                 if (ACPI_FAILURE (status)) {
 514                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
 515                                 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE));
 516                         return_ACPI_STATUS (status);
 517                 }
 518
 519                 mem_rover = acpi_tb_scan_memory_for_rsdp (table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
 520                 acpi_os_unmap_memory (table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
 521
 522                 if (mem_rover) {
 523                         /* Found it, return the physical address */
 524
 525                         physical_address = ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (mem_rover, table_ptr);
 526
 527                         table_info->physical_address = (acpi_physical_address) physical_address;
 528                         return_ACPI_STATUS (AE_OK);
 529                 }
 530         }
 531
 532         /*
 533          * Physical addressing
 534          */
 535         else {
 536                 /*
 537                  * 1a) Get the location of the EBDA
 538                  */
 539                 ACPI_MOVE_16_TO_32 (&physical_address, ACPI_EBDA_PTR_LOCATION);
 540                 physical_address <<= 4;     /* Convert segment to physical address */
 541
 542                 /* EBDA present? */
 543
 544                 if (physical_address > 0x400) {
 545                         /*
 546                          * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of 1_k length)
 547                          */
 548                         mem_rover = acpi_tb_scan_memory_for_rsdp (ACPI_PHYSADDR_TO_PTR (physical_address),
 549                                           ACPI_EBDA_WINDOW_SIZE);
 550                         if (mem_rover) {
 551                                 /* Found it, return the physical address */
 552
 553                                 table_info->physical_address = ACPI_TO_INTEGER (mem_rover);
 554                                 return_ACPI_STATUS (AE_OK);
 555                         }
 556                 }
 557
 558                 /*
 559                  * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
 560                  */
 561                 mem_rover = acpi_tb_scan_memory_for_rsdp (ACPI_PHYSADDR_TO_PTR (ACPI_HI_RSDP_WINDOW_BASE),
 562                                   ACPI_HI_RSDP_WINDOW_SIZE);
 563                 if (mem_rover) {
 564                         /* Found it, return the physical address */
 565
 566                         table_info->physical_address = ACPI_TO_INTEGER (mem_rover);
 567                         return_ACPI_STATUS (AE_OK);
 568                 }
 569         }
 570
 571         /* RSDP signature was not found */
 572
 573         return_ACPI_STATUS (AE_NOT_FOUND);
 574 }
 575
 576 #endif
 577