err.no Git - linux-2.6/blob - 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 - 2006, 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 <acpi/acpi.h>
  45 #include <acpi/actables.h>
  46
  47 #define _COMPONENT          ACPI_TABLES
  48 ACPI_MODULE_NAME("tbxfroot")
  49
  50 /* Local prototypes */
  51 static acpi_status
  52 acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags);
  53
  54 static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
  55
  56 /*******************************************************************************
  57  *
  58  * FUNCTION:    acpi_tb_validate_rsdp
  59  *
  60  * PARAMETERS:  Rsdp        - Pointer to unvalidated RSDP
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Validate the RSDP (ptr)
  65  *
  66  ******************************************************************************/
  67
  68 acpi_status acpi_tb_validate_rsdp(struct rsdp_descriptor *rsdp)
  69 {
  70         ACPI_FUNCTION_ENTRY();
  71
  72         /*
  73          *  The signature and checksum must both be correct
  74          */
  75         if (ACPI_STRNCMP((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0) {
  76
  77                 /* Nope, BAD Signature */
  78
  79                 return (AE_BAD_SIGNATURE);
  80         }
  81
  82         /* Check the standard checksum */
  83
  84         if (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
  85                 return (AE_BAD_CHECKSUM);
  86         }
  87
  88         /* Check extended checksum if table version >= 2 */
  89
  90         if ((rsdp->revision >= 2) &&
  91             (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) !=
  92              0)) {
  93                 return (AE_BAD_CHECKSUM);
  94         }
  95
  96         return (AE_OK);
  97 }
  98
  99 /*******************************************************************************
 100  *
 101  * FUNCTION:    acpi_tb_find_table
 102  *
 103  * PARAMETERS:  Signature           - String with ACPI table signature
 104  *              oem_id              - String with the table OEM ID
 105  *              oem_table_id        - String with the OEM Table ID
 106  *              table_ptr           - Where the table pointer is returned
 107  *
 108  * RETURN:      Status
 109  *
 110  * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
 111  *              Signature, OEM ID and OEM Table ID.
 112  *
 113  ******************************************************************************/
 114
 115 acpi_status
 116 acpi_tb_find_table(char *signature,
 117                    char *oem_id,
 118                    char *oem_table_id, struct acpi_table_header ** table_ptr)
 119 {
 120         acpi_status status;
 121         struct acpi_table_header *table;
 122
 123         ACPI_FUNCTION_TRACE("tb_find_table");
 124
 125         /* Validate string lengths */
 126
 127         if ((ACPI_STRLEN(signature) > ACPI_NAME_SIZE) ||
 128             (ACPI_STRLEN(oem_id) > sizeof(table->oem_id)) ||
 129             (ACPI_STRLEN(oem_table_id) > sizeof(table->oem_table_id))) {
 130                 return_ACPI_STATUS(AE_AML_STRING_LIMIT);
 131         }
 132
 133         if (!ACPI_STRNCMP(signature, DSDT_SIG, ACPI_NAME_SIZE)) {
 134                 /*
 135                  * The DSDT pointer is contained in the FADT, not the RSDT.
 136                  * This code should suffice, because the only code that would perform
 137                  * a "find" on the DSDT is the data_table_region() AML opcode -- in
 138                  * which case, the DSDT is guaranteed to be already loaded.
 139                  * If this becomes insufficient, the FADT will have to be found first.
 140                  */
 141                 if (!acpi_gbl_DSDT) {
 142                         return_ACPI_STATUS(AE_NO_ACPI_TABLES);
 143                 }
 144                 table = acpi_gbl_DSDT;
 145         } else {
 146                 /* Find the table */
 147
 148                 status = acpi_get_firmware_table(signature, 1,
 149                                                  ACPI_LOGICAL_ADDRESSING,
 150                                                  &table);
 151                 if (ACPI_FAILURE(status)) {
 152                         return_ACPI_STATUS(status);
 153                 }
 154         }
 155
 156         /* Check oem_id and oem_table_id */
 157
 158         if ((oem_id[0] && ACPI_STRNCMP(oem_id, table->oem_id,
 159                                        sizeof(table->oem_id))) ||
 160             (oem_table_id[0] && ACPI_STRNCMP(oem_table_id, table->oem_table_id,
 161                                              sizeof(table->oem_table_id)))) {
 162                 return_ACPI_STATUS(AE_AML_NAME_NOT_FOUND);
 163         }
 164
 165         ACPI_DEBUG_PRINT((ACPI_DB_TABLES, "Found table [%4.4s]\n",
 166                           table->signature));
 167
 168         *table_ptr = table;
 169         return_ACPI_STATUS(AE_OK);
 170 }
 171
 172 /*******************************************************************************
 173  *
 174  * FUNCTION:    acpi_get_firmware_table
 175  *
 176  * PARAMETERS:  Signature       - Any ACPI table signature
 177  *              Instance        - the non zero instance of the table, allows
 178  *                                support for multiple tables of the same type
 179  *              Flags           - Physical/Virtual support
 180  *              table_pointer   - Where a buffer containing the table is
 181  *                                returned
 182  *
 183  * RETURN:      Status
 184  *
 185  * DESCRIPTION: This function is called to get an ACPI table. A buffer is
 186  *              allocated for the table and returned in table_pointer.
 187  *              This table will be a complete table including the header.
 188  *
 189  ******************************************************************************/
 190
 191 acpi_status
 192 acpi_get_firmware_table(acpi_string signature,
 193                         u32 instance,
 194                         u32 flags, struct acpi_table_header **table_pointer)
 195 {
 196         acpi_status status;
 197         struct acpi_pointer address;
 198         struct acpi_table_header *header = NULL;
 199         struct acpi_table_desc *table_info = NULL;
 200         struct acpi_table_desc *rsdt_info;
 201         u32 table_count;
 202         u32 i;
 203         u32 j;
 204
 205         ACPI_FUNCTION_TRACE("acpi_get_firmware_table");
 206
 207         /*
 208          * Ensure that at least the table manager is initialized.  We don't
 209          * require that the entire ACPI subsystem is up for this interface.
 210          * If we have a buffer, we must have a length too
 211          */
 212         if ((instance == 0) || (!signature) || (!table_pointer)) {
 213                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 214         }
 215
 216         /* Ensure that we have a RSDP */
 217
 218         if (!acpi_gbl_RSDP) {
 219
 220                 /* Get the RSDP */
 221
 222                 status = acpi_os_get_root_pointer(flags, &address);
 223                 if (ACPI_FAILURE(status)) {
 224                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "RSDP not found\n"));
 225                         return_ACPI_STATUS(AE_NO_ACPI_TABLES);
 226                 }
 227
 228                 /* Map and validate the RSDP */
 229
 230                 if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
 231                         status = acpi_os_map_memory(address.pointer.physical,
 232                                                     sizeof(struct
 233                                                            rsdp_descriptor),
 234                                                     (void *)&acpi_gbl_RSDP);
 235                         if (ACPI_FAILURE(status)) {
 236                                 return_ACPI_STATUS(status);
 237                         }
 238                 } else {
 239                         acpi_gbl_RSDP = address.pointer.logical;
 240                 }
 241
 242                 /* The RDSP signature and checksum must both be correct */
 243
 244                 status = acpi_tb_validate_rsdp(acpi_gbl_RSDP);
 245                 if (ACPI_FAILURE(status)) {
 246                         return_ACPI_STATUS(status);
 247                 }
 248         }
 249
 250         /* Get the RSDT address via the RSDP */
 251
 252         acpi_tb_get_rsdt_address(&address);
 253         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 254                           "RSDP located at %p, RSDT physical=%8.8X%8.8X\n",
 255                           acpi_gbl_RSDP,
 256                           ACPI_FORMAT_UINT64(address.pointer.value)));
 257
 258         /* Insert processor_mode flags */
 259
 260         address.pointer_type |= flags;
 261
 262         /* Get and validate the RSDT */
 263
 264         rsdt_info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_table_desc));
 265         if (!rsdt_info) {
 266                 return_ACPI_STATUS(AE_NO_MEMORY);
 267         }
 268
 269         status = acpi_tb_get_table(&address, rsdt_info);
 270         if (ACPI_FAILURE(status)) {
 271                 goto cleanup;
 272         }
 273
 274         status = acpi_tb_validate_rsdt(rsdt_info->pointer);
 275         if (ACPI_FAILURE(status)) {
 276                 goto cleanup;
 277         }
 278
 279         /* Allocate a scratch table header and table descriptor */
 280
 281         header = ACPI_ALLOCATE(sizeof(struct acpi_table_header));
 282         if (!header) {
 283                 status = AE_NO_MEMORY;
 284                 goto cleanup;
 285         }
 286
 287         table_info = ACPI_ALLOCATE(sizeof(struct acpi_table_desc));
 288         if (!table_info) {
 289                 status = AE_NO_MEMORY;
 290                 goto cleanup;
 291         }
 292
 293         /* Get the number of table pointers within the RSDT */
 294
 295         table_count =
 296             acpi_tb_get_table_count(acpi_gbl_RSDP, rsdt_info->pointer);
 297         address.pointer_type = acpi_gbl_table_flags | flags;
 298
 299         /*
 300          * Search the RSDT/XSDT for the correct instance of the
 301          * requested table
 302          */
 303         for (i = 0, j = 0; i < table_count; i++) {
 304                 /*
 305                  * Get the next table pointer, handle RSDT vs. XSDT
 306                  * RSDT pointers are 32 bits, XSDT pointers are 64 bits
 307                  */
 308                 if (acpi_gbl_root_table_type == ACPI_TABLE_TYPE_RSDT) {
 309                         address.pointer.value =
 310                             (ACPI_CAST_PTR
 311                              (RSDT_DESCRIPTOR,
 312                               rsdt_info->pointer))->table_offset_entry[i];
 313                 } else {
 314                         address.pointer.value =
 315                             (ACPI_CAST_PTR
 316                              (XSDT_DESCRIPTOR,
 317                               rsdt_info->pointer))->table_offset_entry[i];
 318                 }
 319
 320                 /* Get the table header */
 321
 322                 status = acpi_tb_get_table_header(&address, header);
 323                 if (ACPI_FAILURE(status)) {
 324                         goto cleanup;
 325                 }
 326
 327                 /* Compare table signatures and table instance */
 328
 329                 if (!ACPI_STRNCMP(header->signature, signature, ACPI_NAME_SIZE)) {
 330
 331                         /* An instance of the table was found */
 332
 333                         j++;
 334                         if (j >= instance) {
 335
 336                                 /* Found the correct instance, get the entire table */
 337
 338                                 status =
 339                                     acpi_tb_get_table_body(&address, header,
 340                                                            table_info);
 341                                 if (ACPI_FAILURE(status)) {
 342                                         goto cleanup;
 343                                 }
 344
 345                                 *table_pointer = table_info->pointer;
 346                                 goto cleanup;
 347                         }
 348                 }
 349         }
 350
 351         /* Did not find the table */
 352
 353         status = AE_NOT_EXIST;
 354
 355       cleanup:
 356         if (rsdt_info->pointer) {
 357                 acpi_os_unmap_memory(rsdt_info->pointer,
 358                                      (acpi_size) rsdt_info->pointer->length);
 359         }
 360         ACPI_FREE(rsdt_info);
 361
 362         if (header) {
 363                 ACPI_FREE(header);
 364         }
 365         if (table_info) {
 366                 ACPI_FREE(table_info);
 367         }
 368         return_ACPI_STATUS(status);
 369 }
 370
 371 ACPI_EXPORT_SYMBOL(acpi_get_firmware_table)
 372
 373 /* TBD: Move to a new file */
 374 #if ACPI_MACHINE_WIDTH != 16
 375 /*******************************************************************************
 376  *
 377  * FUNCTION:    acpi_find_root_pointer
 378  *
 379  * PARAMETERS:  Flags                   - Logical/Physical addressing
 380  *              rsdp_address            - Where to place the RSDP address
 381  *
 382  * RETURN:      Status, Physical address of the RSDP
 383  *
 384  * DESCRIPTION: Find the RSDP
 385  *
 386  ******************************************************************************/
 387 acpi_status acpi_find_root_pointer(u32 flags, struct acpi_pointer *rsdp_address)
 388 {
 389         struct acpi_table_desc table_info;
 390         acpi_status status;
 391
 392         ACPI_FUNCTION_TRACE("acpi_find_root_pointer");
 393
 394         /* Get the RSDP */
 395
 396         status = acpi_tb_find_rsdp(&table_info, flags);
 397         if (ACPI_FAILURE(status)) {
 398                 ACPI_EXCEPTION((AE_INFO, status,
 399                                 "RSDP structure not found - Flags=%X", flags));
 400
 401                 return_ACPI_STATUS(AE_NO_ACPI_TABLES);
 402         }
 403
 404         rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
 405         rsdp_address->pointer.physical = table_info.physical_address;
 406         return_ACPI_STATUS(AE_OK);
 407 }
 408
 409 ACPI_EXPORT_SYMBOL(acpi_find_root_pointer)
 410
 411 /*******************************************************************************
 412  *
 413  * FUNCTION:    acpi_tb_scan_memory_for_rsdp
 414  *
 415  * PARAMETERS:  start_address       - Starting pointer for search
 416  *              Length              - Maximum length to search
 417  *
 418  * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 419  *
 420  * DESCRIPTION: Search a block of memory for the RSDP signature
 421  *
 422  ******************************************************************************/
 423 static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
 424 {
 425         acpi_status status;
 426         u8 *mem_rover;
 427         u8 *end_address;
 428
 429         ACPI_FUNCTION_TRACE("tb_scan_memory_for_rsdp");
 430
 431         end_address = start_address + length;
 432
 433         /* Search from given start address for the requested length */
 434
 435         for (mem_rover = start_address; mem_rover < end_address;
 436              mem_rover += ACPI_RSDP_SCAN_STEP) {
 437
 438                 /* The RSDP signature and checksum must both be correct */
 439
 440                 status =
 441                     acpi_tb_validate_rsdp(ACPI_CAST_PTR
 442                                           (struct rsdp_descriptor, mem_rover));
 443                 if (ACPI_SUCCESS(status)) {
 444
 445                         /* Sig and checksum valid, we have found a real RSDP */
 446
 447                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 448                                           "RSDP located at physical address %p\n",
 449                                           mem_rover));
 450                         return_PTR(mem_rover);
 451                 }
 452
 453                 /* No sig match or bad checksum, keep searching */
 454         }
 455
 456         /* Searched entire block, no RSDP was found */
 457
 458         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 459                           "Searched entire block from %p, valid RSDP was not found\n",
 460                           start_address));
 461         return_PTR(NULL);
 462 }
 463
 464 /*******************************************************************************
 465  *
 466  * FUNCTION:    acpi_tb_find_rsdp
 467  *
 468  * PARAMETERS:  table_info              - Where the table info is returned
 469  *              Flags                   - Current memory mode (logical vs.
 470  *                                        physical addressing)
 471  *
 472  * RETURN:      Status, RSDP physical address
 473  *
 474  * DESCRIPTION: search lower 1_mbyte of memory for the root system descriptor
 475  *              pointer structure.  If it is found, set *RSDP to point to it.
 476  *
 477  *              NOTE1: The RSDp must be either in the first 1_k of the Extended
 478  *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 479  *              Only a 32-bit physical address is necessary.
 480  *
 481  *              NOTE2: This function is always available, regardless of the
 482  *              initialization state of the rest of ACPI.
 483  *
 484  ******************************************************************************/
 485
 486 static acpi_status
 487 acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags)
 488 {
 489         u8 *table_ptr;
 490         u8 *mem_rover;
 491         u32 physical_address;
 492         acpi_status status;
 493
 494         ACPI_FUNCTION_TRACE("tb_find_rsdp");
 495
 496         /*
 497          * Scan supports either logical addressing or physical addressing
 498          */
 499         if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
 500
 501                 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
 502
 503                 status = acpi_os_map_memory((acpi_physical_address)
 504                                             ACPI_EBDA_PTR_LOCATION,
 505                                             ACPI_EBDA_PTR_LENGTH,
 506                                             (void *)&table_ptr);
 507                 if (ACPI_FAILURE(status)) {
 508                         ACPI_ERROR((AE_INFO,
 509                                     "Could not map memory at %8.8X for length %X",
 510                                     ACPI_EBDA_PTR_LOCATION,
 511                                     ACPI_EBDA_PTR_LENGTH));
 512
 513                         return_ACPI_STATUS(status);
 514                 }
 515
 516                 ACPI_MOVE_16_TO_32(&physical_address, table_ptr);
 517
 518                 /* Convert segment part to physical address */
 519
 520                 physical_address <<= 4;
 521                 acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);
 522
 523                 /* EBDA present? */
 524
 525                 if (physical_address > 0x400) {
 526                         /*
 527                          * 1b) Search EBDA paragraphs (EBDa is required to be a
 528                          *     minimum of 1_k length)
 529                          */
 530                         status = acpi_os_map_memory((acpi_physical_address)
 531                                                     physical_address,
 532                                                     ACPI_EBDA_WINDOW_SIZE,
 533                                                     (void *)&table_ptr);
 534                         if (ACPI_FAILURE(status)) {
 535                                 ACPI_ERROR((AE_INFO,
 536                                             "Could not map memory at %8.8X for length %X",
 537                                             physical_address,
 538                                             ACPI_EBDA_WINDOW_SIZE));
 539
 540                                 return_ACPI_STATUS(status);
 541                         }
 542
 543                         mem_rover = acpi_tb_scan_memory_for_rsdp(table_ptr,
 544                                                                  ACPI_EBDA_WINDOW_SIZE);
 545                         acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);
 546
 547                         if (mem_rover) {
 548
 549                                 /* Return the physical address */
 550
 551                                 physical_address +=
 552                                     ACPI_PTR_DIFF(mem_rover, table_ptr);
 553
 554                                 table_info->physical_address =
 555                                     (acpi_physical_address) physical_address;
 556                                 return_ACPI_STATUS(AE_OK);
 557                         }
 558                 }
 559
 560                 /*
 561                  * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
 562                  */
 563                 status = acpi_os_map_memory((acpi_physical_address)
 564                                             ACPI_HI_RSDP_WINDOW_BASE,
 565                                             ACPI_HI_RSDP_WINDOW_SIZE,
 566                                             (void *)&table_ptr);
 567
 568                 if (ACPI_FAILURE(status)) {
 569                         ACPI_ERROR((AE_INFO,
 570                                     "Could not map memory at %8.8X for length %X",
 571                                     ACPI_HI_RSDP_WINDOW_BASE,
 572                                     ACPI_HI_RSDP_WINDOW_SIZE));
 573
 574                         return_ACPI_STATUS(status);
 575                 }
 576
 577                 mem_rover =
 578                     acpi_tb_scan_memory_for_rsdp(table_ptr,
 579                                                  ACPI_HI_RSDP_WINDOW_SIZE);
 580                 acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
 581
 582                 if (mem_rover) {
 583
 584                         /* Return the physical address */
 585
 586                         physical_address =
 587                             ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF(mem_rover,
 588                                                                      table_ptr);
 589
 590                         table_info->physical_address =
 591                             (acpi_physical_address) physical_address;
 592                         return_ACPI_STATUS(AE_OK);
 593                 }
 594         }
 595
 596         /*
 597          * Physical addressing
 598          */
 599         else {
 600                 /* 1a) Get the location of the EBDA */
 601
 602                 ACPI_MOVE_16_TO_32(&physical_address, ACPI_EBDA_PTR_LOCATION);
 603                 physical_address <<= 4; /* Convert segment to physical address */
 604
 605                 /* EBDA present? */
 606
 607                 if (physical_address > 0x400) {
 608                         /*
 609                          * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of
 610                          *     1_k length)
 611                          */
 612                         mem_rover =
 613                             acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
 614                                                          (physical_address),
 615                                                          ACPI_EBDA_WINDOW_SIZE);
 616                         if (mem_rover) {
 617
 618                                 /* Return the physical address */
 619
 620                                 table_info->physical_address =
 621                                     ACPI_TO_INTEGER(mem_rover);
 622                                 return_ACPI_STATUS(AE_OK);
 623                         }
 624                 }
 625
 626                 /* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
 627
 628                 mem_rover =
 629                     acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
 630                                                  (ACPI_HI_RSDP_WINDOW_BASE),
 631                                                  ACPI_HI_RSDP_WINDOW_SIZE);
 632                 if (mem_rover) {
 633
 634                         /* Found it, return the physical address */
 635
 636                         table_info->physical_address =
 637                             ACPI_TO_INTEGER(mem_rover);
 638                         return_ACPI_STATUS(AE_OK);
 639                 }
 640         }
 641
 642         /* A valid RSDP was not found */
 643
 644         ACPI_ERROR((AE_INFO, "No valid RSDP was found"));
 645         return_ACPI_STATUS(AE_NOT_FOUND);
 646 }
 647
 648 #endif