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