Merge branch 'akpm'

[linux-2.6/next.git] / drivers / acpi / acpica / tbutils.c

/******************************************************************************
 *
 * Module Name: tbutils   - table utilities
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2011, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbutils")

/* Local prototypes */
static void acpi_tb_fix_string(char *string, acpi_size length);

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
                             struct acpi_table_header *header);

static acpi_physical_address
acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_check_xsdt
 *
 * PARAMETERS:  address                    - Pointer to the XSDT
 *
 * RETURN:      status
 *              AE_OK - XSDT is okay
 *              AE_NO_MEMORY - can't map XSDT
 *              AE_INVALID_TABLE_LENGTH - invalid table length
 *              AE_NULL_ENTRY - XSDT has NULL entry
 *
 * DESCRIPTION: validate XSDT
******************************************************************************/

static acpi_status
acpi_tb_check_xsdt(acpi_physical_address address)
{
        struct acpi_table_header *table;
        u32 length;
        u64 xsdt_entry_address;
        u8 *table_entry;
        u32 table_count;
        int i;

        table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
        if (!table)
                return AE_NO_MEMORY;

        length = table->length;
        acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
        if (length < sizeof(struct acpi_table_header))
                return AE_INVALID_TABLE_LENGTH;

        table = acpi_os_map_memory(address, length);
        if (!table)
                return AE_NO_MEMORY;

        /* Calculate the number of tables described in XSDT */
        table_count =
                (u32) ((table->length -
                sizeof(struct acpi_table_header)) / sizeof(u64));
        table_entry =
                ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
        for (i = 0; i < table_count; i++) {
                ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry);
                if (!xsdt_entry_address) {
                        /* XSDT has NULL entry */
                        break;
                }
                table_entry += sizeof(u64);
        }
        acpi_os_unmap_memory(table, length);

        if (i < table_count)
                return AE_NULL_ENTRY;
        else
                return AE_OK;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_initialize_facs
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
 *              for accessing the Global Lock and Firmware Waking Vector
 *
 ******************************************************************************/

acpi_status acpi_tb_initialize_facs(void)
{
        acpi_status status;

        status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
                                         ACPI_CAST_INDIRECT_PTR(struct
                                                                acpi_table_header,
                                                                &acpi_gbl_FACS));
        return status;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_tables_loaded
 *
 * PARAMETERS:  None
 *
 * RETURN:      TRUE if required ACPI tables are loaded
 *
 * DESCRIPTION: Determine if the minimum required ACPI tables are present
 *              (FADT, FACS, DSDT)
 *
 ******************************************************************************/

u8 acpi_tb_tables_loaded(void)
{

        if (acpi_gbl_root_table_list.current_table_count >= 3) {
                return (TRUE);
        }

        return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_fix_string
 *
 * PARAMETERS:  String              - String to be repaired
 *              Length              - Maximum length
 *
 * RETURN:      None
 *
 * DESCRIPTION: Replace every non-printable or non-ascii byte in the string
 *              with a question mark '?'.
 *
 ******************************************************************************/

static void acpi_tb_fix_string(char *string, acpi_size length)
{

        while (length && *string) {
                if (!ACPI_IS_PRINT(*string)) {
                        *string = '?';
                }
                string++;
                length--;
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_cleanup_table_header
 *
 * PARAMETERS:  out_header          - Where the cleaned header is returned
 *              Header              - Input ACPI table header
 *
 * RETURN:      Returns the cleaned header in out_header
 *
 * DESCRIPTION: Copy the table header and ensure that all "string" fields in
 *              the header consist of printable characters.
 *
 ******************************************************************************/

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
                             struct acpi_table_header *header)
{

        ACPI_MEMCPY(out_header, header, sizeof(struct acpi_table_header));

        acpi_tb_fix_string(out_header->signature, ACPI_NAME_SIZE);
        acpi_tb_fix_string(out_header->oem_id, ACPI_OEM_ID_SIZE);
        acpi_tb_fix_string(out_header->oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
        acpi_tb_fix_string(out_header->asl_compiler_id, ACPI_NAME_SIZE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_print_table_header
 *
 * PARAMETERS:  Address             - Table physical address
 *              Header              - Table header
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print an ACPI table header. Special cases for FACS and RSDP.
 *
 ******************************************************************************/

void
acpi_tb_print_table_header(acpi_physical_address address,
                           struct acpi_table_header *header)
{
        struct acpi_table_header local_header;

        /*
         * The reason that the Address is cast to a void pointer is so that we
         * can use %p which will work properly on both 32-bit and 64-bit hosts.
         */
        if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_FACS)) {

                /* FACS only has signature and length fields */

                ACPI_INFO((AE_INFO, "%4.4s %p %05X",
                           header->signature, ACPI_CAST_PTR(void, address),
                           header->length));
        } else if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_RSDP)) {

                /* RSDP has no common fields */

                ACPI_MEMCPY(local_header.oem_id,
                            ACPI_CAST_PTR(struct acpi_table_rsdp,
                                          header)->oem_id, ACPI_OEM_ID_SIZE);
                acpi_tb_fix_string(local_header.oem_id, ACPI_OEM_ID_SIZE);

                ACPI_INFO((AE_INFO, "RSDP %p %05X (v%.2d %6.6s)",
                           ACPI_CAST_PTR (void, address),
                           (ACPI_CAST_PTR(struct acpi_table_rsdp, header)->
                            revision >
                            0) ? ACPI_CAST_PTR(struct acpi_table_rsdp,
                                               header)->length : 20,
                           ACPI_CAST_PTR(struct acpi_table_rsdp,
                                         header)->revision,
                           local_header.oem_id));
        } else {
                /* Standard ACPI table with full common header */

                acpi_tb_cleanup_table_header(&local_header, header);

                ACPI_INFO((AE_INFO,
                           "%4.4s %p %05X (v%.2d %6.6s %8.8s %08X %4.4s %08X)",
                           local_header.signature, ACPI_CAST_PTR(void, address),
                           local_header.length, local_header.revision,
                           local_header.oem_id, local_header.oem_table_id,
                           local_header.oem_revision,
                           local_header.asl_compiler_id,
                           local_header.asl_compiler_revision));

        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_checksum
 *
 * PARAMETERS:  Table               - ACPI table to verify
 *              Length              - Length of entire table
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
 *              exception on bad checksum.
 *
 ******************************************************************************/

acpi_status acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length)
{
        u8 checksum;

        /* Compute the checksum on the table */

        checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, table), length);

        /* Checksum ok? (should be zero) */

        if (checksum) {
                ACPI_WARNING((AE_INFO,
                              "Incorrect checksum in table [%4.4s] - 0x%2.2X, should be 0x%2.2X",
                              table->signature, table->checksum,
                              (u8) (table->checksum - checksum)));

#if (ACPI_CHECKSUM_ABORT)

                return (AE_BAD_CHECKSUM);
#endif
        }

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_checksum
 *
 * PARAMETERS:  Buffer          - Pointer to memory region to be checked
 *              Length          - Length of this memory region
 *
 * RETURN:      Checksum (u8)
 *
 * DESCRIPTION: Calculates circular checksum of memory region.
 *
 ******************************************************************************/

u8 acpi_tb_checksum(u8 *buffer, u32 length)
{
        u8 sum = 0;
        u8 *end = buffer + length;

        while (buffer < end) {
                sum = (u8) (sum + *(buffer++));
        }

        return sum;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_check_dsdt_header
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
 *              if the DSDT has been replaced from outside the OS and/or if
 *              the DSDT header has been corrupted.
 *
 ******************************************************************************/

void acpi_tb_check_dsdt_header(void)
{

        /* Compare original length and checksum to current values */

        if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
            acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
                ACPI_ERROR((AE_INFO,
                            "The DSDT has been corrupted or replaced - old, new headers below"));
                acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
                acpi_tb_print_table_header(0, acpi_gbl_DSDT);

                ACPI_ERROR((AE_INFO,
                            "Please send DMI info to linux-acpi@vger.kernel.org\n"
                            "If system does not work as expected, please boot with acpi=copy_dsdt"));

                /* Disable further error messages */

                acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
                acpi_gbl_original_dsdt_header.checksum =
                    acpi_gbl_DSDT->checksum;
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_copy_dsdt
 *
 * PARAMETERS:  table_desc          - Installed table to copy
 *
 * RETURN:      None
 *
 * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
 *              Some very bad BIOSs are known to either corrupt the DSDT or
 *              install a new, bad DSDT. This copy works around the problem.
 *
 ******************************************************************************/

struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
{
        struct acpi_table_header *new_table;
        struct acpi_table_desc *table_desc;

        table_desc = &acpi_gbl_root_table_list.tables[table_index];

        new_table = ACPI_ALLOCATE(table_desc->length);
        if (!new_table) {
                ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
                            table_desc->length));
                return (NULL);
        }

        ACPI_MEMCPY(new_table, table_desc->pointer, table_desc->length);
        acpi_tb_delete_table(table_desc);
        table_desc->pointer = new_table;
        table_desc->flags = ACPI_TABLE_ORIGIN_ALLOCATED;

        ACPI_INFO((AE_INFO,
                   "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
                   new_table->length));

        return (new_table);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_install_table
 *
 * PARAMETERS:  Address                 - Physical address of DSDT or FACS
 *              Signature               - Table signature, NULL if no need to
 *                                        match
 *              table_index             - Index into root table array
 *
 * RETURN:      None
 *
 * DESCRIPTION: Install an ACPI table into the global data structure. The
 *              table override mechanism is implemented here to allow the host
 *              OS to replace any table before it is installed in the root
 *              table array.
 *
 ******************************************************************************/

void
acpi_tb_install_table(acpi_physical_address address,
                      char *signature, u32 table_index)
{
        u8 flags;
        acpi_status status;
        struct acpi_table_header *table_to_install;
        struct acpi_table_header *mapped_table;
        struct acpi_table_header *override_table = NULL;

        if (!address) {
                ACPI_ERROR((AE_INFO,
                            "Null physical address for ACPI table [%s]",
                            signature));
                return;
        }

        /* Map just the table header */

        mapped_table =
            acpi_os_map_memory(address, sizeof(struct acpi_table_header));
        if (!mapped_table) {
                return;
        }

        /* If a particular signature is expected (DSDT/FACS), it must match */

        if (signature && !ACPI_COMPARE_NAME(mapped_table->signature, signature)) {
                ACPI_ERROR((AE_INFO,
                            "Invalid signature 0x%X for ACPI table, expected [%s]",
                            *ACPI_CAST_PTR(u32, mapped_table->signature),
                            signature));
                goto unmap_and_exit;
        }

        /*
         * ACPI Table Override:
         *
         * Before we install the table, let the host OS override it with a new
         * one if desired. Any table within the RSDT/XSDT can be replaced,
         * including the DSDT which is pointed to by the FADT.
         */
        status = acpi_os_table_override(mapped_table, &override_table);
        if (ACPI_SUCCESS(status) && override_table) {
                ACPI_INFO((AE_INFO,
                           "%4.4s @ 0x%p Table override, replaced with:",
                           mapped_table->signature, ACPI_CAST_PTR(void,
                                                                  address)));

                acpi_gbl_root_table_list.tables[table_index].pointer =
                    override_table;
                address = ACPI_PTR_TO_PHYSADDR(override_table);

                table_to_install = override_table;
                flags = ACPI_TABLE_ORIGIN_OVERRIDE;
        } else {
                table_to_install = mapped_table;
                flags = ACPI_TABLE_ORIGIN_MAPPED;
        }

        /* Initialize the table entry */

        acpi_gbl_root_table_list.tables[table_index].address = address;
        acpi_gbl_root_table_list.tables[table_index].length =
            table_to_install->length;
        acpi_gbl_root_table_list.tables[table_index].flags = flags;

        ACPI_MOVE_32_TO_32(&
                           (acpi_gbl_root_table_list.tables[table_index].
                            signature), table_to_install->signature);

        acpi_tb_print_table_header(address, table_to_install);

        if (table_index == ACPI_TABLE_INDEX_DSDT) {

                /* Global integer width is based upon revision of the DSDT */

                acpi_ut_set_integer_width(table_to_install->revision);
        }

      unmap_and_exit:
        acpi_os_unmap_memory(mapped_table, sizeof(struct acpi_table_header));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_get_root_table_entry
 *
 * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
 *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
 *
 * RETURN:      Physical address extracted from the root table
 *
 * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
 *              both 32-bit and 64-bit platforms
 *
 * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
 *              64-bit platforms.
 *
 ******************************************************************************/

static acpi_physical_address
acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
{
        u64 address64;

        /*
         * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
         * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
         */
        if (table_entry_size == sizeof(u32)) {
                /*
                 * 32-bit platform, RSDT: Return 32-bit table entry
                 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
                 */
                return ((acpi_physical_address)
                        (*ACPI_CAST_PTR(u32, table_entry)));
        } else {
                /*
                 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
                 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
                 *  return 64-bit
                 */
                ACPI_MOVE_64_TO_64(&address64, table_entry);

#if ACPI_MACHINE_WIDTH == 32
                if (address64 > ACPI_UINT32_MAX) {

                        /* Will truncate 64-bit address to 32 bits, issue warning */

                        ACPI_WARNING((AE_INFO,
                                      "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
                                      " truncating",
                                      ACPI_FORMAT_UINT64(address64)));
                }
#endif
                return ((acpi_physical_address) (address64));
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_parse_root_table
 *
 * PARAMETERS:  Rsdp                    - Pointer to the RSDP
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to parse the Root System Description
 *              Table (RSDT or XSDT)
 *
 * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
 *              be mapped and cannot be copied because it contains the actual
 *              memory location of the ACPI Global Lock.
 *
 ******************************************************************************/

acpi_status __init
acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
{
        struct acpi_table_rsdp *rsdp;
        u32 table_entry_size;
        u32 i;
        u32 table_count;
        struct acpi_table_header *table;
        acpi_physical_address address;
        acpi_physical_address uninitialized_var(rsdt_address);
        u32 length;
        u8 *table_entry;
        acpi_status status;

        ACPI_FUNCTION_TRACE(tb_parse_root_table);

        /*
         * Map the entire RSDP and extract the address of the RSDT or XSDT
         */
        rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
        if (!rsdp) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        acpi_tb_print_table_header(rsdp_address,
                                   ACPI_CAST_PTR(struct acpi_table_header,
                                                 rsdp));

        /* Differentiate between RSDT and XSDT root tables */

        if (rsdp->revision > 1 && rsdp->xsdt_physical_address
                        && !acpi_rsdt_forced) {
                /*
                 * Root table is an XSDT (64-bit physical addresses). We must use the
                 * XSDT if the revision is > 1 and the XSDT pointer is present, as per
                 * the ACPI specification.
                 */
                address = (acpi_physical_address) rsdp->xsdt_physical_address;
                table_entry_size = sizeof(u64);
                rsdt_address = (acpi_physical_address)
                                        rsdp->rsdt_physical_address;
        } else {
                /* Root table is an RSDT (32-bit physical addresses) */

                address = (acpi_physical_address) rsdp->rsdt_physical_address;
                table_entry_size = sizeof(u32);
        }

        /*
         * It is not possible to map more than one entry in some environments,
         * so unmap the RSDP here before mapping other tables
         */
        acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));

        if (table_entry_size == sizeof(u64)) {
                if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
                        /* XSDT has NULL entry, RSDT is used */
                        address = rsdt_address;
                        table_entry_size = sizeof(u32);
                        ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
                                        "using RSDT"));
                }
        }
        /* Map the RSDT/XSDT table header to get the full table length */

        table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
        if (!table) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        acpi_tb_print_table_header(address, table);

        /* Get the length of the full table, verify length and map entire table */

        length = table->length;
        acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));

        if (length < sizeof(struct acpi_table_header)) {
                ACPI_ERROR((AE_INFO, "Invalid length 0x%X in RSDT/XSDT",
                            length));
                return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
        }

        table = acpi_os_map_memory(address, length);
        if (!table) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Validate the root table checksum */

        status = acpi_tb_verify_checksum(table, length);
        if (ACPI_FAILURE(status)) {
                acpi_os_unmap_memory(table, length);
                return_ACPI_STATUS(status);
        }

        /* Calculate the number of tables described in the root table */

        table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
                            table_entry_size);
        /*
         * First two entries in the table array are reserved for the DSDT
         * and FACS, which are not actually present in the RSDT/XSDT - they
         * come from the FADT
         */
        table_entry =
            ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
        acpi_gbl_root_table_list.current_table_count = 2;

        /*
         * Initialize the root table array from the RSDT/XSDT
         */
        for (i = 0; i < table_count; i++) {
                if (acpi_gbl_root_table_list.current_table_count >=
                    acpi_gbl_root_table_list.max_table_count) {

                        /* There is no more room in the root table array, attempt resize */

                        status = acpi_tb_resize_root_table_list();
                        if (ACPI_FAILURE(status)) {
                                ACPI_WARNING((AE_INFO,
                                              "Truncating %u table entries!",
                                              (unsigned) (table_count -
                                               (acpi_gbl_root_table_list.
                                                          current_table_count -
                                                          2))));
                                break;
                        }
                }

                /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */

                acpi_gbl_root_table_list.tables[acpi_gbl_root_table_list.
                                                current_table_count].address =
                    acpi_tb_get_root_table_entry(table_entry, table_entry_size);

                table_entry += table_entry_size;
                acpi_gbl_root_table_list.current_table_count++;
        }

        /*
         * It is not possible to map more than one entry in some environments,
         * so unmap the root table here before mapping other tables
         */
        acpi_os_unmap_memory(table, length);

        /*
         * Complete the initialization of the root table array by examining
         * the header of each table
         */
        for (i = 2; i < acpi_gbl_root_table_list.current_table_count; i++) {
                acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
                                      address, NULL, i);

                /* Special case for FADT - get the DSDT and FACS */

                if (ACPI_COMPARE_NAME
                    (&acpi_gbl_root_table_list.tables[i].signature,
                     ACPI_SIG_FADT)) {
                        acpi_tb_parse_fadt(i);
                }
        }

        return_ACPI_STATUS(AE_OK);
}