Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

[linux-2.6/linux-2.6-openrd.git] / drivers / acpi / tables / tbxfroot.c

/******************************************************************************
 *
 * Module Name: tbxfroot - Find the root ACPI table (RSDT)
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2006, R. Byron Moore
 * 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 <linux/module.h>

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

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbxfroot")

/* Local prototypes */
static acpi_status
acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags);

static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_rsdp
 *
 * PARAMETERS:  Rsdp        - Pointer to unvalidated RSDP
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Validate the RSDP (ptr)
 *
 ******************************************************************************/

acpi_status acpi_tb_validate_rsdp(struct rsdp_descriptor *rsdp)
{
        ACPI_FUNCTION_ENTRY();

        /*
         *  The signature and checksum must both be correct
         */
        if (ACPI_STRNCMP((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0) {
                /* Nope, BAD Signature */

                return (AE_BAD_SIGNATURE);
        }

        /* Check the standard checksum */

        if (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
                return (AE_BAD_CHECKSUM);
        }

        /* Check extended checksum if table version >= 2 */

        if ((rsdp->revision >= 2) &&
            (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) !=
             0)) {
                return (AE_BAD_CHECKSUM);
        }

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_table
 *
 * PARAMETERS:  Signature           - String with ACPI table signature
 *              oem_id              - String with the table OEM ID
 *              oem_table_id        - String with the OEM Table ID
 *              table_ptr           - Where the table pointer is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
 *              Signature, OEM ID and OEM Table ID.
 *
 ******************************************************************************/

acpi_status
acpi_tb_find_table(char *signature,
                   char *oem_id,
                   char *oem_table_id, struct acpi_table_header ** table_ptr)
{
        acpi_status status;
        struct acpi_table_header *table;

        ACPI_FUNCTION_TRACE("tb_find_table");

        /* Validate string lengths */

        if ((ACPI_STRLEN(signature) > ACPI_NAME_SIZE) ||
            (ACPI_STRLEN(oem_id) > sizeof(table->oem_id)) ||
            (ACPI_STRLEN(oem_table_id) > sizeof(table->oem_table_id))) {
                return_ACPI_STATUS(AE_AML_STRING_LIMIT);
        }

        if (!ACPI_STRNCMP(signature, DSDT_SIG, ACPI_NAME_SIZE)) {
                /*
                 * The DSDT pointer is contained in the FADT, not the RSDT.
                 * This code should suffice, because the only code that would perform
                 * a "find" on the DSDT is the data_table_region() AML opcode -- in
                 * which case, the DSDT is guaranteed to be already loaded.
                 * If this becomes insufficient, the FADT will have to be found first.
                 */
                if (!acpi_gbl_DSDT) {
                        return_ACPI_STATUS(AE_NO_ACPI_TABLES);
                }
                table = acpi_gbl_DSDT;
        } else {
                /* Find the table */

                status = acpi_get_firmware_table(signature, 1,
                                                 ACPI_LOGICAL_ADDRESSING,
                                                 &table);
                if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                }
        }

        /* Check oem_id and oem_table_id */

        if ((oem_id[0] && ACPI_STRNCMP(oem_id, table->oem_id,
                                       sizeof(table->oem_id))) ||
            (oem_table_id[0] && ACPI_STRNCMP(oem_table_id, table->oem_table_id,
                                             sizeof(table->oem_table_id)))) {
                return_ACPI_STATUS(AE_AML_NAME_NOT_FOUND);
        }

        ACPI_DEBUG_PRINT((ACPI_DB_TABLES, "Found table [%4.4s]\n",
                          table->signature));

        *table_ptr = table;
        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_get_firmware_table
 *
 * PARAMETERS:  Signature       - Any ACPI table signature
 *              Instance        - the non zero instance of the table, allows
 *                                support for multiple tables of the same type
 *              Flags           - Physical/Virtual support
 *              table_pointer   - Where a buffer containing the table is
 *                                returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to get an ACPI table. A buffer is
 *              allocated for the table and returned in table_pointer.
 *              This table will be a complete table including the header.
 *
 ******************************************************************************/

acpi_status
acpi_get_firmware_table(acpi_string signature,
                        u32 instance,
                        u32 flags, struct acpi_table_header **table_pointer)
{
        acpi_status status;
        struct acpi_pointer address;
        struct acpi_table_header *header = NULL;
        struct acpi_table_desc *table_info = NULL;
        struct acpi_table_desc *rsdt_info;
        u32 table_count;
        u32 i;
        u32 j;

        ACPI_FUNCTION_TRACE("acpi_get_firmware_table");

        /*
         * Ensure that at least the table manager is initialized.  We don't
         * require that the entire ACPI subsystem is up for this interface.
         * If we have a buffer, we must have a length too
         */
        if ((instance == 0) || (!signature) || (!table_pointer)) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /* Ensure that we have a RSDP */

        if (!acpi_gbl_RSDP) {
                /* Get the RSDP */

                status = acpi_os_get_root_pointer(flags, &address);
                if (ACPI_FAILURE(status)) {
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "RSDP not found\n"));
                        return_ACPI_STATUS(AE_NO_ACPI_TABLES);
                }

                /* Map and validate the RSDP */

                if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
                        status = acpi_os_map_memory(address.pointer.physical,
                                                    sizeof(struct
                                                           rsdp_descriptor),
                                                    (void *)&acpi_gbl_RSDP);
                        if (ACPI_FAILURE(status)) {
                                return_ACPI_STATUS(status);
                        }
                } else {
                        acpi_gbl_RSDP = address.pointer.logical;
                }

                /* The RDSP signature and checksum must both be correct */

                status = acpi_tb_validate_rsdp(acpi_gbl_RSDP);
                if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                }
        }

        /* Get the RSDT address via the RSDP */

        acpi_tb_get_rsdt_address(&address);
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "RSDP located at %p, RSDT physical=%8.8X%8.8X\n",
                          acpi_gbl_RSDP,
                          ACPI_FORMAT_UINT64(address.pointer.value)));

        /* Insert processor_mode flags */

        address.pointer_type |= flags;

        /* Get and validate the RSDT */

        rsdt_info = ACPI_MEM_CALLOCATE(sizeof(struct acpi_table_desc));
        if (!rsdt_info) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        status = acpi_tb_get_table(&address, rsdt_info);
        if (ACPI_FAILURE(status)) {
                goto cleanup;
        }

        status = acpi_tb_validate_rsdt(rsdt_info->pointer);
        if (ACPI_FAILURE(status)) {
                goto cleanup;
        }

        /* Allocate a scratch table header and table descriptor */

        header = ACPI_MEM_ALLOCATE(sizeof(struct acpi_table_header));
        if (!header) {
                status = AE_NO_MEMORY;
                goto cleanup;
        }

        table_info = ACPI_MEM_ALLOCATE(sizeof(struct acpi_table_desc));
        if (!table_info) {
                status = AE_NO_MEMORY;
                goto cleanup;
        }

        /* Get the number of table pointers within the RSDT */

        table_count =
            acpi_tb_get_table_count(acpi_gbl_RSDP, rsdt_info->pointer);
        address.pointer_type = acpi_gbl_table_flags | flags;

        /*
         * Search the RSDT/XSDT for the correct instance of the
         * requested table
         */
        for (i = 0, j = 0; i < table_count; i++) {
                /*
                 * Get the next table pointer, handle RSDT vs. XSDT
                 * RSDT pointers are 32 bits, XSDT pointers are 64 bits
                 */
                if (acpi_gbl_root_table_type == ACPI_TABLE_TYPE_RSDT) {
                        address.pointer.value =
                            (ACPI_CAST_PTR
                             (RSDT_DESCRIPTOR,
                              rsdt_info->pointer))->table_offset_entry[i];
                } else {
                        address.pointer.value =
                            (ACPI_CAST_PTR
                             (XSDT_DESCRIPTOR,
                              rsdt_info->pointer))->table_offset_entry[i];
                }

                /* Get the table header */

                status = acpi_tb_get_table_header(&address, header);
                if (ACPI_FAILURE(status)) {
                        goto cleanup;
                }

                /* Compare table signatures and table instance */

                if (!ACPI_STRNCMP(header->signature, signature, ACPI_NAME_SIZE)) {
                        /* An instance of the table was found */

                        j++;
                        if (j >= instance) {
                                /* Found the correct instance, get the entire table */

                                status =
                                    acpi_tb_get_table_body(&address, header,
                                                           table_info);
                                if (ACPI_FAILURE(status)) {
                                        goto cleanup;
                                }

                                *table_pointer = table_info->pointer;
                                goto cleanup;
                        }
                }
        }

        /* Did not find the table */

        status = AE_NOT_EXIST;

      cleanup:
        if (rsdt_info->pointer) {
                acpi_os_unmap_memory(rsdt_info->pointer,
                                     (acpi_size) rsdt_info->pointer->length);
        }
        ACPI_MEM_FREE(rsdt_info);

        if (header) {
                ACPI_MEM_FREE(header);
        }
        if (table_info) {
                ACPI_MEM_FREE(table_info);
        }
        return_ACPI_STATUS(status);
}

EXPORT_SYMBOL(acpi_get_firmware_table);

/* TBD: Move to a new file */

#if ACPI_MACHINE_WIDTH != 16

/*******************************************************************************
 *
 * FUNCTION:    acpi_find_root_pointer
 *
 * PARAMETERS:  Flags                   - Logical/Physical addressing
 *              rsdp_address            - Where to place the RSDP address
 *
 * RETURN:      Status, Physical address of the RSDP
 *
 * DESCRIPTION: Find the RSDP
 *
 ******************************************************************************/

acpi_status acpi_find_root_pointer(u32 flags, struct acpi_pointer *rsdp_address)
{
        struct acpi_table_desc table_info;
        acpi_status status;

        ACPI_FUNCTION_TRACE("acpi_find_root_pointer");

        /* Get the RSDP */

        status = acpi_tb_find_rsdp(&table_info, flags);
        if (ACPI_FAILURE(status)) {
                ACPI_EXCEPTION((AE_INFO, status,
                                "RSDP structure not found - Flags=%X", flags));

                return_ACPI_STATUS(AE_NO_ACPI_TABLES);
        }

        rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
        rsdp_address->pointer.physical = table_info.physical_address;
        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_scan_memory_for_rsdp
 *
 * PARAMETERS:  start_address       - Starting pointer for search
 *              Length              - Maximum length to search
 *
 * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 *
 * DESCRIPTION: Search a block of memory for the RSDP signature
 *
 ******************************************************************************/

static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
{
        acpi_status status;
        u8 *mem_rover;
        u8 *end_address;

        ACPI_FUNCTION_TRACE("tb_scan_memory_for_rsdp");

        end_address = start_address + length;

        /* Search from given start address for the requested length */

        for (mem_rover = start_address; mem_rover < end_address;
             mem_rover += ACPI_RSDP_SCAN_STEP) {
                /* The RSDP signature and checksum must both be correct */

                status =
                    acpi_tb_validate_rsdp(ACPI_CAST_PTR
                                          (struct rsdp_descriptor, mem_rover));
                if (ACPI_SUCCESS(status)) {
                        /* Sig and checksum valid, we have found a real RSDP */

                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                          "RSDP located at physical address %p\n",
                                          mem_rover));
                        return_PTR(mem_rover);
                }

                /* No sig match or bad checksum, keep searching */
        }

        /* Searched entire block, no RSDP was found */

        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Searched entire block from %p, valid RSDP was not found\n",
                          start_address));
        return_PTR(NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_rsdp
 *
 * PARAMETERS:  table_info              - Where the table info is returned
 *              Flags                   - Current memory mode (logical vs.
 *                                        physical addressing)
 *
 * RETURN:      Status, RSDP physical address
 *
 * DESCRIPTION: search lower 1_mbyte of memory for the root system descriptor
 *              pointer structure.  If it is found, set *RSDP to point to it.
 *
 *              NOTE1: The RSDp must be either in the first 1_k of the Extended
 *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 *              Only a 32-bit physical address is necessary.
 *
 *              NOTE2: This function is always available, regardless of the
 *              initialization state of the rest of ACPI.
 *
 ******************************************************************************/

static acpi_status
acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags)
{
        u8 *table_ptr;
        u8 *mem_rover;
        u32 physical_address;
        acpi_status status;

        ACPI_FUNCTION_TRACE("tb_find_rsdp");

        /*
         * Scan supports either logical addressing or physical addressing
         */
        if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
                /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */

                status = acpi_os_map_memory((acpi_physical_address)
                                            ACPI_EBDA_PTR_LOCATION,
                                            ACPI_EBDA_PTR_LENGTH,
                                            (void *)&table_ptr);
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO,
                                    "Could not map memory at %8.8X for length %X",
                                    ACPI_EBDA_PTR_LOCATION,
                                    ACPI_EBDA_PTR_LENGTH));

                        return_ACPI_STATUS(status);
                }

                ACPI_MOVE_16_TO_32(&physical_address, table_ptr);

                /* Convert segment part to physical address */

                physical_address <<= 4;
                acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);

                /* EBDA present? */

                if (physical_address > 0x400) {
                        /*
                         * 1b) Search EBDA paragraphs (EBDa is required to be a
                         *     minimum of 1_k length)
                         */
                        status = acpi_os_map_memory((acpi_physical_address)
                                                    physical_address,
                                                    ACPI_EBDA_WINDOW_SIZE,
                                                    (void *)&table_ptr);
                        if (ACPI_FAILURE(status)) {
                                ACPI_ERROR((AE_INFO,
                                            "Could not map memory at %8.8X for length %X",
                                            physical_address,
                                            ACPI_EBDA_WINDOW_SIZE));

                                return_ACPI_STATUS(status);
                        }

                        mem_rover = acpi_tb_scan_memory_for_rsdp(table_ptr,
                                                                 ACPI_EBDA_WINDOW_SIZE);
                        acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);

                        if (mem_rover) {
                                /* Return the physical address */

                                physical_address +=
                                    ACPI_PTR_DIFF(mem_rover, table_ptr);

                                table_info->physical_address =
                                    (acpi_physical_address) physical_address;
                                return_ACPI_STATUS(AE_OK);
                        }
                }

                /*
                 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
                 */
                status = acpi_os_map_memory((acpi_physical_address)
                                            ACPI_HI_RSDP_WINDOW_BASE,
                                            ACPI_HI_RSDP_WINDOW_SIZE,
                                            (void *)&table_ptr);

                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO,
                                    "Could not map memory at %8.8X for length %X",
                                    ACPI_HI_RSDP_WINDOW_BASE,
                                    ACPI_HI_RSDP_WINDOW_SIZE));

                        return_ACPI_STATUS(status);
                }

                mem_rover =
                    acpi_tb_scan_memory_for_rsdp(table_ptr,
                                                 ACPI_HI_RSDP_WINDOW_SIZE);
                acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);

                if (mem_rover) {
                        /* Return the physical address */

                        physical_address =
                            ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF(mem_rover,
                                                                     table_ptr);

                        table_info->physical_address =
                            (acpi_physical_address) physical_address;
                        return_ACPI_STATUS(AE_OK);
                }
        }

        /*
         * Physical addressing
         */
        else {
                /* 1a) Get the location of the EBDA */

                ACPI_MOVE_16_TO_32(&physical_address, ACPI_EBDA_PTR_LOCATION);
                physical_address <<= 4; /* Convert segment to physical address */

                /* EBDA present? */

                if (physical_address > 0x400) {
                        /*
                         * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of
                         *     1_k length)
                         */
                        mem_rover =
                            acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
                                                         (physical_address),
                                                         ACPI_EBDA_WINDOW_SIZE);
                        if (mem_rover) {
                                /* Return the physical address */

                                table_info->physical_address =
                                    ACPI_TO_INTEGER(mem_rover);
                                return_ACPI_STATUS(AE_OK);
                        }
                }

                /* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */

                mem_rover =
                    acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
                                                 (ACPI_HI_RSDP_WINDOW_BASE),
                                                 ACPI_HI_RSDP_WINDOW_SIZE);
                if (mem_rover) {
                        /* Found it, return the physical address */

                        table_info->physical_address =
                            ACPI_TO_INTEGER(mem_rover);
                        return_ACPI_STATUS(AE_OK);
                }
        }

        /* A valid RSDP was not found */

        ACPI_ERROR((AE_INFO, "No valid RSDP was found"));
        return_ACPI_STATUS(AE_NOT_FOUND);
}

#endif