[PATCH] fix semaphore handling in __unregister_chrdev_region

[linux/fpc-iii.git] / drivers / acpi / tables / tbxfroot.c

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

/*
 * Copyright (C) 2000 - 2005, 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")


/*******************************************************************************
 *
 * 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.
 *
 * 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 signature and checksum must both be correct */

                if (ACPI_STRNCMP ((char *) acpi_gbl_RSDP, RSDP_SIG, sizeof (RSDP_SIG)-1) != 0) {
                        /* Nope, BAD Signature */

                        return_ACPI_STATUS (AE_BAD_SIGNATURE);
                }

                if (acpi_tb_checksum (acpi_gbl_RSDP, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
                        /* Nope, BAD Checksum */

                        return_ACPI_STATUS (AE_BAD_CHECKSUM);
                }
        }

        /* 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 */

                if (acpi_gbl_RSDP->revision < 2) {
                        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:
        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:  **rsdp_address          - Where to place the RSDP address
 *              Flags                   - Logical/Physical addressing
 *
 * 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_DEBUG_PRINT ((ACPI_DB_ERROR,
                        "RSDP structure not found, %s Flags=%X\n",
                        acpi_format_exception (status), 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
 *
 ******************************************************************************/

u8 *
acpi_tb_scan_memory_for_rsdp (
        u8                              *start_address,
        u32                             length)
{
        u8                              *mem_rover;
        u8                              *end_address;
        u8                              checksum;


        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 signature and checksum must both be correct */

                if (ACPI_STRNCMP ((char *) mem_rover, RSDP_SIG, sizeof (RSDP_SIG)-1) != 0) {
                        /* No signature match, keep looking */

                        continue;
                }

                /* Signature matches, check the appropriate checksum */

                if ((ACPI_CAST_PTR (struct rsdp_descriptor, mem_rover))->revision < 2) {
                        /* ACPI version 1.0 */

                        checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_CHECKSUM_LENGTH);
                }
                else {
                        /* Post ACPI 1.0, use extended_checksum */

                        checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_XCHECKSUM_LENGTH);
                }

                if (checksum == 0) {
                        /* Checksum valid, we have found a valid RSDP */

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

                ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
                        "Found an RSDP at physical address %p, but it has a bad checksum\n",
                        mem_rover));
        }

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

        ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
                "Searched entire block, no valid RSDP was found.\n"));
        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.
 *
 ******************************************************************************/

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 1) Logical addressing or 2) Physical addressing
         */
        if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
                /*
                 * 1a) Get the location of the 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_DEBUG_PRINT ((ACPI_DB_ERROR,
                                "Could not map memory at %8.8X for length %X\n",
                                ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
                        return_ACPI_STATUS (status);
                }

                ACPI_MOVE_16_TO_32 (&physical_address, table_ptr);
                physical_address <<= 4;                 /* Convert segment to physical address */
                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_DEBUG_PRINT ((ACPI_DB_ERROR,
                                        "Could not map memory at %8.8X for length %X\n",
                                        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) {
                                /* Found it, 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_DEBUG_PRINT ((ACPI_DB_ERROR,
                                "Could not map memory at %8.8X for length %X\n",
                                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) {
                        /* Found it, 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) {
                                /* Found it, 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);
                }
        }

        /* RSDP signature was not found */

        return_ACPI_STATUS (AE_NOT_FOUND);
}

#endif