tbxfload.c

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/******************************************************************************
 *
 * Module Name: tbxfload - Table load/unload external interfaces
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, 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 <linux/export.h>
#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "actables.h"

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbxfload")

/* Local prototypes */
static acpi_status acpi_tb_load_namespace(void);

static int no_auto_ssdt;

/*******************************************************************************
 *
 * FUNCTION:    acpi_load_tables
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
 *
 ******************************************************************************/

acpi_status acpi_load_tables(void)
{
    acpi_status status;

    ACPI_FUNCTION_TRACE(acpi_load_tables);

    /* Load the namespace from the tables */

    status = acpi_tb_load_namespace();
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status,
                "While loading namespace from ACPI tables"));
    }

    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_load_tables)

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_load_namespace
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
 *              the RSDT/XSDT.
 *
 ******************************************************************************/
static acpi_status acpi_tb_load_namespace(void)
{
    acpi_status status;
    u32 i;
    struct acpi_table_header *new_dsdt;

    ACPI_FUNCTION_TRACE(tb_load_namespace);

    (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);

    /*
     * Load the namespace. The DSDT is required, but any SSDT and
     * PSDT tables are optional. Verify the DSDT.
     */
    if (!acpi_gbl_root_table_list.current_table_count ||
        !ACPI_COMPARE_NAME(&
                   (acpi_gbl_root_table_list.
                tables[ACPI_TABLE_INDEX_DSDT].signature),
                   ACPI_SIG_DSDT)
        ||
        ACPI_FAILURE(acpi_tb_verify_table
             (&acpi_gbl_root_table_list.
              tables[ACPI_TABLE_INDEX_DSDT]))) {
        status = AE_NO_ACPI_TABLES;
        goto unlock_and_exit;
    }

    /*
     * Save the DSDT pointer for simple access. This is the mapped memory
     * address. We must take care here because the address of the .Tables
     * array can change dynamically as tables are loaded at run-time. Note:
     * .Pointer field is not validated until after call to acpi_tb_verify_table.
     */
    acpi_gbl_DSDT =
        acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer;

    /*
     * Optionally copy the entire DSDT to local memory (instead of simply
     * mapping it.) There are some BIOSs that corrupt or replace the original
     * DSDT, creating the need for this option. Default is FALSE, do not copy
     * the DSDT.
     */
    if (acpi_gbl_copy_dsdt_locally) {
        new_dsdt = acpi_tb_copy_dsdt(ACPI_TABLE_INDEX_DSDT);
        if (new_dsdt) {
            acpi_gbl_DSDT = new_dsdt;
        }
    }

    /*
     * Save the original DSDT header for detection of table corruption
     * and/or replacement of the DSDT from outside the OS.
     */
    ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT,
            sizeof(struct acpi_table_header));

    (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);

    /* Load and parse tables */

    status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Load any SSDT or PSDT tables. Note: Loop leaves tables locked */

    (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
    for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
        if ((!ACPI_COMPARE_NAME
             (&(acpi_gbl_root_table_list.tables[i].signature),
              ACPI_SIG_SSDT)
             &&
             !ACPI_COMPARE_NAME(&
                    (acpi_gbl_root_table_list.tables[i].
                     signature), ACPI_SIG_PSDT))
            ||
            ACPI_FAILURE(acpi_tb_verify_table
                 (&acpi_gbl_root_table_list.tables[i]))) {
            continue;
        }

        if (no_auto_ssdt) {
            printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
            continue;
        }

        /* Ignore errors while loading tables, get as many as possible */

        (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
        (void)acpi_ns_load_table(i, acpi_gbl_root_node);
        (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
    }

    ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));

      unlock_and_exit:
    (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
    return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_load_table
 *
 * PARAMETERS:  table               - Pointer to a buffer containing the ACPI
 *                                    table to be loaded.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dynamically load an ACPI table from the caller's buffer. Must
 *              be a valid ACPI table with a valid ACPI table header.
 *              Note1: Mainly intended to support hotplug addition of SSDTs.
 *              Note2: Does not copy the incoming table. User is reponsible
 *              to ensure that the table is not deleted or unmapped.
 *
 ******************************************************************************/

acpi_status acpi_load_table(struct acpi_table_header *table)
{
    acpi_status status;
    struct acpi_table_desc table_desc;
    u32 table_index;

    ACPI_FUNCTION_TRACE(acpi_load_table);

    /* Parameter validation */

    if (!table) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    /* Init local table descriptor */

    ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
    table_desc.address = ACPI_PTR_TO_PHYSADDR(table);
    table_desc.pointer = table;
    table_desc.length = table->length;
    table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;

    /* Must acquire the interpreter lock during this operation */

    status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Install the table and load it into the namespace */

    ACPI_INFO((AE_INFO, "Host-directed Dynamic ACPI Table Load:"));
    status = acpi_tb_add_table(&table_desc, &table_index);
    if (ACPI_FAILURE(status)) {
        goto unlock_and_exit;
    }

    status = acpi_ns_load_table(table_index, acpi_gbl_root_node);

    /* Invoke table handler if present */

    if (acpi_gbl_table_handler) {
        (void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD, table,
                         acpi_gbl_table_handler_context);
    }

      unlock_and_exit:
    (void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_load_table)

/*******************************************************************************
 *
 * FUNCTION:    acpi_unload_parent_table
 *
 * PARAMETERS:  object              - Handle to any namespace object owned by
 *                                    the table to be unloaded
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Via any namespace object within an SSDT or OEMx table, unloads
 *              the table and deletes all namespace objects associated with
 *              that table. Unloading of the DSDT is not allowed.
 *              Note: Mainly intended to support hotplug removal of SSDTs.
 *
 ******************************************************************************/
acpi_status acpi_unload_parent_table(acpi_handle object)
{
    struct acpi_namespace_node *node =
        ACPI_CAST_PTR(struct acpi_namespace_node, object);
    acpi_status status = AE_NOT_EXIST;
    acpi_owner_id owner_id;
    u32 i;

    ACPI_FUNCTION_TRACE(acpi_unload_parent_table);

    /* Parameter validation */

    if (!object) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    /*
     * The node owner_id is currently the same as the parent table ID.
     * However, this could change in the future.
     */
    owner_id = node->owner_id;
    if (!owner_id) {

        /* owner_id==0 means DSDT is the owner. DSDT cannot be unloaded */

        return_ACPI_STATUS(AE_TYPE);
    }

    /* Must acquire the interpreter lock during this operation */

    status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Find the table in the global table list */

    for (i = 0; i < acpi_gbl_root_table_list.current_table_count; i++) {
        if (owner_id != acpi_gbl_root_table_list.tables[i].owner_id) {
            continue;
        }

        /*
         * Allow unload of SSDT and OEMx tables only. Do not allow unload
         * of the DSDT. No other types of tables should get here, since
         * only these types can contain AML and thus are the only types
         * that can create namespace objects.
         */
        if (ACPI_COMPARE_NAME
            (acpi_gbl_root_table_list.tables[i].signature.ascii,
             ACPI_SIG_DSDT)) {
            status = AE_TYPE;
            break;
        }

        /* Ensure the table is actually loaded */

        if (!acpi_tb_is_table_loaded(i)) {
            status = AE_NOT_EXIST;
            break;
        }

        /* Invoke table handler if present */

        if (acpi_gbl_table_handler) {
            (void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_UNLOAD,
                             acpi_gbl_root_table_list.
                             tables[i].pointer,
                             acpi_gbl_table_handler_context);
        }

        /*
         * Delete all namespace objects owned by this table. Note that
         * these objects can appear anywhere in the namespace by virtue
         * of the AML "Scope" operator. Thus, we need to track ownership
         * by an ID, not simply a position within the hierarchy.
         */
        status = acpi_tb_delete_namespace_by_owner(i);
        if (ACPI_FAILURE(status)) {
            break;
        }

        status = acpi_tb_release_owner_id(i);
        acpi_tb_set_table_loaded_flag(i, FALSE);
        break;
    }

    (void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_unload_parent_table)

static int __init acpi_no_auto_ssdt_setup(char *s) {

        printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");

        no_auto_ssdt = 1;

        return 1;
}

__setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);