drivers/acpi/acpica/tbxfload.c

/******************************************************************************
 *
 * 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);
}

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);