path: root/drivers/acpi/tables/tbrsdt.c

/******************************************************************************
 *
 * Module Name: tbrsdt - ACPI RSDT table utilities
 *
 *****************************************************************************/

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


#define _COMPONENT          ACPI_TABLES
	 ACPI_MODULE_NAME    ("tbrsdt")


/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_verify_rsdp
 *
 * PARAMETERS:  Address         - RSDP (Pointer to RSDT)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load and validate the RSDP (ptr) and RSDT (table)
 *
 ******************************************************************************/

acpi_status
acpi_tb_verify_rsdp (
	struct acpi_pointer             *address)
{
	struct acpi_table_desc          table_info;
	acpi_status                     status;
	struct rsdp_descriptor          *rsdp;


	ACPI_FUNCTION_TRACE ("tb_verify_rsdp");


	switch (address->pointer_type) {
	case ACPI_LOGICAL_POINTER:

		rsdp = address->pointer.logical;
		break;

	case ACPI_PHYSICAL_POINTER:
		/*
		 * Obtain access to the RSDP structure
		 */
		status = acpi_os_map_memory (address->pointer.physical, sizeof (struct rsdp_descriptor),
				  (void *) &rsdp);
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}
		break;

	default:
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}

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

		status = AE_BAD_SIGNATURE;
		goto cleanup;
	}

	/* Check the standard checksum */

	if (acpi_tb_checksum (rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
		status = AE_BAD_CHECKSUM;
		goto cleanup;
	}

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

	if (rsdp->revision >= 2) {
		if (acpi_tb_checksum (rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0) {
			status = AE_BAD_CHECKSUM;
			goto cleanup;
		}
	}

	/* The RSDP supplied is OK */

	table_info.pointer     = ACPI_CAST_PTR (struct acpi_table_header, rsdp);
	table_info.length      = sizeof (struct rsdp_descriptor);
	table_info.allocation  = ACPI_MEM_MAPPED;

	/* Save the table pointers and allocation info */

	status = acpi_tb_init_table_descriptor (ACPI_TABLE_RSDP, &table_info);
	if (ACPI_FAILURE (status)) {
		goto cleanup;
	}

	/* Save the RSDP in a global for easy access */

	acpi_gbl_RSDP = ACPI_CAST_PTR (struct rsdp_descriptor, table_info.pointer);
	return_ACPI_STATUS (status);


	/* Error exit */
cleanup:

	if (acpi_gbl_table_flags & ACPI_PHYSICAL_POINTER) {
		acpi_os_unmap_memory (rsdp, sizeof (struct rsdp_descriptor));
	}
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_get_rsdt_address
 *
 * PARAMETERS:  None
 *
 * RETURN:      RSDT physical address
 *
 * DESCRIPTION: Extract the address of the RSDT or XSDT, depending on the
 *              version of the RSDP
 *
 ******************************************************************************/

void
acpi_tb_get_rsdt_address (
	struct acpi_pointer             *out_address)
{

	ACPI_FUNCTION_ENTRY ();


	out_address->pointer_type = acpi_gbl_table_flags | ACPI_LOGICAL_ADDRESSING;

	/*
	 * For RSDP revision 0 or 1, we use the RSDT.
	 * For RSDP revision 2 (and above), we use the XSDT
	 */
	if (acpi_gbl_RSDP->revision < 2) {
		out_address->pointer.value = acpi_gbl_RSDP->rsdt_physical_address;
	}
	else {
		out_address->pointer.value = acpi_gbl_RSDP->xsdt_physical_address;
	}
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_rsdt
 *
 * PARAMETERS:  table_ptr       - Addressable pointer to the RSDT.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Validate signature for the RSDT or XSDT
 *
 ******************************************************************************/

acpi_status
acpi_tb_validate_rsdt (
	struct acpi_table_header        *table_ptr)
{
	int                             no_match;


	ACPI_FUNCTION_NAME ("tb_validate_rsdt");


	/*
	 * For RSDP revision 0 or 1, we use the RSDT.
	 * For RSDP revision 2 and above, we use the XSDT
	 */
	if (acpi_gbl_RSDP->revision < 2) {
		no_match = ACPI_STRNCMP ((char *) table_ptr, RSDT_SIG,
				  sizeof (RSDT_SIG) -1);
	}
	else {
		no_match = ACPI_STRNCMP ((char *) table_ptr, XSDT_SIG,
				  sizeof (XSDT_SIG) -1);
	}

	if (no_match) {
		/* Invalid RSDT or XSDT signature */

		ACPI_REPORT_ERROR (("Invalid signature where RSDP indicates RSDT/XSDT should be located\n"));

		ACPI_DUMP_BUFFER (acpi_gbl_RSDP, 20);

		ACPI_DEBUG_PRINT_RAW ((ACPI_DB_ERROR,
			"RSDT/XSDT signature at %X (%p) is invalid\n",
			acpi_gbl_RSDP->rsdt_physical_address,
			(void *) (acpi_native_uint) acpi_gbl_RSDP->rsdt_physical_address));

		if (acpi_gbl_RSDP->revision < 2) {
			ACPI_REPORT_ERROR (("Looking for RSDT (RSDP->Rev < 2)\n"))
		}
		else {
			ACPI_REPORT_ERROR (("Looking for XSDT (RSDP->Rev >= 2)\n"))
		}

		ACPI_DUMP_BUFFER ((char *) table_ptr, 48);

		return (AE_BAD_SIGNATURE);
	}

	return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_get_table_rsdt
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load and validate the RSDP (ptr) and RSDT (table)
 *
 ******************************************************************************/

acpi_status
acpi_tb_get_table_rsdt (
	void)
{
	struct acpi_table_desc          table_info;
	acpi_status                     status;
	struct acpi_pointer             address;


	ACPI_FUNCTION_TRACE ("tb_get_table_rsdt");


	/* Get the RSDT/XSDT via the RSDP */

	acpi_tb_get_rsdt_address (&address);

	table_info.type = ACPI_TABLE_XSDT;
	status = acpi_tb_get_table (&address, &table_info);
	if (ACPI_FAILURE (status)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not get the RSDT/XSDT, %s\n",
			acpi_format_exception (status)));
		return_ACPI_STATUS (status);
	}

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

	/* Check the RSDT or XSDT signature */

	status = acpi_tb_validate_rsdt (table_info.pointer);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	/* Get the number of tables defined in the RSDT or XSDT */

	acpi_gbl_rsdt_table_count = acpi_tb_get_table_count (acpi_gbl_RSDP, table_info.pointer);

	/* Convert and/or copy to an XSDT structure */

	status = acpi_tb_convert_to_xsdt (&table_info);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	/* Save the table pointers and allocation info */

	status = acpi_tb_init_table_descriptor (ACPI_TABLE_XSDT, &table_info);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	acpi_gbl_XSDT = ACPI_CAST_PTR (XSDT_DESCRIPTOR, table_info.pointer);

	ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "XSDT located at %p\n", acpi_gbl_XSDT));
	return_ACPI_STATUS (status);
}