ACPICA: Tables: Cleanup table checksum verification code.

[mirror_ubuntu-artful-kernel.git] / drivers / acpi / acpica / tbprint.c

/******************************************************************************
 *
 * Module Name: tbprint - Table output utilities
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2013, 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 <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbprint")

/* Local prototypes */
static void acpi_tb_fix_string(char *string, acpi_size length);

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
			     struct acpi_table_header *header);

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_fix_string
 *
 * PARAMETERS:  string              - String to be repaired
 *              length              - Maximum length
 *
 * RETURN:      None
 *
 * DESCRIPTION: Replace every non-printable or non-ascii byte in the string
 *              with a question mark '?'.
 *
 ******************************************************************************/

static void acpi_tb_fix_string(char *string, acpi_size length)
{

	while (length && *string) {
		if (!ACPI_IS_PRINT(*string)) {
			*string = '?';
		}
		string++;
		length--;
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_cleanup_table_header
 *
 * PARAMETERS:  out_header          - Where the cleaned header is returned
 *              header              - Input ACPI table header
 *
 * RETURN:      Returns the cleaned header in out_header
 *
 * DESCRIPTION: Copy the table header and ensure that all "string" fields in
 *              the header consist of printable characters.
 *
 ******************************************************************************/

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
			     struct acpi_table_header *header)
{

	ACPI_MEMCPY(out_header, header, sizeof(struct acpi_table_header));

	acpi_tb_fix_string(out_header->signature, ACPI_NAME_SIZE);
	acpi_tb_fix_string(out_header->oem_id, ACPI_OEM_ID_SIZE);
	acpi_tb_fix_string(out_header->oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
	acpi_tb_fix_string(out_header->asl_compiler_id, ACPI_NAME_SIZE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_print_table_header
 *
 * PARAMETERS:  address             - Table physical address
 *              header              - Table header
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print an ACPI table header. Special cases for FACS and RSDP.
 *
 ******************************************************************************/

void
acpi_tb_print_table_header(acpi_physical_address address,
			   struct acpi_table_header *header)
{
	struct acpi_table_header local_header;

	/*
	 * The reason that the Address is cast to a void pointer is so that we
	 * can use %p which will work properly on both 32-bit and 64-bit hosts.
	 */
	if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_FACS)) {

		/* FACS only has signature and length fields */

		ACPI_INFO((AE_INFO, "%4.4s %p %05X",
			   header->signature, ACPI_CAST_PTR(void, address),
			   header->length));
	} else if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_RSDP)) {

		/* RSDP has no common fields */

		ACPI_MEMCPY(local_header.oem_id,
			    ACPI_CAST_PTR(struct acpi_table_rsdp,
					  header)->oem_id, ACPI_OEM_ID_SIZE);
		acpi_tb_fix_string(local_header.oem_id, ACPI_OEM_ID_SIZE);

		ACPI_INFO((AE_INFO, "RSDP %p %05X (v%.2d %6.6s)",
			   ACPI_CAST_PTR(void, address),
			   (ACPI_CAST_PTR(struct acpi_table_rsdp, header)->
			    revision >
			    0) ? ACPI_CAST_PTR(struct acpi_table_rsdp,
					       header)->length : 20,
			   ACPI_CAST_PTR(struct acpi_table_rsdp,
					 header)->revision,
			   local_header.oem_id));
	} else {
		/* Standard ACPI table with full common header */

		acpi_tb_cleanup_table_header(&local_header, header);

		ACPI_INFO((AE_INFO,
			   "%4.4s %p %05X (v%.2d %6.6s %8.8s %08X %4.4s %08X)",
			   local_header.signature, ACPI_CAST_PTR(void, address),
			   local_header.length, local_header.revision,
			   local_header.oem_id, local_header.oem_table_id,
			   local_header.oem_revision,
			   local_header.asl_compiler_id,
			   local_header.asl_compiler_revision));
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_checksum
 *
 * PARAMETERS:  table               - ACPI table to verify
 *              length              - Length of entire table
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
 *              exception on bad checksum.
 *
 ******************************************************************************/

acpi_status acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length)
{
	u8 checksum;

	/*
	 * FACS/S3PT:
	 * They are the odd tables, have no standard ACPI header and no checksum
	 */

	if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_S3PT) ||
	    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_FACS)) {
		return (AE_OK);
	}

	/* Compute the checksum on the table */

	checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, table), length);

	/* Checksum ok? (should be zero) */

	if (checksum) {
		ACPI_BIOS_WARNING((AE_INFO,
				   "Incorrect checksum in table [%4.4s] - 0x%2.2X, "
				   "should be 0x%2.2X",
				   table->signature, table->checksum,
				   (u8)(table->checksum - checksum)));

#if (ACPI_CHECKSUM_ABORT)
		return (AE_BAD_CHECKSUM);
#endif
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_checksum
 *
 * PARAMETERS:  buffer          - Pointer to memory region to be checked
 *              length          - Length of this memory region
 *
 * RETURN:      Checksum (u8)
 *
 * DESCRIPTION: Calculates circular checksum of memory region.
 *
 ******************************************************************************/

u8 acpi_tb_checksum(u8 *buffer, u32 length)
{
	u8 sum = 0;
	u8 *end = buffer + length;

	while (buffer < end) {
		sum = (u8)(sum + *(buffer++));
	}

	return (sum);
}