xref: /openbmc/linux/drivers/acpi/acpica/tbprint.c (revision a3e525fe)

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: tbprint - Table output utilities
 *
 * Copyright (C) 2000 - 2021, Intel Corp.
 *
 *****************************************************************************/

#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 (!isprint((int)*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)
{

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

	acpi_tb_fix_string(out_header->signature, ACPI_NAMESEG_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_NAMESEG_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;

	if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_FACS)) {

		/* FACS only has signature and length fields */

		ACPI_INFO(("%-4.4s 0x%8.8X%8.8X %06X",
			   header->signature, ACPI_FORMAT_UINT64(address),
			   header->length));
	} else if (ACPI_VALIDATE_RSDP_SIG(ACPI_CAST_PTR(struct acpi_table_rsdp,
							header)->signature)) {

		/* RSDP has no common fields */

		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(("RSDP 0x%8.8X%8.8X %06X (v%.2d %-6.6s)",
			   ACPI_FORMAT_UINT64(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(("%-4.4s 0x%8.8X%8.8X"
			   " %06X (v%.2d %-6.6s %-8.8s %08X %-4.4s %08X)",
			   local_header.signature, ACPI_FORMAT_UINT64(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_NAMESEG(table->signature, ACPI_SIG_S3PT) ||
	    ACPI_COMPARE_NAMESEG(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);
}