linux/drivers/char/tpm/tpm_eventlog_acpi.c

113 lines
2.5 KiB
C

/*
* Copyright (C) 2005 IBM Corporation
*
* Authors:
* Seiji Munetoh <munetoh@jp.ibm.com>
* Stefan Berger <stefanb@us.ibm.com>
* Reiner Sailer <sailer@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
* Nayna Jain <nayna@linux.vnet.ibm.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Access to the event log extended by the TCG BIOS of PC platform
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/tpm_eventlog.h>
#include "tpm.h"
struct acpi_tcpa {
struct acpi_table_header hdr;
u16 platform_class;
union {
struct client_hdr {
u32 log_max_len __packed;
u64 log_start_addr __packed;
} client;
struct server_hdr {
u16 reserved;
u64 log_max_len __packed;
u64 log_start_addr __packed;
} server;
};
};
/* read binary bios log */
int tpm_read_log_acpi(struct tpm_chip *chip)
{
struct acpi_tcpa *buff;
acpi_status status;
void __iomem *virt;
u64 len, start;
struct tpm_bios_log *log;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
return -ENODEV;
log = &chip->log;
/* Unfortuntely ACPI does not associate the event log with a specific
* TPM, like PPI. Thus all ACPI TPMs will read the same log.
*/
if (!chip->acpi_dev_handle)
return -ENODEV;
/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
status = acpi_get_table(ACPI_SIG_TCPA, 1,
(struct acpi_table_header **)&buff);
if (ACPI_FAILURE(status))
return -ENODEV;
switch(buff->platform_class) {
case BIOS_SERVER:
len = buff->server.log_max_len;
start = buff->server.log_start_addr;
break;
case BIOS_CLIENT:
default:
len = buff->client.log_max_len;
start = buff->client.log_start_addr;
break;
}
if (!len) {
dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
return -EIO;
}
/* malloc EventLog space */
log->bios_event_log = kmalloc(len, GFP_KERNEL);
if (!log->bios_event_log)
return -ENOMEM;
log->bios_event_log_end = log->bios_event_log + len;
virt = acpi_os_map_iomem(start, len);
if (!virt)
goto err;
memcpy_fromio(log->bios_event_log, virt, len);
acpi_os_unmap_iomem(virt, len);
return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
err:
kfree(log->bios_event_log);
log->bios_event_log = NULL;
return -EIO;
}