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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
*/
#include <linux/device.h>
#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"
#include "common.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;
};
};
/* Check that the given log is indeed a TPM2 log. */
static bool tpm_is_tpm2_log(void *bios_event_log, u64 len)
{
struct tcg_efi_specid_event_head *efispecid;
struct tcg_pcr_event *event_header;
int n;
if (len < sizeof(*event_header))
return false;
len -= sizeof(*event_header);
event_header = bios_event_log;
if (len < sizeof(*efispecid))
return false;
efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
n = memcmp(efispecid->signature, TCG_SPECID_SIG,
sizeof(TCG_SPECID_SIG));
return n == 0;
}
/* 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;
struct acpi_table_tpm2 *tbl;
struct acpi_tpm2_phy *tpm2_phy;
int format;
int ret;
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;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
status = acpi_get_table("TPM2", 1,
(struct acpi_table_header **)&tbl);
if (ACPI_FAILURE(status))
return -ENODEV;
if (tbl->header.length <
sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) {
acpi_put_table((struct acpi_table_header *)tbl);
return -ENODEV;
}
tpm2_phy = (void *)tbl + sizeof(*tbl);
len = tpm2_phy->log_area_minimum_length;
start = tpm2_phy->log_area_start_address;
if (!start || !len) {
acpi_put_table((struct acpi_table_header *)tbl);
return -ENODEV;
}
acpi_put_table((struct acpi_table_header *)tbl);
format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
} else {
/* 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;
}
acpi_put_table((struct acpi_table_header *)buff);
format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
}
if (!len) {
dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
return -EIO;
}
/* malloc EventLog space */
log->bios_event_log = devm_kmalloc(&chip->dev, len, GFP_KERNEL);
if (!log->bios_event_log)
return -ENOMEM;
log->bios_event_log_end = log->bios_event_log + len;
ret = -EIO;
virt = acpi_os_map_iomem(start, len);
if (!virt) {
dev_warn(&chip->dev, "%s: Failed to map ACPI memory\n", __func__);
/* try EFI log next */
ret = -ENODEV;
goto err;
}
memcpy_fromio(log->bios_event_log, virt, len);
acpi_os_unmap_iomem(virt, len);
if (chip->flags & TPM_CHIP_FLAG_TPM2 &&
!tpm_is_tpm2_log(log->bios_event_log, len)) {
/* try EFI log next */
ret = -ENODEV;
goto err;
}
return format;
err:
devm_kfree(&chip->dev, log->bios_event_log);
log->bios_event_log = NULL;
return ret;
}
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