linux/drivers/char/tpm/tpm_eventlog_of.c
Thiebaud Weksteen 58cc1e4faf tpm: parse TPM event logs based on EFI table
If we are not able to retrieve the TPM event logs from the ACPI table,
check the EFI configuration table (Linux-specific GUID).

The format version of the log is now returned by the provider function.

Signed-off-by: Thiebaud Weksteen <tweek@google.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>
2018-01-08 12:58:35 +02:00

83 lines
2.2 KiB
C

/*
* Copyright 2012 IBM Corporation
*
* Author: Ashley Lai <ashleydlai@gmail.com>
* Nayna Jain <nayna@linux.vnet.ibm.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Read the event log created by the firmware on PPC64
*
* 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/slab.h>
#include <linux/of.h>
#include <linux/tpm_eventlog.h>
#include "tpm.h"
int tpm_read_log_of(struct tpm_chip *chip)
{
struct device_node *np;
const u32 *sizep;
const u64 *basep;
struct tpm_bios_log *log;
u32 size;
u64 base;
log = &chip->log;
if (chip->dev.parent && chip->dev.parent->of_node)
np = chip->dev.parent->of_node;
else
return -ENODEV;
if (of_property_read_bool(np, "powered-while-suspended"))
chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
sizep = of_get_property(np, "linux,sml-size", NULL);
basep = of_get_property(np, "linux,sml-base", NULL);
if (sizep == NULL && basep == NULL)
return -ENODEV;
if (sizep == NULL || basep == NULL)
return -EIO;
/*
* For both vtpm/tpm, firmware has log addr and log size in big
* endian format. But in case of vtpm, there is a method called
* sml-handover which is run during kernel init even before
* device tree is setup. This sml-handover function takes care
* of endianness and writes to sml-base and sml-size in little
* endian format. For this reason, vtpm doesn't need conversion
* but physical tpm needs the conversion.
*/
if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
size = be32_to_cpup(sizep);
base = be64_to_cpup(basep);
} else {
size = *sizep;
base = *basep;
}
if (size == 0) {
dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
return -EIO;
}
log->bios_event_log = kmalloc(size, GFP_KERNEL);
if (!log->bios_event_log)
return -ENOMEM;
log->bios_event_log_end = log->bios_event_log + size;
memcpy(log->bios_event_log, __va(base), size);
if (chip->flags & TPM_CHIP_FLAG_TPM2)
return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
}