Commit 85467f63 authored by Stefan Berger's avatar Stefan Berger Committed by Jarkko Sakkinen
Browse files

tpm: Add support for event log pointer found in TPM2 ACPI table 



In case a TPM2 is attached, search for a TPM2 ACPI table when trying
to get the event log from ACPI. If one is found, use it to get the
start and length of the log area. This allows non-UEFI systems, such
as SeaBIOS, to pass an event log when using a TPM2.

Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent 18306111

drivers/char/tpm/eventlog/acpi.c

+42 −21
Original line number Diff line number Diff line
@@ -49,9 +49,9 @@ int tpm_read_log_acpi(struct tpm_chip *chip) 
	void __iomem *virt;

	u64 len, start;

	struct tpm_bios_log *log;



	if (chip->flags & TPM_CHIP_FLAG_TPM2)

		return -ENODEV;

	struct acpi_table_tpm2 *tbl;

	struct acpi_tpm2_phy *tpm2_phy;

	int format;



	log = &chip->log;
@@ -61,10 +61,28 @@ int tpm_read_log_acpi(struct tpm_chip *chip) 
	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))

			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)

			return -ENODEV;



		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;
@@ -79,6 +97,9 @@ int tpm_read_log_acpi(struct tpm_chip *chip) 
			start = buff->client.log_start_addr;

			break;

		}



		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;

	}

	if (!len) {

		dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);

		return -EIO;
@@ -98,7 +119,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip) 
	memcpy_fromio(log->bios_event_log, virt, len);



	acpi_os_unmap_iomem(virt, len);

	return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;

	return format;



err:

	kfree(log->bios_event_log);

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