[v2,0/5] Add support for the TPM FF-A start method

Message

Stuart Yoder Feb. 12, 2025, 10:05 p.m. UTC

Firmware Framework for Arm A-profile (FF-A) is a messaging framework
for Arm-based systems, and in the context of the TPM CRB driver is used
to signal 'start' to a CRB-based TPM service which is hosted in an
FF-A secure partition running in TrustZone.

These patches add support for the CRB FF-A start method defined
in the TCG ACPI specification v1.4 and the FF-A ABI defined
in the Arm TPM Service CRB over FF-A (DEN0138) specification:
https://developer.arm.com/documentation/den0138/latest/

The first patch adds an FF-A driver to handle the FF-A messaging when
communicating with a CRB-based TPM secure partition built on FF-A.
The driver is probed when the TPM secure partition is discovered by
the Linux FF-A infrastructure.

The second patch consolidates the check for idle support in the CRB
driver to one place.

The third patch defines the new ACPI start method enumeration for
CRB over FF-A.

The fourth patch adds support for the FF-A ACPI start method to
the TPM crb driver.

The fifth patch adds documentation explaining how the CRB driver
and FF-A relate.

Version 2
-updates to cover letter to define FF-A
-added new patch with documentation
-created pull request in ACPIA and added link to the patch
 updating actbl3.h
-added tpm_ prefix to the FF-A CRB driver

Stuart Yoder (5):
  tpm_crb: implement driver compliant to CRB over FF-A
  tpm_crb: refactor check for idle support into TPM into inline function
  ACPICA: add start method for Arm FF-A
  tpm_crb: add support for the Arm FF-A start method
  Documentation: tpm: add documentation for the CRB FF-A interface

 Documentation/security/tpm/tpm_ffa_crb.rst |  65 +++++
 drivers/char/tpm/Kconfig                   |   9 +
 drivers/char/tpm/Makefile                  |   1 +
 drivers/char/tpm/tpm_crb.c                 |  81 +++++-
 drivers/char/tpm/tpm_ffa_crb.c             | 310 +++++++++++++++++++++
 drivers/char/tpm/tpm_ffa_crb.h             |  30 ++
 include/acpi/actbl3.h                      |   1 +
 7 files changed, 491 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/security/tpm/tpm_ffa_crb.rst
 create mode 100644 drivers/char/tpm/tpm_ffa_crb.c
 create mode 100644 drivers/char/tpm/tpm_ffa_crb.h