tpm_crb: request and relinquish locality 0
authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Fri, 24 Mar 2017 09:45:49 +0000 (11:45 +0200)
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Mon, 3 Apr 2017 19:46:02 +0000 (22:46 +0300)
commit877c57d0d0cac2c8fc661f708d8ee3fa7aa8d28b
tree36fcb0bf566df51a40ce092141394426800e02d0
parent84d25940678b7f93665d0964c9729680fa4a97e9
tpm_crb: request and relinquish locality 0

This commit adds support for requesting and relinquishing locality 0 in
tpm_crb for the course of command transmission.

In order to achieve this, two new callbacks are added to struct
tpm_class_ops:

- request_locality
- relinquish_locality

With CRB interface you first set either requestAccess or relinquish bit
from TPM_LOC_CTRL_x register and then wait for locAssigned and
tpmRegValidSts bits to be set in the TPM_LOC_STATE_x register.

The reason why were are doing this is to make sure that the driver
will work properly with Intel TXT that uses locality 2. There's no
explicit guarantee that it would relinquish this locality. In more
general sense this commit enables tpm_crb to be a well behaving
citizen in a multi locality environment.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Jerry Snitselaar <jsnitsel@redhat.com>
drivers/char/tpm/tpm-chip.c
drivers/char/tpm/tpm-interface.c
drivers/char/tpm/tpm.h
drivers/char/tpm/tpm_crb.c
include/linux/tpm.h