tpm: cmd_ready command can be issued only after granting locality
authorTomas Winkler <tomas.winkler@intel.com>
Mon, 5 Mar 2018 11:34:49 +0000 (13:34 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 29 Apr 2018 09:33:10 +0000 (11:33 +0200)
commitac5881b7814d53d9834b25f3845d6f18a0f027ba
tree36e0630d2ef555cae943a02e7685fd76be47c343
parent3b38734ed9fe7e12fa71aa9a99e31e92a7d74f53
tpm: cmd_ready command can be issued only after granting locality

commit 888d867df4417deffc33927e6fc2c6925736fe92 upstream.

The correct sequence is to first request locality and only after
that perform cmd_ready handshake, otherwise the hardware will drop
the subsequent message as from the device point of view the cmd_ready
handshake wasn't performed. Symmetrically locality has to be relinquished
only after going idle handshake has completed, this requires that
go_idle has to poll for the completion and as well locality
relinquish has to poll for completion so it is not overridden
in back to back commands flow.

Two wrapper functions are added (request_locality relinquish_locality)
to simplify the error handling.

The issue is only visible on devices that support multiple localities.

Fixes: 877c57d0d0ca ("tpm_crb: request and relinquish locality 0")
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/char/tpm/tpm-interface.c
drivers/char/tpm/tpm_crb.c
drivers/char/tpm/tpm_tis_core.c
include/linux/tpm.h