On Fri, Mar 24, 2017 at 12:10:30PM +0200, Jarkko Sakkinen wrote: > 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.sakki...@linux.intel.com> > --- > v2: > - TPM driver level calllbacks > v3: > - Call ops->relinquish_locality only if ops->request_locality has been > successful. > - Do not reserve locality in nested tpm_transmit calls. > - Check for tpmRegValidSts to make sure that the value in TPM_LOC_STATE_x is > stable. > v4: > - Removed tpm_tis_core changes. It needs to be done separately. It will be > postponed to 4.13. > - Store locality to struct tpm_chip while active. > drivers/char/tpm/tpm-chip.c | 1 + > drivers/char/tpm/tpm-interface.c | 13 +++++++++++++ > drivers/char/tpm/tpm.h | 3 +++ > drivers/char/tpm/tpm_crb.c | 41 > ++++++++++++++++++++++++++++++++++++++++ > include/linux/tpm.h | 3 ++- > 5 files changed, 60 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index aade699..a321bd5 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -231,6 +231,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, > goto out; > } > > + chip->locality = -1; > return chip; > > out: > diff --git a/drivers/char/tpm/tpm-interface.c > b/drivers/char/tpm/tpm-interface.c > index 95c6f98..1815666 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -384,6 +384,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct > tpm_space *space, > ssize_t len = 0; > u32 count, ordinal; > unsigned long stop; > + bool need_locality = chip->locality == -1;
This must be set *after* taking the mutex. Otherwise, I think this should be fine now. /Jarkko
