Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754263AbdCMUM4 (ORCPT ); Mon, 13 Mar 2017 16:12:56 -0400 Received: from mga03.intel.com ([134.134.136.65]:16818 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbdCMUMr (ORCPT ); Mon, 13 Mar 2017 16:12:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,160,1486454400"; d="scan'208";a="834156522" Date: Mon, 13 Mar 2017 22:12:35 +0200 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, Jerry Snitselaar , gang.wei@intel.com, Peter Huewe , Marcel Selhorst , open list Subject: Re: [PATCH v2] tpm_crb: request and relinquish locality 0 Message-ID: <20170313201235.tvcyugdh7awqfrfq@intel.com> References: <20170311130216.21419-1-jarkko.sakkinen@linux.intel.com> <20170313163452.GD22997@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170313163452.GD22997@obsidianresearch.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2440 Lines: 68 On Mon, Mar 13, 2017 at 10:34:52AM -0600, Jason Gunthorpe wrote: > On Sat, Mar 11, 2017 at 03:02:14PM +0200, Jarkko Sakkinen wrote: > > Added two new callbacks to struct tpm_class_ops: > > > > - request_locality > > - relinquish_locality > > > > These are called before sending and receiving data from the TPM. We > > update also tpm_tis_core to use these callbacks. Small modification to > > request_locality() is done so that it returns -EBUSY instead of locality > > number when check_locality() fails. > > Make sense > > I think you may as well do the other two drivers, even though you > can't run them the transformation looks safe enough to me. > > > Signed-off-by: Jarkko Sakkinen > > drivers/char/tpm/tpm-interface.c | 9 +++++++++ > > drivers/char/tpm/tpm_crb.c | 41 +++++++++++++++++++++++++++++++++++++++- > > drivers/char/tpm/tpm_tis_core.c | 12 ++++-------- > > include/linux/tpm.h | 3 ++- > > 4 files changed, 55 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > > index e38c792..9c56581 100644 > > +++ b/drivers/char/tpm/tpm-interface.c > > @@ -407,6 +407,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, > > if (chip->dev.parent) > > pm_runtime_get_sync(chip->dev.parent); > > > > + if (chip->ops->request_locality) { > > + rc = chip->ops->request_locality(chip, 0); > > + if (rc) > > + goto out; > > If request_locality fails we probably shouldn't call > relinquish_locality on the unwind path.. > > I think you should also put a relinquish_locality inside tpm_remove ? Right. I was wondering why release_locality is called inside tpm_tis_remove(). So is the idea of checking pendingRequest such that the release part is "lazy" and not like what I'm doing in tpm_crb (always relinquish). Is that done for performance reasons? Should I do the same (pr similar in tpm_crb? > > + int (*request_locality)(struct tpm_chip *chip, int loc); > > + void (*relinquish_locality)(struct tpm_chip *chip, int loc, > > bool force); > > Let us document what force is supposed to do... > > I'm not sure why we have it? > > Jason I guess since it is lazy in tpm_tis_core the force is done in tpm_tis_remove so that you always relinquish the locality even if someone is not requesting it, right? Where should this be documented, to the header? /Jarkko