From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nayna Jain Subject: [PATCH v2 0/4] additional TPM performance improvements Date: Wed, 6 Sep 2017 08:56:35 -0400 Message-ID: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Cc: patrickc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ima-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net After further discussions with the Device Driver working group (ddwg), the following changes were made: * Check for burstcount at least once to confirm the TPM is ready to accept the data. Similarly, query for the TPM Expect status as sanity check at the end. * Make the sleep for status check during send() in the loop less than 5msec. * Make the sleep in the loop while querying for burstcount less than 5msec. Below is the list of patches along with the performance improvements seen with a TPM 1.2 with an 8 byte burstcount for 1000 extends: Patch |Improvement(time in sec) tpm: ignore burstcount to improve tpm_tis | ~41 - ~14 send() performance. tpm: define __wait_for_tpm_stat to specify | ~14 - ~10 variable polling sleep time tpm: reduce tpm_msleep() time in | ~10 - ~9 get_burstcount() tpm: modify tpm_msleep() function to have | ~9 - ~8 max range Changelog v2: * Add module parameter to handle ignoring of burst count during tpm tis send() operation. * Add improvements over sleep time to reduce delays. Nayna Jain (4): tpm: ignore burstcount to improve tpm_tis send() performance. tpm: define __wait_for_tpm_stat to specify variable polling sleep time tpm: reduce tpm_msleep() time in get_burstcount() tpm: use tpm_msleep() value as max delay Documentation/admin-guide/kernel-parameters.txt | 8 ++++++ drivers/char/tpm/tpm-interface.c | 15 ++++++++-- drivers/char/tpm/tpm.h | 7 +++-- drivers/char/tpm/tpm_tis_core.c | 37 +++++++++++++++++++------ 4 files changed, 53 insertions(+), 14 deletions(-) -- 2.13.3 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot