Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754452AbdIFNBd (ORCPT ); Wed, 6 Sep 2017 09:01:33 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46949 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754281AbdIFM6S (ORCPT ); Wed, 6 Sep 2017 08:58:18 -0400 From: Nayna Jain To: tpmdd-devel@lists.sourceforge.net Cc: peterhuewe@gmx.de, tpmdd@selhorst.net, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, patrickc@us.ibm.com, Nayna Jain Subject: [PATCH v2 0/4] additional TPM performance improvements Date: Wed, 6 Sep 2017 08:56:35 -0400 X-Mailer: git-send-email 2.13.3 X-TM-AS-MML: disable x-cbid: 17090612-0040-0000-0000-000003534AE4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17090612-0041-0000-0000-00000CD1617C Message-Id: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-09-06_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=5 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709060179 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1667 Lines: 50 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