From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39378 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753473AbeDQNN4 (ORCPT ); Tue, 17 Apr 2018 09:13:56 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3HD9mOr026115 for ; Tue, 17 Apr 2018 09:13:56 -0400 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2hdekvhc2d-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Tue, 17 Apr 2018 09:13:42 -0400 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Apr 2018 14:12:56 +0100 From: Nayna Jain To: linux-integrity@vger.kernel.org Cc: zohar@linux.vnet.ibm.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com, patrickc@us.ibm.com, Nayna Jain Subject: [PATCH v2 1/2] tpm: reduce poll sleep time in tpm_transmit() Date: Tue, 17 Apr 2018 09:12:45 -0400 In-Reply-To: <20180417131246.434-1-nayna@linux.vnet.ibm.com> References: <20180417131246.434-1-nayna@linux.vnet.ibm.com> Message-Id: <20180417131246.434-2-nayna@linux.vnet.ibm.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: The TPM polling code in tpm_transmit sleeps in each loop iteration for 5 msecs. However, the TPM might return earlier, and thus waiting for 5 msecs adds an unnecessary delay. This patch reduces the polling sleep time in tpm_transmit() from 5 msecs to 1 msecs. Additionally, this patch renames TPM_POLL_SLEEP and moves it to tpm.h as an enum value. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~14 sec to ~10.7 sec. Signed-off-by: Nayna Jain --- drivers/char/tpm/tpm-interface.c | 2 +- drivers/char/tpm/tpm.h | 3 ++- drivers/char/tpm/tpm_tis_core.c | 10 ++-------- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 9e80a953d693..a676d8ad5992 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -470,7 +470,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, goto out; } - tpm_msleep(TPM_TIMEOUT); + tpm_msleep(TPM_TIMEOUT_POLL); rmb(); } while (time_before(jiffies, stop)); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index f895fba4e20d..7e797377e1eb 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -53,7 +53,8 @@ enum tpm_const { enum tpm_timeout { TPM_TIMEOUT = 5, /* msecs */ TPM_TIMEOUT_RETRY = 100, /* msecs */ - TPM_TIMEOUT_RANGE_US = 300 /* usecs */ + TPM_TIMEOUT_RANGE_US = 300, /* usecs */ + TPM_TIMEOUT_POLL = 1 /* msecs */ }; /* TPM addresses */ diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index da074e3db19b..021e6b68f2db 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -31,12 +31,6 @@ #include "tpm.h" #include "tpm_tis_core.h" -/* This is a polling delay to check for status and burstcount. - * As per ddwg input, expectation is that status check and burstcount - * check should return within few usecs. - */ -#define TPM_POLL_SLEEP 1 /* msec */ - static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value); static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, @@ -90,7 +84,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, } } else { do { - tpm_msleep(TPM_POLL_SLEEP); + tpm_msleep(TPM_TIMEOUT_POLL); status = chip->ops->status(chip); if ((status & mask) == mask) return 0; @@ -232,7 +226,7 @@ static int get_burstcount(struct tpm_chip *chip) burstcnt = (value >> 8) & 0xFFFF; if (burstcnt) return burstcnt; - tpm_msleep(TPM_POLL_SLEEP); + tpm_msleep(TPM_TIMEOUT_POLL); } while (time_before(jiffies, stop)); return -EBUSY; } -- 2.13.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: nayna@linux.vnet.ibm.com (Nayna Jain) Date: Tue, 17 Apr 2018 09:12:45 -0400 Subject: [PATCH v2 1/2] tpm: reduce poll sleep time in tpm_transmit() In-Reply-To: <20180417131246.434-1-nayna@linux.vnet.ibm.com> References: <20180417131246.434-1-nayna@linux.vnet.ibm.com> Message-ID: <20180417131246.434-2-nayna@linux.vnet.ibm.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org The TPM polling code in tpm_transmit sleeps in each loop iteration for 5 msecs. However, the TPM might return earlier, and thus waiting for 5 msecs adds an unnecessary delay. This patch reduces the polling sleep time in tpm_transmit() from 5 msecs to 1 msecs. Additionally, this patch renames TPM_POLL_SLEEP and moves it to tpm.h as an enum value. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~14 sec to ~10.7 sec. Signed-off-by: Nayna Jain --- drivers/char/tpm/tpm-interface.c | 2 +- drivers/char/tpm/tpm.h | 3 ++- drivers/char/tpm/tpm_tis_core.c | 10 ++-------- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 9e80a953d693..a676d8ad5992 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -470,7 +470,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, goto out; } - tpm_msleep(TPM_TIMEOUT); + tpm_msleep(TPM_TIMEOUT_POLL); rmb(); } while (time_before(jiffies, stop)); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index f895fba4e20d..7e797377e1eb 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -53,7 +53,8 @@ enum tpm_const { enum tpm_timeout { TPM_TIMEOUT = 5, /* msecs */ TPM_TIMEOUT_RETRY = 100, /* msecs */ - TPM_TIMEOUT_RANGE_US = 300 /* usecs */ + TPM_TIMEOUT_RANGE_US = 300, /* usecs */ + TPM_TIMEOUT_POLL = 1 /* msecs */ }; /* TPM addresses */ diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index da074e3db19b..021e6b68f2db 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -31,12 +31,6 @@ #include "tpm.h" #include "tpm_tis_core.h" -/* This is a polling delay to check for status and burstcount. - * As per ddwg input, expectation is that status check and burstcount - * check should return within few usecs. - */ -#define TPM_POLL_SLEEP 1 /* msec */ - static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value); static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, @@ -90,7 +84,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, } } else { do { - tpm_msleep(TPM_POLL_SLEEP); + tpm_msleep(TPM_TIMEOUT_POLL); status = chip->ops->status(chip); if ((status & mask) == mask) return 0; @@ -232,7 +226,7 @@ static int get_burstcount(struct tpm_chip *chip) burstcnt = (value >> 8) & 0xFFFF; if (burstcnt) return burstcnt; - tpm_msleep(TPM_POLL_SLEEP); + tpm_msleep(TPM_TIMEOUT_POLL); } while (time_before(jiffies, stop)); return -EBUSY; } -- 2.13.3 -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html