From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH v2 2/4] tpm: define __wait_for_tpm_stat to specify variable polling sleep time Date: Tue, 12 Sep 2017 17:58:23 -0700 Message-ID: <20170913005823.n7oqknkedlo22xe6@linux.intel.com> References: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> <20170906125643.5070-3-nayna@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170906125643.5070-3-nayna@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: Nayna Jain Cc: tpmdd-devel@lists.sourceforge.net, peterhuewe@gmx.de, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, patrickc@us.ibm.com List-Id: tpmdd-devel@lists.sourceforge.net On Wed, Sep 06, 2017 at 08:56:37AM -0400, Nayna Jain wrote: > The existing wait_for_tpm_stat() checks the chip status before > sleeping for 5 msec in a polling loop. For some functions although > the status isn't ready immediately, the status returns extremely > quickly. Waiting for 5 msec causes an unnecessary delay. An > example is the send() call in the tpms_tis driver. > > This patch defines __wait_for_tpm_stat(), allowing the caller > to specify the polling sleep timeout value within the loop. > The existing wait_for_tpm_stat() becomes a wrapper for this > function. > > After this change, performance on a TPM 1.2 with an 8 byte > burstcount for 1000 extends improved from ~14sec to ~10sec. > > Signed-off-by: Nayna Jain > Acked-by: Mimi Zohar Please get rid of wait_for_tpm_stat() rather than further making it more complex. It's hardware specific stuff. This function should not exist in tpm-interface.c. /Jarkko > --- > drivers/char/tpm/tpm-interface.c | 15 ++++++++++++--- > drivers/char/tpm/tpm.h | 3 +++ > drivers/char/tpm/tpm_tis_core.c | 11 ++++++----- > 3 files changed, 21 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 1d6729be4cd6..b23d006243b7 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -1050,8 +1050,9 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, > return false; > } > > -int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > - wait_queue_head_t *queue, bool check_cancel) > +int __wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > + unsigned int poll_sleep, wait_queue_head_t *queue, > + bool check_cancel) > { > unsigned long stop; > long rc; > @@ -1085,7 +1086,7 @@ int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > } > } else { > do { > - tpm_msleep(TPM_TIMEOUT); > + tpm_msleep(poll_sleep); > status = chip->ops->status(chip); > if ((status & mask) == mask) > return 0; > @@ -1093,6 +1094,14 @@ int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > } > return -ETIME; > } > +EXPORT_SYMBOL_GPL(__wait_for_tpm_stat); > + > +int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > + wait_queue_head_t *queue, bool check_cancel) > +{ > + return __wait_for_tpm_stat(chip, mask, timeout, TPM_TIMEOUT, > + queue, check_cancel); > +} > EXPORT_SYMBOL_GPL(wait_for_tpm_stat); > > #define TPM_ORD_SAVESTATE 152 > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 2d5466a72e40..eb2f8818eded 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -525,6 +525,9 @@ int tpm_do_selftest(struct tpm_chip *chip); > unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal); > int tpm_pm_suspend(struct device *dev); > int tpm_pm_resume(struct device *dev); > +int __wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > + unsigned long timeout, unsigned int poll_sleep, > + wait_queue_head_t *queue, bool check_cancel); > int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, > wait_queue_head_t *queue, bool check_cancel); > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index 6b9bf4c4d434..d1eab29cb447 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -268,8 +268,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) > status = tpm_tis_status(chip); > if ((status & TPM_STS_COMMAND_READY) == 0) { > tpm_tis_ready(chip); > - if (wait_for_tpm_stat > - (chip, TPM_STS_COMMAND_READY, chip->timeout_b, > + if (__wait_for_tpm_stat > + (chip, TPM_STS_COMMAND_READY, chip->timeout_b, 1, > &priv->int_queue, false) < 0) { > rc = -ETIME; > goto out_err; > @@ -303,7 +303,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) > if (ignore_burst_count) > continue; > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > + if (__wait_for_tpm_stat(chip, TPM_STS_VALID, > + chip->timeout_c, 1, > &priv->int_queue, false) < 0) { > rc = -ETIME; > goto out_err; > @@ -320,8 +321,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) > if (rc < 0) > goto out_err; > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > - &priv->int_queue, false) < 0) { > + if (__wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > + 1, &priv->int_queue, false) < 0) { > rc = -ETIME; > goto out_err; > } > -- > 2.13.3 >