Patchwork [v2,2/4] tpm: define __wait_for_tpm_stat to specify variable polling sleep time

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Submitter Nayna Jain
Date Sept. 6, 2017, 12:56 p.m.
Message ID <20170906125643.5070-3-nayna@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/332967/
State New
Headers show

Comments

Nayna Jain - Sept. 6, 2017, 12:56 p.m.
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 <nayna@linux.vnet.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 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(-)
Jarkko Sakkinen - Sept. 13, 2017, 12:58 a.m.
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 <nayna@linux.vnet.ibm.com>
> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

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
> 

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Nayna Jain - Sept. 15, 2017, 12:37 p.m.
On 09/13/2017 06:28 AM, Jarkko Sakkinen wrote:
> 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 <nayna@linux.vnet.ibm.com>
>> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> 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.

I think I didn't understand the meaning of "get rid of wait_for_tpm_stat()".
Do you mean to take care of it in driver specific file ?
Can you please elaborate it ?

Thanks & Regards,
     - Nayna

>
> /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
>>


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Jarkko Sakkinen - Sept. 15, 2017, 3:20 p.m.
On Fri, Sep 15, 2017 at 06:07:26PM +0530, Nayna Jain wrote:
> 
> 
> On 09/13/2017 06:28 AM, Jarkko Sakkinen wrote:
> > 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 <nayna@linux.vnet.ibm.com>
> > > Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> > 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.
> 
> I think I didn't understand the meaning of "get rid of wait_for_tpm_stat()".
> Do you mean to take care of it in driver specific file ?
> Can you please elaborate it ?
> 
> Thanks & Regards,
>     - Nayna

It's not a generic function. It's used only in tpm_tis and tpm-xenfront.
They should have their owen private functions for this. Here the sharing
of code makes zero sense.

/Jarkko

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Patch

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;
 	}