[tpmdd-devel,v2,2/3] tpm_crb: encapsulate crb_wait_for_reg_32
diff mbox

Message ID 20161203175213.10210-3-jarkko.sakkinen@linux.intel.com
State New
Headers show

Commit Message

Jarkko Sakkinen Dec. 3, 2016, 5:52 p.m. UTC
Encapsulated crb_wait_for_reg32() so that state changes in other CRB
registers than TPM_CRB_CTRL_REQ_x can be waited.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm_crb.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

Comments

Jarkko Sakkinen Dec. 3, 2016, 6:41 p.m. UTC | #1
CC linux-security-module

On Sat, Dec 03, 2016 at 07:52:12PM +0200, Jarkko Sakkinen wrote:
> Encapsulated crb_wait_for_reg32() so that state changes in other CRB
> registers than TPM_CRB_CTRL_REQ_x can be waited.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  drivers/char/tpm/tpm_crb.c | 37 +++++++++++++++++++++++--------------
>  1 file changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 8d81b66..f986d02 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -121,6 +121,25 @@ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
>  	return 0;
>  }
>  
> +static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
> +				unsigned long timeout)
> +{
> +	ktime_t start;
> +	ktime_t stop;
> +
> +	start = ktime_get();
> +	stop = ktime_add(start, ms_to_ktime(timeout));
> +
> +	do {
> +		if ((ioread32(reg) & mask) == value)
> +			return true;
> +
> +		usleep_range(50, 100);
> +	} while (ktime_before(ktime_get(), stop));
> +
> +	return false;
> +}
> +
>  /**
>   * crb_cmd_ready - request tpm crb device to enter ready state
>   *
> @@ -138,24 +157,14 @@ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
>  static int __maybe_unused crb_cmd_ready(struct device *dev,
>  					struct crb_priv *priv)
>  {
> -	ktime_t stop, start;
> -	u32 req;
> -
>  	if (priv->flags & CRB_FL_ACPI_START)
>  		return 0;
>  
>  	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
> -
> -	start = ktime_get();
> -	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
> -	do {
> -		req = ioread32(&priv->regs_t->ctrl_req);
> -		if (!(req & CRB_CTRL_REQ_CMD_READY))
> -			return 0;
> -		usleep_range(50, 100);
> -	} while (ktime_before(ktime_get(), stop));
> -
> -	if (ioread32(&priv->regs_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY) {
> +	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
> +				 CRB_CTRL_REQ_CMD_READY /* mask */,
> +				 0, /* value */
> +				 TPM2_TIMEOUT_C)) {
>  		dev_warn(dev, "cmdReady timed out\n");
>  		return -ETIME;
>  	}
> -- 
> 2.9.3
> 

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Winkler, Tomas Dec. 5, 2016, 9:34 p.m. UTC | #2
> CC linux-security-module
> 
> On Sat, Dec 03, 2016 at 07:52:12PM +0200, Jarkko Sakkinen wrote:
> > Encapsulated crb_wait_for_reg32() so that state changes in other CRB
> > registers than TPM_CRB_CTRL_REQ_x can be waited.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> >  drivers/char/tpm/tpm_crb.c | 37 +++++++++++++++++++++++--------------
> >  1 file changed, 23 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > index 8d81b66..f986d02 100644
> > --- a/drivers/char/tpm/tpm_crb.c
> > +++ b/drivers/char/tpm/tpm_crb.c
> > @@ -121,6 +121,25 @@ static int __maybe_unused crb_go_idle(struct
> device *dev, struct crb_priv *priv)
> >  	return 0;
> >  }
> >
> > +static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
> > +				unsigned long timeout)
> > +{
> > +	ktime_t start;
> > +	ktime_t stop;
> > +
> > +	start = ktime_get();
> > +	stop = ktime_add(start, ms_to_ktime(timeout));
> > +
> > +	do {
> > +		if ((ioread32(reg) & mask) == value)
> > +			return true;
> > +
> > +		usleep_range(50, 100);
This was tuned for power management, have you tuned it for locality? 

> > +	} while (ktime_before(ktime_get(), stop));
> > +
> > +	return false;
> > +}
> > +
> >  /**
> >   * crb_cmd_ready - request tpm crb device to enter ready state
> >   *
> > @@ -138,24 +157,14 @@ static int __maybe_unused crb_go_idle(struct
> > device *dev, struct crb_priv *priv)  static int __maybe_unused
> crb_cmd_ready(struct device *dev,
> >  					struct crb_priv *priv)
> >  {
> > -	ktime_t stop, start;
> > -	u32 req;
> > -
> >  	if (priv->flags & CRB_FL_ACPI_START)
> >  		return 0;
> >
> >  	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
> > -
> > -	start = ktime_get();
> > -	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
> > -	do {
> > -		req = ioread32(&priv->regs_t->ctrl_req);
> > -		if (!(req & CRB_CTRL_REQ_CMD_READY))
> > -			return 0;
> > -		usleep_range(50, 100);
> > -	} while (ktime_before(ktime_get(), stop));
> > -
> > -	if (ioread32(&priv->regs_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY)
> {
> > +	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
> > +				 CRB_CTRL_REQ_CMD_READY /* mask */,
> > +				 0, /* value */
> > +				 TPM2_TIMEOUT_C)) {
> >  		dev_warn(dev, "cmdReady timed out\n");
> >  		return -ETIME;
> >  	}
> > --
> > 2.9.3
> >
> 
> ------------------------------------------------------------------------------
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> https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

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Jarkko Sakkinen Dec. 6, 2016, 6:38 p.m. UTC | #3
On Mon, Dec 05, 2016 at 09:34:50PM +0000, Winkler, Tomas wrote:
> > CC linux-security-module
> > 
> > On Sat, Dec 03, 2016 at 07:52:12PM +0200, Jarkko Sakkinen wrote:
> > > Encapsulated crb_wait_for_reg32() so that state changes in other CRB
> > > registers than TPM_CRB_CTRL_REQ_x can be waited.
> > >
> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > ---
> > >  drivers/char/tpm/tpm_crb.c | 37 +++++++++++++++++++++++--------------
> > >  1 file changed, 23 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > > index 8d81b66..f986d02 100644
> > > --- a/drivers/char/tpm/tpm_crb.c
> > > +++ b/drivers/char/tpm/tpm_crb.c
> > > @@ -121,6 +121,25 @@ static int __maybe_unused crb_go_idle(struct
> > device *dev, struct crb_priv *priv)
> > >  	return 0;
> > >  }
> > >
> > > +static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
> > > +				unsigned long timeout)
> > > +{
> > > +	ktime_t start;
> > > +	ktime_t stop;
> > > +
> > > +	start = ktime_get();
> > > +	stop = ktime_add(start, ms_to_ktime(timeout));
> > > +
> > > +	do {
> > > +		if ((ioread32(reg) & mask) == value)
> > > +			return true;
> > > +
> > > +		usleep_range(50, 100);
> This was tuned for power management, have you tuned it for locality? 

We don't want million different wait functions and the current values
work without issues for locale.

/Jarkko

> > > +	} while (ktime_before(ktime_get(), stop));
> > > +
> > > +	return false;
> > > +}
> > > +
> > >  /**
> > >   * crb_cmd_ready - request tpm crb device to enter ready state
> > >   *
> > > @@ -138,24 +157,14 @@ static int __maybe_unused crb_go_idle(struct
> > > device *dev, struct crb_priv *priv)  static int __maybe_unused
> > crb_cmd_ready(struct device *dev,
> > >  					struct crb_priv *priv)
> > >  {
> > > -	ktime_t stop, start;
> > > -	u32 req;
> > > -
> > >  	if (priv->flags & CRB_FL_ACPI_START)
> > >  		return 0;
> > >
> > >  	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
> > > -
> > > -	start = ktime_get();
> > > -	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
> > > -	do {
> > > -		req = ioread32(&priv->regs_t->ctrl_req);
> > > -		if (!(req & CRB_CTRL_REQ_CMD_READY))
> > > -			return 0;
> > > -		usleep_range(50, 100);
> > > -	} while (ktime_before(ktime_get(), stop));
> > > -
> > > -	if (ioread32(&priv->regs_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY)
> > {
> > > +	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
> > > +				 CRB_CTRL_REQ_CMD_READY /* mask */,
> > > +				 0, /* value */
> > > +				 TPM2_TIMEOUT_C)) {
> > >  		dev_warn(dev, "cmdReady timed out\n");
> > >  		return -ETIME;
> > >  	}
> > > --
> > > 2.9.3
> > >
> > 
> > ------------------------------------------------------------------------------
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, SlashDot.org! http://sdm.link/slashdot
> > _______________________________________________
> > tpmdd-devel mailing list
> > tpmdd-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

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Patch
diff mbox

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 8d81b66..f986d02 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -121,6 +121,25 @@  static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 	return 0;
 }
 
+static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
+				unsigned long timeout)
+{
+	ktime_t start;
+	ktime_t stop;
+
+	start = ktime_get();
+	stop = ktime_add(start, ms_to_ktime(timeout));
+
+	do {
+		if ((ioread32(reg) & mask) == value)
+			return true;
+
+		usleep_range(50, 100);
+	} while (ktime_before(ktime_get(), stop));
+
+	return false;
+}
+
 /**
  * crb_cmd_ready - request tpm crb device to enter ready state
  *
@@ -138,24 +157,14 @@  static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 static int __maybe_unused crb_cmd_ready(struct device *dev,
 					struct crb_priv *priv)
 {
-	ktime_t stop, start;
-	u32 req;
-
 	if (priv->flags & CRB_FL_ACPI_START)
 		return 0;
 
 	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
-
-	start = ktime_get();
-	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
-	do {
-		req = ioread32(&priv->regs_t->ctrl_req);
-		if (!(req & CRB_CTRL_REQ_CMD_READY))
-			return 0;
-		usleep_range(50, 100);
-	} while (ktime_before(ktime_get(), stop));
-
-	if (ioread32(&priv->regs_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY) {
+	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
+				 CRB_CTRL_REQ_CMD_READY /* mask */,
+				 0, /* value */
+				 TPM2_TIMEOUT_C)) {
 		dev_warn(dev, "cmdReady timed out\n");
 		return -ETIME;
 	}