[RFC PATCH 0/1] tpm_tis: convert to use locality callbacks

[RFC PATCH 0/1] tpm_tis: convert to use locality callbacks

[Jerry Snitselaar]

This is an attempt to convert tpm_tis over to using the locality
callbacks added by Jarkko's tpm_crb patch. Requires the patch
currently on tpmdd/locality which has moved the need_locality
assignment inside the mutex in tpm_transmit.

This is pretty much the same as Jarkko's earlier patch (I think),
with the addition of my changes to probe_itpm and tpm_tis_core_init.
If this looks good Jarkko, if you want to split it out and have my
changes go on top of your patch, or fold my changes into your patch
that is fine.

Tested on TPM2.0 based tpm_tis device. Will test on TPM1.2 device
this afternoon when I dig out the laptop and switch it over to
the discrete tpm.

[RFC PATCH 1/1] tpm_tis: convert to using locality callbacks

[Jerry Snitselaar]

This patch converts tpm_tis to use of the new tpm class ops
request_locality, and relinquish_locality.

With the move to using the callbacks, release_locality is changed so
that we now release the locality even if there is no request pending.

This required some changes to the tpm_tis_core_init code path to
make sure locality is requested when needed:

  - tpm2_probe code path will end up calling request/release through
    callbacks, so request_locality prior to tpm2_probe not needed.

  - probe_itpm makes calls to tpm_tis_send_data which no longer calls
    request_locality, so add request_locality prior to tpm_tis_send_data
    calls. Also drop release_locality call in middleof probe_itpm, and
    keep locality until release_locality called at end of probe_itpm.

Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
---
 drivers/char/tpm/tpm_tis_core.c | 35 +++++++++--------------------------
 1 file changed, 9 insertions(+), 26 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index f31fc831c8f9..4483f6f25e17 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -75,21 +75,11 @@ static bool check_locality(struct tpm_chip *chip, int l)
 	return false;
 }
 
-static void release_locality(struct tpm_chip *chip, int l, int force)
+static void release_locality(struct tpm_chip *chip, int l)
 {
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
-	int rc;
-	u8 access;
-
-	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
-	if (rc < 0)
-		return;
-
-	if (force || (access &
-		      (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
-	    (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
-		tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
 
+	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
 }
 
 static int request_locality(struct tpm_chip *chip, int l)
@@ -254,7 +244,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 
 out:
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality, 0);
 	return size;
 }
 
@@ -270,9 +259,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
 	size_t count = 0;
 	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
 
-	if (request_locality(chip, 0) < 0)
-		return -EBUSY;
-
 	status = tpm_tis_status(chip);
 	if ((status & TPM_STS_COMMAND_READY) == 0) {
 		tpm_tis_ready(chip);
@@ -331,7 +317,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
 
 out_err:
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality, 0);
 	return rc;
 }
 
@@ -392,7 +377,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
 	return len;
 out_err:
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality, 0);
 	return rc;
 }
 
@@ -479,12 +463,14 @@ static int probe_itpm(struct tpm_chip *chip)
 	if (vendor != TPM_VID_INTEL)
 		return 0;
 
+	if (request_locality(chip, 0) != 0)
+		return -EBUSY;
+
 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
 	if (rc == 0)
 		goto out;
 
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality, 0);
 
 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
 
@@ -498,7 +484,7 @@ static int probe_itpm(struct tpm_chip *chip)
 
 out:
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality, 0);
+	release_locality(chip, priv->locality);
 
 	return rc;
 }
@@ -672,7 +658,7 @@ void tpm_tis_remove(struct tpm_chip *chip)
 		interrupt = 0;
 
 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
-	release_locality(chip, priv->locality, 1);
+	release_locality(chip, priv->locality);
 }
 EXPORT_SYMBOL_GPL(tpm_tis_remove);
 
@@ -686,6 +672,8 @@ static const struct tpm_class_ops tpm_tis = {
 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_canceled = tpm_tis_req_canceled,
+	.request_locality = request_locality,
+	.relinquish_locality = release_locality,
 };
 
 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
@@ -728,11 +716,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
 
-	if (request_locality(chip, 0) != 0) {
-		rc = -ENODEV;
-		goto out_err;
-	}
-
 	rc = tpm2_probe(chip);
 	if (rc)
 		goto out_err;
-- 
2.11.0.258.ge05806da9

Re: [RFC PATCH 1/1] tpm_tis: convert to using locality callbacks

[Jason Gunthorpe]

On Sat, Mar 25, 2017 at 01:05:21PM -0700, Jerry Snitselaar wrote:

> @@ -672,7 +658,7 @@ void tpm_tis_remove(struct tpm_chip *chip)
>  		interrupt = 0;
>  
>  	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
> -	release_locality(chip, priv->locality, 1);
> +	release_locality(chip, priv->locality);

Why is this done during remove? The tpm core should now keep things so
that there is not a requested locality except during command so execution
we should not get here with a requested locality..

Jason

Re: [RFC PATCH 1/1] tpm_tis: convert to using locality callbacks

[Jerry Snitselaar]

----- Original Message -----
> From: "Jason Gunthorpe" <jgunthorpe@obsidianresearch.com>
> To: "Jerry Snitselaar" <jsnitsel@redhat.com>
> Cc: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, "Peter Huewe" <peterhuewe@gmx.de>, "Jarkko
> Sakkinen" <jarkko.sakkinen@linux.intel.com>, "Marcel Selhorst" <tpmdd@selhorst.net>
> Sent: Sunday, March 26, 2017 1:36:28 PM
> Subject: Re: [RFC PATCH 1/1] tpm_tis: convert to using locality callbacks
> 
> On Sat, Mar 25, 2017 at 01:05:21PM -0700, Jerry Snitselaar wrote:
> 
> > @@ -672,7 +658,7 @@ void tpm_tis_remove(struct tpm_chip *chip)
> >  		interrupt = 0;
> >  
> >  	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
> > -	release_locality(chip, priv->locality, 1);
> > +	release_locality(chip, priv->locality);
> 
> Why is this done during remove? The tpm core should now keep things so
> that there is not a requested locality except during command so execution
> we should not get here with a requested locality..
> 
> Jason
> 

You're right, this call should be dropped. With release_locality always releasing
now it shouldn't have a locality when going into remove. I'll drop this in v2.

Thanks,
Jerry

Re: [RFC PATCH 1/1] tpm_tis: convert to using locality callbacks

[Jarkko Sakkinen]

On Sat, Mar 25, 2017 at 01:05:21PM -0700, Jerry Snitselaar wrote:
> This patch converts tpm_tis to use of the new tpm class ops
> request_locality, and relinquish_locality.
> 
> With the move to using the callbacks, release_locality is changed so
> that we now release the locality even if there is no request pending.
> 
> This required some changes to the tpm_tis_core_init code path to
> make sure locality is requested when needed:
> 
>   - tpm2_probe code path will end up calling request/release through
>     callbacks, so request_locality prior to tpm2_probe not needed.
> 
>   - probe_itpm makes calls to tpm_tis_send_data which no longer calls
>     request_locality, so add request_locality prior to tpm_tis_send_data
>     calls. Also drop release_locality call in middleof probe_itpm, and
>     keep locality until release_locality called at end of probe_itpm.
> 
> Cc: Peter Huewe <peterhuewe@gmx.de>
> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> Cc: Marcel Selhorst <tpmdd@selhorst.net>
> Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
> ---
>  drivers/char/tpm/tpm_tis_core.c | 35 +++++++++--------------------------
>  1 file changed, 9 insertions(+), 26 deletions(-)

LGTM except what Jason said earlier.

/Jarkko