* [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction
@ 2016-06-30 17:25 apronin
2016-07-01 8:43 ` Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: apronin @ 2016-06-30 17:25 UTC (permalink / raw)
To: Jarkko Sakkinen
Cc: Peter Huewe, Marcel Selhorst, Jason Gunthorpe, Christophe Ricard,
tpmdd-devel, linux-kernel, Andrey Pronin
From: Andrey Pronin <apronin@chromium.org>
Some chips incorrectly support partial reads from TPM_STS register
at non-zero offsets. Read the entire 32-bits register instead of
making two 8-bit reads to support such devices and reduce the number
of bus transactions when obtaining the burstcount from TPM_STS.
Signed-off-by: Andrey Pronin <apronin@chromium.org>
---
No changes.
Re-sending to tpmdd-devel member-only list after subscribing.
drivers/char/tpm/tpm_tis_core.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 03a06b3..8110b52 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -157,22 +157,17 @@ static int get_burstcount(struct tpm_chip *chip)
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
unsigned long stop;
int burstcnt, rc;
- u8 value;
+ u32 value;
/* wait for burstcount */
/* which timeout value, spec has 2 answers (c & d) */
stop = jiffies + chip->timeout_d;
do {
- rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 1, &value);
+ rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
if (rc < 0)
return rc;
- burstcnt = value;
- rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 2, &value);
- if (rc < 0)
- return rc;
-
- burstcnt += value << 8;
+ burstcnt = (value >> 8) & 0xFFFF;
if (burstcnt)
return burstcnt;
msleep(TPM_TIMEOUT);
--
2.6.6
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction
2016-06-30 17:25 [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction apronin
@ 2016-07-01 8:43 ` Jarkko Sakkinen
2016-07-01 8:45 ` Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: Jarkko Sakkinen @ 2016-07-01 8:43 UTC (permalink / raw)
To: apronin
Cc: Peter Huewe, Marcel Selhorst, Jason Gunthorpe, Christophe Ricard,
tpmdd-devel, linux-kernel
On Thu, Jun 30, 2016 at 10:25:43AM -0700, apronin@chromium.org wrote:
> From: Andrey Pronin <apronin@chromium.org>
>
> Some chips incorrectly support partial reads from TPM_STS register
> at non-zero offsets. Read the entire 32-bits register instead of
> making two 8-bit reads to support such devices and reduce the number
> of bus transactions when obtaining the burstcount from TPM_STS.
>
> Signed-off-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
/Jarkko
> ---
>
> No changes.
> Re-sending to tpmdd-devel member-only list after subscribing.
>
> drivers/char/tpm/tpm_tis_core.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 03a06b3..8110b52 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -157,22 +157,17 @@ static int get_burstcount(struct tpm_chip *chip)
> struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> unsigned long stop;
> int burstcnt, rc;
> - u8 value;
> + u32 value;
>
> /* wait for burstcount */
> /* which timeout value, spec has 2 answers (c & d) */
> stop = jiffies + chip->timeout_d;
> do {
> - rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 1, &value);
> + rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
> if (rc < 0)
> return rc;
>
> - burstcnt = value;
> - rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 2, &value);
> - if (rc < 0)
> - return rc;
> -
> - burstcnt += value << 8;
> + burstcnt = (value >> 8) & 0xFFFF;
> if (burstcnt)
> return burstcnt;
> msleep(TPM_TIMEOUT);
> --
> 2.6.6
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction
2016-07-01 8:43 ` Jarkko Sakkinen
@ 2016-07-01 8:45 ` Jarkko Sakkinen
2016-07-19 14:41 ` [tpmdd-devel] " Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: Jarkko Sakkinen @ 2016-07-01 8:45 UTC (permalink / raw)
To: apronin
Cc: Peter Huewe, Marcel Selhorst, Jason Gunthorpe, Christophe Ricard,
tpmdd-devel, linux-kernel
On Fri, Jul 01, 2016 at 11:43:23AM +0300, Jarkko Sakkinen wrote:
> On Thu, Jun 30, 2016 at 10:25:43AM -0700, apronin@chromium.org wrote:
> > From: Andrey Pronin <apronin@chromium.org>
> >
> > Some chips incorrectly support partial reads from TPM_STS register
> > at non-zero offsets. Read the entire 32-bits register instead of
> > making two 8-bit reads to support such devices and reduce the number
> > of bus transactions when obtaining the burstcount from TPM_STS.
> >
> > Signed-off-by: Andrey Pronin <apronin@chromium.org>
>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Applied to my master branch.
/Jarkko
>
> /Jarkko
>
> > ---
> >
> > No changes.
> > Re-sending to tpmdd-devel member-only list after subscribing.
> >
> > drivers/char/tpm/tpm_tis_core.c | 11 +++--------
> > 1 file changed, 3 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > index 03a06b3..8110b52 100644
> > --- a/drivers/char/tpm/tpm_tis_core.c
> > +++ b/drivers/char/tpm/tpm_tis_core.c
> > @@ -157,22 +157,17 @@ static int get_burstcount(struct tpm_chip *chip)
> > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > unsigned long stop;
> > int burstcnt, rc;
> > - u8 value;
> > + u32 value;
> >
> > /* wait for burstcount */
> > /* which timeout value, spec has 2 answers (c & d) */
> > stop = jiffies + chip->timeout_d;
> > do {
> > - rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 1, &value);
> > + rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
> > if (rc < 0)
> > return rc;
> >
> > - burstcnt = value;
> > - rc = tpm_tis_read8(priv, TPM_STS(priv->locality) + 2, &value);
> > - if (rc < 0)
> > - return rc;
> > -
> > - burstcnt += value << 8;
> > + burstcnt = (value >> 8) & 0xFFFF;
> > if (burstcnt)
> > return burstcnt;
> > msleep(TPM_TIMEOUT);
> > --
> > 2.6.6
> >
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [tpmdd-devel] [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction
2016-07-01 8:45 ` Jarkko Sakkinen
@ 2016-07-19 14:41 ` Jarkko Sakkinen
0 siblings, 0 replies; 4+ messages in thread
From: Jarkko Sakkinen @ 2016-07-19 14:41 UTC (permalink / raw)
To: apronin
Cc: Christophe Ricard, linux-kernel, tpmdd-devel,
linux-security-module, leendert
On Fri, Jul 01, 2016 at 11:45:45AM +0300, Jarkko Sakkinen wrote:
> On Fri, Jul 01, 2016 at 11:43:23AM +0300, Jarkko Sakkinen wrote:
> > On Thu, Jun 30, 2016 at 10:25:43AM -0700, apronin@chromium.org wrote:
> > > From: Andrey Pronin <apronin@chromium.org>
> > >
> > > Some chips incorrectly support partial reads from TPM_STS register
> > > at non-zero offsets. Read the entire 32-bits register instead of
> > > making two 8-bit reads to support such devices and reduce the number
> > > of bus transactions when obtaining the burstcount from TPM_STS.
> > >
> > > Signed-off-by: Andrey Pronin <apronin@chromium.org>
> >
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>
> Applied to my master branch.
I added also added a fixes line.
/Jarkko
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-06-30 17:25 [RESEND][PATCH] tpm: read burstcount from TPM_STS in one 32-bit transaction apronin
2016-07-01 8:43 ` Jarkko Sakkinen
2016-07-01 8:45 ` Jarkko Sakkinen
2016-07-19 14:41 ` [tpmdd-devel] " Jarkko Sakkinen
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