diff mbox

[1/2] tpm: Clean up reading of timeout and duration capabilities

Message ID 1474316530-17315-2-git-send-email-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jarkko Sakkinen Sept. 19, 2016, 8:22 p.m. UTC 
From: Ed Swierk <eswierk@skyportsystems.com>

Call tpm_getcap() from tpm_get_timeouts() to eliminate redundant
code. Return all errors to the caller rather than swallowing them
(e.g. when tpm_transmit_cmd() returns nonzero).

Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm-interface.c | 65 +++++++++++-----------------------------
 1 file changed, 17 insertions(+), 48 deletions(-)

Comments

Jason Gunthorpe Sept. 19, 2016, 11:24 p.m. UTC | #1 
On Mon, Sep 19, 2016 at 11:22:08PM +0300, Jarkko Sakkinen wrote:
> From: Ed Swierk <eswierk@skyportsystems.com>
> 
> Call tpm_getcap() from tpm_get_timeouts() to eliminate redundant
> code. Return all errors to the caller rather than swallowing them
> (e.g. when tpm_transmit_cmd() returns nonzero).

I didn't look at these closely, but I agree with the idea.

Jason

------------------------------------------------------------------------------
Jarkko Sakkinen Oct. 21, 2016, 8:33 p.m. UTC | #2 
On Mon, Sep 19, 2016 at 05:24:06PM -0600, Jason Gunthorpe wrote:
> On Mon, Sep 19, 2016 at 11:22:08PM +0300, Jarkko Sakkinen wrote:
> > From: Ed Swierk <eswierk@skyportsystems.com>
> > 
> > Call tpm_getcap() from tpm_get_timeouts() to eliminate redundant
> > code. Return all errors to the caller rather than swallowing them
> > (e.g. when tpm_transmit_cmd() returns nonzero).
> 
> I didn't look at these closely, but I agree with the idea.

Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/Jarkko

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Jarkko Sakkinen Oct. 21, 2016, 8:35 p.m. UTC | #3 
On Fri, Oct 21, 2016 at 11:33:44PM +0300, Jarkko Sakkinen wrote:
> On Mon, Sep 19, 2016 at 05:24:06PM -0600, Jason Gunthorpe wrote:
> > On Mon, Sep 19, 2016 at 11:22:08PM +0300, Jarkko Sakkinen wrote:
> > > From: Ed Swierk <eswierk@skyportsystems.com>
> > > 
> > > Call tpm_getcap() from tpm_get_timeouts() to eliminate redundant
> > > code. Return all errors to the caller rather than swallowing them
> > > (e.g. when tpm_transmit_cmd() returns nonzero).
> > 
> > I didn't look at these closely, but I agree with the idea.
> 
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

I applied this. 

/Jarkko

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diff mbox

Patch

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8de6187..ca6162e 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -488,10 +488,9 @@  static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 
 int tpm_get_timeouts(struct tpm_chip *chip)
 {
-	struct tpm_cmd_t tpm_cmd;
+	cap_t cap;
 	unsigned long new_timeout[4];
 	unsigned long old_timeout[4];
-	struct duration_t *duration_cap;
 	ssize_t rc;
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
@@ -509,43 +508,25 @@  int tpm_get_timeouts(struct tpm_chip *chip)
 		return 0;
 	}
 
-	tpm_cmd.header.in = tpm_getcap_header;
-	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
-	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
-			      NULL);
-
+	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+			"attempting to determine the timeouts");
 	if (rc == TPM_ERR_INVALID_POSTINIT) {
 		/* The TPM is not started, we are the first to talk to it.
 		   Execute a startup command. */
-		dev_info(&chip->dev, "Issuing TPM_STARTUP");
+		dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
 		if (tpm_startup(chip, TPM_ST_CLEAR))
 			return rc;
 
-		tpm_cmd.header.in = tpm_getcap_header;
-		tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-		tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
-		rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
-				      0, NULL);
+		rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+				"attempting to determine the timeouts");
 	}
-	if (rc) {
-		dev_err(&chip->dev,
-			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
-			rc);
-		goto duration;
-	}
-
-	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
-	    be32_to_cpu(tpm_cmd.header.out.length)
-	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
-		return -EINVAL;
+	if (rc)
+		return rc;
 
-	old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
-	old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
-	old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
-	old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
+	old_timeout[0] = be32_to_cpu(cap.timeout.a);
+	old_timeout[1] = be32_to_cpu(cap.timeout.b);
+	old_timeout[2] = be32_to_cpu(cap.timeout.c);
+	old_timeout[3] = be32_to_cpu(cap.timeout.d);
 	memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 
 	/*
@@ -583,29 +564,17 @@  int tpm_get_timeouts(struct tpm_chip *chip)
 	chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
 	chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 
-duration:
-	tpm_cmd.header.in = tpm_getcap_header;
-	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
-
-	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
-			      "attempting to determine the durations");
+	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
+			"attempting to determine the durations");
 	if (rc)
 		return rc;
 
-	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
-	    be32_to_cpu(tpm_cmd.header.out.length)
-	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
-		return -EINVAL;
-
-	duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 	chip->duration[TPM_SHORT] =
-	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
+		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 	chip->duration[TPM_MEDIUM] =
-	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
+		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 	chip->duration[TPM_LONG] =
-	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
+		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 
 	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 	 * value wrong and apparently reports msecs rather than usecs. So we