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

Jarkko Sakkinen
2016-09-19T20:22:31Z

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(-)

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
--
2.7.4