[PATCH v3 06/16] tpm: clean up tpm_try_transmit() error handling flow

Jarkko Sakkinen
2018-11-05T01:46:59Z

Move locking, locality handling and power management to tpm_transmit()
in order to simplify the flow.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
drivers/char/tpm/tpm-interface.c | 90 ++++++++++++++------------------
1 file changed, 39 insertions(+), 51 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ecda6f96cde0..0f343407daf8 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -171,7 +171,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
ssize_t len = 0;
u32 count, ordinal;
unsigned long stop;
- bool need_locality;

rc = tpm_validate_command(chip, space, buf, bufsiz);
if (rc == -EINVAL)
@@ -201,30 +200,9 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
return -E2BIG;
}

- if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
- mutex_lock(&chip->tpm_mutex);
-
- if (chip->ops->clk_enable != NULL)
- chip->ops->clk_enable(chip, true);
-
- /* Store the decision as chip->locality will be changed. */
- need_locality = chip->locality == -1;
-
- if (need_locality) {
- rc = tpm_request_locality(chip, flags);
- if (rc < 0) {
- need_locality = false;
- goto out_locality;
- }
- }
-
- rc = tpm_cmd_ready(chip, flags);
- if (rc)
- goto out_locality;
-
rc = tpm2_prepare_space(chip, space, ordinal, buf);
if (rc)
- goto out_idle;
+ return rc;

rc = chip->ops->send(chip, buf, count);
if (rc < 0) {
@@ -265,40 +243,16 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
rc = len;
dev_err(&chip->dev,
"tpm_transmit: tpm_recv: error %d\n", rc);
- goto out_idle;
- } else if (len < TPM_HEADER_SIZE) {
- rc = -EFAULT;
- goto out_idle;
- }
-
- if (len != be32_to_cpu(header->length)) {
+ tpm2_flush_space(chip);
+ } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
rc = -EFAULT;
- goto out_idle;
- }

out_space:
- if (rc) {
+ if (rc)
tpm2_flush_space(chip);
- } else {
+ else
rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
- if (rc)
- dev_err(&chip->dev, "tpm2_commit_space: error %d\n",
- rc);
- }
-
-out_idle:
- /* may fail but do not override previous error value in rc */
- tpm_go_idle(chip, flags);
-
-out_locality:
- if (need_locality)
- tpm_relinquish_locality(chip, flags);
-
- if (chip->ops->clk_enable != NULL)
- chip->ops->clk_enable(chip, false);

- if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
- mutex_unlock(&chip->tpm_mutex);
return rc ? rc : len;
}

@@ -328,6 +282,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
/* space for header and handles */
u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
unsigned int delay_msec = TPM2_DURATION_SHORT;
+ bool has_locality = false;
u32 rc = 0;
ssize_t ret;
const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
@@ -343,7 +298,40 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
memcpy(save, buf, save_size);

for (;;) {
+ if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
+ !(flags & TPM_TRANSMIT_NESTED))
+ mutex_lock(&chip->tpm_mutex);
+
+ if (chip->ops->clk_enable != NULL)
+ chip->ops->clk_enable(chip, true);
+
+ if (chip->locality == -1) {
+ ret = tpm_request_locality(chip, flags);
+ if (ret)
+ goto out_locality;
+ has_locality = true;
+ }
+
+ ret = tpm_cmd_ready(chip, flags);
+ if (ret)
+ goto out_locality;
+
ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
+
+ /* This may fail but do not override ret. */
+ tpm_go_idle(chip, flags);
+
+out_locality:
+ if (has_locality)
+ tpm_relinquish_locality(chip, flags);
+
+ if (chip->ops->clk_enable != NULL)
+ chip->ops->clk_enable(chip, false);
+
+ if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
+ !(flags & TPM_TRANSMIT_NESTED))
+ mutex_unlock(&chip->tpm_mutex);
+
if (ret < 0)
break;
rc = be32_to_cpu(header->return_code);
--
2.19.1