[PATCH v8 09/17] tpm: clean up tpm_try_transmit() error handling flow

[Jarkko Sakkinen]

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

Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
Reviewed-by: Stefan Berger <stef...@linux.ibm.com>
---
 drivers/char/tpm/tpm-interface.c | 71 ++++++++++++++++----------------
 1 file changed, 35 insertions(+), 36 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ef00b698ec02..f2280bf15339 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) {
@@ -273,19 +251,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
        else
                rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
 
-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;
 }
 
@@ -315,6 +280,7 @@ 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,
@@ -330,7 +296,40 @@ 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