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Subject[PATCH v11 08/16] tpm: clean up tpm_try_transmit() error handling flow
Date
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>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
drivers/char/tpm/tpm-interface.c | 94 +++++++++++++++-----------------
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm2-space.c | 2 +-
3 files changed, 45 insertions(+), 52 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index c28ffef92f1a..f5f5224f68b0 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -167,7 +167,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
ssize_t len = 0;
u32 count, ordinal;
unsigned long stop;
- bool need_locality;

rc = tpm_validate_command(chip, space, buf, bufsiz);
if (rc == -EINVAL)
@@ -197,37 +196,16 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
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;
+ return rc;

rc = chip->ops->send(chip, buf, count);
if (rc < 0) {
if (rc != -EPIPE)
dev_err(&chip->dev,
"%s: tpm_send: error %d\n", __func__, rc);
- goto out;
+ goto out_rc;
}

if (chip->flags & TPM_CHIP_FLAG_IRQ)
@@ -243,7 +221,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
if (chip->ops->req_canceled(chip, status)) {
dev_err(&chip->dev, "Operation Canceled\n");
rc = -ECANCELED;
- goto out;
+ goto out_rc;
}

tpm_msleep(TPM_TIMEOUT_POLL);
@@ -253,40 +231,20 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
chip->ops->cancel(chip);
dev_err(&chip->dev, "Operation Timed out\n");
rc = -ETIME;
- goto out;
+ goto out_rc;

out_recv:
len = chip->ops->recv(chip, buf, bufsiz);
if (len < 0) {
rc = len;
- dev_err(&chip->dev,
- "tpm_transmit: tpm_recv: error %d\n", rc);
- goto out;
- } else if (len < TPM_HEADER_SIZE) {
+ dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
+ } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
rc = -EFAULT;
- goto out;
- }

- if (len != be32_to_cpu(header->length)) {
- rc = -EFAULT;
- goto out;
- }
-
- rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
+out_rc:
+ if (!rc)
+ rc = tpm2_commit_space(chip, space, ordinal, buf, &len);

-out:
- /* 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;
}

@@ -316,6 +274,7 @@ 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,
@@ -331,7 +290,40 @@ 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);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 1454ef19d2f4..6eb67ccad2a3 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -576,6 +576,7 @@ int tpm2_probe(struct tpm_chip *chip);
int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
int tpm2_init_space(struct tpm_space *space);
void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space);
+void tpm2_flush_space(struct tpm_chip *chip);
int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
u8 *cmd);
int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 39cb3915771e..5d6487575074 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -162,7 +162,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
return 0;
}

-static void tpm2_flush_space(struct tpm_chip *chip)
+void tpm2_flush_space(struct tpm_chip *chip)
{
struct tpm_space *space = &chip->work_space;
int i;
--
2.19.1
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