[PATCH v3 14/16] tpm: introduce tpm_chip_start() and tpm_chip_stop()

Jarkko Sakkinen
2018-11-05T01:48:30Z

Encapsulate power gating and locality functionality to tpm_chip_start()
and tpm_chip_stop() in order to clean up the branching mess in
tpm_transmit().

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
drivers/char/tpm/tpm-chip.c | 110 +++++++++++++++++++++++++++++++
drivers/char/tpm/tpm-interface.c | 87 +-----------------------
drivers/char/tpm/tpm.h | 2 +
3 files changed, 115 insertions(+), 84 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 157505b0f755..65f1561eba81 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -37,6 +37,116 @@ struct class *tpm_class;
struct class *tpmrm_class;
dev_t tpm_devt;

+static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
+{
+ int rc;
+
+ if (flags & TPM_TRANSMIT_NESTED)
+ return 0;
+
+ if (!chip->ops->request_locality)
+ return 0;
+
+ rc = chip->ops->request_locality(chip, 0);
+ if (rc < 0)
+ return rc;
+
+ chip->locality = rc;
+ return 0;
+}
+
+static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
+{
+ int rc;
+
+ if (flags & TPM_TRANSMIT_NESTED)
+ return;
+
+ if (!chip->ops->relinquish_locality)
+ return;
+
+ rc = chip->ops->relinquish_locality(chip, chip->locality);
+ if (rc)
+ dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
+
+ chip->locality = -1;
+}
+
+static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
+{
+ if (flags & TPM_TRANSMIT_NESTED)
+ return 0;
+
+ if (!chip->ops->cmd_ready)
+ return 0;
+
+ return chip->ops->cmd_ready(chip);
+}
+
+static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
+{
+ if (flags & TPM_TRANSMIT_NESTED)
+ return 0;
+
+ if (!chip->ops->go_idle)
+ return 0;
+
+ return chip->ops->go_idle(chip);
+}
+
+/**
+ * tpm_chip_start() - power on the TPM
+ * @chip: a TPM chip to use
+ * @flags: TPM transmit flags
+ *
+ * Return:
+ * * The response length - OK
+ * * -errno - A system error
+ */
+int tpm_chip_start(struct tpm_chip *chip, unsigned int flags)
+{
+ int ret;
+
+ if (chip->ops->clk_enable)
+ chip->ops->clk_enable(chip, true);
+
+ if (chip->locality == -1) {
+ ret = tpm_request_locality(chip, flags);
+ if (ret) {
+ chip->ops->clk_enable(chip, false);
+ return ret;
+ }
+ }
+
+ ret = tpm_cmd_ready(chip, flags);
+ if (ret) {
+ tpm_relinquish_locality(chip, flags);
+ if (chip->ops->clk_enable)
+ chip->ops->clk_enable(chip, false);
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * tpm_chip_stop() - power off the TPM
+ * @chip: a TPM chip to use
+ * @flags: TPM transmit flags
+ *
+ * Return:
+ * * The response length - OK
+ * * -errno - A system error
+ */
+void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags)
+{
+ tpm_go_idle(chip, flags);
+ tpm_relinquish_locality(chip, flags);
+ if (chip->ops->clk_enable)
+ chip->ops->clk_enable(chip, false);
+}
+
+
/**
* tpm_try_get_ops() - Get a ref to the tpm_chip
* @chip: Chip to ref
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8456162e1260..866e5405ca46 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -62,64 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);

-static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
-{
- int rc;
-
- if (flags & TPM_TRANSMIT_NESTED)
- return 0;
-
- if (!chip->ops->request_locality)
- return 0;
-
- rc = chip->ops->request_locality(chip, 0);
- if (rc < 0)
- return rc;
-
- chip->locality = rc;
-
- return 0;
-}
-
-static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
-{
- int rc;
-
- if (flags & TPM_TRANSMIT_NESTED)
- return;
-
- if (!chip->ops->relinquish_locality)
- return;
-
- rc = chip->ops->relinquish_locality(chip, chip->locality);
- if (rc)
- dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
-
- chip->locality = -1;
-}
-
-static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
-{
- if (flags & TPM_TRANSMIT_NESTED)
- return 0;
-
- if (!chip->ops->cmd_ready)
- return 0;
-
- return chip->ops->cmd_ready(chip);
-}
-
-static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
-{
- if (flags & TPM_TRANSMIT_NESTED)
- return 0;
-
- if (!chip->ops->go_idle)
- return 0;
-
- return chip->ops->go_idle(chip);
-}
-
static ssize_t tpm_try_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
unsigned int flags)
{
@@ -214,7 +156,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
/* 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(sizeof(save), bufsiz);
@@ -229,34 +170,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
memcpy(save, buf, save_size);

for (;;) {
- 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);
+ ret = tpm_chip_start(chip, flags);
if (ret)
- goto out_locality;
-
+ return ret;
ret = tpm_try_transmit(chip, buf, bufsiz, flags);
+ tpm_chip_stop(chip, 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 (ret < 0)
- break;
rc = be32_to_cpu(header->return_code);
if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
break;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index addd699317e4..9d4065804477 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -526,6 +526,8 @@ static inline void tpm_msleep(unsigned int delay_msec)
delay_msec * 1000);
};

+int tpm_chip_start(struct tpm_chip *chip, unsigned int flags);
+void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags);
struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);
__must_check int tpm_try_get_ops(struct tpm_chip *chip);
void tpm_put_ops(struct tpm_chip *chip);
--
2.19.1