[PATCH v2] tpm_tis: convert to using locality callbacks

From: Jerry Snitselaar
Date: Mon Mar 27 2017 - 11:46:57 EST


This patch converts tpm_tis to use of the new tpm class ops
request_locality, and relinquish_locality.

With the move to using the callbacks, release_locality is changed so
that we now release the locality even if there is no request pending.

This required some changes to the tpm_tis_core_init code path to
make sure locality is requested when needed:

- tpm2_probe code path will end up calling request/release through
callbacks, so request_locality prior to tpm2_probe not needed.

- probe_itpm makes calls to tpm_tis_send_data which no longer calls
request_locality, so add request_locality prior to tpm_tis_send_data
calls. Also drop release_locality call in middleof probe_itpm, and
keep locality until release_locality called at end of probe_itpm.

Cc: Peter Huewe <peterhuewe@xxxxxx>
Cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Cc: Marcel Selhorst <tpmdd@xxxxxxxxxxxx>
Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
---
v2: drop release_locality call in tpm_tis_remove

drivers/char/tpm/tpm_tis_core.c | 34 ++++++++--------------------------
1 file changed, 8 insertions(+), 26 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index f31fc831c8f9..b617b2eeb080 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -75,21 +75,11 @@ static bool check_locality(struct tpm_chip *chip, int l)
return false;
}

-static void release_locality(struct tpm_chip *chip, int l, int force)
+static void release_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
- int rc;
- u8 access;
-
- rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
- if (rc < 0)
- return;
-
- if (force || (access &
- (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
- (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
- tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);

+ tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
}

static int request_locality(struct tpm_chip *chip, int l)
@@ -254,7 +244,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)

out:
tpm_tis_ready(chip);
- release_locality(chip, priv->locality, 0);
return size;
}

@@ -270,9 +259,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
size_t count = 0;
bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;

- if (request_locality(chip, 0) < 0)
- return -EBUSY;
-
status = tpm_tis_status(chip);
if ((status & TPM_STS_COMMAND_READY) == 0) {
tpm_tis_ready(chip);
@@ -331,7 +317,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)

out_err:
tpm_tis_ready(chip);
- release_locality(chip, priv->locality, 0);
return rc;
}

@@ -392,7 +377,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
return len;
out_err:
tpm_tis_ready(chip);
- release_locality(chip, priv->locality, 0);
return rc;
}

@@ -479,12 +463,14 @@ static int probe_itpm(struct tpm_chip *chip)
if (vendor != TPM_VID_INTEL)
return 0;

+ if (request_locality(chip, 0) != 0)
+ return -EBUSY;
+
rc = tpm_tis_send_data(chip, cmd_getticks, len);
if (rc == 0)
goto out;

tpm_tis_ready(chip);
- release_locality(chip, priv->locality, 0);

priv->flags |= TPM_TIS_ITPM_WORKAROUND;

@@ -498,7 +484,7 @@ static int probe_itpm(struct tpm_chip *chip)

out:
tpm_tis_ready(chip);
- release_locality(chip, priv->locality, 0);
+ release_locality(chip, priv->locality);

return rc;
}
@@ -672,7 +658,6 @@ void tpm_tis_remove(struct tpm_chip *chip)
interrupt = 0;

tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
- release_locality(chip, priv->locality, 1);
}
EXPORT_SYMBOL_GPL(tpm_tis_remove);

@@ -686,6 +671,8 @@ static const struct tpm_class_ops tpm_tis = {
.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_canceled = tpm_tis_req_canceled,
+ .request_locality = request_locality,
+ .relinquish_locality = release_locality,
};

int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
@@ -728,11 +715,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
intmask &= ~TPM_GLOBAL_INT_ENABLE;
tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);

- if (request_locality(chip, 0) != 0) {
- rc = -ENODEV;
- goto out_err;
- }
-
rc = tpm2_probe(chip);
if (rc)
goto out_err;
--
2.11.0.258.ge05806da9