[PATCH v2] tpm_crb: request and relinquish locality 0
From: Jarkko Sakkinen
Date: Sat Mar 11 2017 - 08:02:56 EST
Added two new callbacks to struct tpm_class_ops:
- request_locality
- relinquish_locality
These are called before sending and receiving data from the TPM. We
update also tpm_tis_core to use these callbacks. Small modification to
request_locality() is done so that it returns -EBUSY instead of locality
number when check_locality() fails.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 9 +++++++++
drivers/char/tpm/tpm_crb.c | 41 +++++++++++++++++++++++++++++++++++++++-
drivers/char/tpm/tpm_tis_core.c | 12 ++++--------
include/linux/tpm.h | 3 ++-
4 files changed, 55 insertions(+), 10 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e38c792..9c56581 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -407,6 +407,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
if (chip->dev.parent)
pm_runtime_get_sync(chip->dev.parent);
+ if (chip->ops->request_locality) {
+ rc = chip->ops->request_locality(chip, 0);
+ if (rc)
+ goto out;
+ }
+
rc = tpm2_prepare_space(chip, space, ordinal, buf);
if (rc)
goto out;
@@ -466,6 +472,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
out:
+ if (chip->ops->relinquish_locality)
+ chip->ops->relinquish_locality(chip, 0, false);
+
if (chip->dev.parent)
pm_runtime_put_sync(chip->dev.parent);
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 3245618..15b22a0 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -34,6 +34,15 @@ enum crb_defaults {
CRB_ACPI_START_INDEX = 1,
};
+enum crb_loc_ctrl {
+ CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
+ CRB_LOC_CTRL_RELINQUISH = BIT(1),
+};
+
+enum crb_loc_state {
+ CRB_LOC_STATE_LOC_ASSIGNED = BIT(1),
+};
+
enum crb_ctrl_req {
CRB_CTRL_REQ_CMD_READY = BIT(0),
CRB_CTRL_REQ_GO_IDLE = BIT(1),
@@ -172,6 +181,35 @@ static int __maybe_unused crb_cmd_ready(struct device *dev,
return 0;
}
+static int crb_request_locality(struct tpm_chip *chip, int loc)
+{
+ struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+ if (!priv->regs_h)
+ return 0;
+
+ iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
+ if (!crb_wait_for_reg_32(&priv->regs_h->loc_state,
+ CRB_LOC_STATE_LOC_ASSIGNED, /* mask */
+ CRB_LOC_STATE_LOC_ASSIGNED, /* value */
+ TPM2_TIMEOUT_C)) {
+ dev_warn(&chip->dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
+ return -ETIME;
+ }
+
+ return 0;
+}
+
+static void crb_relinquish_locality(struct tpm_chip *chip, int loc, bool force)
+{
+ struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+ if (!priv->regs_h)
+ return;
+
+ iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
+}
+
static u8 crb_status(struct tpm_chip *chip)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
@@ -198,7 +236,6 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
memcpy_fromio(buf, priv->rsp, 6);
expected = be32_to_cpup((__be32 *) &buf[2]);
-
if (expected > count)
return -EIO;
@@ -279,6 +316,8 @@ static const struct tpm_class_ops tpm_crb = {
.send = crb_send,
.cancel = crb_cancel,
.req_canceled = crb_req_canceled,
+ .request_locality = crb_request_locality,
+ .relinquish_locality = crb_relinquish_locality,
.req_complete_mask = CRB_DRV_STS_COMPLETE,
.req_complete_val = CRB_DRV_STS_COMPLETE,
};
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index fc0e9a2..c3cbe24 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -73,7 +73,7 @@ static int check_locality(struct tpm_chip *chip, int l)
return -1;
}
-static void release_locality(struct tpm_chip *chip, int l, int force)
+static void release_locality(struct tpm_chip *chip, int l, bool force)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc;
@@ -97,7 +97,7 @@ static int request_locality(struct tpm_chip *chip, int l)
long rc;
if (check_locality(chip, l) >= 0)
- return l;
+ return -EBUSY;
rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
if (rc < 0)
@@ -252,7 +252,6 @@ 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;
}
@@ -268,9 +267,6 @@ 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);
@@ -329,7 +325,6 @@ 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;
}
@@ -390,7 +385,6 @@ 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;
}
@@ -681,6 +675,8 @@ static const struct tpm_class_ops tpm_tis = {
.send = tpm_tis_send,
.cancel = tpm_tis_ready,
.update_timeouts = tpm_tis_update_timeouts,
+ .request_locality = request_locality,
+ .relinquish_locality = release_locality,
.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,
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index da158f0..65e05f9 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -48,7 +48,8 @@ struct tpm_class_ops {
u8 (*status) (struct tpm_chip *chip);
bool (*update_timeouts)(struct tpm_chip *chip,
unsigned long *timeout_cap);
-
+ int (*request_locality)(struct tpm_chip *chip, int loc);
+ void (*relinquish_locality)(struct tpm_chip *chip, int loc, bool force);
};
#if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
--
2.9.3