[RFC PATCH 1/4] tpm, tpm_tis: Close all localities

[Jarkko Sakkinen <jarkko@kernel.org>]

From: "Daniel P. Smith" <dpsmith@apertussolutions.com>

There are environments, for example, those that comply with the TCG D-RTM
specification that requires the TPM to be left in locality 2. Prepare
kernel for such environments by closing all the localities.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
 drivers/char/tpm/tpm_tis_core.c | 11 ++++++++++-
 include/linux/tpm.h             |  6 ++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index fdef214b9f6b..c58f360fb4a4 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1104,7 +1104,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	u32 intmask;
 	u32 clkrun_val;
 	u8 rid;
-	int rc, probe;
+	int rc, probe, i;
 	struct tpm_chip *chip;
 
 	chip = tpmm_chip_alloc(dev, &tpm_tis);
@@ -1166,6 +1166,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		goto out_err;
 	}
 
+	/*
+	 * There are environments, for example, those that comply with the TCG D-RTM
+	 * specification that requires the TPM to be left in Locality 2.
+	 */
+	for (i = 0; i <= TPM_MAX_LOCALITY; i++) {
+		if (check_locality(chip, i))
+			tpm_tis_relinquish_locality(chip, i);
+	}
+
 	/* Take control of the TPM's interrupt hardware and shut it off */
 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 	if (rc < 0)
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 587b96b4418e..0708f744c803 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -147,6 +147,12 @@ struct tpm_chip_seqops {
  */
 #define TPM2_MAX_CONTEXT_SIZE 4096
 
+/*
+ * The maximum locality (0 - 4) for a TPM, as defined in section 3.2 of the
+ * Client Platform Profile Specification.
+ */
+#define TPM_MAX_LOCALITY		4
+
 struct tpm_chip {
 	struct device dev;
 	struct device devs;
-- 
2.47.0