[PATCH v15 08/28] tpm/tpm_tis: Close all localities

Ross Philipson
2025-12-15T23:41:02Z

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

There are environments, for example, those that comply with the TCG DRTM
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 8954a8660ffc..12a2340dd5e0 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1112,7 +1112,7 @@ 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);
@@ -1177,6 +1177,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
goto out_err;
}

+ /*
+ * In order to comply with the TCG D-RTM specification, relinquish all
+ * the localities.
+ */
+ 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 4c02076a8c39..87978cc584ee 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -107,6 +107,12 @@ 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;
--
2.43.7