[PATCH v13 14/19] tpm, tpm_tis: Close all localities

Ross Philipson
2025-04-10T20:49:56Z

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..2edf0ac0f810 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;
}

+ /*
+ * 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 20a40ade8030..c5a4a2d7dd15 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;
--
2.39.3