[v2,11/12] tpm: Allow locality 2 to be set when initializing the TPM for Secure Launch

Commit Message

Ross Philipson June 18, 2021, 4:12 p.m. UTC

The Secure Launch MLE environment uses PCRs that are only accessible from
the DRTM locality 2. By default the TPM drivers always initialize the
locality to 0. When a Secure Launch is in progress, initialize the
locality to 2.

Signed-off-by: Ross Philipson <[e-mail]>
---
 drivers/char/tpm/tpm-chip.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index ddaeceb..48b9351 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -23,6 +23,7 @@ 
 #include <linux/major.h>
 #include <linux/tpm_eventlog.h>
 #include <linux/hw_random.h>
+#include <linux/slaunch.h>
 #include "tpm.h"
 
 DEFINE_IDR(dev_nums_idr);
@@ -34,12 +35,20 @@ 
 
 static int tpm_request_locality(struct tpm_chip *chip)
 {
-	int rc;
+	int rc, locality;
 
 	if (!chip->ops->request_locality)
 		return 0;
 
-	rc = chip->ops->request_locality(chip, 0);
+	if (slaunch_get_flags() & SL_FLAG_ACTIVE) {
+		dev_dbg(&chip->dev, "setting TPM locality to 2 for MLE\n");
+		locality = 2;
+	} else {
+		dev_dbg(&chip->dev, "setting TPM locality to 0\n");
+		locality = 0;
+	}
+
+	rc = chip->ops->request_locality(chip, locality);
 	if (rc < 0)
 		return rc;