[PATCH v16 13/38] tpm/tpm_tis: Allow locality to be set to a different value

[Ross Philipson]

From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>

Provide a one-time function tpm_chip_set_locality() for setting the
correct locality needed by DRTM launches.

Co-developed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxx>
---
 drivers/char/tpm/tpm-chip.c     | 35 ++++++++++++++++++++++++++++++++-
 drivers/char/tpm/tpm_tis_core.c |  2 ++
 include/linux/tpm.h             |  4 ++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 0719577e584d..a9620b27b63d 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -44,7 +44,7 @@ static int tpm_request_locality(struct tpm_chip *chip)
 	if (!chip->ops->request_locality)
 		return 0;
 
-	rc = chip->ops->request_locality(chip, 0);
+	rc = chip->ops->request_locality(chip, chip->kernel_locality);
 	if (rc < 0)
 		return rc;
 
@@ -343,6 +343,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
 	}
 
 	chip->locality = -1;
+	chip->kernel_locality = 0;
 	return chip;
 
 out:
@@ -658,3 +659,35 @@ void tpm_chip_unregister(struct tpm_chip *chip)
 	tpm_del_char_device(chip);
 }
 EXPORT_SYMBOL_GPL(tpm_chip_unregister);
+
+/**
+ * tpm_chip_set_locality() - Set the TPM locality the kernel uses
+ * @chip:	&tpm_chip instance
+ * @locality:   new locality
+ *
+ * This a one time function to set the locality the kernel driver
+ * uses. Returns zero or POSIX error on failure.
+ */
+int tpm_chip_set_locality(struct tpm_chip *chip, u8 locality)
+{
+	int ret;
+
+	if (locality >= TPM_MAX_LOCALITY)
+		return -EINVAL;
+
+	ret = tpm_try_get_ops(chip);
+	if (ret)
+		return ret;
+
+	if (!(chip->flags & TPM_CHIP_FLAG_SET_LOCALITY_ENABLED)) {
+		tpm_put_ops(chip);
+		return -EPERM;
+	}
+
+	chip->kernel_locality = locality;
+	chip->flags &= ~TPM_CHIP_FLAG_SET_LOCALITY_ENABLED;
+	tpm_put_ops(chip);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_chip_set_locality);
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 70aba05f4ee1..cf6d929ce5aa 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1125,6 +1125,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	if (IS_ERR(chip))
 		return PTR_ERR(chip);
 
+	chip->flags |= TPM_CHIP_FLAG_SET_LOCALITY_ENABLED;
+
 #ifdef CONFIG_ACPI
 	chip->acpi_dev_handle = acpi_dev_handle;
 #endif
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 0db277af45c3..4a26a49040b9 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -159,6 +159,8 @@ struct tpm_chip {
 
 	/* active locality */
 	int locality;
+	/* the locality used by kernel */
+	u8 kernel_locality;
 
 #ifdef CONFIG_TCG_TPM2_HMAC
 	/* details for communication security via sessions */
@@ -197,6 +199,7 @@ enum tpm_chip_flags {
 	TPM_CHIP_FLAG_HWRNG_DISABLED		= BIT(9),
 	TPM_CHIP_FLAG_DISABLE			= BIT(10),
 	TPM_CHIP_FLAG_SYNC			= BIT(11),
+	TPM_CHIP_FLAG_SET_LOCALITY_ENABLED	= BIT(12),
 };
 
 #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
@@ -244,6 +247,7 @@ static inline ssize_t tpm_ret_to_err(ssize_t ret)
 extern int tpm_is_tpm2(struct tpm_chip *chip);
 extern __must_check int tpm_try_get_ops(struct tpm_chip *chip);
 extern void tpm_put_ops(struct tpm_chip *chip);
+int tpm_chip_set_locality(struct tpm_chip *chip, u8 locality);
 extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
 				size_t min_rsp_body_length, const char *desc);
 extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
-- 
2.47.3