[PATCH v2 7/7] tpm: Allow committing non-volatile data

[Simon Glass]

Add an option to tell the TPM to commit non-volatile data immediately it
is changed, rather than waiting until later. This is needed in some
situations, since if the device reboots it may not write the data.

Add definitions for the rest of the Cr50 commands while we are here.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

(no changes since v1)

 include/tpm-v2.h | 14 ++++++++++++++
 lib/tpm-v2.c     | 20 ++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 8e90a616220..0a03994740d 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -712,4 +712,18 @@ u32 tpm2_submit_command(struct udevice *dev, const u8 *sendbuf,
  */
 u32 tpm2_cr50_report_state(struct udevice *dev, u8 *recvbuf, size_t *recv_size);
 
+/*
+ * tpm2_cr50_enable_nvcommits() - Tell Cr50 to commit NV data immediately
+ *
+ * For Chromium OS verified boot, we may reboot or reset at different times,
+ * possibly leaving non-volatile data unwritten by the TPM.
+ *
+ * This vendor command is used to indicate that non-volatile data should be
+ * written to its store immediately.
+ *
+ * @dev		TPM device
+ * Return: result of the operation
+ */
+u32 tpm2_cr50_enable_nvcommits(struct udevice *dev);
+
 #endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 3de4841974a..d68c311651b 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -703,3 +703,23 @@ u32 tpm2_cr50_report_state(struct udevice *dev, u8 *recvbuf, size_t *recv_size)
 
 	return 0;
 }
+
+u32 tpm2_cr50_enable_nvcommits(struct udevice *dev)
+{
+	u8 command_v2[COMMAND_BUFFER_SIZE] = {
+		/* header 10 bytes */
+		tpm_u16(TPM2_ST_NO_SESSIONS),		/* TAG */
+		tpm_u32(10 + 2),			/* Length */
+		tpm_u32(TPM2_CR50_VENDOR_COMMAND),	/* Command code */
+
+		tpm_u16(TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS),
+	};
+	int ret;
+
+	ret = tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+	log_debug("ret=%s, %x\n", dev->name, ret);
+	if (ret)
+		return ret;
+
+	return 0;
+}
-- 
2.37.1.595.g718a3a8f04-goog