tpm: consolidate the TPM startup code

Consolidated all the "manual" TPM startup code to a single function
in order to make code flows a bit cleaner and migrate to tpm_buf.

Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

1 files changed, 42 insertions, 25 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index d2b4df6d9894..3123a6e44687 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -540,6 +540,47 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 }
 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
 
+#define TPM_ORD_STARTUP 153
+#define TPM_ST_CLEAR 1
+
+/**
+ * tpm_startup - turn on the TPM
+ * @chip: TPM chip to use
+ *
+ * Normally the firmware should start the TPM. This function is provided as a
+ * workaround if this does not happen. A legal case for this could be for
+ * example when a TPM emulator is used.
+ *
+ * Return: same as tpm_transmit_cmd()
+ */
+int tpm_startup(struct tpm_chip *chip)
+{
+	struct tpm_buf buf;
+	int rc;
+
+	dev_info(&chip->dev, "starting up the TPM manually\n");
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
+		if (rc < 0)
+			return rc;
+
+		tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
+	} else {
+		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
+		if (rc < 0)
+			return rc;
+
+		tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
+	}
+
+	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+			      "attempting to start the TPM");
+
+	tpm_buf_destroy(&buf);
+	return rc;
+}
+
 #define TPM_DIGEST_SIZE 20
 #define TPM_RET_CODE_IDX 6
 #define TPM_INTERNAL_RESULT_SIZE 200
@@ -586,27 +627,6 @@ ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 }
 EXPORT_SYMBOL_GPL(tpm_getcap);
 
-#define TPM_ORD_STARTUP 153
-#define TPM_ST_CLEAR cpu_to_be16(1)
-#define TPM_ST_STATE cpu_to_be16(2)
-#define TPM_ST_DEACTIVATED cpu_to_be16(3)
-static const struct tpm_input_header tpm_startup_header = {
-	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
-	.length = cpu_to_be32(12),
-	.ordinal = cpu_to_be32(TPM_ORD_STARTUP)
-};
-
-static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
-{
-	struct tpm_cmd_t start_cmd;
-	start_cmd.header.in = tpm_startup_header;
-
-	start_cmd.params.startup_in.startup_type = startup_type;
-	return tpm_transmit_cmd(chip, NULL, &start_cmd,
-				TPM_INTERNAL_RESULT_SIZE, 0,
-				0, "attempting to start the TPM");
-}
-
 int tpm_get_timeouts(struct tpm_chip *chip)
 {
 	cap_t cap;
@@ -636,10 +656,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
 			sizeof(cap.timeout));
 	if (rc == TPM_ERR_INVALID_POSTINIT) {
-		/* The TPM is not started, we are the first to talk to it.
-		   Execute a startup command. */
-		dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
-		if (tpm_startup(chip, TPM_ST_CLEAR))
+		if (tpm_startup(chip))
 			return rc;
 
 		rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,