3 files changed, 39 insertions, 15 deletions

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index a2ce3797e3e0..f8319a0860fd 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -435,4 +435,5 @@ extern int tpm2_startup(struct tpm_chip *chip, u16 startup_type);
 extern void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type);
 extern unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *, u32);
 extern int tpm2_do_selftest(struct tpm_chip *chip);
-extern int tpm2_gen_interrupt(struct tpm_chip *chip, bool quiet);
+extern int tpm2_gen_interrupt(struct tpm_chip *chip);
+extern int tpm2_probe(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index f2f38a5ee632..011909a9be96 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -601,20 +601,46 @@ EXPORT_SYMBOL_GPL(tpm2_do_selftest);
 /**
  * tpm2_gen_interrupt() - generate an interrupt
  * @chip: TPM chip to use
- * @quiet: surpress the error message
  *
  * 0 is returned when the operation is successful. If a negative number is
  * returned it remarks a POSIX error code. If a positive number is returned
  * it remarks a TPM error.
  */
-int tpm2_gen_interrupt(struct tpm_chip *chip, bool quiet)
+int tpm2_gen_interrupt(struct tpm_chip *chip)
 {
-	const char *desc = NULL;
 	u32 dummy;
 
-	if (!quiet)
-		desc = "attempting to generate an interrupt";
-
-	return tpm2_get_tpm_pt(chip, TPM2_CAP_TPM_PROPERTIES, &dummy, desc);
+	return tpm2_get_tpm_pt(chip, 0x100, &dummy,
+			       "attempting to generate an interrupt");
 }
 EXPORT_SYMBOL_GPL(tpm2_gen_interrupt);
+
+/**
+ * tpm2_probe() - probe TPM 2.0
+ * @chip: TPM chip to use
+ *
+ * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
+ * the reply tag.
+ */
+int tpm2_probe(struct tpm_chip *chip)
+{
+	struct tpm2_cmd cmd;
+	int rc;
+
+	cmd.header.in = tpm2_get_tpm_pt_header;
+	cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
+	cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
+	cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+
+	rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd));
+	if (rc <  0)
+		return rc;
+	else if (rc < TPM_HEADER_SIZE)
+		return -EFAULT;
+
+	if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
+		chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm2_probe);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index e12b3ab215cf..f2dffa770b8e 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -642,12 +642,9 @@ static int tpm_tis_init(struct device *dev, acpi_handle acpi_dev_handle,
 		goto out_err;
 	}
 
-	/* Every TPM 2.x command has a higher ordinal than TPM 1.x commands.
-	 * Therefore, we can use an idempotent TPM 2.x command to probe TPM 2.x.
-	 */
-	rc = tpm2_gen_interrupt(chip, true);
-	if (rc == 0 || rc == TPM2_RC_INITIALIZE)
-		chip->flags |= TPM_CHIP_FLAG_TPM2;
+	rc = tpm2_probe(chip);
+	if (rc)
+		goto out_err;
 
 	vendor = ioread32(chip->vendor.iobase + TPM_DID_VID(0));
 	chip->vendor.manufacturer_id = vendor;
@@ -750,7 +747,7 @@ static int tpm_tis_init(struct device *dev, acpi_handle acpi_dev_handle,
 
 			/* Generate Interrupts */
 			if (chip->flags & TPM_CHIP_FLAG_TPM2)
-				tpm2_gen_interrupt(chip, false);
+				tpm2_gen_interrupt(chip);
 			else
 				tpm_gen_interrupt(chip);