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path: root/drivers/char/tpm/tpm_crb.c
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Diffstat (limited to 'drivers/char/tpm/tpm_crb.c')
-rw-r--r--drivers/char/tpm/tpm_crb.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index cbbedf52607c..7f7f3bded453 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -463,6 +463,28 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
 	return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
 }
 
+static int crb_check_flags(struct tpm_chip *chip)
+{
+	u32 val;
+	int ret;
+
+	ret = crb_request_locality(chip, 0);
+	if (ret)
+		return ret;
+
+	ret = tpm2_get_tpm_pt(chip, TPM2_PT_MANUFACTURER, &val, NULL);
+	if (ret)
+		goto release;
+
+	if (val == 0x414D4400U /* AMD */)
+		chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED;
+
+release:
+	crb_relinquish_locality(chip, 0);
+
+	return ret;
+}
+
 static const struct tpm_class_ops tpm_crb = {
 	.flags = TPM_OPS_AUTO_STARTUP,
 	.status = crb_status,
@@ -800,6 +822,14 @@ static int crb_acpi_add(struct acpi_device *device)
 	chip->acpi_dev_handle = device->handle;
 	chip->flags = TPM_CHIP_FLAG_TPM2;
 
+	rc = tpm_chip_bootstrap(chip);
+	if (rc)
+		goto out;
+
+	rc = crb_check_flags(chip);
+	if (rc)
+		goto out;
+
 	rc = tpm_chip_register(chip);
 
 out: