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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 1a5d09b18513..9eb1a1859012 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: