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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.c38
1 files changed, 11 insertions, 27 deletions
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 9eb1a1859012..ea085b14ab7c 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -463,28 +463,6 @@ 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,
@@ -797,12 +775,13 @@ static int crb_acpi_add(struct acpi_device *device)
FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
buf->header.length,
ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON);
- return -EINVAL;
+ rc = -EINVAL;
+ goto out;
}
crb_pluton = ACPI_ADD_PTR(struct tpm2_crb_pluton, buf, sizeof(*buf));
rc = crb_map_pluton(dev, priv, buf, crb_pluton);
if (rc)
- return rc;
+ goto out;
}
priv->sm = sm;
@@ -826,9 +805,14 @@ static int crb_acpi_add(struct acpi_device *device)
if (rc)
goto out;
- rc = crb_check_flags(chip);
- if (rc)
- goto out;
+#ifdef CONFIG_X86
+ /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+ priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
+ dev_info(dev, "Disabling hwrng\n");
+ chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED;
+ }
+#endif /* CONFIG_X86 */
rc = tpm_chip_register(chip);