[SeaBIOS] [PATCH v1 3/3] tpm: Handle unimplemented TIS_REG_IFACE_ID in tis_get_tpm_version()
Stephen Douthit
stephend at silicom-usa.com
Tue Feb 27 20:17:11 CET 2018
If a device reports 0xf in the InterfaceType field of the TPM_INTERFACE_ID,
then the rest of the fields are invalid, and the InterfaceVersion field of
the TPM_INTF_CAPABILITY register must be checked instead.
Signed-off-by: Stephen Douthit <stephend at silicom-usa.com>
---
src/hw/tpm_drivers.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/src/hw/tpm_drivers.c b/src/hw/tpm_drivers.c
index da8bb63..ed58bf5 100644
--- a/src/hw/tpm_drivers.c
+++ b/src/hw/tpm_drivers.c
@@ -142,13 +142,23 @@ static u32 tis_probe(void)
static TPMVersion tis_get_tpm_version(void)
{
- /* TPM 2 has an interface register */
- u32 ifaceid = readl(TIS_REG(0, TIS_REG_IFACE_ID));
-
- if ((ifaceid & 0xf) == 0) {
- /* TPM 2 */
+ u32 reg = readl(TIS_REG(0, TIS_REG_IFACE_ID));
+
+ /*
+ * FIFO interface as defined in TIS1.3 is active
+ * Interface capabilities are defined in TIS_REG_INTF_CAPABILITY
+ */
+ if ((reg & 0xf) == 0xf) {
+ reg = readl(TIS_REG(0, TIS_REG_INTF_CAPABILITY));
+ /* Interface 1.3 for TPM 2.0 */
+ if (((reg >> 28) & 0x7) == 3)
+ return TPM_VERSION_2;
+ }
+ /* FIFO interface as defined in PTP for TPM 2.0 is active */
+ else if ((reg & 0xf) == 0) {
return TPM_VERSION_2;
}
+
return TPM_VERSION_1_2;
}
--
2.14.3
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