From: Stefan Berger stefanb@linux.vnet.ibm.com
Extend the probing of the interface with TPM 2 specifics.
Use the new interface ID register of the TIS to check whether a TPM 1.2 or a TPM 2 is underneath.
We select the TIS if possible and lock it so we can issue commands during S3 for example and prevent the OS from changing to CRB type of interface.
The register is described in table 13 here:
http://www.trustedcomputinggroup.org/resources/pc_client_platform_tpm_profil...
Signed-off-by: Stefan Berger stefanb@linux.vnet.ibm.com --- src/hw/tpm_drivers.c | 38 ++++++++++++++++++++++++++++++++++---- src/hw/tpm_drivers.h | 9 ++++++++- src/tcgbios.c | 12 +++++++++--- 3 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/src/hw/tpm_drivers.c b/src/hw/tpm_drivers.c index 08fd101..a137e62 100644 --- a/src/hw/tpm_drivers.c +++ b/src/hw/tpm_drivers.c @@ -23,6 +23,7 @@ struct tpm_driver { u32 *durations; void (*set_timeouts)(u32 timeouts[4], u32 durations[3]); u32 (*probe)(void); + TPMVersion (*get_tpm_version)(void); u32 (*init)(void); u32 (*activate)(u8 locty); u32 (*ready)(void); @@ -56,7 +57,6 @@ static const u32 tpm_default_durations[3] = { static u32 tpm_default_dur[3]; static u32 tpm_default_to[4];
- /* if device is not there, return '0', '1' otherwise */ static u32 tis_probe(void) { @@ -69,9 +69,39 @@ static u32 tis_probe(void) if ((didvid != 0) && (didvid != 0xffffffff)) rc = 1;
+ /* TPM 2 has an interface register */ + u32 ifaceid = readl(TIS_REG(0, TIS_REG_IFACE_ID)); + + if ((ifaceid & 0xf) != 0xf) { + if ((ifaceid & 0xf) == 1) { + /* CRB is active; no TIS */ + return 0; + } + if ((ifaceid & (1 << 13)) == 0) { + /* TIS cannot be selected */ + return 0; + } + /* write of 0 to bits 17-18 selects TIS */ + writel(TIS_REG(0, TIS_REG_IFACE_ID), 0); + /* since we only support TIS, we lock it */ + writel(TIS_REG(0, TIS_REG_IFACE_ID), (1 << 19)); + } + return rc; }
+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 */ + return TPM_VERSION_2; + } + return TPM_VERSION_1_2; +} + static u32 tis_init(void) { if (!CONFIG_TCGBIOS) @@ -323,7 +353,7 @@ struct tpm_driver tpm_drivers[TPM_NUM_DRIVERS] = {
static u8 TPMHW_driver_to_use = TPM_INVALID_DRIVER;
-int +TPMVersion tpmhw_probe(void) { unsigned int i; @@ -332,10 +362,10 @@ tpmhw_probe(void) if (td->probe() != 0) { td->init(); TPMHW_driver_to_use = i; - return 0; + return tis_get_tpm_version(); } } - return -1; + return TPM_VERSION_NONE; }
int diff --git a/src/hw/tpm_drivers.h b/src/hw/tpm_drivers.h index 15a60af..7dfb4ae 100644 --- a/src/hw/tpm_drivers.h +++ b/src/hw/tpm_drivers.h @@ -10,7 +10,13 @@ enum tpmDurationType { TPM_DURATION_TYPE_LONG, };
-int tpmhw_probe(void); +typedef enum TPMVersion { + TPM_VERSION_NONE = 0, + TPM_VERSION_1_2 = 1, + TPM_VERSION_2 = 2, +} TPMVersion; + +TPMVersion tpmhw_probe(void); int tpmhw_is_present(void); struct tpm_req_header; int tpmhw_transmit(u8 locty, struct tpm_req_header *req, @@ -33,6 +39,7 @@ void tpmhw_set_timeouts(u32 timeouts[4], u32 durations[3]); #define TIS_REG_INTF_CAPABILITY 0x14 #define TIS_REG_STS 0x18 #define TIS_REG_DATA_FIFO 0x24 +#define TIS_REG_IFACE_ID 0x30 #define TIS_REG_DID_VID 0xf00 #define TIS_REG_RID 0xf04
diff --git a/src/tcgbios.c b/src/tcgbios.c index 7077426..0559083 100644 --- a/src/tcgbios.c +++ b/src/tcgbios.c @@ -62,6 +62,8 @@ struct {
static int TPM_has_physical_presence;
+static TPMVersion TPM_version; + static struct tcpa_descriptor_rev2 * find_tcpa_by_rsdp(struct rsdp_descriptor *rsdp) { @@ -498,11 +500,15 @@ tpm_setup(void) if (!CONFIG_TCGBIOS) return;
- int ret = tpmhw_probe(); - if (ret) + TPM_version = tpmhw_probe(); + if (TPM_version == TPM_VERSION_NONE) return;
- ret = tpm_tcpa_probe(); + dprintf(DEBUG_tcg, + "TCGBIOS: Detected a TPM %s.\n", + (TPM_version == TPM_VERSION_1_2) ? "1.2" : "2"); + + int ret = tpm_tcpa_probe(); if (ret) return;