Re: [tpmdd-devel] [PATCH v9 8/8] tpm: TPM 2.0 FIFO Interface

[Stefan Berger]

On 12/05/2014 10:01 AM, Peter Huewe wrote:
> > > Am Donnerstag, 4. Dezember 2014, 06:55:18 schrieb Jarkko Sakkinen:
> > > > From: Will Arthur <will.c.arthur@xxxxxxxxx>
> > > >
> > > > Detect TPM 2.0 by using the extended STS (STS3) register. For TPM 2.0,
> > > > instead of calling tpm_get_timeouts(), assign duration and timeout
> > > > values defined in the TPM 2.0 PTP specification.
> > > >
> > > > Signed-off-by: Will Arthur <will.c.arthur@xxxxxxxxx>
> > > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > > > + sts3 = ioread8(chip->vendor.iobase + TPM_STS3(1));
> > > > + if ((sts3 & TPM_STS3_TPM2_FAM) == TPM_STS3_TPM2_FAM)
> > > > + chip->flags = TPM_CHIP_FLAG_TPM2;
> > > > +
> > > When loading tpm_tis force=1 with my tpm1.2 chip on a machine without bios
> > > integration, it fets detected as a TPM2.0 chip :/
> > >
> > > sudo rmmod tpm_tis
> > > # modprobe tpm_tis force=1
> > > modprobe: ERROR: could not insert 'tpm_tis': No such device
> > > # dmesg
> > > [ 263.903828] tpm_tis tpm_tis: 2.0 TPM (device-id 0xB, rev-id 16)
> > > [ 263.948049] tpm_tis tpm_tis: A TPM error (10) occurred continue selftest
> > > [ 263.948120] tpm_tis tpm_tis: TPM self test failed
> > >
> > >
> > > sts3 is reported as 0xff from my TPM1.2
> >
> > Hmm,
> > my TPM2.0 chip also reports sts3 as 0xff (when loading with force=1 on a
> > machine without bios integration)
> >
> > [ 307.095344] sts3 ff
> > [ 307.095366] tpm_tis tpm_tis: 2.0 TPM (device-id 0x1A, rev-id 16)
> > [ 307.140047] tpm_tis tpm_tis: A TPM error (256) occurred continue selftest
> > [ 307.140056] tpm_tis tpm_tis: TPM self test failed
>
> You are reading "sts3" - before requesting the locality and thus it returns 0xff for a TPM20 chip as well.
> --> You have to have an active locality first.
>
>
> For a TPM2.0 0xFF is not a valid value (if active locality is set), since reading commandCancel and resetEstablishment bit always return 0 on reads (according to spec).
>
> --> 0xFF should be treated as a TPM1.2 (older tpms with TIS 1.2)
> --> 0x04 should be treated as TPM 2.0
> --> 0x08 should be treated as TPM1.2 (newer tpms with TIS1.3 enhanced)

> + sts3 = ioread8(chip->vendor.iobase + TPM_STS3(1));
> + if ((sts3 & TPM_STS3_TPM2_FAM) == TPM_STS3_TPM2_FAM)
> + chip->flags = TPM_CHIP_FLAG_TPM2;

#define TPM_STS3_TPM2_FAM_MASK = 0x0c

then:

if ((sts3 & TPM_STS3_TPM2_FAM_MASK) == TPM_STS3_TPM2_FAM) ...

[see my previous review on this]

   Stefan






> Thanks,
> Peter
>
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