On Wed, Apr 10, 2019 at 11:19 AM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > On Tue, Apr 09, 2019 at 04:18:29PM -0500, Rob Herring wrote: > >On Tue, Apr 9, 2019 at 1:50 PM Sasha Levin <sashal@xxxxxxxxxx> wrote: > >> > >> The parameters are similar to the ones used by IBM's vTPM and the > >> various I2C tpm drivers. > > > >Bindings describe h/w (or firmware interfaces in this case), not drivers. > > > >> > >> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > >> --- > >> .../bindings/security/tpm/tpm_ftpm_tee.txt | 13 +++++++++++++ > >> .../devicetree/bindings/vendor-prefixes.txt | 1 + > >> 2 files changed, 14 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt > >> > >> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt > >> new file mode 100644 > >> index 000000000000..20fca67a56c4 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt > >> @@ -0,0 +1,13 @@ > >> +Required properties: > >> +- compatible: should be "microsoft,ftpm" > >> +- linux,sml-base: 64-bit base address of the reserved memory allocated > >> + for the firmware event log > >> +- linux,sml-size: size of the memory allocated for the firmware event log > > > >Firmware is defining linux specific properties? What if I want to run > >BSD? We should use 'reg' here instead. > > This is based on already existing code that defines these names, see > tpm_read_log_of() in drivers/char/tpm/eventlog/of.c . BTW, that probably needs updating to handle endianness correctly. > These properties were described similarily by other interfaces (see > Documentation/devicetree/bindings/security/tpm/ibmvtpm.txt or > Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt for example). > > We could rename them all if you'd like, I was just trying to follow the > existing code. > > >What memory is used here? This should be under /reserved-memory if it > >is part of "main" memory. > > That's my understanding, yes. > > >Really, I'd prefer to not see this in DT at all. Make the firmware > >discoverable. Why repeat the mistakes of non-discoverable h/w in s/w > >interfaces? OP-Tee at least has defined a mechanism to enumerate TEE > >functions IIRC. > > Sadly the firmware already exists as-is on live hardware, there is a > paper describing it back from 2016 and we're stuck having to support > that. Does the firmware depend on this binding or the DT just gets statically populated with the address/size the firmware hardcodes? I'd prefer not to propagate the IBM binding that we were kind of stuck with. I had similar comments on it... Are there other parts of the TEE firmware that need to be described in DT? Rob
