On Fri, 26 Mar 2021 at 16:25, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: > > On Fri, Mar 26, 2021 at 10:35:23AM +0530, Sumit Garg wrote: > > Hi Sudeep, > > > > Apologies for catching up late on this patch-set. > > > > On Thu, 25 Mar 2021 at 20:05, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: > > > > > > Since the FF-A v1.0 specification doesn't list the UUID of all the > > > partitions in the discovery API, we need to specify the UUID of the > > > partitions that need to be accessed by drivers within the kernel. > > > > > > > Wouldn't we be able to implement auto-discovery of ffa partitions? I > > think enumeration of ffa partitions on FFA bus should be quite similar > > to enumeration of TAs on TEE bus (see [1]). Otherwise we need to put > > these redundant DT entries for every ffa partition which IMHO would > > bloat up device trees for every platform. > > > > Any suggestions on how to ? Clearly spec doesn't have that provision, I > had raised this point in the past. Jens has similar concern and he did > ask the same[1]. As I replied to him in that thread[2]. > > I am open to suggestion on how to auto-discover, currently as I see spec > doesn't support it. > Thanks for sharing links to prior discussions and I can see that currently spec doesn't support it. But from an implementation perspective, I can't find any reason that we can't support auto-discover. Have a look at below proposed simple FFA ABI: FFA_LIST_PARTITIONS - No input params. - Returns an array of secure partition UUIDs to which this non-secure virtual/physical FF-A instance is allowed to communicate with. I think with auto-discovery, one of the major benefits is that if the OEM is using a common platform to cater to multiple use-cases which rely on different secure partitions then OEM doesn't have to bother about shipping separate DTs. -Sumit > -- > Regards, > Sudeep > > [1] https://lore.kernel.org/linux-arm-kernel/20201216134659.GA4146223@jade/ > [2] https://lore.kernel.org/linux-arm-kernel/20210113092236.pnabzaufzuzwprmw@bogus/
