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>> >> I think you forgot to derive the value from the relevant sources, i.e. physical >> bus, DMA controller and MMU capabilities. >> >> I assume not all GPU architectures / generations have the exact same capabilities? > > Right. Long term we need a HAL for this, and I believe John was going to look > at that. In the short term everything we care about supports the same 47-bit Yes. This will arrive with the Hopper/Blackwell support patchset. > address width. And when I say "everything" I mean Turing and Ampere, although > I'm pretty sure 47-bits goes back to at least Pascal. > > Newer GPU architectures (Hopper+) support greater widths (52-bits), but there's > no real impact to constraining these for now until a proper HAL is in place. Yes. The "soul" of these various patchsets so far is, "get GSP responsive for Ampere/Ada". To that end, it's OK to temporarily act as if the only thing that matters in this driver is Ampere/Ada. :) > > And that sounds like an excellent addition that I should make to the commit > logs and/or the comment on the constant definition, which fell off my radar when > reworking the rest of this series but will fix for v4. thanks, -- John Hubbard