Re: [PATCH] cxl: set root decoder granularity based on region params

[Dan Williams <dan.j.williams@intel.com>]

Jim Harris wrote:
[..]
> > If a BIOS tries to ship such a config in production that's when I expect
> > that policy needs to be revisited, but outside of being forced to
> > reconsider that stance the complexity reduction is the benefit.
> > 
> > In the meantime maybe add an "effective granularity" concept for x1 root
> > decoders and x1 switches so the math can use that value?
> 
> Ack. Use “effective_granularity” (EG) for the topology math and
> “interleave_granularity” (IG) for programming the decoders.
> 
> For the x1 switches, is your intent here to set IG = 256 since the IG is
> really a don’t care from the decoder’s perspective? Or is there another
> reason we would need to track different IG v. EG for x1 switches?

Hmm, I see what you are saying. If the value is a don't care, might as well
just update interleave_granularity to make the math friendly. So "effective
granularity" is probably just a documentation update to the 'struct
cxl_decoder' kdoc so people are not surprised about why this may differ
from CFMWS value.