Re: [PATCH 1/6] drivers/cxl: add cxl_memctrl_mode and region->memctrl

[Gregory Price <gourry@gourry.net>]

On Tue, Jan 13, 2026 at 11:00:42AM -0700, Dave Jiang wrote:
> 
> > 
> > This is a "probe" operation not an "enable" in terms of runtime ABI and
> > presentation that starts decorating the region. In that respect it also
> > is not a "control" as much as an "operation model / driver". So no need
> > for a "control" concept, i.e.:
> > 
> > s/CXL_CONTROL_{NONE,AUTO,DAX}/CXL_DRIVER_{NONE,AUTO,DAX}/
> > s/enum cxl_memctrl_mode/enum cxl_region_driver/
> > 
> > ...otherwise there is nothing in this proposal that makes me want to
> > abandon the traditional meaning of a "driver" probing a "resource" in a
> > certain way to make it usable with the rest of the kernel.
> > 
> > Rest of this looks fine. With that fixup if we are going to have a set
> > of different region driver modes then the directory can be:
> > 
> > drivers/cxl/core/region/
> 
> Do we still have reasons to keep the region drivers in core? I know Fabio has been looking at moving the region drivers to drivers/cxl/ so the LMH cxl_test stuff doesn't doesn't need to do all the weird stuff to make it work. Maybe we just do the refactor now and move the region drivers outside of core. How about drivers/cxl/region/?
> 

I pulled them out into drivers/cxl/core for now, but this is a trivial
move.  I think it may still use some core.h functions, so it would be
more work to pull them all the way out into cxl.

will submit a v2 here shortly with just the refactor work w/ the new
sysfs entry (but no sysram driver, going to defer that to a separate
line on top of this).

~Gregory