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

[Gregory Price <gourry@gourry.net>]

On Mon, Jan 12, 2026 at 12:59:44PM -0800, dan.j.williams@intel.com wrote:
> Gregory Price wrote:
> > --- a/drivers/cxl/core/core.h
> > +++ b/drivers/cxl/core/core.h
> > @@ -42,6 +42,8 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port);
> >  struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa);
> >  u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
> >  		   u64 dpa);
> > +int cxl_enable_memctrl(struct cxl_region *cxlr);
> 
> 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/
> 

Ack.

> ...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/

Mostly I imagine we'll end up with at least 5-6 of these, and the
directory makes it clear for any new comers "This is what you must do if
you want a new region".

but if folks would rather have it directly in core/ then `git mv...` 

either way, ack.

~Gregory