On Mon, Feb 06, 2023 at 01:57:05PM -0800, Dan Williams wrote:
> Gregory Price wrote:
> > On Sun, Feb 05, 2023 at 05:02:56PM -0800, Dan Williams wrote:
> > > Expand the region creation infrastructure to enable 'ram'
> > > (volatile-memory) regions. The internals of create_pmem_region_store()
> > > and create_pmem_region_show() are factored out into helpers
> > > __create_region() and __create_region_show() for the 'ram' case to
> > > reuse.
> > >
> > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> > > ---
> > >
> [..]
> > > @@ -305,6 +306,13 @@ static bool can_create_pmem(struct cxl_root_decoder *cxlrd)
> > > return (cxlrd->cxlsd.cxld.flags & flags) == flags;
> > > }
> > >
> > > +static bool can_create_ram(struct cxl_root_decoder *cxlrd)
> > > +{
> > > + unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_RAM;
> > > +
> > > + return (cxlrd->cxlsd.cxld.flags & flags) == flags;
> > > +}
> > > +
> >
> > does this collide with either CXL_DECODE_F_ENABLE or CXL_DECODER_F_AUTO?
> >
> > I think obviously if it's already enabled creating new regions in a
> > decoder doesn't make sense, but if F_AUTO is set, does that imply
> > the region settings cannot be changed?
>
> That just cares if the root decoder supports TYPE3 and RAM independent
> of ENABLE or AUTO. Root decoders are always enabled. The AUTO flag,
> which is not applicable to root decoders, is just there to hold off
> userspace racing the attachment of endpoint decoders to a region until
> the autodiscovery process has completed. Once that completes and the
> region has been enabled then it can be destroyed to clear AUTO.
Reviewed-by: Gregory Price <gregory.price@xxxxxxxxxxxx>
