Re: [RFC PATCH 4/4] cxl/region: Introduce cxl_memdev_attach_region

[Lukas Wunner <lukas@wunner.de>]

On Sat, Apr 11, 2026 at 04:02:34PM -0700, Dan Williams wrote:
> Cheatham, Benjamin wrote:
> > On 4/3/2026 4:00 PM, Dan Williams wrote:
> > > To date, platform firmware maps accelerator memory and accelerator drivers
> > > simply want an address range that they can map themselves. This typically
> > > results in a single region being auto-assembled upon registration of a
> > > memory device.  Use the @attach mechanism of devm_cxl_add_memdev()
> > > parameter to retrieve that region while also adhering to CXL subsystem
> > > locking and lifetime rules. As part of adhering to current object lifetime
> > > rules, if the region or the CXL port topology is invalidated, the CXL core
> > > arranges for the accelertor driver to be detached as well.

Nit: s/accelertor/accelerator/ and wrap to 72 chars

> I think that is possible, and also is not really a CXL specific feature. A
> capability to move resources in active use by drivers has been proposed before
> [1] (credit: Lukas).

There's no link provided for [1] in your e-mail but you may be referring to:

https://lore.kernel.org/all/20201218174011.340514-1-s.miroshnichenko@yadro.com/

Thanks,

Lukas