Re: [PATCH 02/15] mm, dax: introduce pfn_t_special()

[Michael Ellerman]

Dan Williams <dan.j.williams@xxxxxxxxx> writes:

> In support of removing the VM_MIXEDMAP indication from DAX VMAs,
> introduce pfn_t_special() for drivers to indicate that _PAGE_SPECIAL
> should be used for DAX ptes. This also helps identify drivers like
> dccssblk that only want to use DAX in a read-only fashion without
> get_user_pages() support.
>
> Ideally we could delete axonram and dcssblk DAX support, but if we need
> to keep it better make it explicit that axonram and dcssblk only support
> a sub-set of DAX due to missing _PAGE_DEVMAP support.

I sent a patch to remove axonram (sorry meant to Cc you):

  http://patchwork.ozlabs.org/patch/833588/

Will see if there's any feedback.

cheers