Re: [PATCH/RFC 0/6] Allow compile-testing NO_DMA

[Arnd Bergmann]

On Tue, Feb 6, 2018 at 2:05 PM, Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> It looks like we have only one real arch (score) without IOMEM, and two
> (s390 and tile) where it is possible to configure out, so it does seem like
> a reasonable feature to assume. Maybe we could have something like
> asm-generic/no-io.h to provide an "unimplemented" version of those
> interfaces.

Agreed, there is no use trying to optimize for any of those three cases:

For s390, all new machines come with PCI, so distros will enable it all
the time. Few users run their own kernels even on older machines.

score has been de-facto unmaintained for a few years, and tile has
recently been orphaned with the hardware platform being abandoned by
Mellanox.

      Arnd