On Tue, Oct 27, 2015 at 03:20:10PM -0700, Nishanth Aravamudan wrote:

On 26.10.2015 [18:27:46 -0700], David Miller wrote:

quoted

From: Nishanth Aravamudan <redacted>
Date: Fri, 23 Oct 2015 13:54:20 -0700

quoted

1) add a generic dma_get_page_shift implementation that just returns
PAGE_SHIFT

I won't object to this patch series, but if I had implemented this I
would have required the architectures to implement this explicitly,
one-by-one.  I think it is less error prone and more likely to end
up with all the architectures setting this correctly.

Well, looks like I should spin up a v4 anyways for the powerpc changes.
So, to make sure I understand your point, should I make the generic
dma_get_page_shift a compile-error kind of thing? It will only fail on
architectures that actually build the NVME driver (as the only caller).
But I'm not sure how exactly to achieve that, if you could give a bit
more detail I'd appreciate it!

If you're suggesting to compile-time break architectures that currently
work just fine with NVMe, let me stop you right there.