[PATCH 1/2] of: Fix DMA mask generation

On Fri, Aug 11, 2017 at 05:29:56PM +0100, Robin Murphy wrote:

Historically, DMA masks have suffered some ambiguity between whether
they represent the range of physical memory a device can access, or the
address bits a device is capable of driving, particularly since on many
platforms the two are equivalent. Whilst there are some stragglers left
(dma_max_pfn(), I'm looking at you...), the majority of DMA code has
been cleaned up to follow the latter definition, not least since it is
the only one which makes sense once IOMMUs are involved.

I think it always was supposed to be the latter, but that doesn't mean
that everyone got the message :)

Either of these patches alone should be sufficient to un-break RPi3,
and they apply independently, so I'm quite happy for one to go in as a
fix now and the other to wait for 4.14.

This one is something I'm comfortable feeding to Linus for 4.13
if I get a few ACKs from people familar with the OF code and intended
meaning of the ranges in the device tree.