[PATCH 1/7] arm: use generic fixmap.h

Nicolas Pitre nicolas.pitre at linaro.org
Thu Aug 7 08:32:07 PDT 2014

On Thu, 7 Aug 2014, Rob Herring wrote:

> On Thu, Aug 7, 2014 at 10:15 AM, Max Filippov <jcmvbkbc at gmail.com> wrote:
> > Hi,
> >
> > On Wed, Aug 6, 2014 at 11:32 PM, Kees Cook <keescook at chromium.org> wrote:
> >> ARM is different from other architectures in that fixmap pages are indexed
> >> with a positive offset from FIXADDR_START.  Other architectures index with
> >> a negative offset from FIXADDR_TOP.  In order to use the generic fixmap.h
> >
> > Does anybody know if there's any reason why generic fixmap.h uses negative
> > offsets? It complicates things with no obvious benefit if you e.g. try to align
> > virtual address in the fixmap region with physical page color (that's why I've
> > switched xtensa to positive fixmap addressing in v3.17).
> No, but each arch doing it differently is even more annoying.

Why not switching everybody to positive offsets then?


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