[PATCH v2 3/3] ARM: pxa/pj4: Port problematic pj4 support code to v7/Thumb-2

Dave Martin dave.martin at linaro.org
Thu Sep 8 13:23:46 EDT 2011


On Thu, Sep 08, 2011 at 06:44:21PM +0200, Arnd Bergmann wrote:
> On Thursday 08 September 2011, Dave Martin wrote:
> >         __asm__ __volatile__ (
> >                 "mcr    p15, 0, %1, c1, c0, 2\n\t"
> > +#ifdef __LINUX_ARM_ARCH__ >= 7
> > +               "isb\n\t"
> > +#else
> >                 "mrc    p15, 0, %0, c1, c0, 2\n\t"
> >                 "mov    %0, %0\n\t"
> >                 "sub    pc, pc, #4\n\t"
> > +#endif
> >                 : "=r" (temp) : "r" (value));
> >  }
> 
> I thought we had concluded that we don't actually need the #else
> path because there is no pre-v7 support for pj4 any more.
> 

Ah, OK -- I somewhat missed the point, the was focusing on the other
patches (I notice I didn't fix #ifdef to #if either...)

Anyway, this patch can be drastically simplified -- i.e.,
the #if conditional should just go away, along with the
xscale-style code (which really doesn't make sense for a v7-only
file).

So we'd end up with something like:

        __asm__ __volatile__ (
                "mcr    p15, 0, %0, c1, c0, 2\n\t"
                "isb"
                : "r" (value));

Better?

Cheers
---Dave



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