[RFC PATCH 2/3] ARM: iwmmxt: Port problematic iwmmxt support code to v7/Thumb-2
Arnd Bergmann
arnd at arndb.de
Wed Sep 7 16:35:46 EDT 2011
On Wednesday 07 September 2011 09:13:38 Eric Miao wrote:
> >
> > +/*
> > + * When enough people have binutils which support -march=...+iwmmxt, this
> > + * should change to #if __LINUX_ARM_ARCH__ < 7.
> > + */
> > +#ifndef CONFIG_THUMB2_KERNEL
> > mrc p15, 0, r1, c2, c0, 0
> > sub pc, lr, r1, lsr #32 @ cpwait and return
> > +#else
> > + isb @ ISB needed instead on ARMv7
> > + mov pc, lr
> > +#endif
>
> Or maybe using ARM() and THUMB() will be a better fit here?
I think it would be logical to use XSC() and PJ4() instead, as those are used
elsehere in this file. However, that doesn't work with the only binutils.
If the !THUMB code above is actually correct for v7 in ARM mode (i.e. it performs
the equivalent of an ISB), then I think we should leave it.
It does look like it's whitespace broken though.
Arnd
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