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

[Russell King - ARM Linux]

On Mon, Sep 12, 2011 at 03:37:08PM +0100, Dave Martin wrote:
> Agreed, but the trouble is that what constitutes a suitable data
> dependency is completely microarchitecture dependent -- we're relying
> on side-effects outside the architecture here.
> 
> We can't code _exactly_ the same thing in Thumb-2 because of restrictions
> in the instruction set, so we have to settle for something that "looks
> similar" -- but there's no guarantee it will work.
> 
> Do you feel your judgement on this is authoritative?  If so, then
> we can go ahead with your suggestion; otherwise we might need input
> from someone else.

How about we ask Haojian Zhuang what the recommended sequence is for
ensuring that writes hit CP15 when executing in Thumb-2 mode on PJ4,
instead of blindly beating around the issue without really knowing
what we're doing?