[PATCH 4/4] ARM: hwcap: disable HWCAP_SWP if the CPU advertises it has exclusives

[Arnd Bergmann]

On Friday 04 July 2014 21:51:44 Russell King - ARM Linux wrote:
> Hmm, we need guidance from ARM people on that.
> 
> There may well be a better way to detect between ARMv6 and ARMv6K, which
> is given by the architecture spec.  G7.3 of an early DDI0406 says that
> the MPIDR (mp affinity register) aliases to MIDR for ARMv6, but is of
> course implemented for ARMv6K.
> 
> This seems to be carried through to the latest ARM ARM.  So it seems
> this would be a more correct way to tell ARMv6 from ARMv6K.
> 
> If so, we can certainly expand cpu_architecture() to detect between the
> two and add a CPU_ARCH_ARMv6K in there.
> 
> Let's see what Will has to say about that when he's next around...
> though I think it'll require another trawl through lots of
> documentation.

I was thinking of a simpler check in __get_cpu_architecture, just
checking if the CPUID is ARM1136r0 since that is the only ARMv6
CPU core we support. Anything else that we currently report as
ARMv6 is actually ARMv6K.

	Arnd