ARM atomics overhaul for musl

[Szabolcs Nagy]

* Catalin Marinas <catalin.marinas at arm.com> [2014-11-17 13:54:13 +0000]:
> ARM11MPCore). ARM is trying to move away from architecture version
> numbers, which are rather useful for marketing, to proper feature
> detection based on CPUID. Whether there is an ARMv9 or not, it's
> irrelevant to what Linux should do (i.e. use CPUID rather than guess
> features based on architecture version numbers).
> 

how to use cpuid from userspace?

should linux export those bits into hwcap?

(i assume all relevant info will be available in /proc/cpuinfo but
that does not work for libc)