On 8/10/23 02:50, Wilco Dijkstra wrote:
Hi Richard,
Why would HWCAP_USCAT not be set by the kernel?
Failing that, I would think you would check ID_AA64MMFR2_EL1.AT.
Answering my own question, N1 does not officially have FEAT_LSE2.
It doesn't indeed. However most cores support atomic 128-bit load/store
(part of LSE2), so we can still use the LSE2 ifunc for those cores. Since there
isn't a feature bit for this in the CPU or HWCAP, I check the CPUID register.
That would be a really nice bit to add to HWCAP, then, to consolidate this knowledge in
one place. Certainly I would use it in QEMU as well.
r~
