[PATCH RFC 2/2] arm64: atomics: add optimization support for implementations using near atomics

[Will Deacon]

On Fri, Sep 19, 2025 at 05:17:47PM +0800, Yicong Yang wrote:
> From: Yicong Yang <yangyicong at hisilicon.com>
> 
> Atomic operations can be implemented in the CPU (near atomics) or
> in the interconnect or at the Subordinate holding the data (far
> atomics) [1]. The former one can be further optimized by prefetching
> the destination prior to the atomic operations, similar to the
> optimization for LL/SC operations mentioned in
> commit 0ea366f5e1b6 ("arm64: atomics: prefetch the destination word for write prior to stxr")

Sorry, but I'm strongly against this. The CPU needs to do better if
the system is configured for near atomics.

Will