[PATCH v2] arm64: errata: Workaround NVIDIA Olympus device store/load ordering erratum

[Jason Gunthorpe]

On Wed, Jun 10, 2026 at 08:20:28AM -0500, Shanker Donthineni wrote:

> Based on the existing code comments and after reviewing this path again,
> __const_memcpy_toio_aligned32() and __const_memcpy_toio_aligned64()
> appear to be intended for WC regions. Since the erratum is scoped to
> Device-nGnR* accesses, and WC mappings are Normal-NC on arm64, I don’t
> think the STLR workaround should apply to these helpers by default.

Hmm, unfortunately I think the APIs mix together IO and WC both as
__iomem things. However I recall when I was looking a this everyone
was using it for WC.

Jason