Re: [PATCH] arm64: errata: match the target implementation CPU's own MIDR

[Will Deacon]

On Sun, 06 Sep 2026 13:14:16 +0100, David Carlier wrote:
> __is_affected_midr_range() is handed the MIDR and REVIDR of one target
> implementation CPU, but tests the erratum's range with is_midr_in_range(),
> which re-scans all of target_impl_cpus[] and ignores the @midr argument.
> The range test is thus constant across the per-CPU loop in
> is_affected_midr_range() and only answers "is any target CPU in range".
> 
> Since just the fixed_revs REVIDR check uses the iteration's own registers,
> an out-of-range target CPU can decide whether a MIDR_FIXED() exemption
> applies. A VM then enables a workaround whose only in-range CPU is fixed
> silicon, e.g. erratum 2658417 on a Cortex-A510 r1p1 with REVIDR_EL1[25]
> set.
> 
> [...]

Applied to arm64 (for-next/fixes), thanks!

[1/1] arm64: errata: match the target implementation CPU's own MIDR
      https://git.kernel.org/arm64/c/b7403afb7a5f

Cheers,
-- 
Will

https://fixes.arm64.dev
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