Re: [PATCH v3 5/8] arm64/fpsimd: Drop special handling for EFI runtime services

From: Mark Brown

Date: Thu Sep 18 2025 - 09:10:32 EST


On Thu, Sep 18, 2025 at 12:30:16PM +0200, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@xxxxxxxxxx>

> Now that the use of kernel mode FP/SIMD is generally permitted when IRQs
> are disabled, the only purpose served by the EFI-specific fallback code
> in fpsimd.c is the case where an EFI call occurs from hardirq or NMI
> context. No such cases are known to occur in practice, and it is
> doubtful whether calling into the EFI firmware for any reason under such
> conditions would be a good idea to begin with.
>
> So disallow EFI runtime services in such cases. This means all the
> fallback code can be dropped.

This is a really nice simplification, with the fixup rolled in:

Reviewed-by: Mark Brown <broonie@xxxxxxxxxx>

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