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

On Thu, Sep 18, 2025 at 12:30:16PM +0200, Ard Biesheuvel wrote:

From: Ard Biesheuvel <ardb@kernel.org>

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@kernel.org>