Re: [PATCH] lib/crc: arm64: Drop check for CONFIG_KERNEL_MODE_NEON

From: Ard Biesheuvel

Date: Tue Mar 17 2026 - 07:10:49 EST




On Sat, 14 Mar 2026, at 18:57, Eric Biggers wrote:
> CONFIG_KERNEL_MODE_NEON is always enabled on arm64, and it always has
> been since its introduction in 2013. Given that and the fact that the
> usefulness of kernel-mode NEON has only been increasing over time,
> checking for this option in arm64-specific code is unnecessary. Remove
> this check from lib/crc/ to simplify the code and prevent any future
> bugs where e.g. code gets disabled due to a typo in this logic.
>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
>
> This patch is targeting crc-next
> (https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=crc-next)
>
> lib/crc/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>

> diff --git a/lib/crc/Kconfig b/lib/crc/Kconfig
> index cca228879bb5a..52e216f397468 100644
> --- a/lib/crc/Kconfig
> +++ b/lib/crc/Kconfig
> @@ -46,11 +46,11 @@ config CRC_T10DIF
>
> config CRC_T10DIF_ARCH
> bool
> depends on CRC_T10DIF && CRC_OPTIMIZATIONS
> default y if ARM && KERNEL_MODE_NEON
> - default y if ARM64 && KERNEL_MODE_NEON
> + default y if ARM64
> default y if PPC64 && ALTIVEC
> default y if RISCV && RISCV_ISA_ZBC
> default y if X86
>
> config CRC32
>
> base-commit: c13cee2fc7f137dd25ed50c63eddcc578624f204
> --
> 2.53.0