[PATCH 0/3] arm64: Support FEAT_LSFE (Large System Float Extension)
Ben Horgan
ben.horgan at arm.com
Mon Jun 30 03:21:14 PDT 2025
Hi Mark,
On 6/27/25 18:20, Mark Brown wrote:
> FEAT_LSFE is optional from v9.5, it adds new instructions for atomic
> memory operations with floating point values. We have no immediate use
> for it in kernel, provide a hwcap so userspace can discover it and allow
> the ID register field to be exposed to KVM guests.
>
> Signed-off-by: Mark Brown <broonie at kernel.org>
> ---
> Mark Brown (3):
> arm64/hwcap: Add hwcap for FEAT_LSFE
> KVM: arm64: Expose FEAT_LSFE to guests
> kselftest/arm64: Add lsfe to the hwcaps test
>
> Documentation/arch/arm64/elf_hwcaps.rst | 4 ++++
> arch/arm64/include/asm/hwcap.h | 1 +
> arch/arm64/include/uapi/asm/hwcap.h | 1 +
> arch/arm64/kernel/cpufeature.c | 2 ++
> arch/arm64/kernel/cpuinfo.c | 1 +
> arch/arm64/kvm/sys_regs.c | 4 +++-
> tools/testing/selftests/arm64/abi/hwcap.c | 21 +++++++++++++++++++++
> 7 files changed, 33 insertions(+), 1 deletion(-)
I have looked through the series and it looks good to me modulo a couple
of minor comments left on the patches. Bare in mind fairly new here and
this is the first use of hwcap3 so I expect more experienced review is
required.
Reviewed-by: Ben Horgan <ben.horgan at arm.com>
> ---
> base-commit: 86731a2a651e58953fc949573895f2fa6d456841
> change-id: 20250625-arm64-lsfe-0810cf98adc2
>
> Best regards,
> --
> Mark Brown <broonie at kernel.org>
>
>
Thanks,
Ben
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