Workarounds and optimizations for Neoverse-V3AE

[PATCH v1 0/3] Workarounds and optimizations for Neoverse-V3AE

Posted by Ryan Roberts 1 week, 5 days ago

Hi All,

I know it's late in the cycle, but I thought I'd try my luck at sneaking this
in.

Neoverse-V3AE has a different MIDR value to Neoverse-V3, but qualifies for the
same workarounds and optimizations ("SSBS not fully self-synchronizing" and
BBML2_NOABORT) so this just adds Neoverse-V3AE wherever Neoverse-V3 appears.
Details in the commits.

The last patch adds Neoverse-3VAE to the BBML2_NOABORT allow list. That will
conflict with the patch you have already queued to add AmpereOne, and with the
patch you said you would do to remove X4. But this is a one-liner so trivial to
resolve.

Applies on v6.17-rc5.

Thanks,
Ryan


Mark Rutland (2):
  arm64: cputype: Add Neoverse-V3AE definitions
  arm64: errata: Apply workarounds for Neoverse-V3AE

Ryan Roberts (1):
  arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list

 Documentation/arch/arm64/silicon-errata.rst | 2 ++
 arch/arm64/Kconfig                          | 1 +
 arch/arm64/include/asm/cputype.h            | 2 ++
 arch/arm64/kernel/cpu_errata.c              | 1 +
 arch/arm64/kernel/cpufeature.c              | 1 +
 5 files changed, 7 insertions(+)

--
2.43.0

Re: [PATCH v1 0/3] Workarounds and optimizations for Neoverse-V3AE

Posted by Will Deacon 1 week, 2 days ago

On Fri, 19 Sep 2025 15:58:27 +0100, Ryan Roberts wrote:
> I know it's late in the cycle, but I thought I'd try my luck at sneaking this
> in.
> 
> Neoverse-V3AE has a different MIDR value to Neoverse-V3, but qualifies for the
> same workarounds and optimizations ("SSBS not fully self-synchronizing" and
> BBML2_NOABORT) so this just adds Neoverse-V3AE wherever Neoverse-V3 appears.
> Details in the commits.
> 
> [...]

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

[1/3] arm64: cputype: Add Neoverse-V3AE definitions
      https://git.kernel.org/arm64/c/3bbf004c4808
[2/3] arm64: errata: Apply workarounds for Neoverse-V3AE
      https://git.kernel.org/arm64/c/0c33aa1804d1
[3/3] arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
      https://git.kernel.org/arm64/c/8fca3852e33d

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev

Re: [PATCH v1 0/3] Workarounds and optimizations for Neoverse-V3AE

Posted by Ryan Roberts 1 week, 2 days ago

On 22/09/2025 14:14, Will Deacon wrote:
> On Fri, 19 Sep 2025 15:58:27 +0100, Ryan Roberts wrote:
>> I know it's late in the cycle, but I thought I'd try my luck at sneaking this
>> in.
>>
>> Neoverse-V3AE has a different MIDR value to Neoverse-V3, but qualifies for the
>> same workarounds and optimizations ("SSBS not fully self-synchronizing" and
>> BBML2_NOABORT) so this just adds Neoverse-V3AE wherever Neoverse-V3 appears.
>> Details in the commits.
>>
>> [...]
> 
> Applied to arm64 (for-next/cpufeature), thanks!
> 
> [1/3] arm64: cputype: Add Neoverse-V3AE definitions
>       https://git.kernel.org/arm64/c/3bbf004c4808
> [2/3] arm64: errata: Apply workarounds for Neoverse-V3AE
>       https://git.kernel.org/arm64/c/0c33aa1804d1
> [3/3] arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
>       https://git.kernel.org/arm64/c/8fca3852e33d
> 
> Cheers,

Thank you!