Re: [PATCH v4 3/5] arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list

[Trilok Soni]

On 1/7/2025 12:06 PM, Douglas Anderson wrote:
> Qualcomm has confirmed that, much like Cortex A53 and A55, KRYO
> 2XX/3XX/4XX silver cores are unaffected by Spectre BHB. Add them to
> the safe list.
> 
> 
> Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Scott Bauer <sbauer@xxxxxxxxxxx>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---
> 
> Changes in v4:
> - Re-added KRYO 2XX/3XX/4XX silver patch after Qualcomm confirmed.
> 
> Changes in v3:
> - Removed KRYO 2XX/3XX/4XX silver patch.
> 
> Changes in v2:
> - New
> 
>  arch/arm64/kernel/proton-pack.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
> index 17aa836fe46d..89405be53d8f 100644
> --- a/arch/arm64/kernel/proton-pack.c
> +++ b/arch/arm64/kernel/proton-pack.c
> @@ -854,6 +854,9 @@ static bool is_spectre_bhb_safe(int scope)
>  		MIDR_ALL_VERSIONS(MIDR_CORTEX_A510),
>  		MIDR_ALL_VERSIONS(MIDR_CORTEX_A520),
>  		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
>  		{},
>  	};
>  	static bool all_safe = true;

Acked-by: Trilok Soni <quic_tsoni@xxxxxxxxxxx>

-- 
---Trilok Soni