Re: [PATCH] arm64: Enable repeat tlbi workaround on KRYO4XX gold CPUs

[Sai Prakash Ranjan]

Hi Shreyas,

On 5/11/2022 1:32 PM, Shreyas K K wrote:
> Add KRYO4XX gold/big cores to the list of CPUs that need the
> repeat TLBI workaround. Apply this to the affected
> KRYO4XX cores (rcpe to rdpe).
>
> The variant and revision bits are implementation defined and are
> different from the their Cortex CPU counterparts on which they are
> based on, i.e., (r0p0 to r1p0) is equivalent to (rcpe to rdpe).
>
> Signed-off-by: Shreyas K K <quic_shrekk@xxxxxxxxxxx>
> ---
>   Documentation/arm64/silicon-errata.rst | 3 +++
>   arch/arm64/kernel/cpu_errata.c         | 2 ++
>   2 files changed, 5 insertions(+)
>
> diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
> index 466cb9e89047..d27db84d585e 100644
> --- a/Documentation/arm64/silicon-errata.rst
> +++ b/Documentation/arm64/silicon-errata.rst
> @@ -189,6 +189,9 @@ stable kernels.
>   +----------------+-----------------+-----------------+-----------------------------+
>   | Qualcomm Tech. | Kryo4xx Silver  | N/A             | ARM64_ERRATUM_1024718       |
>   +----------------+-----------------+-----------------+-----------------------------+
> +| Qualcomm Tech. | Kryo4xx Gold    | N/A             | ARM64_ERRATUM_1286807       |
> ++----------------+-----------------+-----------------+-----------------------------+
> +
>   +----------------+-----------------+-----------------+-----------------------------+
>   | Fujitsu        | A64FX           | E#010001        | FUJITSU_ERRATUM_010001      |
>   +----------------+-----------------+-----------------+-----------------------------+
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index 4c9b5b4b7a0b..2518657e6de1 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -208,6 +208,8 @@ static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] = {
>   #ifdef CONFIG_ARM64_ERRATUM_1286807
>   	{
>   		ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 3, 0),
> +		/* Kryo4xx Gold (rcpe to rdpe) => (r0p0 to r1p0) */
> +		ERRATA_MIDR_RANGE(QCOM_CPU_PART_KRYO_4XX_GOLD, 0xc, 0xe, 0xd, 0xe),
>   	},
>   #endif
>   	{},

Why not include r2p0 and r3p0 which are affected by this erratum? I see these revisions are present
in our SoCs as per the document.

Thanks,
Sai