[PATCH v2 11/13] arm64: Add MIDR-based overrides for ID_AA64MMFR4_EL1.E2H0

[Suzuki K Poulose]

On 20/11/2023 12:37, Marc Zyngier wrote:
> None the Apple M1/M2 CPUs effectively implement E2H=0, and M2
> doesn't correctly implement NV1=1 (the EL2 S1 PTW seems to barf
> on the nVHE format).
> 
> Override ID_AA64MMFR4_EL1.E2H0 for these CPUs to reflect what they
> actually support.
> 
> Signed-off-by: Marc Zyngier <maz at kernel.org>

Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>


> ---
>   arch/arm64/kernel/idreg-override.c | 36 ++++++++++++++++++++++++++++++
>   1 file changed, 36 insertions(+)
> 
> diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
> index 57c145bf50b7..f7be459e5ff3 100644
> --- a/arch/arm64/kernel/idreg-override.c
> +++ b/arch/arm64/kernel/idreg-override.c
> @@ -326,7 +326,43 @@ struct midr_override_data {
>   	const struct midr_range	ranges[];
>   };
>   
> +static const struct midr_override_data e2h0_ni __initconst = {
> +	/*
> +	 * These CPUs predate FEAT_E2H0, but have HCR_EL2.E2H RES1
> +	 * anyway.
> +	 */
> +	.feature	= "id_aa64mmfr4.e2h0=0xf",
> +	.ranges	= {
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX),
> +		{}
> +	},
> +};
> +
> +static const struct midr_override_data e2h0_nv1_ni __initconst = {
> +	/*
> +	 * These CPUs predate FEAT_E2H0, but have both HCR_EL2.E2H
> +	 * RES1 and a non-functional HCR_EL2.NV1.
> +	 */
> +	.feature	= "id_aa64mmfr4.e2h0=0xe",
> +	.ranges	= {
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX),
> +		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX),
> +		{}
> +	},
> +};
> +
>   static const struct midr_override_data * const midr_ovr_data[] __initconst = {
> +	&e2h0_ni,
> +	&e2h0_nv1_ni,
>   };
>   
>   static void __init apply_midr_overrides(void)