Re: [PATCH 1/2] arm64: Rename ARM64_WORKAROUND_2966298

[Mark Rutland]

On Wed, Jan 10, 2024 at 11:29:20AM -0600, Rob Herring wrote:
> In preparation to apply ARM64_WORKAROUND_2966298 for multiple errata,
> rename the kconfig and capability. No functional change.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>

This looks good to me.

I applied this atop v6.7 and checked that with and without
CONFIG_ARM64_ERRATUM_2966298 selected the Kconfig bits looked right and the
kernel built cleanly and booted. I don't have a Cortex-A520 to test on, but I
cannot see any reason this would have a functional change.

Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>

Mark.

> ---
>  arch/arm64/Kconfig             | 4 ++++
>  arch/arm64/kernel/cpu_errata.c | 4 ++--
>  arch/arm64/kernel/entry.S      | 2 +-
>  arch/arm64/tools/cpucaps       | 2 +-
>  4 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7b071a00425d..ba9f6ceddbbe 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1037,8 +1037,12 @@ config ARM64_ERRATUM_2645198
>  
>  	  If unsure, say Y.
>  
> +config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
> +	bool
> +
>  config ARM64_ERRATUM_2966298
>  	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
> +	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
>  	default y
>  	help
>  	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index e29e0fea63fb..cb5e0622168d 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -713,10 +713,10 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
>  		MIDR_FIXED(MIDR_CPU_VAR_REV(1,1), BIT(25)),
>  	},
>  #endif
> -#ifdef CONFIG_ARM64_ERRATUM_2966298
> +#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
>  	{
>  		.desc = "ARM erratum 2966298",
> -		.capability = ARM64_WORKAROUND_2966298,
> +		.capability = ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD,
>  		/* Cortex-A520 r0p0 - r0p1 */
>  		ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A520, 0, 0, 1),
>  	},
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index a6030913cd58..544ab46649f3 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -428,7 +428,7 @@ alternative_else_nop_endif
>  	ldp	x28, x29, [sp, #16 * 14]
>  
>  	.if	\el == 0
> -alternative_if ARM64_WORKAROUND_2966298
> +alternative_if ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
>  	tlbi	vale1, xzr
>  	dsb	nsh
>  alternative_else_nop_endif
> diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
> index b98c38288a9d..3781ad1d0b26 100644
> --- a/arch/arm64/tools/cpucaps
> +++ b/arch/arm64/tools/cpucaps
> @@ -84,7 +84,6 @@ WORKAROUND_2077057
>  WORKAROUND_2457168
>  WORKAROUND_2645198
>  WORKAROUND_2658417
> -WORKAROUND_2966298
>  WORKAROUND_AMPERE_AC03_CPU_38
>  WORKAROUND_TRBE_OVERWRITE_FILL_MODE
>  WORKAROUND_TSB_FLUSH_FAILURE
> @@ -100,3 +99,4 @@ WORKAROUND_NVIDIA_CARMEL_CNP
>  WORKAROUND_QCOM_FALKOR_E1003
>  WORKAROUND_REPEAT_TLBI
>  WORKAROUND_SPECULATIVE_AT
> +WORKAROUND_SPECULATIVE_UNPRIV_LOAD
> 
> -- 
> 2.43.0
> 
>