Re: [PATCH] arm64: entry: Save some nops when CONFIG_ARM64_PSEUDO_NMI is not set

[He Ying]

Hi all,

Ping. Any comments?

在 2022/1/12 11:24, He Ying 写道:
> Arm64 pseudo-NMI feature code brings some additional nops
> when CONFIG_ARM64_PSEUDO_NMI is not set, which is not
> necessary. So add necessary ifdeffery to avoid it.
>
> Signed-off-by: He Ying <heying24@xxxxxxxxxx>
> ---
>   arch/arm64/kernel/entry.S | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 2f69ae43941d..ffc32d3d909a 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -300,6 +300,7 @@ alternative_else_nop_endif
>   	str	w21, [sp, #S_SYSCALLNO]
>   	.endif
>   
> +#ifdef CONFIG_ARM64_PSEUDO_NMI
>   	/* Save pmr */
>   alternative_if ARM64_HAS_IRQ_PRIO_MASKING
>   	mrs_s	x20, SYS_ICC_PMR_EL1
> @@ -307,6 +308,7 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING
>   	mov	x20, #GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET
>   	msr_s	SYS_ICC_PMR_EL1, x20
>   alternative_else_nop_endif
> +#endif
>   
>   	/* Re-enable tag checking (TCO set on exception entry) */
>   #ifdef CONFIG_ARM64_MTE
> @@ -330,6 +332,7 @@ alternative_else_nop_endif
>   	disable_daif
>   	.endif
>   
> +#ifdef CONFIG_ARM64_PSEUDO_NMI
>   	/* Restore pmr */
>   alternative_if ARM64_HAS_IRQ_PRIO_MASKING
>   	ldr	x20, [sp, #S_PMR_SAVE]
> @@ -339,6 +342,7 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING
>   	dsb	sy				// Ensure priority change is seen by redistributor
>   .L__skip_pmr_sync\@:
>   alternative_else_nop_endif
> +#endif
>   
>   	ldp	x21, x22, [sp, #S_PC]		// load ELR, SPSR
>