Re: [PATCH v5 04/16] x86/smpboot: smp init nodelay and no flush caches before sleep

[Borislav Petkov]

On Wed, Aug 29, 2018 at 08:43:41PM +0800, Pu Wen wrote:
> Dhyana use no delay in smp_quirk_init_udelay(), and return in
> mwait_play_dead() as AMD does.
> 
> Signed-off-by: Pu Wen <puwen@xxxxxxxx>
> ---
>  arch/x86/kernel/smpboot.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
> index f02ecaf..5369d7f 100644
> --- a/arch/x86/kernel/smpboot.c
> +++ b/arch/x86/kernel/smpboot.c
> @@ -676,6 +676,7 @@ static void __init smp_quirk_init_udelay(void)
>  
>  	/* if modern processor, use no delay */
>  	if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
> +	    ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) && (boot_cpu_data.x86 >= 0x18)) ||
>  	    ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) {
>  		init_udelay = 0;
>  		return;
> @@ -1592,7 +1593,8 @@ static inline void mwait_play_dead(void)
>  	void *mwait_ptr;
>  	int i;
>  
> -	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
> +	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
> +	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
>  		return;
>  	if (!this_cpu_has(X86_FEATURE_MWAIT))
>  		return;
> -- 

Reviewed-by: Borislav Petkov <bp@xxxxxxx>

-- 
Regards/Gruss,
    Boris.

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