linux-kernel - Re: [PATCH] arm64: Remove system_uses_lse

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Message-ID: <ZS5jgCNm8jV9E8Ao@FVFF77S0Q05N>
Date:   Tue, 17 Oct 2023 11:35:44 +0100
From:   Mark Rutland <mark.rutland@....com>
To:     Gavin Shan <gshan@...hat.com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        catalin.marinas@....com, will@...nel.org, suzuki.poulose@....com,
        anshuman.khandual@....com, shan.gavin@...il.com
Subject: Re: [PATCH] arm64: Remove system_uses_lse_atomics()

On Tue, Oct 17, 2023 at 10:50:36AM +1000, Gavin Shan wrote:
> There are two variants of system_uses_lse_atomics(), depending on
> CONFIG_ARM64_LSE_ATOMICS. The function isn't called anywhere when
> CONFIG_ARM64_LSE_ATOMICS is disabled. It can be directly replaced
> by alternative_has_cap_likely(ARM64_HAS_LSE_ATOMICS) when the kernel
> option is enabled.
> 
> No need to keep system_uses_lse_atomics() and just remove it.
> 
> Signed-off-by: Gavin Shan <gshan@...hat.com>

I had meant to remove this already, so:

Acked-by: Mark Rutland <mark.rutland@....com>

Mark.

> ---
>  arch/arm64/include/asm/lse.h | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
> index cbbcdc35c4cd..3129a5819d0e 100644
> --- a/arch/arm64/include/asm/lse.h
> +++ b/arch/arm64/include/asm/lse.h
> @@ -16,14 +16,9 @@
>  #include <asm/atomic_lse.h>
>  #include <asm/cpucaps.h>
>  
> -static __always_inline bool system_uses_lse_atomics(void)
> -{
> -	return alternative_has_cap_likely(ARM64_HAS_LSE_ATOMICS);
> -}
> -
>  #define __lse_ll_sc_body(op, ...)					\
>  ({									\
> -	system_uses_lse_atomics() ?					\
> +	alternative_has_cap_likely(ARM64_HAS_LSE_ATOMICS) ?		\
>  		__lse_##op(__VA_ARGS__) :				\
>  		__ll_sc_##op(__VA_ARGS__);				\
>  })
> @@ -34,8 +29,6 @@ static __always_inline bool system_uses_lse_atomics(void)
>  
>  #else	/* CONFIG_ARM64_LSE_ATOMICS */
>  
> -static inline bool system_uses_lse_atomics(void) { return false; }
> -
>  #define __lse_ll_sc_body(op, ...)		__ll_sc_##op(__VA_ARGS__)
>  
>  #define ARM64_LSE_ATOMIC_INSN(llsc, lse)	llsc
> -- 
> 2.41.0
>