Re: [cocci] [PATCH v3 3/6] arm64: tlb: Convert the opencoded field modify

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Thu, Apr 17, 2025 at 06:47:10PM +0800, Luo Jie wrote:
> Replaced below code with the wrapper FIELD_MODIFY(MASK, &reg, val)
> - reg &= ~MASK;
> - reg |= FIELD_PREP(MASK, val);
> The semantic patch that makes this change is available
> in scripts/coccinelle/misc/field_modify.cocci.
> 
> More information about semantic patching is available at
> https://coccinelle.gitlabpages.inria.fr/website
> 
> Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
> ---
>  arch/arm64/include/asm/tlbflush.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index eba1a98657f1..0d250ef4161c 100644
> --- a/arch/arm64/include/asm/tlbflush.h
> +++ b/arch/arm64/include/asm/tlbflush.h
> @@ -112,8 +112,7 @@ static inline unsigned long get_trans_granule(void)
>  	    level >= 0 && level <= 3) {					\
>  		u64 ttl = level & 3;					\
>  		ttl |= get_trans_granule() << 2;			\
> -		arg &= ~TLBI_TTL_MASK;					\
> -		arg |= FIELD_PREP(TLBI_TTL_MASK, ttl);			\
> +		FIELD_MODIFY(TLBI_TTL_MASK, &arg, ttl);			\

This could equally be:
		arg = u64_replace_bits(arg, ttl, TLBI_TTL_MASK);

which already exists, so doesn't require a new macro to be introduced.

-- 
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