Re: [PATCH 6/9] asm-generic/bitops/atomic.h: Rewrite using atomic_fetch_*

[Peter Zijlstra]

On Thu, May 24, 2018 at 11:59:43AM +0100, Will Deacon wrote:
> +static inline void set_bit(unsigned int nr, volatile unsigned long *p)
>  {
> +	p += BIT_WORD(nr);
> +	atomic_long_fetch_or_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
>  }
>  
> +static inline void clear_bit(unsigned int nr, volatile unsigned long *p)
>  {
> +	p += BIT_WORD(nr);
> +	atomic_long_fetch_andnot_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
>  }
>  
> +static inline void change_bit(unsigned int nr, volatile unsigned long *p)
>  {
> +	p += BIT_WORD(nr);
> +	atomic_long_fetch_xor_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
>  }

Why use the fetch variants here?