Re: [PATCH 3/9] bitmap: Use FIELD_PREP() in expansion of FIELD_PREP_WM16()

[Andy Shevchenko]

On Tue, Dec 09, 2025 at 10:03:07AM +0000, david.laight.linux@xxxxxxxxx wrote:

> Instead of directly expanding __BF_FIELD_CHECK() (which really ought
> not be used outside bitfield) and open-coding the generation of the
> masked value, just call FIELD_PREP() and add an extra check for
> the mask being at most 16 bits.

...

> +#define FIELD_PREP_WM16(mask, val)				\
> +({								\
> +	__auto_type _mask = mask;				\
> +	u32 _val = FIELD_PREP(_mask, val);			\

> +	BUILD_BUG_ON_MSG(_mask > 0xffffu,			\
> +			 "FIELD_PREP_WM16: mask too large");	\

Can it be static_assert() instead?

> +	_val | (_mask << 16);					\
> +})

-- 
With Best Regards,
Andy Shevchenko