Re: [PATCH v5 1/7] bits: split the definition of the asm and non-asm GENMASK()

[Lucas De Marchi]

On Thu, Mar 06, 2025 at 08:29:52PM +0900, Vincent Mailhol via B4 Relay wrote:
> From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
>
> In an upcoming change, GENMASK() and its friends will indirectly
> depend on sizeof() which is not available in asm.
>
> Instead of adding further complexity to __GENMASK() to make it work
> for both asm and non asm, just split the definition of the two
> variants.
>
> Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
> ---
> Changelog:
>
>  v4 -> v5:
>
>    - Use tab indentations instead of single space to separate the
>      macro name from its body.
>
>  v3 -> v4:
>
>    - New patch in the series
> ---
> include/linux/bits.h | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/bits.h b/include/linux/bits.h
> index 14fd0ca9a6cd17339dd2f69e449558312a8a001b..4819cbe7bd48fbae796fc6005c9f92b1c93a034c 100644
> --- a/include/linux/bits.h
> +++ b/include/linux/bits.h
> @@ -19,23 +19,17 @@
>  * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
>  */
> #if !defined(__ASSEMBLY__)
> +
> #include <linux/build_bug.h>
> #include <linux/compiler.h>
> +
> #define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h)))
> -#else
> -/*
> - * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
> - * disable the input check if that is the case.
> - */

it seems we now have 1 inconsistency that we comment why
GENMASK_U128() is not available in asm, but we don't comment why
GENMASK_INPUT_CHECK() is not available there. Maybe move this comment on
top of GENMASK_INPUT_CHECK().

Anyway,

	Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>

thanks for picking up this series.

Lucas De Marchi

> -#define GENMASK_INPUT_CHECK(h, l) 0
> -#endif
>
> #define GENMASK(h, l) \
> 	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> #define GENMASK_ULL(h, l) \
> 	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
>
> -#if !defined(__ASSEMBLY__)
> /*
>  * Missing asm support
>  *
> @@ -48,6 +42,12 @@
>  */
> #define GENMASK_U128(h, l) \
> 	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))
> -#endif
> +
> +#else /* defined(__ASSEMBLY__) */
> +
> +#define GENMASK(h, l)		__GENMASK(h, l)
> +#define GENMASK_ULL(h, l)	__GENMASK_ULL(h, l)
> +
> +#endif /* !defined(__ASSEMBLY__) */
>
> #endif	/* __LINUX_BITS_H */
>
> --
> 2.45.3