Re: [PATCHv3 04/10] linux/kernel: introduce lower_48_bits macro

Joe Perches
2022-02-22T16:46:01Z

On Tue, 2022-02-22 at 08:31 -0800, Keith Busch wrote:
> Recent data integrity field enhancements allow 48-bit reference tags.
> Introduce a helper macro since this will be a repeated operation.
[]
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
[]
> @@ -63,6 +63,12 @@
> } \
> )
>
> +/**
> + * lower_48_bits - return bits 0-47 of a number
> + * @n: the number we're accessing
> + */
> +#define lower_48_bits(n) ((u64)((n) & 0xffffffffffffull))

why not make this a static inline function?
And visually, it's difficult to quickly count a repeated character to 12.

Perhaps:

static inline u64 lower_48_bits(u64 val)
{
return val & GENMASK_ULL(47, 0);
}