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); }