Messages in this thread | | | Date | Tue, 22 Feb 2022 17:50:45 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCHv3 04/10] linux/kernel: introduce lower_48_bits macro |
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On Tue, Feb 22, 2022 at 08:45:53AM -0800, Joe Perches wrote: > 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?
Agreed.
> 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); > }
For anyone who has a minimum knowledge of C and hardware your version is an obsfucated clusterfuck, while the version Keith wrote is trivial to read.
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