Re: [PATCH v2 1/2] linux/bits.h: Clarify macro argument names

From: Joe Perches
Date: Sat Aug 10 2019 - 15:20:46 EST


On Thu, 2019-08-08 at 12:46 +0900, Masahiro Yamada wrote:
> On Fri, Aug 2, 2019 at 8:04 AM Rikard Falkeborn
> <rikard.falkeborn@xxxxxxxxx> wrote:
> > Be a little more verbose to improve readability.
> >
> > Signed-off-by: Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx>
>
> BTW, I do not understand what the improvement is.
> I tend to regard this as a noise commit.

Non verbose naming clarity is good.

Perhaps adding kernel-doc is good too.

>
> > ---
> > Changes in v2:
> > - This patch is new in v2
> >
> > include/linux/bits.h | 16 ++++++++--------
> > 1 file changed, 8 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/linux/bits.h b/include/linux/bits.h
> > index 669d69441a62..d4466aa42a9c 100644
> > --- a/include/linux/bits.h
> > +++ b/include/linux/bits.h
> > @@ -14,16 +14,16 @@
> > #define BITS_PER_BYTE 8
> >
> > /*
> > - * Create a contiguous bitmask starting at bit position @l and ending at
> > - * position @h. For example
> > + * Create a contiguous bitmask starting at bit position @low and ending at
> > + * position @high. For example
> > * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
> > */
> > -#define GENMASK(h, l) \
> > - (((~UL(0)) - (UL(1) << (l)) + 1) & \
> > - (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
> > +#define GENMASK(high, low) \
> > + (((~UL(0)) - (UL(1) << (low)) + 1) & \
> > + (~UL(0) >> (BITS_PER_LONG - 1 - (high))))
> >
> > -#define GENMASK_ULL(h, l) \
> > - (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
> > - (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
> > +#define GENMASK_ULL(high, low) \
> > + (((~ULL(0)) - (ULL(1) << (low)) + 1) & \
> > + (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (high))))
> >
> > #endif /* __LINUX_BITS_H */
> > --
> > 2.22.0
> >
>
>