Messages in this thread | | | Date | Mon, 9 Nov 2020 12:31:23 -0500 | From | William Breathitt Gray <> | Subject | Re: [PATCH v12 4/4] gpio: xilinx: Utilize generic bitmap_get_value and _set_value |
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On Mon, Nov 09, 2020 at 07:22:20PM +0200, Andy Shevchenko wrote: > On Mon, Nov 09, 2020 at 12:11:40PM -0500, William Breathitt Gray wrote: > > On Mon, Nov 09, 2020 at 10:15:29PM +0530, Syed Nayyar Waris wrote: > > > On Mon, Nov 09, 2020 at 03:41:53PM +0100, Arnd Bergmann wrote: > > ... > > > > static inline void bitmap_set_value(unsigned long *map, > > > - unsigned long value, > > > + unsigned long value, const size_t length, > > > unsigned long start, unsigned long nbits) > > > { > > > const size_t index = BIT_WORD(start); > > > @@ -15,6 +15,10 @@ static inline void bitmap_set_value(unsigned long *map, > > > } else { > > > map[index + 0] &= ~BITMAP_FIRST_WORD_MASK(start); > > > map[index + 0] |= value << offset; > > > + > > > + if (index + 1 >= length) > > > + __builtin_unreachable(); > > > + > > > map[index + 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits); > > > map[index + 1] |= value >> space; > > > } > > > > Hi Syed, > > > > Let's rename 'length' to 'nbits' as Arnd suggested, and rename 'nbits' > > to value_width. > > length here is in longs. I guess this is the point of entire patch.
Ah yes, this should become 'const unsigned long nbits' and represent the length of the bitmap in bits and not longs.
> But to me sounds like it would be better to have simply bitmap_set_value64() / > bitmap_set_value32() with proper optimization done and forget about variadic > ones for now.
The gpio-xilinx driver can have arbitrary sizes for width[0] and width[1], so unfortunately that means we don't know the start position nor the width of the value beforehand.
William Breathitt Gray [unhandled content-type:application/pgp-signature] | |