Re: [PATCH v13 01/11] bitops: Introduce the for_each_set_clump8 macro

From: Andy Shevchenko
Date: Wed Mar 27 2019 - 08:31:07 EST


On Wed, Mar 27, 2019 at 01:58:45PM +0900, William Breathitt Gray wrote:
> This macro iterates for each 8-bit group of bits (clump) with set bits,
> within a bitmap memory region. For each iteration, "start" is set to the
> bit offset of the found clump, while the respective clump value is
> stored to the location pointed by "clump". Additionally, the
> bitmap_get_value8 and bitmap_set_value8 functions are introduced to
> respectively get and set an 8-bit value in a bitmap memory region.

> +unsigned long bitmap_get_value8(const unsigned long *addr, unsigned long start)
> +{
> + const size_t idx = BIT_WORD(start);
> + const unsigned long offset = start % BITS_PER_LONG;
> +
> + return (addr[idx] >> offset) & 0xFF;

I would spell index instead of idx, but it's minor and up to you.

> +}

--
With Best Regards,
Andy Shevchenko