Messages in this thread | | | Date | Mon, 7 Oct 2019 11:21:56 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH v16 01/14] bitops: Introduce the for_each_set_clump8 macro |
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On Sun, Oct 06, 2019 at 11:10:58AM -0400, 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.
Very much thank you for an update! I have comments below.
> +/** > + * bitmap_get_value8 - get an 8-bit value within a memory region
Since it's in find.h I would not collide with bitmap namespace. How about
find_and_get_value8()
> + * @addr: address to the bitmap memory region > + * @start: bit offset of the 8-bit value; must be a multiple of 8 > + * > + * Returns the 8-bit value located at the @start bit offset within the @addr > + * memory region. > + */ > +static inline unsigned long bitmap_get_value8(const unsigned long *addr, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + return (addr[index] >> offset) & 0xFF; > +} > + > +/** > + * bitmap_set_value8 - set an 8-bit value within a memory region
find_and_set_value8()
?
> + * @addr: address to the bitmap memory region > + * @value: the 8-bit value; values wider than 8 bits may clobber bitmap > + * @start: bit offset of the 8-bit value; must be a multiple of 8 > + */ > +static inline void bitmap_set_value8(unsigned long *addr, unsigned long value, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + addr[index] &= ~(0xFF << offset); > + addr[index] |= value << offset; > +}
-- With Best Regards, Andy Shevchenko
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