> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Yury Norov via Intel-wired-lan
> Sent: Monday, March 2, 2026 2:12 AM
> To: Nguyen, Anthony L <[email protected]>; David S. Miller
> <[email protected]>; Thomas Hellström
> <[email protected]>; Andrew Lunn
> <[email protected]>; Andrew Morton <[email protected]>;
> David Airlie <[email protected]>; Eric Dumazet <[email protected]>;
> Jakub Kicinski <[email protected]>; Brost, Matthew
> <[email protected]>; Paolo Abeni <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; Vivi, Rodrigo
> <[email protected]>; Simona Vetter <[email protected]>; Yury Norov
> <[email protected]>; Rasmus Villemoes <[email protected]>;
> [email protected]; [email protected];
> [email protected]; [email protected]; intel-wired-
> [email protected]
> Cc: Yury Norov <[email protected]>; Simon Horman <[email protected]>;
> David Laight <[email protected]>
> Subject: [Intel-wired-lan] [PATCH v2 1/4] bitmap: introduce
> bitmap_weighted_xor()
>
> The function helps to XOR bitmaps and calculate Hamming weight of the
> result in one pass.
>
> Signed-off-by: Yury Norov <[email protected]>
> ---
> include/linux/bitmap.h | 15 +++++++++++++++
> lib/bitmap.c | 7 +++++++
> 2 files changed, 22 insertions(+)
>
> diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index
> b0395e4ccf90..874f744870ef 100644
> --- a/include/linux/bitmap.h
> +++ b/include/linux/bitmap.h
> @@ -46,6 +46,7 @@ struct device;
> * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
> * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
> * bitmap_weighted_or(dst, src1, src2, nbits) *dst = *src1 | *src2.
> Returns Hamming Weight of dst
> + * bitmap_weighted_xor(dst, src1, src2, nbits) *dst = *src1 ^
> *src2. Returns Hamming Weight of dst
> * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
> * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 &
> ~(*src2)
> * bitmap_complement(dst, src, nbits) *dst = ~(*src)
> @@ -168,6 +169,8 @@ void __bitmap_or(unsigned long *dst, const
> unsigned long *bitmap1,
> const unsigned long *bitmap2, unsigned int nbits);
> unsigned int __bitmap_weighted_or(unsigned long *dst, const unsigned
> long *bitmap1,
> const unsigned long *bitmap2, unsigned
> int nbits);
> +unsigned int __bitmap_weighted_xor(unsigned long *dst, const unsigned
> long *bitmap1,
> + const unsigned long *bitmap2, unsigned
> int nbits);
> void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
> const unsigned long *bitmap2, unsigned int nbits);
> bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
> @@ -352,6 +355,18 @@ unsigned int bitmap_weighted_or(unsigned long
> *dst, const unsigned long *src1,
> }
> }
>
> +static __always_inline
> +unsigned int bitmap_weighted_xor(unsigned long *dst, const unsigned
> long *src1,
> + const unsigned long *src2, unsigned int
> nbits) {
> + if (small_const_nbits(nbits)) {
> + *dst = *src1 ^ *src2;
> + return hweight_long(*dst &
> BITMAP_LAST_WORD_MASK(nbits));
> + } else {
> + return __bitmap_weighted_xor(dst, src1, src2, nbits);
> + }
> +}
> +
> static __always_inline
> void bitmap_xor(unsigned long *dst, const unsigned long *src1,
> const unsigned long *src2, unsigned int nbits) diff --
> git a/lib/bitmap.c b/lib/bitmap.c index 9dc526507875..a2bcb5b1fe99
> 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -361,6 +361,13 @@ unsigned int __bitmap_weighted_or(unsigned long
> *dst, const unsigned long *bitma
> return BITMAP_WEIGHT(({dst[idx] = bitmap1[idx] | bitmap2[idx];
> dst[idx]; }), bits); }
>
> +unsigned int __bitmap_weighted_xor(unsigned long *dst, const unsigned
> long *bitmap1,
> + const unsigned long *bitmap2, unsigned
> int bits) {
> + return BITMAP_WEIGHT(({dst[idx] = bitmap1[idx] ^ bitmap2[idx];
> +dst[idx]; }), bits); } EXPORT_SYMBOL(__bitmap_weighted_xor);
> +
> void __bitmap_set(unsigned long *map, unsigned int start, int len) {
> unsigned long *p = map + BIT_WORD(start);
> --
> 2.43.0
Reviewed-by: Aleksandr Loktionov <[email protected]>
