Re: [PATCH v2 04/13] tools: bitmap: add missing bitmap_[subset(), andnot()]

Liam R. Howlett
2026-02-09T18:46:26Z

* Lorenzo Stoakes <lorenzo.stoakes@oracle.com> [260122 16:06]:
> The bitmap_subset() and bitmap_andnot() functions are not present in the
> tools version of include/linux/bitmap.h, so add them as subsequent patches
> implement test code that requires them.
>
> We also add the missing __bitmap_subset() to tools/lib/bitmap.c.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>

> ---
> tools/include/linux/bitmap.h | 22 ++++++++++++++++++++++
> tools/lib/bitmap.c | 29 +++++++++++++++++++++++++++++
> 2 files changed, 51 insertions(+)
>
> diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
> index 0d992245c600..250883090a5d 100644
> --- a/tools/include/linux/bitmap.h
> +++ b/tools/include/linux/bitmap.h
> @@ -24,6 +24,10 @@ void __bitmap_set(unsigned long *map, unsigned int start, int len);
> void __bitmap_clear(unsigned long *map, unsigned int start, int len);
> bool __bitmap_intersects(const unsigned long *bitmap1,
> const unsigned long *bitmap2, unsigned int bits);
> +bool __bitmap_subset(const unsigned long *bitmap1,
> + const unsigned long *bitmap2, unsigned int nbits);
> +bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
> + const unsigned long *bitmap2, unsigned int nbits);
>
> #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
> #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
> @@ -81,6 +85,15 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
> __bitmap_or(dst, src1, src2, nbits);
> }
>
> +static __always_inline
> +bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
> + const unsigned long *src2, unsigned int nbits)
> +{
> + if (small_const_nbits(nbits))
> + return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
> + return __bitmap_andnot(dst, src1, src2, nbits);
> +}
> +
> static inline unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags __maybe_unused)
> {
> return malloc(bitmap_size(nbits));
> @@ -157,6 +170,15 @@ static inline bool bitmap_intersects(const unsigned long *src1,
> return __bitmap_intersects(src1, src2, nbits);
> }
>
> +static __always_inline
> +bool bitmap_subset(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
> +{
> + if (small_const_nbits(nbits))
> + return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
> + else
> + return __bitmap_subset(src1, src2, nbits);
> +}
> +
> static inline void bitmap_set(unsigned long *map, unsigned int start, unsigned int nbits)
> {
> if (__builtin_constant_p(nbits) && nbits == 1)
> diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
> index 51255c69754d..aa83d22c45e3 100644
> --- a/tools/lib/bitmap.c
> +++ b/tools/lib/bitmap.c
> @@ -140,3 +140,32 @@ void __bitmap_clear(unsigned long *map, unsigned int start, int len)
> *p &= ~mask_to_clear;
> }
> }
> +
> +bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
> + const unsigned long *bitmap2, unsigned int bits)
> +{
> + unsigned int k;
> + unsigned int lim = bits/BITS_PER_LONG;
> + unsigned long result = 0;
> +
> + for (k = 0; k < lim; k++)
> + result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
> + if (bits % BITS_PER_LONG)
> + result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
> + BITMAP_LAST_WORD_MASK(bits));
> + return result != 0;
> +}
> +
> +bool __bitmap_subset(const unsigned long *bitmap1,
> + const unsigned long *bitmap2, unsigned int bits)
> +{
> + unsigned int k, lim = bits/BITS_PER_LONG;
> + for (k = 0; k < lim; ++k)
> + if (bitmap1[k] & ~bitmap2[k])
> + return false;
> +
> + if (bits % BITS_PER_LONG)
> + if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
> + return false;
> + return true;
> +}
> --
> 2.52.0
>