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

Lorenzo Stoakes
2026-01-22T16:07:55Z

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>
---
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