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cpumask: add cpumask_weight_andnot()

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Similarly to cpumask_weight_and(), cpumask_weight_andnot() is a handy
helper that may help to avoid creating an intermediate mask just to
calculate number of bits that set in a 1st given mask, and clear in 2nd
one.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Yury Norov 2024-01-28 22:21:04 -08:00 committed by Paolo Abeni
parent 3723b56d6f
commit c1f5204efc
3 changed files with 32 additions and 0 deletions
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12
include/linux/bitmap.h
View File

@ -54,6 +54,7 @@ struct device;
* bitmap_full(src, nbits) Are all bits set in *src?
* bitmap_weight(src, nbits) Hamming Weight: number set bits
* bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
* bitmap_weight_andnot(src1, src2, nbits) Hamming Weight of andnot'ed bitmap
* bitmap_set(dst, pos, nbits) Set specified bit area
* bitmap_clear(dst, pos, nbits) Clear specified bit area
* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
@ -169,6 +170,8 @@ bool __bitmap_subset(const unsigned long *bitmap1,
unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
void __bitmap_set(unsigned long *map, unsigned int start, int len);
void __bitmap_clear(unsigned long *map, unsigned int start, int len);
@ -425,6 +428,15 @@ unsigned long bitmap_weight_and(const unsigned long *src1,
return __bitmap_weight_and(src1, src2, nbits);
}
static __always_inline
unsigned long bitmap_weight_andnot(const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
return hweight_long(*src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits));
return __bitmap_weight_andnot(src1, src2, nbits);
}
static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
unsigned int nbits)
{

13
include/linux/cpumask.h
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@ -719,6 +719,19 @@ static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1,
return bitmap_weight_and(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
}
/**
* cpumask_weight_andnot - Count of bits in (*srcp1 & ~*srcp2)
* @srcp1: the cpumask to count bits (< nr_cpu_ids) in.
* @srcp2: the cpumask to count bits (< nr_cpu_ids) in.
*
* Return: count of bits set in both *srcp1 and *srcp2
*/
static inline unsigned int cpumask_weight_andnot(const struct cpumask *srcp1,
const struct cpumask *srcp2)
{
return bitmap_weight_andnot(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
}
/**
* cpumask_shift_right - *dstp = *srcp >> n
* @dstp: the cpumask result

7
lib/bitmap.c
View File

@ -348,6 +348,13 @@ unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
}
EXPORT_SYMBOL(__bitmap_weight_and);
unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
return BITMAP_WEIGHT(bitmap1[idx] & ~bitmap2[idx], bits);
}
EXPORT_SYMBOL(__bitmap_weight_andnot);
void __bitmap_set(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);