diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index f58e97446abc..90528f12bdfa 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -120,6 +120,10 @@ extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); extern int __bitmap_equal(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); +extern bool __pure __bitmap_or_equal(const unsigned long *src1, + const unsigned long *src2, + const unsigned long *src3, + unsigned int nbits); extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int nbits); extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, @@ -321,6 +325,25 @@ static inline int bitmap_equal(const unsigned long *src1, return __bitmap_equal(src1, src2, nbits); } +/** + * bitmap_or_equal - Check whether the or of two bitnaps is equal to a third + * @src1: Pointer to bitmap 1 + * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1 + * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2 + * + * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise + */ +static inline bool bitmap_or_equal(const unsigned long *src1, + const unsigned long *src2, + const unsigned long *src3, + unsigned int nbits) +{ + if (!small_const_nbits(nbits)) + return __bitmap_or_equal(src1, src2, src3, nbits); + + return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits)); +} + static inline int bitmap_intersects(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 693124900f0a..0c7db5efe66c 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -475,6 +475,20 @@ static inline bool cpumask_equal(const struct cpumask *src1p, nr_cpumask_bits); } +/** + * cpumask_or_equal - *src1p | *src2p == *src3p + * @src1p: the first input + * @src2p: the second input + * @src3p: the third input + */ +static inline bool cpumask_or_equal(const struct cpumask *src1p, + const struct cpumask *src2p, + const struct cpumask *src3p) +{ + return bitmap_or_equal(cpumask_bits(src1p), cpumask_bits(src2p), + cpumask_bits(src3p), nr_cpumask_bits); +} + /** * cpumask_intersects - (*src1p & *src2p) != 0 * @src1p: the first input diff --git a/lib/bitmap.c b/lib/bitmap.c index bbe2589e8497..f9e834841e94 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -59,6 +59,26 @@ int __bitmap_equal(const unsigned long *bitmap1, } EXPORT_SYMBOL(__bitmap_equal); +bool __bitmap_or_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, + const unsigned long *bitmap3, + unsigned int bits) +{ + unsigned int k, lim = bits / BITS_PER_LONG; + unsigned long tmp; + + for (k = 0; k < lim; ++k) { + if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) + return false; + } + + if (!(bits % BITS_PER_LONG)) + return true; + + tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; + return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; +} + void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) { unsigned int k, lim = BITS_TO_LONGS(bits);