3 files changed, 57 insertions, 0 deletions

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
@@ -476,6 +476,20 @@ static inline bool cpumask_equal(const struct cpumask *src1p,
 }
 
 /**
+ * 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
  * @src2p: the second 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);