[PATCH v2 1/4] linux/bitmap.h: add bitmap_empty helper

[Caleb Connolly]

Import this function from Linux.

Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
---
 include/linux/bitmap.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 0a8503af9f14..40ca2212cb40 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -195,8 +195,16 @@ static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 		memset(dst, 0xff, len);
 	}
 }
 
+static inline bool bitmap_empty(const unsigned long *src, unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		return !(*src & BITMAP_LAST_WORD_MASK(nbits));
+
+	return find_first_bit(src, nbits) == nbits;
+}
+
 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 			     const unsigned long *src2, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))

-- 
2.45.2