From: Wei Wang <wei.w.wang@intel.com>
Count the number of 1s in a bitmap starting from an offset.
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1544516693-5395-3-git-send-email-wei.w.wang@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
include/qemu/bitmap.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
index 679f1bdce4..5c313346b9 100644
--- a/include/qemu/bitmap.h
+++ b/include/qemu/bitmap.h
@@ -232,6 +232,19 @@ static inline long bitmap_count_one(const unsigned long *bitmap, long nbits)
}
}
+static inline long bitmap_count_one_with_offset(const unsigned long *bitmap,
+ long offset, long nbits)
+{
+ long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG);
+ long redundant_bits = offset - aligned_offset;
+ long bits_to_count = nbits + redundant_bits;
+ const unsigned long *bitmap_start = bitmap +
+ aligned_offset / BITS_PER_LONG;
+
+ return bitmap_count_one(bitmap_start, bits_to_count) -
+ bitmap_count_one(bitmap_start, redundant_bits);
+}
+
void bitmap_set(unsigned long *map, long i, long len);
void bitmap_set_atomic(unsigned long *map, long i, long len);
void bitmap_clear(unsigned long *map, long start, long nr);
--
2.20.1