It is used to invert the whole bitmap.
Signed-off-by: Peter Xu <[email protected]>
---
include/qemu/bitmap.h | 10 ++++++++++
util/bitmap.c | 13 +++++++++++++
2 files changed, 23 insertions(+)
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
index c318da1..460d899 100644
--- a/include/qemu/bitmap.h
+++ b/include/qemu/bitmap.h
@@ -82,6 +82,7 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned
long *bitmap1,
const unsigned long *bitmap2, long bits);
int slow_bitmap_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, long bits);
+void slow_bitmap_invert(unsigned long *bitmap, long nbits);
static inline unsigned long *bitmap_try_new(long nbits)
{
@@ -216,6 +217,15 @@ static inline int bitmap_intersects(const unsigned long
*src1,
}
}
+static inline void bitmap_invert(unsigned long *bitmap, long nbits)
+{
+ if (small_nbits(nbits)) {
+ *bitmap ^= BITMAP_LAST_WORD_MASK(nbits);
+ } else {
+ slow_bitmap_invert(bitmap, nbits);
+ }
+}
+
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);
diff --git a/util/bitmap.c b/util/bitmap.c
index efced9a..9b7408c 100644
--- a/util/bitmap.c
+++ b/util/bitmap.c
@@ -355,3 +355,16 @@ int slow_bitmap_intersects(const unsigned long *bitmap1,
}
return 0;
}
+
+void slow_bitmap_invert(unsigned long *bitmap, long nbits)
+{
+ long k, lim = nbits/BITS_PER_LONG;
+
+ for (k = 0; k < lim; k++) {
+ bitmap[k] ^= ULONG_MAX;
+ }
+
+ if (nbits % BITS_PER_LONG) {
+ bitmap[k] ^= BITMAP_LAST_WORD_MASK(nbits);
+ }
+}
--
2.7.4
