[01/10] bitmap: add bitmap_copy_and_clear_atomic

Commit Message

Gerd Hoffmann April 4, 2017, 10:23 a.m. UTC

Signed-off-by: Gerd Hoffmann <[e-mail]>
---
 include/qemu/bitmap.h |  2 ++
 util/bitmap.c         | 11 +++++++++++
 2 files changed, 13 insertions(+)

Patch

diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
index 63ea2d0..c318da1 100644
--- a/include/qemu/bitmap.h
+++ b/include/qemu/bitmap.h
@@ -220,6 +220,8 @@  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);
 bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr);
+void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src,
+                                  long nr);
 unsigned long bitmap_find_next_zero_area(unsigned long *map,
                                          unsigned long size,
                                          unsigned long start,
diff --git a/util/bitmap.c b/util/bitmap.c
index c1a84ca..efced9a 100644
--- a/util/bitmap.c
+++ b/util/bitmap.c
@@ -287,6 +287,17 @@  bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr)
     return dirty != 0;
 }
 
+void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src,
+                                  long nr)
+{
+    while (nr > 0) {
+        *dst = atomic_xchg(src, 0);
+        dst++;
+        src++;
+        nr -= BITS_PER_LONG;
+    }
+}
+
 #define ALIGN_MASK(x,mask)      (((x)+(mask))&~(mask))
 
 /**