1 files changed, 37 insertions, 0 deletions
diff --git a/sys/gnu/fs/xfs/FreeBSD/support/atomic.h b/sys/gnu/fs/xfs/FreeBSD/support/atomic.h
new file mode 100644
index 0000000..f8b6c91
--- /dev/null
+++ b/sys/gnu/fs/xfs/FreeBSD/support/atomic.h
@@ -0,0 +1,37 @@
+#ifndef __XFS_SUPPORT_ATOMIC_H__
+
+#include <sys/types.h>
+#include <machine/atomic.h>
+
+typedef struct {
+	volatile unsigned int	val;
+} atomic_t;
+
+#define	atomic_read(v)			((v)->val)
+#define atomic_set(v, i)		((v)->val = (i))
+
+#define	atomic_add(i, v)		atomic_add_int(&(v)->val, (i))
+#define	atomic_inc(v)			atomic_add_int(&(v)->val, 1)
+#define	atomic_dec(v)			atomic_subtract_int(&(v)->val, 1)
+#define	atomic_sub(i, v)		atomic_subtract_int(&(v)->val, (i))
+#define	atomic_sub_and_test(i, v)	(atomic_fetchadd_int(&(v)->val, (-i) == i)
+#define	atomic_dec_and_test(v)		(atomic_fetchadd_int(&(v)->val, -1) == 1)
+
+/*
+ * This is used for two variables in XFS, one of which is a debug trace
+ * buffer index.
+ */
+
+static __inline__ int atomicIncWithWrap(volatile unsigned int *ip, int val)
+{
+	unsigned int oldval, newval;
+
+	do {
+		oldval = *ip;
+		newval = (oldval + 1 >= val) ? 0 : oldval + 1;
+        } while (atomic_cmpset_rel_int(ip, oldval, newval) == 0);
+
+	return oldval;
+}
+
+#endif /* __XFS_SUPPORT_ATOMIC_H__ */