Imported Genode release 11.11

base-fiasco/include/arm/cpu/atomic.h

@@ -0,0 +1,39 @@
+/*
+ * \brief  Atomic operations for ARM
+ * \author Norman Feske
+ * \date   2007-04-28
+ */
+
+/*
+ * Copyright (C) 2007-2011 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _INCLUDE__ARM__CPU__ATOMIC_H_
+#define _INCLUDE__ARM__CPU__ATOMIC_H_
+
+namespace Genode {
+
+	extern "C" long int
+	l4_atomic_cmpxchg(volatile long int*, long int, long int);
+
+	/**
+	 * Atomic compare and exchange
+	 *
+	 * This function compares the value at dest with cmp_val.
+	 * If both values are equal, dest is set to new_val. If
+	 * both values are different, the value at dest remains
+	 * unchanged.
+	 *
+	 * \return  1 if the value was successfully changed to new_val,
+	 *          0 if cmp_val and the value at dest differ.
+	 */
+	inline int cmpxchg(volatile int *dest, int cmp_val, int new_val)
+	{
+		return l4_atomic_cmpxchg((volatile long int *)dest, cmp_val, new_val);
+	}
+}
+
+#endif /* _INCLUDE__ARM__CPU__ATOMIC_H_ */