1 files changed, 53 insertions, 0 deletions

diff --git a/firmware/kernel/include/corelock.h b/firmware/kernel/include/corelock.h
new file mode 100644
index 0000000000..79302e0e3c
--- /dev/null
+++ b/firmware/kernel/include/corelock.h
@@ -0,0 +1,53 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Ulf Ralberg
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+
+#ifndef CORELOCK_H
+#define CORELOCK_H
+
+#include "config.h"
+
+#ifndef HAVE_CORELOCK_OBJECT
+
+/* No atomic corelock op needed or just none defined */
+#define corelock_init(cl)
+#define corelock_lock(cl)
+#define corelock_try_lock(cl)
+#define corelock_unlock(cl)
+
+#else
+
+/* No reliable atomic instruction available - use Peterson's algorithm */
+struct corelock
+{
+    volatile unsigned char myl[NUM_CORES];
+    volatile unsigned char turn;
+} __attribute__((packed));
+
+/* Too big to inline everywhere */
+extern void corelock_init(struct corelock *cl);
+extern void corelock_lock(struct corelock *cl);
+extern int  corelock_try_lock(struct corelock *cl);
+extern void corelock_unlock(struct corelock *cl);
+
+#endif /* HAVE_CORELOCK_OBJECT */
+
+#endif /* CORELOCK_H */