1 files changed, 54 insertions, 0 deletions
diff --git a/libopencm3/include/libopencm3/cm3/sync.h b/libopencm3/include/libopencm3/cm3/sync.h
new file mode 100644
index 0000000..e80e348
--- /dev/null
+++ b/libopencm3/include/libopencm3/cm3/sync.h
@@ -0,0 +1,54 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Fergus Noble <fergusnoble@gmail.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBOPENCM3_CM3_SYNC_H
+#define LIBOPENCM3_CM3_SYNC_H
+
+#include "common.h"
+
+void __dmb(void);
+
+/* Implements synchronisation primitives as discussed in the ARM document
+ * DHT0008A (ID081709) "ARM Synchronization Primitives" and the ARM v7-M
+ * Architecture Reference Manual.
+*/
+
+/* --- Exclusive load and store instructions ------------------------------- */
+
+/* Those are defined only on CM3 or CM4 */
+#if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__)
+
+uint32_t __ldrex(volatile uint32_t *addr);
+uint32_t __strex(uint32_t val, volatile uint32_t *addr);
+
+/* --- Convenience functions ----------------------------------------------- */
+
+/* Here we implement some simple synchronisation primitives. */
+
+typedef uint32_t mutex_t;
+
+#define MUTEX_UNLOCKED 0
+#define MUTEX_LOCKED	 1
+
+void mutex_lock(mutex_t *m);
+void mutex_unlock(mutex_t *m);
+
+#endif
+
+#endif