1 files changed, 89 insertions, 0 deletions
diff --git a/StdLib/Include/Arm/machine/lock.h b/StdLib/Include/Arm/machine/lock.h
new file mode 100644
index 0000000000..be11a470ab
--- /dev/null
+++ b/StdLib/Include/Arm/machine/lock.h
@@ -0,0 +1,89 @@
+/*	$NetBSD: lock.h,v 1.7 2005/12/28 19:09:29 perry Exp $	*/
+
+/*-
+ * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Machine-dependent spin lock operations.
+ *
+ * NOTE: The SWP insn used here is available only on ARM architecture
+ * version 3 and later (as well as 2a).  What we are going to do is
+ * expect that the kernel will trap and emulate the insn.  That will
+ * be slow, but give us the atomicity that we need.
+ */
+
+#ifndef _ARM_LOCK_H_
+#define	_ARM_LOCK_H_
+
+static __inline int
+__swp(int __val, volatile int *__ptr)
+{
+
+	__asm volatile("swp %0, %1, [%2]"
+	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
+	return __val;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock(__cpu_simple_lock_t *alp)
+{
+
+	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
+		continue;
+}
+
+static __inline int __attribute__((__unused__))
+__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
+{
+
+	return (__swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED);
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_unlock(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+#endif /* _ARM_LOCK_H_ */