1 files changed, 46 insertions, 0 deletions
diff --git a/lib/libc/arch/sh/gen/_atomic_lock.c b/lib/libc/arch/sh/gen/_atomic_lock.c
new file mode 100644
index 00000000000..36b7c8c6d34
--- /dev/null
+++ b/lib/libc/arch/sh/gen/_atomic_lock.c
@@ -0,0 +1,46 @@
+/*	$OpenBSD: _atomic_lock.c,v 1.1 2017/08/15 06:13:24 guenther Exp $	*/
+
+/*-
+ * Copyright (c) 2002 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Gregory McGarry.
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <machine/spinlock.h>
+
+int
+_atomic_lock(volatile _atomic_lock_t *lock)
+{
+	_atomic_lock_t old;
+
+	__asm volatile(
+		"	tas.b	%0	\n"
+		"	mov	#0, %1	\n"
+		"	rotcl	%1	\n"
+		: "=m" (*lock), "=r" (old));
+
+	return (old == 0);
+}