Initial file dump from open source releaseHEADmaster

1 files changed, 50 insertions, 0 deletions

diff --git a/arch/mn10300/lib/bitops.c b/arch/mn10300/lib/bitops.c
new file mode 100644
index 00000000..37309cdb
--- /dev/null
+++ b/arch/mn10300/lib/bitops.c
@@ -0,0 +1,50 @@
+/* MN10300 Non-trivial bit operations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <asm/bitops.h>
+
+/*
+ * try flipping a bit using BSET and BCLR
+ */
+void change_bit(unsigned long nr, volatile void *addr)
+{
+	if (test_bit(nr, addr))
+		goto try_clear_bit;
+
+try_set_bit:
+	if (!test_and_set_bit(nr, addr))
+		return;
+
+try_clear_bit:
+	if (test_and_clear_bit(nr, addr))
+		return;
+
+	goto try_set_bit;
+}
+
+/*
+ * try flipping a bit using BSET and BCLR and returning the old value
+ */
+int test_and_change_bit(unsigned long nr, volatile void *addr)
+{
+	if (test_bit(nr, addr))
+		goto try_clear_bit;
+
+try_set_bit:
+	if (!test_and_set_bit(nr, addr))
+		return 0;
+
+try_clear_bit:
+	if (test_and_clear_bit(nr, addr))
+		return 1;
+
+	goto try_set_bit;
+}