1/* MN10300 Non-trivial bit operations
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#include <linux/module.h>
12#include <asm/bitops.h>
13
14/*
15 * try flipping a bit using BSET and BCLR
16 */
17void change_bit(unsigned long nr, volatile void *addr)
18{
19	if (test_bit(nr, addr))
20		goto try_clear_bit;
21
22try_set_bit:
23	if (!test_and_set_bit(nr, addr))
24		return;
25
26try_clear_bit:
27	if (test_and_clear_bit(nr, addr))
28		return;
29
30	goto try_set_bit;
31}
32
33/*
34 * try flipping a bit using BSET and BCLR and returning the old value
35 */
36int test_and_change_bit(unsigned long nr, volatile void *addr)
37{
38	if (test_bit(nr, addr))
39		goto try_clear_bit;
40
41try_set_bit:
42	if (!test_and_set_bit(nr, addr))
43		return 0;
44
45try_clear_bit:
46	if (test_and_clear_bit(nr, addr))
47		return 1;
48
49	goto try_set_bit;
50}
51