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 #include <asm/system.h>
14
15 /*
16 * try flipping a bit using BSET and BCLR
17 */
change_bit(unsigned long nr,volatile void * addr)18 void change_bit(unsigned long nr, volatile void *addr)
19 {
20 if (test_bit(nr, addr))
21 goto try_clear_bit;
22
23 try_set_bit:
24 if (!test_and_set_bit(nr, addr))
25 return;
26
27 try_clear_bit:
28 if (test_and_clear_bit(nr, addr))
29 return;
30
31 goto try_set_bit;
32 }
33
34 /*
35 * try flipping a bit using BSET and BCLR and returning the old value
36 */
test_and_change_bit(unsigned long nr,volatile void * addr)37 int test_and_change_bit(unsigned long nr, volatile void *addr)
38 {
39 if (test_bit(nr, addr))
40 goto try_clear_bit;
41
42 try_set_bit:
43 if (!test_and_set_bit(nr, addr))
44 return 0;
45
46 try_clear_bit:
47 if (test_and_clear_bit(nr, addr))
48 return 1;
49
50 goto try_set_bit;
51 }
52