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b920de1b DH |
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 | */ | |
18 | void change_bit(int 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 | */ | |
37 | int test_and_change_bit(int 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 | } |