projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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> | |
| b920de1b DH |
13 | |
| 14 | /* | |
| 15 | * try flipping a bit using BSET and BCLR | |
| 16 | */ | |
| e4acfcac | 17 | void change_bit(unsigned long nr, volatile void *addr) |
| b920de1b DH |
18 | { |
| 19 | if (test_bit(nr, addr)) | |
| 20 | goto try_clear_bit; | |
| 21 | ||
| 22 | try_set_bit: | |
| 23 | if (!test_and_set_bit(nr, addr)) | |
| 24 | return; | |
| 25 | ||
| 26 | try_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 | */ | |
| e4acfcac | 36 | int test_and_change_bit(unsigned long nr, volatile void *addr) |
| b920de1b DH |
37 | { |
| 38 | if (test_bit(nr, addr)) | |
| 39 | goto try_clear_bit; | |
| 40 | ||
| 41 | try_set_bit: | |
| 42 | if (!test_and_set_bit(nr, addr)) | |
| 43 | return 0; | |
| 44 | ||
| 45 | try_clear_bit: | |
| 46 | if (test_and_clear_bit(nr, addr)) | |
| 47 | return 1; | |
| 48 | ||
| 49 | goto try_set_bit; | |
| 50 | } |