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52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
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/* MN10300 Non-trivial bit operations
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <asm/bitops.h>
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#include <asm/system.h>
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/*
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* try flipping a bit using BSET and BCLR
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*/
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void change_bit(int nr, volatile void *addr)
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{
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if (test_bit(nr, addr))
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goto try_clear_bit;
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try_set_bit:
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if (!test_and_set_bit(nr, addr))
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return;
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try_clear_bit:
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if (test_and_clear_bit(nr, addr))
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return;
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goto try_set_bit;
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}
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/*
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* try flipping a bit using BSET and BCLR and returning the old value
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*/
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int test_and_change_bit(int nr, volatile void *addr)
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{
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if (test_bit(nr, addr))
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goto try_clear_bit;
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try_set_bit:
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if (!test_and_set_bit(nr, addr))
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return 0;
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try_clear_bit:
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if (test_and_clear_bit(nr, addr))
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return 1;
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goto try_set_bit;
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}
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