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