From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/mn10300/lib/bitops.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 arch/mn10300/lib/bitops.c (limited to 'arch/mn10300/lib/bitops.c') diff --git a/arch/mn10300/lib/bitops.c b/arch/mn10300/lib/bitops.c new file mode 100644 index 000000000..37309cdb7 --- /dev/null +++ b/arch/mn10300/lib/bitops.c @@ -0,0 +1,50 @@ +/* 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 +#include + +/* + * try flipping a bit using BSET and BCLR + */ +void change_bit(unsigned long 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(unsigned long 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; +} -- cgit v1.2.3-54-g00ecf