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Diffstat (limited to 'tools/testing/selftests/futex/include/atomic.h')
-rw-r--r-- | tools/testing/selftests/futex/include/atomic.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/tools/testing/selftests/futex/include/atomic.h b/tools/testing/selftests/futex/include/atomic.h new file mode 100644 index 000000000000..f861da3e31ab --- /dev/null +++ b/tools/testing/selftests/futex/include/atomic.h @@ -0,0 +1,83 @@ +/****************************************************************************** + * + * Copyright © International Business Machines Corp., 2009 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * DESCRIPTION + * GCC atomic builtin wrappers + * http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html + * + * AUTHOR + * Darren Hart <dvhart@linux.intel.com> + * + * HISTORY + * 2009-Nov-17: Initial version by Darren Hart <dvhart@linux.intel.com> + * + *****************************************************************************/ + +#ifndef _ATOMIC_H +#define _ATOMIC_H + +typedef struct { + volatile int val; +} atomic_t; + +#define ATOMIC_INITIALIZER { 0 } + +/** + * atomic_cmpxchg() - Atomic compare and exchange + * @uaddr: The address of the futex to be modified + * @oldval: The expected value of the futex + * @newval: The new value to try and assign the futex + * + * Return the old value of addr->val. + */ +static inline int +atomic_cmpxchg(atomic_t *addr, int oldval, int newval) +{ + return __sync_val_compare_and_swap(&addr->val, oldval, newval); +} + +/** + * atomic_inc() - Atomic incrememnt + * @addr: Address of the variable to increment + * + * Return the new value of addr->val. + */ +static inline int +atomic_inc(atomic_t *addr) +{ + return __sync_add_and_fetch(&addr->val, 1); +} + +/** + * atomic_dec() - Atomic decrement + * @addr: Address of the variable to decrement + * + * Return the new value of addr-val. + */ +static inline int +atomic_dec(atomic_t *addr) +{ + return __sync_sub_and_fetch(&addr->val, 1); +} + +/** + * atomic_set() - Atomic set + * @addr: Address of the variable to set + * @newval: New value for the atomic_t + * + * Return the new value of addr->val. + */ +static inline int +atomic_set(atomic_t *addr, int newval) +{ + addr->val = newval; + return newval; +} + +#endif |