diff options
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index defeaac0745f..299e76b59fe9 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -227,6 +227,22 @@ static inline unsigned long __ffs64(u64 word) }) #endif +#ifndef bit_clear_unless +#define bit_clear_unless(ptr, _clear, _test) \ +({ \ + const typeof(*ptr) clear = (_clear), test = (_test); \ + typeof(*ptr) old, new; \ + \ + do { \ + old = ACCESS_ONCE(*ptr); \ + new = old & ~clear; \ + } while (!(old & test) && \ + cmpxchg(ptr, old, new) != old); \ + \ + !(old & test); \ +}) +#endif + #ifndef find_last_bit /** * find_last_bit - find the last set bit in a memory region |