diff options
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/include/asm/bitops.h | 7 | ||||
| -rw-r--r-- | arch/ia64/include/uapi/asm/cmpxchg.h | 9 |
2 files changed, 11 insertions, 5 deletions
diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h index c27eccd33349..feb8117ed06a 100644 --- a/arch/ia64/include/asm/bitops.h +++ b/arch/ia64/include/asm/bitops.h @@ -65,11 +65,8 @@ __set_bit (int nr, volatile void *addr) *((__u32 *) addr + (nr >> 5)) |= (1 << (nr & 31)); } -/* - * clear_bit() has "acquire" semantics. - */ -#define smp_mb__before_clear_bit() smp_mb() -#define smp_mb__after_clear_bit() do { /* skip */; } while (0) +#define smp_mb__before_clear_bit() barrier(); +#define smp_mb__after_clear_bit() barrier(); /** * clear_bit - Clears a bit in memory diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h index 4f37dbbb8640..f35109b1d907 100644 --- a/arch/ia64/include/uapi/asm/cmpxchg.h +++ b/arch/ia64/include/uapi/asm/cmpxchg.h @@ -118,6 +118,15 @@ extern long ia64_cmpxchg_called_with_bad_pointer(void); #define cmpxchg_rel(ptr, o, n) \ ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr))) +/* + * Worse still - early processor implementations actually just ignored + * the acquire/release and did a full fence all the time. Unfortunately + * this meant a lot of badly written code that used .acq when they really + * wanted .rel became legacy out in the wild - so when we made a cpu + * that strictly did the .acq or .rel ... all that code started breaking - so + * we had to back-pedal and keep the "legacy" behavior of a full fence :-( + */ + /* for compatibility with other platforms: */ #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) |