From a3ebdb6c423dff420168a3faf25c76e9e5f59258 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 18 Dec 2007 16:22:46 -0800 Subject: IA64: Slim down __clear_bit_unlock __clear_bit_unlock does not need to perform atomic operations on the variable. Avoid a cmpxchg and simply do a store with release semantics. Add a barrier to be safe that the compiler does not do funky things. Tony: Use intrinsic rather than inline assembler Signed-off-by: Christoph Lameter Acked-by: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Tony Luck --- include/asm-ia64/bitops.h | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'include/asm-ia64/bitops.h') diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h index a977affaebe..a1b9719f5fb 100644 --- a/include/asm-ia64/bitops.h +++ b/include/asm-ia64/bitops.h @@ -124,10 +124,21 @@ clear_bit_unlock (int nr, volatile void *addr) /** * __clear_bit_unlock - Non-atomically clear a bit with release * - * This is like clear_bit_unlock, but the implementation may use a non-atomic - * store (this one uses an atomic, however). + * This is like clear_bit_unlock, but the implementation uses a store + * with release semantics. See also __raw_spin_unlock(). */ -#define __clear_bit_unlock clear_bit_unlock +static __inline__ void +__clear_bit_unlock(int nr, volatile void *addr) +{ + __u32 mask, new; + volatile __u32 *m; + + m = (volatile __u32 *)addr + (nr >> 5); + mask = ~(1 << (nr & 31)); + new = *m & mask; + barrier(); + ia64_st4_rel_nta(m, new); +} /** * __clear_bit - Clears a bit in memory (non-atomic version) -- cgit v1.2.3