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| author | Kyle McMartin <kyle@parisc-linux.org> | 2007-05-29 02:51:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-05-29 02:51:13 -0700 |
| commit | 6197fe4d720ea3e2ee94cdc7ef32d6c0151199de (patch) | |
| tree | c521b677a8ca7ab24f12c0e8275a3cbdd00131c0 /arch/sparc | |
| parent | 679292993c77c06f7ade4e317c13256b92c2651b (diff) | |
| download | linux-6197fe4d720ea3e2ee94cdc7ef32d6c0151199de.tar.bz2 | |
[SPARC]: Emulate cmpxchg like parisc
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc')
| -rw-r--r-- | arch/sparc/lib/atomic32.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c index 559335f4917d..617d29832e19 100644 --- a/arch/sparc/lib/atomic32.c +++ b/arch/sparc/lib/atomic32.c @@ -2,6 +2,7 @@ * atomic32.c: 32-bit atomic_t implementation * * Copyright (C) 2004 Keith M Wesolowski + * Copyright (C) 2007 Kyle McMartin * * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf */ @@ -117,3 +118,17 @@ unsigned long ___change_bit(unsigned long *addr, unsigned long mask) return old & mask; } EXPORT_SYMBOL(___change_bit); + +unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new) +{ + unsigned long flags; + u32 prev; + + spin_lock_irqsave(ATOMIC_HASH(addr), flags); + if ((prev = *ptr) == old) + *ptr = new; + spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); + + return (unsigned long)prev; +} +EXPORT_SYMBOL(__cmpxchg_u32); |