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Diffstat (limited to 'include/asm-sh/atomic.h')
-rw-r--r--include/asm-sh/atomic.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/asm-sh/atomic.h b/include/asm-sh/atomic.h
index 3c4f805da1a..a148c762d36 100644
--- a/include/asm-sh/atomic.h
+++ b/include/asm-sh/atomic.h
@@ -87,6 +87,20 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
#define atomic_inc(v) atomic_add(1,(v))
#define atomic_dec(v) atomic_sub(1,(v))
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ int ret;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ ret = v->counter;
+ if (likely(ret == old))
+ v->counter = new;
+ local_irq_restore(flags);
+
+ return ret;
+}
+
static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
unsigned long flags;