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-rw-r--r--include/asm-powerpc/atomic.h8
1 files changed, 5 insertions, 3 deletions
diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index 53283e2540b..f038e33e6d4 100644
--- a/include/asm-powerpc/atomic.h
+++ b/include/asm-powerpc/atomic.h
@@ -207,7 +207,8 @@ static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
/*
* Atomically test *v and decrement if it is greater than 0.
- * The function returns the old value of *v minus 1.
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
*/
static __inline__ int atomic_dec_if_positive(atomic_t *v)
{
@@ -216,14 +217,15 @@ static __inline__ int atomic_dec_if_positive(atomic_t *v)
__asm__ __volatile__(
LWSYNC_ON_SMP
"1: lwarx %0,0,%1 # atomic_dec_if_positive\n\
- addic. %0,%0,-1\n\
+ cmpwi %0,1\n\
+ addi %0,%0,-1\n\
blt- 2f\n"
PPC405_ERR77(0,%1)
" stwcx. %0,0,%1\n\
bne- 1b"
ISYNC_ON_SMP
"\n\
-2:" : "=&r" (t)
+2:" : "=&b" (t)
: "r" (&v->counter)
: "cc", "memory");