Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 5 insertions, 3 deletions

diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index 53283e2540b3..f038e33e6d48 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");