fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / include / asm-powerpc / atomic.h

diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index 53283e2..f038e33 100644 (file)
--- 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");