X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=include%2Fasm-powerpc%2Fatomic.h;h=f038e33e6d48677d0da1d5150dfc0b5f1f8a6931;hb=9b96ea662b404b9ed882c78cb844510d804a83e6;hp=147a38dcc766ed20129a497080bbcb42cd1026b2;hpb=0825788ff27c7145e9d558cb2a26f3837d1f9be5;p=linux-2.6-omap-h63xx.git

diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index 147a38dcc76..f038e33e6d4 100644
--- a/include/asm-powerpc/atomic.h
+++ b/include/asm-powerpc/atomic.h
@@ -8,6 +8,7 @@
 typedef struct { volatile int counter; } atomic_t;
 
 #ifdef __KERNEL__
+#include <linux/compiler.h>
 #include <asm/synch.h>
 #include <asm/asm-compat.h>
 
@@ -26,8 +27,8 @@ static __inline__ void atomic_add(int a, atomic_t *v)
 	PPC405_ERR77(0,%3)
 "	stwcx.	%0,0,%3 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (a), "r" (&v->counter)
 	: "cc");
 }
 
@@ -62,8 +63,8 @@ static __inline__ void atomic_sub(int a, atomic_t *v)
 	PPC405_ERR77(0,%3)
 "	stwcx.	%0,0,%3 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (a), "r" (&v->counter)
 	: "cc");
 }
 
@@ -96,8 +97,8 @@ static __inline__ void atomic_inc(atomic_t *v)
 	PPC405_ERR77(0,%2)
 "	stwcx.	%0,0,%2 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (&v->counter)
 	: "cc");
 }
 
@@ -140,8 +141,8 @@ static __inline__ void atomic_dec(atomic_t *v)
 	PPC405_ERR77(0,%2)\
 "	stwcx.	%0,0,%2\n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (&v->counter)
 	: "cc");
 }
 
@@ -176,20 +177,29 @@ static __inline__ int atomic_dec_return(atomic_t *v)
  * Atomically adds @a to @v, so long as it was not @u.
  * Returns non-zero if @v was not @u, and zero otherwise.
  */
-#define atomic_add_unless(v, a, u)			\
-({							\
-	int c, old;					\
-	c = atomic_read(v);				\
-	for (;;) {					\
-		if (unlikely(c == (u)))			\
-			break;				\
-		old = atomic_cmpxchg((v), c, c + (a));	\
-		if (likely(old == c))			\
-			break;				\
-		c = old;				\
-	}						\
-	c != (u);					\
-})
+static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
+{
+	int t;
+
+	__asm__ __volatile__ (
+	LWSYNC_ON_SMP
+"1:	lwarx	%0,0,%1		# atomic_add_unless\n\
+	cmpw	0,%0,%3 \n\
+	beq-	2f \n\
+	add	%0,%2,%0 \n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%0,0,%1 \n\
+	bne-	1b \n"
+	ISYNC_ON_SMP
+"	subf	%0,%2,%0 \n\
+2:"
+	: "=&r" (t)
+	: "r" (&v->counter), "r" (a), "r" (u)
+	: "cc", "memory");
+
+	return t != u;
+}
+
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 
 #define atomic_sub_and_test(a, v)	(atomic_sub_return((a), (v)) == 0)
@@ -197,7 +207,8 @@ static __inline__ int atomic_dec_return(atomic_t *v)
 
 /*
  * 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)
 {
@@ -206,14 +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");
 
@@ -243,8 +255,8 @@ static __inline__ void atomic64_add(long a, atomic64_t *v)
 	add	%0,%2,%0\n\
 	stdcx.	%0,0,%3 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (a), "r" (&v->counter)
 	: "cc");
 }
 
@@ -277,8 +289,8 @@ static __inline__ void atomic64_sub(long a, atomic64_t *v)
 	subf	%0,%2,%0\n\
 	stdcx.	%0,0,%3 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (a), "r" (&v->counter)
 	: "cc");
 }
 
@@ -309,8 +321,8 @@ static __inline__ void atomic64_inc(atomic64_t *v)
 	addic	%0,%0,1\n\
 	stdcx.	%0,0,%2 \n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (&v->counter)
 	: "cc");
 }
 
@@ -351,8 +363,8 @@ static __inline__ void atomic64_dec(atomic64_t *v)
 	addic	%0,%0,-1\n\
 	stdcx.	%0,0,%2\n\
 	bne-	1b"
-	: "=&r" (t), "=m" (v->counter)
-	: "r" (&v->counter), "m" (v->counter)
+	: "=&r" (t), "+m" (v->counter)
+	: "r" (&v->counter)
 	: "cc");
 }