powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER

For performance reasons we are about to change ISYNC_ON_SMP to sometimes be
lwsync. Now that the macro name doesn't make sense, change it and LWSYNC_ON_SMP
to better explain what the barriers are doing.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/mutex.h b/arch/powerpc/include/asm/mutex.h
index dabc01c..5399f7e 100644
--- a/arch/powerpc/include/asm/mutex.h
+++ b/arch/powerpc/include/asm/mutex.h
@@ -15,7 +15,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%3,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	PPC_ACQUIRE_BARRIER
 	"\n\
 2:"
 	: "=&r" (t)
@@ -35,7 +35,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	PPC_ACQUIRE_BARRIER
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "memory");
@@ -48,7 +48,7 @@
 	int t;
 
 	__asm__ __volatile__(
-	LWSYNC_ON_SMP
+	PPC_RELEASE_BARRIER
 "1:	lwarx	%0,0,%1		# mutex unlock\n\
 	addic	%0,%0,1\n"
 	PPC405_ERR77(0,%1)