[src/trunk]: src/sys/arch/arm/include Clarify/merge two comments

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b8565c31d12a
branches:  trunk
changeset: 803700:b8565c31d12a
user:      skrll <skrll%NetBSD.org@localhost>
date:      Sat Nov 08 17:18:54 2014 +0000

description:
Clarify/merge two comments

diffstat:

 sys/arch/arm/include/mutex.h |  9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diffs (30 lines):

diff -r c1e68b9af643 -r b8565c31d12a sys/arch/arm/include/mutex.h
--- a/sys/arch/arm/include/mutex.h      Sat Nov 08 17:18:22 2014 +0000
+++ b/sys/arch/arm/include/mutex.h      Sat Nov 08 17:18:54 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mutex.h,v 1.18 2014/10/12 06:00:14 skrll Exp $ */
+/*     $NetBSD: mutex.h,v 1.19 2014/11/08 17:18:54 skrll Exp $ */
 
 /*-
  * Copyright (c) 2002, 2007 The NetBSD Foundation, Inc.
@@ -85,8 +85,8 @@
 #define        __HAVE_SIMPLE_MUTEXES           1
 
 /*
- * MUTEX_RECEIVE: no memory barrier required; we're synchronizing against
- * interrupts, not multiple processors.
+ * MUTEX_{GIVE,RECEIVE}: no memory barrier is required in the UP case;
+ * we're synchronizing against interrupts, not multiple processors.
  */
 #ifdef MULTIPROCESSOR
 #ifdef _ARM_ARCH_7
@@ -98,9 +98,6 @@
 #define        MUTEX_RECEIVE(mtx)              /* nothing */
 #endif
 
-/*
- * MUTEX_GIVE: no memory barrier required; same reason.
- */
 #ifdef MULTIPROCESSOR
 #ifdef _ARM_ARCH_7
 #define        MUTEX_GIVE(mtx)                 __asm __volatile("dsb")