[src/trunk]: src/sys/external/bsd/common/include/asm Fix mb/wmb/rmb on aarch6...

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

details:   https://anonhg.NetBSD.org/src/rev/0753f164fcc9
branches:  trunk
changeset: 955919:0753f164fcc9
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Fri Oct 16 22:39:21 2020 +0000

description:
Fix mb/wmb/rmb on aarch64 to use dsb instead of dmb.

diffstat:

 sys/external/bsd/common/include/asm/barrier.h |  14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diffs (38 lines):

diff -r d446220d9320 -r 0753f164fcc9 sys/external/bsd/common/include/asm/barrier.h
--- a/sys/external/bsd/common/include/asm/barrier.h     Fri Oct 16 20:51:54 2020 +0000
+++ b/sys/external/bsd/common/include/asm/barrier.h     Fri Oct 16 22:39:21 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: barrier.h,v 1.4 2018/08/28 15:04:58 riastradh Exp $    */
+/*     $NetBSD: barrier.h,v 1.5 2020/10/16 22:39:21 jmcneill Exp $     */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -40,9 +40,15 @@
 #define        MULTIPROCESSOR  1       /* safer to assume multiprocessor */
 #endif
 
+#if defined(__aarch64__)
+#define        mb()    __asm __volatile ("dsb sy" ::: "memory")
+#define        wmb()   __asm __volatile ("dsb st" ::: "memory")
+#define        rmb()   __asm __volatile ("dsb ld" ::: "memory")
+#else
 #define        mb      membar_sync
 #define        wmb     membar_producer
 #define        rmb     membar_consumer
+#endif
 
 #ifdef __alpha__               /* XXX As if...  */
 #  define      read_barrier_depends    membar_sync
@@ -51,9 +57,9 @@
 #endif
 
 #ifdef MULTIPROCESSOR
-#  define      smp_mb                          mb
-#  define      smp_wmb                         wmb
-#  define      smp_rmb                         rmb
+#  define      smp_mb                          membar_sync
+#  define      smp_wmb                         membar_producer
+#  define      smp_rmb                         membar_consumer
 #  define      smp_read_barrier_depends        read_barrier_depends
 #else
 #  define      smp_mb()                        do {} while (0)