From 45fadd520b7219dfb039a6bc5e8c5c1d5b66480a Mon Sep 17 00:00:00 2001
From: kettenis <kettenis@openbsd.org>
Date: Sat, 13 Jan 2018 10:58:50 +0000
Subject: [PATCH] Add a barrier at the end of pmap_map_early() such that the
 new mapping is guaranteed to be available after pmap_map_early() returns. 
 Fixes a hang seen with the in-progress SMP work.

ok patrick@
---
 sys/arch/arm64/arm64/pmap.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/arch/arm64/arm64/pmap.c b/sys/arch/arm64/arm64/pmap.c
index cfa70ba46ec..65503d8d33d 100644
--- a/sys/arch/arm64/arm64/pmap.c
+++ b/sys/arch/arm64/arm64/pmap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pmap.c,v 1.44 2018/01/12 14:52:55 kettenis Exp $ */
+/* $OpenBSD: pmap.c,v 1.45 2018/01/13 10:58:50 kettenis Exp $ */
 /*
  * Copyright (c) 2008-2009,2014-2016 Dale Rahn <drahn@dalerahn.com>
  *
@@ -2055,6 +2055,8 @@ pmap_map_early(paddr_t spa, psize_t len)
 		    ATTR_IDX(PTE_ATTR_WB) | ATTR_SH(SH_INNER) |
 		    ATTR_nG | ATTR_UXN | ATTR_AF | ATTR_AP(0);
 	}
+	__asm volatile("dsb sy");
+	__asm volatile("isb");
 }
 
 /*
-- 
2.20.1