From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 8 May 2008 10:55:13 +0000 (+0100)
Subject: minios: in non-x86 case, use wmb to enforce ordering between
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14215^2~46
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=aec0c76f2272eb6551a370a24a0c53b32efbb9bf;p=xen.git

minios: in non-x86 case, use wmb to enforce ordering between
evtchn_upcall_pending and evtchn_pending_sel stores.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
---

diff --git a/extras/mini-os/hypervisor.c b/extras/mini-os/hypervisor.c
index 3bb47a424d..acc9494c01 100644
--- a/extras/mini-os/hypervisor.c
+++ b/extras/mini-os/hypervisor.c
@@ -46,7 +46,11 @@ void do_hypervisor_callback(struct pt_regs *regs)
     in_callback = 1;
    
     vcpu_info->evtchn_upcall_pending = 0;
-    /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
+    /* NB x86. No need for a barrier here -- XCHG is a barrier on x86. */
+#if !defined(__i386__) && !defined(__x86_64__)
+    /* Clear master flag /before/ clearing selector flag. */
+    wmb();
+#endif
     l1 = xchg(&vcpu_info->evtchn_pending_sel, 0);
     while ( l1 != 0 )
     {