[Xen-changelog] [xen-unstable] minios: in non-x86 case, use wmb to enforce ordering between

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1210244113 -3600
# Node ID 37cf8747f55bb1e18c01bca4ed6a2bb41c34adb6
# Parent  addfc2db07a3bfaf4b117c3fc6a34a7eb7dc6ab8
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@xxxxxxxxxxxxx>
---
 extras/mini-os/hypervisor.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletion(-)

diff -r addfc2db07a3 -r 37cf8747f55b extras/mini-os/hypervisor.c
--- a/extras/mini-os/hypervisor.c       Thu May 08 11:53:39 2008 +0100
+++ b/extras/mini-os/hypervisor.c       Thu May 08 11:55:13 2008 +0100
@@ -46,7 +46,11 @@ void do_hypervisor_callback(struct pt_re
     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 )
     {

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