[PATCH 3.16 309/410] xen: Add xen_arch_suspend()

[Ben Hutchings]

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>

This is based on commit 2b953a5e994ce279904ec70220f7d4f31d380a0a
upstream, "xen: Suspend ticks on all CPUs during suspend", but
excluding the bug fix in that commit which is not needed in 3.16.
We only need the xen_arch_suspend() hook for the following fix.

Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/arch/x86/xen/suspend.c
+++ b/arch/x86/xen/suspend.c
@@ -91,8 +91,17 @@ static void xen_vcpu_notify_restore(void
 	clockevents_notify(reason, NULL);
 }
 
+static void xen_vcpu_notify_suspend(void *data)
+{
+}
+
 void xen_arch_resume(void)
 {
 	on_each_cpu(xen_vcpu_notify_restore,
 		    (void *)CLOCK_EVT_NOTIFY_RESUME, 1);
 }
+
+void xen_arch_suspend(void)
+{
+	on_each_cpu(xen_vcpu_notify_suspend, NULL, 1);
+}
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -131,6 +131,8 @@ static void do_suspend(void)
 		goto out_resume;
 	}
 
+	xen_arch_suspend();
+
 	si.cancelled = 1;
 
 	err = stop_machine(xen_suspend, &si, cpumask_of(0));
@@ -148,11 +150,12 @@ static void do_suspend(void)
 		si.cancelled = 1;
 	}
 
+	xen_arch_resume();
+
 out_resume:
-	if (!si.cancelled) {
-		xen_arch_resume();
+	if (!si.cancelled)
 		xs_resume();
-	} else
+	else
 		xs_suspend_cancel();
 
 	dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -12,6 +12,7 @@ void xen_arch_post_suspend(int suspend_c
 
 void xen_timer_resume(void);
 void xen_arch_resume(void);
+void xen_arch_suspend(void);
 
 void xen_resume_notifier_register(struct notifier_block *nb);
 void xen_resume_notifier_unregister(struct notifier_block *nb);