xen: maintain clock offset over save/restore

Hook into the device model to make sure that timekeeping's resume handler
is called.  This deals with our clocksource's non-monotonicity over the
save/restore.  Explicitly call clock_has_changed() to make sure that
all the timers get retriggered properly.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/xen/time.c

@@ -572,14 +572,6 @@ void xen_setup_cpu_clockevents(void)
 	clockevents_register_device(&__get_cpu_var(xen_clock_events));
 }
 
-void xen_time_suspend(void)
-{
-}
-
-void xen_time_resume(void)
-{
-}
-
 __init void xen_time_init(void)
 {
 	int cpu = smp_processor_id();

drivers/xen/manage.c

@@ -34,14 +34,21 @@ static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
 static int xen_suspend(void *data)
 {
 	int *cancelled = data;
+	int err;
 
 	BUG_ON(!irqs_disabled());
 
 	load_cr3(swapper_pg_dir);
 
+	err = device_power_down(PMSG_SUSPEND);
+	if (err) {
+		printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n",
+		       err);
+		return err;
+	}
+
 	xen_mm_pin_all();
 	gnttab_suspend();
-	xen_time_suspend();
 	xen_pre_suspend();
 
 	/*
@@ -52,10 +59,11 @@ static int xen_suspend(void *data)
 	*cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info));
 
 	xen_post_suspend(*cancelled);
-	xen_time_resume();
 	gnttab_resume();
 	xen_mm_unpin_all();
 
+	device_power_up();
+
 	if (!*cancelled) {
 		xen_irq_resume();
 		xen_console_resume();
@@ -105,7 +113,8 @@ static void do_suspend(void)
 
 	device_resume();
 
-
+	/* Make sure timer events get retriggered on all CPUs */
+	clock_was_set();
 out:
 #ifdef CONFIG_PREEMPT
 	thaw_processes();

include/xen/xen-ops.h

@@ -11,7 +11,4 @@ void xen_post_suspend(int suspend_cancelled);
 void xen_mm_pin_all(void);
 void xen_mm_unpin_all(void);
 
-void xen_time_suspend(void);
-void xen_time_resume(void);
-
 #endif /* INCLUDE_XEN_OPS_H */