xen/time: Encapsulate the struct clock_event_device in another structure.

We don't do any code movement. We just encapsulate the struct clock_event_device
in a new structure which contains said structure and a pointer to
a char *name. The 'name' will be used in 'xen/time: Don't leak interrupt
name when offlining'.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/xen/time.c

@@ -377,11 +377,16 @@ static const struct clock_event_device xen_vcpuop_clockevent = {
 
 static const struct clock_event_device *xen_clockevent =
 	&xen_timerop_clockevent;
-static DEFINE_PER_CPU(struct clock_event_device, xen_clock_events) = { .irq = -1 };
+
+struct xen_clock_event_device {
+	struct clock_event_device evt;
+	char *name;
+};
+static DEFINE_PER_CPU(struct xen_clock_event_device, xen_clock_events) = { .evt.irq = -1 };
 
 static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
 {
-	struct clock_event_device *evt = &__get_cpu_var(xen_clock_events);
+	struct clock_event_device *evt = &__get_cpu_var(xen_clock_events).evt;
 	irqreturn_t ret;
 
 	ret = IRQ_NONE;
@@ -401,7 +406,7 @@ void xen_setup_timer(int cpu)
 	struct clock_event_device *evt;
 	int irq;
 
-	evt = &per_cpu(xen_clock_events, cpu);
+	evt = &per_cpu(xen_clock_events, cpu).evt;
 	WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu);
 
 	printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu);
@@ -426,7 +431,7 @@ void xen_teardown_timer(int cpu)
 {
 	struct clock_event_device *evt;
 	BUG_ON(cpu == 0);
-	evt = &per_cpu(xen_clock_events, cpu);
+	evt = &per_cpu(xen_clock_events, cpu).evt;
 	unbind_from_irqhandler(evt->irq, NULL);
 	evt->irq = -1;
 }
@@ -435,7 +440,7 @@ void xen_setup_cpu_clockevents(void)
 {
 	BUG_ON(preemptible());
 
-	clockevents_register_device(&__get_cpu_var(xen_clock_events));
+	clockevents_register_device(&__get_cpu_var(xen_clock_events).evt);
 }
 
 void xen_timer_resume(void)