xen/time: Free onlined per-cpu data structure if we want to online it again.

[mirror_ubuntu-artful-kernel.git] / arch / x86 / xen / time.c

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 3d88bfdf9e1c092a23e9d4be143630a074a92926..aec0b14b6d76b5d62de30b4405171c5e88963913 100644 (file)
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -14,6 +14,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/math64.h>
 #include <linux/gfp.h>
+#include <linux/slab.h>
 
 #include <asm/pvclock.h>
 #include <asm/xen/hypervisor.h>
@@ -377,11 +378,16 @@ 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;
@@ -395,14 +401,30 @@ static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
        return ret;
 }
 
+void xen_teardown_timer(int cpu)
+{
+       struct clock_event_device *evt;
+       BUG_ON(cpu == 0);
+       evt = &per_cpu(xen_clock_events, cpu).evt;
+
+       if (evt->irq >= 0) {
+               unbind_from_irqhandler(evt->irq, NULL);
+               evt->irq = -1;
+               kfree(per_cpu(xen_clock_events, cpu).name);
+               per_cpu(xen_clock_events, cpu).name = NULL;
+       }
+}
+
 void xen_setup_timer(int cpu)
 {
-       const char *name;
+       char *name;
        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);
+       if (evt->irq >= 0)
+               xen_teardown_timer(cpu);
 
        printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu);
 
@@ -420,22 +442,15 @@ void xen_setup_timer(int cpu)
 
        evt->cpumask = cpumask_of(cpu);
        evt->irq = irq;
+       per_cpu(xen_clock_events, cpu).name = name;
 }
 
-void xen_teardown_timer(int cpu)
-{
-       struct clock_event_device *evt;
-       BUG_ON(cpu == 0);
-       evt = &per_cpu(xen_clock_events, cpu);
-       unbind_from_irqhandler(evt->irq, NULL);
-       evt->irq = -1;
-}
 
 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)