1 files changed, 112 insertions, 2 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 76e5b7386af9..332dd63750a0 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -355,7 +355,7 @@ static void unbind_from_irq(unsigned int irq)
 
         spin_lock(&irq_mapping_update_lock);
 
-        if (VALID_EVTCHN(evtchn) && (--irq_bindcount[irq] == 0)) {
+        if ((--irq_bindcount[irq] == 0) && VALID_EVTCHN(evtchn)) {
                 close.port = evtchn;
                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
                         BUG();
@@ -375,7 +375,7 @@ static void unbind_from_irq(unsigned int irq)
                 evtchn_to_irq[evtchn] = -1;
                 irq_info[irq] = IRQ_UNBOUND;
 
-                dynamic_irq_init(irq);
+                dynamic_irq_cleanup(irq);
         }
 
         spin_unlock(&irq_mapping_update_lock);
@@ -557,6 +557,33 @@ out:
         put_cpu();
 }
 
+/* Rebind a new event channel to an existing irq. */
+void rebind_evtchn_irq(int evtchn, int irq)
+{
+        /* Make sure the irq is masked, since the new event channel
+           will also be masked. */
+        disable_irq(irq);
+
+        spin_lock(&irq_mapping_update_lock);
+
+        /* After resume the irq<->evtchn mappings are all cleared out */
+        BUG_ON(evtchn_to_irq[evtchn] != -1);
+        /* Expect irq to have been bound before,
+           so the bindcount should be non-0 */
+        BUG_ON(irq_bindcount[irq] == 0);
+
+        evtchn_to_irq[evtchn] = irq;
+        irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+
+        spin_unlock(&irq_mapping_update_lock);
+
+        /* new event channels are always bound to cpu 0 */
+        irq_set_affinity(irq, cpumask_of_cpu(0));
+
+        /* Unmask the event channel. */
+        enable_irq(irq);
+}
+
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
 static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 {
@@ -647,6 +674,89 @@ static int retrigger_dynirq(unsigned int irq)
         return ret;
 }
 
+static void restore_cpu_virqs(unsigned int cpu)
+{
+        struct evtchn_bind_virq bind_virq;
+        int virq, irq, evtchn;
+
+        for (virq = 0; virq < NR_VIRQS; virq++) {
+                if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
+                        continue;
+
+                BUG_ON(irq_info[irq].type != IRQT_VIRQ);
+                BUG_ON(irq_info[irq].index != virq);
+
+                /* Get a new binding from Xen. */
+                bind_virq.virq = virq;
+                bind_virq.vcpu = cpu;
+                if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+                                                &bind_virq) != 0)
+                        BUG();
+                evtchn = bind_virq.port;
+
+                /* Record the new mapping. */
+                evtchn_to_irq[evtchn] = irq;
+                irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+                bind_evtchn_to_cpu(evtchn, cpu);
+
+                /* Ready for use. */
+                unmask_evtchn(evtchn);
+        }
+}
+
+static void restore_cpu_ipis(unsigned int cpu)
+{
+        struct evtchn_bind_ipi bind_ipi;
+        int ipi, irq, evtchn;
+
+        for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
+                if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
+                        continue;
+
+                BUG_ON(irq_info[irq].type != IRQT_IPI);
+                BUG_ON(irq_info[irq].index != ipi);
+
+                /* Get a new binding from Xen. */
+                bind_ipi.vcpu = cpu;
+                if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
+                                                &bind_ipi) != 0)
+                        BUG();
+                evtchn = bind_ipi.port;
+
+                /* Record the new mapping. */
+                evtchn_to_irq[evtchn] = irq;
+                irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+                bind_evtchn_to_cpu(evtchn, cpu);
+
+                /* Ready for use. */
+                unmask_evtchn(evtchn);
+
+        }
+}
+
+void xen_irq_resume(void)
+{
+        unsigned int cpu, irq, evtchn;
+
+        init_evtchn_cpu_bindings();
+
+        /* New event-channel space is not 'live' yet. */
+        for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
+                mask_evtchn(evtchn);
+
+        /* No IRQ <-> event-channel mappings. */
+        for (irq = 0; irq < NR_IRQS; irq++)
+                irq_info[irq].evtchn = 0; /* zap event-channel binding */
+
+        for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
+                evtchn_to_irq[evtchn] = -1;
+
+        for_each_possible_cpu(cpu) {
+                restore_cpu_virqs(cpu);
+                restore_cpu_ipis(cpu);
+        }
+}
+
 static struct irq_chip xen_dynamic_chip __read_mostly = {
         .name           = "xen-dyn",
         .mask           = disable_dynirq,