[PATCH 11/13] xen: introduce xen_event_channel_register_nlevel

[Wei Liu <wei.liu2@citrix.com>]

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 drivers/xen/events.c |   46 ++++++++++++++++++++++++++++++++++++++++------
 include/xen/events.h |    6 ++++++
 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 9038211..f77909d 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -2217,17 +2217,51 @@ err:
 	return rc;
 }
 
+int xen_event_channel_register_nlevel(unsigned int level)
+{
+	int rc;
+
+	switch (level) {
+	case 3:
+		rc = xen_event_channel_register_3level();
+		break;
+	default:
+		printk(KERN_INFO "Trying to register unsupported %d-level event channel\n",
+		       level);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+void xen_set_event_channel_nlevel(unsigned int level)
+{
+	struct shared_info *s = HYPERVISOR_shared_info;
+	switch (level) {
+	case 2:
+		evtchn_pending = s->evtchn_pending;
+		evtchn_mask = s->evtchn_mask;
+		evtchn_level = 2;
+		nr_event_channels = NR_EVENT_CHANNELS_L2;
+		break;
+	case 3:
+		/* evtchn_pending/mask already set */
+		evtchn_level = 3;
+		nr_event_channels = NR_EVENT_CHANNELS_L3;
+		break;
+	default:
+		printk(KERN_EMERG "Trying to set unsupported %d-level event channel\n",
+		       level);
+		BUG();
+	}
+}
+
 void __init xen_init_IRQ(void)
 {
 	int i, rc;
 	int cpu;
-	struct shared_info *s = HYPERVISOR_shared_info;
-
-	evtchn_pending = s->evtchn_pending;
-	evtchn_mask = s->evtchn_mask;
 
-	evtchn_level = 2;
-	nr_event_channels = NR_EVENT_CHANNELS_L2;
+	xen_set_event_channel_nlevel(2);
 
 	evtchn_to_irq = kcalloc(nr_event_channels, sizeof(*evtchn_to_irq),
 				    GFP_KERNEL);
diff --git a/include/xen/events.h b/include/xen/events.h
index 6b117ac..cbc1b71 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -111,4 +111,10 @@ int xen_test_irq_shared(int irq);
 
 extern unsigned int nr_event_channels;
 
+/* Register N-level event channel */
+int xen_event_channel_register_nlevel(unsigned int level);
+
+/* Set event channel to N-level if registration succeed */
+void xen_set_event_channel_nlevel(unsigned int level);
+
 #endif	/* _XEN_EVENTS_H */
-- 
1.7.10.4