xen/evtchn: support more than 4096 ports

Remove the check during unbind for NR_EVENT_CHANNELS as this limits
support to less than 4096 ports.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

3 files changed, 14 insertions, 6 deletions

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index c6d64f1e191c..9d0d88cf74af 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -952,6 +952,19 @@ static int find_virq(unsigned int virq, unsigned int cpu)
 	return rc;
 }
 
+/**
+ * xen_evtchn_nr_channels - number of usable event channel ports
+ *
+ * This may be less than the maximum supported by the current
+ * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
+ * supported.
+ */
+unsigned xen_evtchn_nr_channels(void)
+{
+        return evtchn_ops->nr_channels();
+}
+EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
+
 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 {
 	struct evtchn_bind_virq bind_virq;
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index a3d9aeceda1a..2862e1cccf1c 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -85,11 +85,6 @@ static inline unsigned xen_evtchn_max_channels(void)
 	return evtchn_ops->max_channels();
 }
 
-static inline unsigned xen_evtchn_nr_channels(void)
-{
-	return evtchn_ops->nr_channels();
-}
-
 /*
  * Do any ABI specific setup for a bound event channel before it can
  * be unmasked and used.
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 5de2063e16d3..00f40f051d95 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -417,7 +417,7 @@ static long evtchn_ioctl(struct file *file,
 			break;
 
 		rc = -EINVAL;
-		if (unbind.port >= NR_EVENT_CHANNELS)
+		if (unbind.port >= xen_evtchn_nr_channels())
 			break;
 
 		rc = -ENOTCONN;