+static inline struct per_user_data *get_port_user(unsigned port)
+{
+ return (struct per_user_data *)(port_user[port] & ~1);
+}
+
+static inline void set_port_user(unsigned port, struct per_user_data *u)
+{
+ port_user[port] = (unsigned long)u;
+}
+
+static inline bool get_port_enabled(unsigned port)
+{
+ return port_user[port] & 1;
+}
+
+static inline void set_port_enabled(unsigned port, bool enabled)
+{
+ if (enabled)
+ port_user[port] |= 1;
+ else
+ port_user[port] &= ~1;
+}
+
+static irqreturn_t evtchn_interrupt(int irq, void *data)