199 	unsigned int c, p, bytes1 = 0, bytes2 = 0;  in evtchn_read()  local
236 		bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) *  in evtchn_read()
240 		bytes1 = (p - c) * sizeof(evtchn_port_t);  in evtchn_read()
245 	if (bytes1 > count) {  in evtchn_read()
246 		bytes1 = count;  in evtchn_read()
248 	} else if ((bytes1 + bytes2) > count) {  in evtchn_read()
249 		bytes2 = count - bytes1;  in evtchn_read()
254 	if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) ||  in evtchn_read()
256 	     copy_to_user(&buf[bytes1], &u->ring[0], bytes2)))  in evtchn_read()
259 	WRITE_ONCE(u->ring_cons, c + (bytes1 + bytes2) / sizeof(evtchn_port_t));  in evtchn_read()
260 	rc = bytes1 + bytes2;  in evtchn_read()