bridge: mrp: Add support for role MRA

A node that has the MRA role, it can behave as MRM or MRC.

Initially it starts as MRM and sends MRP_Test frames on both ring ports.
If it detects that there are MRP_Test send by another MRM, then it
checks if these frames have a lower priority than itself. In this case
it would send MRP_Nack frames to notify the other node that it needs to
stop sending MRP_Test frames.
If it receives a MRP_Nack frame then it stops sending MRP_Test frames
and starts to behave as a MRC but it would continue to monitor the
MRP_Test frames send by MRM. If at a point the MRM stops to send
MRP_Test frames it would get the MRM role and start to send MRP_Test
frames.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private_mrp.h b/net/bridge/br_private_mrp.h
index 558941c..33b255e 100644
--- a/net/bridge/br_private_mrp.h
+++ b/net/bridge/br_private_mrp.h
@@ -26,6 +26,7 @@ struct br_mrp {
 	unsigned long			test_end;
 	u32				test_count_miss;
 	u32				test_max_miss;
+	bool				test_monitor;
 
 	u32				seq_id;
 
@@ -52,7 +53,8 @@ int br_mrp_switchdev_set_ring_role(struct net_bridge *br, struct br_mrp *mrp,
 int br_mrp_switchdev_set_ring_state(struct net_bridge *br, struct br_mrp *mrp,
 				    enum br_mrp_ring_state_type state);
 int br_mrp_switchdev_send_ring_test(struct net_bridge *br, struct br_mrp *mrp,
-				    u32 interval, u8 max_miss, u32 period);
+				    u32 interval, u8 max_miss, u32 period,
+				    bool monitor);
 int br_mrp_port_switchdev_set_state(struct net_bridge_port *p,
 				    enum br_mrp_port_state_type state);
 int br_mrp_port_switchdev_set_role(struct net_bridge_port *p,