[RFC net-next v5 4/9] bridge: mrp: Add MRP interface.

From: Horatiu Vultur
Date: Tue Apr 14 2020 - 07:31:48 EST


Define the MRP interface.
This interface is used by the netlink to update the MRP instances and by the MRP
to make the calls to switchdev to offload it to HW.

It defines an MRP instance 'struct br_mrp' which is a list of MRP instances.
Which will be part of the 'struct net_bridge'. Each instance has 2 ring ports,
a bridge and an ID.

In case the HW can't generate MRP Test frames then the SW will generate those.

br_mrp_add - adds a new MRP instance.

br_mrp_del - deletes an existing MRP instance. Each instance has an ID(ring_id).

br_mrp_set_port_state - changes the port state. The port can be in forwarding
state, which means that the frames can pass through or in blocked state which
means that the frames can't pass through except MRP frames. This will
eventually call the switchdev API to notify the HW. This information is used
also by the SW bridge to know how to forward frames in case the HW doesn't
have this capability.

br_mrp_set_port_role - a port role can be primary or secondary. This
information is required to be pushed to HW in case the HW can generate
MRP_Test frames. Because the MRP_Test frames contains a file with this
information. Otherwise the HW will not be able to generate the frames
correctly.

br_mrp_set_ring_state - a ring can be in state open or closed. State open means
that the mrp port stopped receiving MRP_Test frames, while closed means that
the mrp port received MRP_Test frames. Similar with br_mrp_port_role, this
information is pushed in HW because the MRP_Test frames contain this
information.

br_mrp_set_ring_role - a ring can have the following roles MRM or MRC. For the
role MRM it is expected that the HW can terminate the MRP frames, notify the
SW that it stopped receiving MRP_Test frames and trapp all the other MRP
frames. While for MRC mode it is expected that the HW can forward the MRP
frames only between the MRP ports and copy MRP_Topology frames to CPU. In
case the HW doesn't support a role it needs to return an error code different
than -EOPNOTSUPP.

br_mrp_start_test - this starts/stops the generation of MRP_Test frames. To stop
the generation of frames the interval needs to have a value of 0. In this case
the userspace needs to know if the HW supports this or not. Not to have
duplicate frames(generated by HW and SW). Because if the HW supports this then
the SW will not generate anymore frames and will expect that the HW will
notify when it stopped receiving MRP frames using the function
br_mrp_port_open.

br_mrp_port_open - this function is used by drivers to notify the userspace via
a netlink callback that one of the ports stopped receiving MRP_Test frames.
This function is called only when the node has the role MRM. It is not
supposed to be called from userspace.

br_mrp_port_switchdev_add - this corresponds to the function br_mrp_add,
and will notify the HW that a MRP instance is added. The function gets
as parameter the MRP instance.

br_mrp_port_switchdev_del - this corresponds to the function br_mrp_del,
and will notify the HW that a MRP instance is removed. The function
gets as parameter the ID of the MRP instance that is removed.

br_mrp_port_switchdev_set_state - this corresponds to the function
br_mrp_set_port_state. It would notify the HW if it should block or not
non-MRP frames.

br_mrp_port_switchdev_set_port - this corresponds to the function
br_mrp_set_port_role. It would set the port role, primary or secondary.

br_mrp_switchdev_set_role - this corresponds to the function
br_mrp_set_ring_role and would set one of the role MRM or MRC.

br_mrp_switchdev_set_ring_state - this corresponds to the function
br_mrp_set_ring_state and would set the ring to be open or closed.

br_mrp_switchdev_send_ring_test - this corresponds to the function
br_mrp_start_test. This will notify the HW to start or stop generating
MRP_Test frames. Value 0 for the interval parameter means to stop generating
the frames.

Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
net/bridge/br_private_mrp.h | 61 +++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
create mode 100644 net/bridge/br_private_mrp.h

diff --git a/net/bridge/br_private_mrp.h b/net/bridge/br_private_mrp.h
new file mode 100644
index 000000000000..4915ba01c5a1
--- /dev/null
+++ b/net/bridge/br_private_mrp.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _BR_PRIVATE_MRP_H_
+#define _BR_PRIVATE_MRP_H_
+
+#include "br_private.h"
+#include <uapi/linux/mrp_bridge.h>
+
+struct br_mrp {
+ /* list of mrp instances */
+ struct list_head __rcu list;
+
+ struct net_bridge_port __rcu *p_port;
+ struct net_bridge_port __rcu *s_port;
+
+ u32 ring_id;
+
+ enum br_mrp_ring_role_type ring_role;
+ u8 ring_role_offloaded;
+ enum br_mrp_ring_state_type ring_state;
+ u32 ring_transitions;
+
+ struct delayed_work test_work;
+ u32 test_interval;
+ unsigned long test_end;
+ u32 test_count_miss;
+ u32 test_max_miss;
+
+ u32 seq_id;
+};
+
+/* br_mrp.c */
+int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance);
+int br_mrp_del(struct net_bridge *br, struct br_mrp_instance *instance);
+int br_mrp_set_port_state(struct net_bridge_port *p,
+ enum br_mrp_port_state_type state);
+int br_mrp_set_port_role(struct net_bridge_port *p,
+ struct br_mrp_port_role *role);
+int br_mrp_set_ring_state(struct net_bridge *br,
+ struct br_mrp_ring_state *state);
+int br_mrp_set_ring_role(struct net_bridge *br, struct br_mrp_ring_role *role);
+int br_mrp_start_test(struct net_bridge *br, struct br_mrp_start_test *test);
+
+/* br_mrp_switchdev.c */
+int br_mrp_switchdev_add(struct net_bridge *br, struct br_mrp *mrp);
+int br_mrp_switchdev_del(struct net_bridge *br, struct br_mrp *mrp);
+int br_mrp_switchdev_set_ring_role(struct net_bridge *br, struct br_mrp *mrp,
+ enum br_mrp_ring_role_type role);
+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);
+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,
+ enum br_mrp_port_role_type role);
+
+/* br_mrp_netlink.c */
+int br_mrp_port_open(struct net_device *dev, u8 loc);
+
+#endif /* _BR_PRIVATE_MRP_H */
--
2.17.1