Merge branch 'dsa-add-fabric-notifier'

Vivien Didelot says:

====================
net: dsa: add fabric notifier

When a switch fabric is composed of multiple switch chips, these chips
must be programmed accordingly when an event occurred on one of them.

Examples of such event include hardware bridging: when a Linux bridge
spans interconnected chips, they must be programmed to allow external
ports to ingress frames on their internal ports.

Another example is cross-chip hardware VLANs. Switch chips in-between
interconnected bridge ports must also configure a given VLAN to allow
packets to pass through them.

In order to support that, this patchset introduces a non-intrusive
notifier mechanism. It adds a notifier head in every DSA switch tree
(the said fabric), and a notifier block in every DSA switch chip.

When an even occurs, it is chained to all notifiers of the fabric.
Switch chips can react accordingly if they are cross-chip capable.

On a dynamic debug enabled system, bridging a port in a multi-chip
fabric will print something like this (ZII Rev B board):

    # brctl addif br0 lan3
    mv88e6085 0.1:00: crosschip DSA port 1.0 bridged to br0
    mv88e6085 0.4:00: crosschip DSA port 1.0 bridged to br0
    # brctl delif br0 lan3
    mv88e6085 0.1:00: crosschip DSA port 1.0 unbridged from br0
    mv88e6085 0.4:00: crosschip DSA port 1.0 unbridged from br0

Currently only bridging events are added. A patchset introducing support
for cross-chip hardware bridging configuration in mv88e6xxx will follow
right after. Then events for switchdev operations are next on the line.

We should note that non-switchdev events do not support rolling-back
switch-wide operations. We'll have to work on closer integration with
switchdev for that, like introducing new attributes or objects, to
benefit from the prepare and commit phases.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 2cb77e64d648..e9c940c8936f 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -13,6 +13,7 @@
 
 #include <linux/if_ether.h>
 #include <linux/list.h>
+#include <linux/notifier.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/of.h>
@@ -92,6 +93,9 @@ struct packet_type;
 struct dsa_switch_tree {
 	struct list_head	list;
 
+	/* Notifier chain for switch-wide events */
+	struct raw_notifier_head	nh;
+
 	/* Tree identifier */
 	u32 tree;
 
@@ -182,6 +186,9 @@ struct dsa_switch {
 	struct dsa_switch_tree	*dst;
 	int			index;
 
+	/* Listener for switch fabric events */
+	struct notifier_block	nb;
+
 	/*
 	 * Give the switch driver somewhere to hang its private data
 	 * structure.
@@ -261,6 +268,16 @@ struct switchdev_obj_port_fdb;
 struct switchdev_obj_port_mdb;
 struct switchdev_obj_port_vlan;
 
+#define DSA_NOTIFIER_BRIDGE_JOIN		1
+#define DSA_NOTIFIER_BRIDGE_LEAVE		2
+
+/* DSA_NOTIFIER_BRIDGE_* */
+struct dsa_notifier_bridge_info {
+	struct net_device *br;
+	int sw_index;
+	int port;
+};
+
 struct dsa_switch_ops {
 	/*
 	 * Probing and setup.