net: dsa: add switch notifier

Add a notifier block per DSA switch, registered against a notifier head
in the switch fabric they belong to.

This infrastructure will allow to propagate fabric-wide events such as
port bridging, VLAN configuration, etc. If a DSA switch driver cares
about cross-chip configuration, such events can be caught.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 2cb77e64d64831796a1d621e71e0f65b826ae316..ac4ea7c3a1023684ab2bc65677bac1204cdf13ab 100644 (file)
--- 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.

diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index a3380ed0e0be56d1cc3a22be1929c63ba9090288..72912982de3d7bdfcc06be9b9b7f1aadfd419b00 100644 (file)
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -1,6 +1,7 @@
 # the core
 obj-$(CONFIG_NET_DSA) += dsa_core.o
 dsa_core-y += dsa.o slave.o dsa2.o
+dsa_core-y += dsa.o slave.o dsa2.o switch.o
 
 # tagging formats
 dsa_core-$(CONFIG_NET_DSA_TAG_BRCM) += tag_brcm.o

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index beb79ccf0f59c52cbf413c9ca684d4ce73fbf5c2..22e44f691ab9331399265addf8cd4f6d7cbc5a0e 100644 (file)
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -275,6 +275,10 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
        if (ret < 0)
                return ret;
 
+       ret = dsa_switch_register_notifier(ds);
+       if (ret)
+               return ret;
+
        if (ops->set_addr) {
                ret = ops->set_addr(ds, dst->master_netdev->dev_addr);
                if (ret < 0)
@@ -400,6 +404,8 @@ static void dsa_switch_destroy(struct dsa_switch *ds)
 
        if (ds->slave_mii_bus && ds->ops->phy_read)
                mdiobus_unregister(ds->slave_mii_bus);
+
+       dsa_switch_unregister_notifier(ds);
 }
 
 #ifdef CONFIG_PM_SLEEP

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 9f8cc26be9eac1fc3c9017636d418ceed4814aea..1c546b6621ee4545d15e68a16b4bcdb518a55eef 100644 (file)
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -294,6 +294,10 @@ static int dsa_ds_apply(struct dsa_switch_tree *dst, struct dsa_switch *ds)
        if (err < 0)
                return err;
 
+       err = dsa_switch_register_notifier(ds);
+       if (err)
+               return err;
+
        if (ds->ops->set_addr) {
                err = ds->ops->set_addr(ds, dst->master_netdev->dev_addr);
                if (err < 0)
@@ -364,6 +368,8 @@ static void dsa_ds_unapply(struct dsa_switch_tree *dst, struct dsa_switch *ds)
 
        if (ds->slave_mii_bus && ds->ops->phy_read)
                mdiobus_unregister(ds->slave_mii_bus);
+
+       dsa_switch_unregister_notifier(ds);
 }
 
 static int dsa_dst_apply(struct dsa_switch_tree *dst)

diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 591a40aea9ca0f93ef8541c4f0633a50acc4d51c..0706a511244e92ff0174173eb388a41ff59141f4 100644 (file)
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -66,6 +66,10 @@ int dsa_slave_resume(struct net_device *slave_dev);
 int dsa_slave_register_notifier(void);
 void dsa_slave_unregister_notifier(void);
 
+/* switch.c */
+int dsa_switch_register_notifier(struct dsa_switch *ds);
+void dsa_switch_unregister_notifier(struct dsa_switch *ds);
+
 /* tag_dsa.c */
 extern const struct dsa_device_ops dsa_netdev_ops;
 

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
new file mode 100644 (file)
index 0000000..e22fa76
--- /dev/null
+++ b/net/dsa/switch.c
@@ -0,0 +1,53 @@
+/*
+ * Handling of a single switch chip, part of a switch fabric
+ *
+ * Copyright (c) 2017 Vivien Didelot <vivien.didelot@savoirfairelinux.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <net/dsa.h>
+
+static int dsa_switch_event(struct notifier_block *nb,
+                           unsigned long event, void *info)
+{
+       struct dsa_switch *ds = container_of(nb, struct dsa_switch, nb);
+       int err;
+
+       switch (event) {
+       default:
+               err = -EOPNOTSUPP;
+               break;
+       }
+
+       /* Non-switchdev operations cannot be rolled back. If a DSA driver
+        * returns an error during the chained call, switch chips may be in an
+        * inconsistent state.
+        */
+       if (err)
+               dev_dbg(ds->dev, "breaking chain for DSA event %lu (%d)\n",
+                       event, err);
+
+       return notifier_from_errno(err);
+}
+
+int dsa_switch_register_notifier(struct dsa_switch *ds)
+{
+       ds->nb.notifier_call = dsa_switch_event;
+
+       return raw_notifier_chain_register(&ds->dst->nh, &ds->nb);
+}
+
+void dsa_switch_unregister_notifier(struct dsa_switch *ds)
+{
+       int err;
+
+       err = raw_notifier_chain_unregister(&ds->dst->nh, &ds->nb);
+       if (err)
+               dev_err(ds->dev, "failed to unregister notifier (%d)\n", err);
+}