net: dsa: introduce bridge notifier

A slave device will now notify the switch fabric once its port is
bridged or unbridged, instead of calling directly its switch operations.

This code allows propagating cross-chip bridging events in the fabric.

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 ac4ea7c..e9c940c 100644 (file)
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -268,6 +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.

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index d8c3c0f..061a49c 100644 (file)
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -27,6 +27,17 @@
 
 static bool dsa_slave_dev_check(struct net_device *dev);
 
+static int dsa_slave_notify(struct net_device *dev, unsigned long e, void *v)
+{
+       struct dsa_slave_priv *p = netdev_priv(dev);
+       struct raw_notifier_head *nh = &p->dp->ds->dst->nh;
+       int err;
+
+       err = raw_notifier_call_chain(nh, e, v);
+
+       return notifier_to_errno(err);
+}
+
 /* slave mii_bus handling ***************************************************/
 static int dsa_slave_phy_read(struct mii_bus *bus, int addr, int reg)
 {
@@ -562,39 +573,46 @@ static int dsa_slave_bridge_port_join(struct net_device *dev,
                                      struct net_device *br)
 {
        struct dsa_slave_priv *p = netdev_priv(dev);
-       struct dsa_switch *ds = p->dp->ds;
-       int ret = -EOPNOTSUPP;
+       struct dsa_notifier_bridge_info info = {
+               .sw_index = p->dp->ds->index,
+               .port = p->dp->index,
+               .br = br,
+       };
+       int err;
 
        /* Here the port is already bridged. Reflect the current configuration
         * so that drivers can program their chips accordingly.
         */
        p->dp->bridge_dev = br;
 
-       if (ds->ops->port_bridge_join)
-               ret = ds->ops->port_bridge_join(ds, p->dp->index, br);
+       err = dsa_slave_notify(dev, DSA_NOTIFIER_BRIDGE_JOIN, &info);
 
        /* The bridging is rolled back on error */
-       if (ret && ret != -EOPNOTSUPP) {
+       if (err)
                p->dp->bridge_dev = NULL;
-               return ret;
-       }
 
-       return 0;
+       return err;
 }
 
 static void dsa_slave_bridge_port_leave(struct net_device *dev,
                                        struct net_device *br)
 {
        struct dsa_slave_priv *p = netdev_priv(dev);
-       struct dsa_switch *ds = p->dp->ds;
+       struct dsa_notifier_bridge_info info = {
+               .sw_index = p->dp->ds->index,
+               .port = p->dp->index,
+               .br = br,
+       };
+       int err;
 
        /* Here the port is already unbridged. Reflect the current configuration
         * so that drivers can program their chips accordingly.
         */
        p->dp->bridge_dev = NULL;
 
-       if (ds->ops->port_bridge_leave)
-               ds->ops->port_bridge_leave(ds, p->dp->index, br);
+       err = dsa_slave_notify(dev, DSA_NOTIFIER_BRIDGE_LEAVE, &info);
+       if (err)
+               netdev_err(dev, "failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");
 
        /* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
         * so allow it to be in BR_STATE_FORWARDING to be kept functional

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index e22fa76..6456dac 100644 (file)
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -13,6 +13,32 @@
 #include <linux/notifier.h>
 #include <net/dsa.h>
 
+static int dsa_switch_bridge_join(struct dsa_switch *ds,
+                                 struct dsa_notifier_bridge_info *info)
+{
+       if (ds->index == info->sw_index && ds->ops->port_bridge_join)
+               return ds->ops->port_bridge_join(ds, info->port, info->br);
+
+       if (ds->index != info->sw_index)
+               dev_dbg(ds->dev, "crosschip DSA port %d.%d bridged to %s\n",
+                       info->sw_index, info->port, netdev_name(info->br));
+
+       return 0;
+}
+
+static int dsa_switch_bridge_leave(struct dsa_switch *ds,
+                                  struct dsa_notifier_bridge_info *info)
+{
+       if (ds->index == info->sw_index && ds->ops->port_bridge_leave)
+               ds->ops->port_bridge_leave(ds, info->port, info->br);
+
+       if (ds->index != info->sw_index)
+               dev_dbg(ds->dev, "crosschip DSA port %d.%d unbridged from %s\n",
+                       info->sw_index, info->port, netdev_name(info->br));
+
+       return 0;
+}
+
 static int dsa_switch_event(struct notifier_block *nb,
                            unsigned long event, void *info)
 {
@@ -20,6 +46,12 @@ static int dsa_switch_event(struct notifier_block *nb,
        int err;
 
        switch (event) {
+       case DSA_NOTIFIER_BRIDGE_JOIN:
+               err = dsa_switch_bridge_join(ds, info);
+               break;
+       case DSA_NOTIFIER_BRIDGE_LEAVE:
+               err = dsa_switch_bridge_leave(ds, info);
+               break;
        default:
                err = -EOPNOTSUPP;
                break;