Merge branch 'dsa-distribute-switch-events'

Vivien Didelot says:

====================
net: dsa: distribute switch events

DSA is by nature the support for a switch fabric, which can be composed
of a single, or multiple interconnected Ethernet switch chips.

The current DSA core behavior is to identify the slave port targeted by
a request (e.g. adding a VLAN entry), and program the switch chip to
which it belongs accordingly.

This is problematic in a multi-chip environment, since all chips of a
fabric must be aware of most configuration changes. Here are some
concrete examples in a 3-chip environment:

         [CPU].................... (mdio)
    (eth0) |   :       :          :
          _|_____    _______    _______
         [__sw0__]--[__sw1__]--[__sw2__]
          |  |  |    |  |  |    |  |  |
          v  v  v    v  v  v    v  v  v
          p1 p2 p3   p4 p5 p6   p7 p8 p9

If you add a VLAN entry on p7, sw2 gets programmed, but frames won't
reach the CPU interface in a VLAN filtered setup. sw0 and sw1 also need
to be programmed. The same problem comes with MAC addresses (FDB, MDB),
or ageing time changes for instance.

This patch series uses the notification chain introduced for bridging,
to notify not only bridge, but switchdev attributes and objects events
to all switch chips of the fabric.

An ugly debug message printing the ignored event and switch info in the
code handling the switch VLAN events would give us:

    # bridge vlan add dev p7 vid 42
    sw0: ignoring DSA_NOTIFIER_VLAN_ADD for sw2 (prepare phase)
    sw1: ignoring DSA_NOTIFIER_VLAN_ADD for sw2 (prepare phase)
    sw0: ignoring DSA_NOTIFIER_VLAN_ADD for sw2 (commit phase)
    sw1: ignoring DSA_NOTIFIER_VLAN_ADD for sw2 (commit phase)

To achieve that, patches 1-8 change the scope of the bridge and
switchdev callbacks from the DSA slave device to the generic DSA port,
so that the port-wide API can be used later for switch ports not exposed
to userspace, such as CPU and DSA links.

Patches 9-15 move the DSA port specific functions in a new port.c file.

Patches 16-20 introduce new events to notify the fabric about switchdev
attributes and objects manipulation.

This patch series only adds the plumbing to support a distributed
configuration, but for the moment, each switch chip ignores events from
other chips of the fabric, to keep the current behavior.

The next patch series will add support for cross-chip configuration of
bridge ageing time, VLAN and MAC address databases operations, etc.
====================
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -285,16 +285,6 @@ static inline u8 dsa_upstream_port(struct dsa_switch *ds)
 		return ds->rtable[dst->cpu_dp->ds->index];
 }
 
-#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 {
 	/*
 	 * Legacy probing.

net/dsa/Makefile

 # the core
 obj-$(CONFIG_NET_DSA) += dsa_core.o
-dsa_core-y += dsa.o slave.o dsa2.o switch.o legacy.o
+dsa_core-y += dsa.o dsa2.o legacy.o port.o slave.o switch.o
 
 # tagging formats
 dsa_core-$(CONFIG_NET_DSA_TAG_BRCM) += tag_brcm.o

net/dsa/dsa_priv.h

@@ -16,6 +16,56 @@
 #include <linux/netpoll.h>
 #include <net/dsa.h>
 
+enum {
+	DSA_NOTIFIER_AGEING_TIME,
+	DSA_NOTIFIER_BRIDGE_JOIN,
+	DSA_NOTIFIER_BRIDGE_LEAVE,
+	DSA_NOTIFIER_FDB_ADD,
+	DSA_NOTIFIER_FDB_DEL,
+	DSA_NOTIFIER_MDB_ADD,
+	DSA_NOTIFIER_MDB_DEL,
+	DSA_NOTIFIER_VLAN_ADD,
+	DSA_NOTIFIER_VLAN_DEL,
+};
+
+/* DSA_NOTIFIER_AGEING_TIME */
+struct dsa_notifier_ageing_time_info {
+	struct switchdev_trans *trans;
+	unsigned int ageing_time;
+	int sw_index;
+};
+
+/* DSA_NOTIFIER_BRIDGE_* */
+struct dsa_notifier_bridge_info {
+	struct net_device *br;
+	int sw_index;
+	int port;
+};
+
+/* DSA_NOTIFIER_FDB_* */
+struct dsa_notifier_fdb_info {
+	const struct switchdev_obj_port_fdb *fdb;
+	struct switchdev_trans *trans;
+	int sw_index;
+	int port;
+};
+
+/* DSA_NOTIFIER_MDB_* */
+struct dsa_notifier_mdb_info {
+	const struct switchdev_obj_port_mdb *mdb;
+	struct switchdev_trans *trans;
+	int sw_index;
+	int port;
+};
+
+/* DSA_NOTIFIER_VLAN_* */
+struct dsa_notifier_vlan_info {
+	const struct switchdev_obj_port_vlan *vlan;
+	struct switchdev_trans *trans;
+	int sw_index;
+	int port;
+};
+
 struct dsa_device_ops {
 	struct sk_buff *(*xmit)(struct sk_buff *skb, struct net_device *dev);
 	struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev,
@@ -60,6 +110,39 @@ void dsa_cpu_port_ethtool_restore(struct dsa_switch *ds);
 int dsa_legacy_register(void);
 void dsa_legacy_unregister(void);
 
+/* port.c */
+int dsa_port_set_state(struct dsa_port *dp, u8 state,
+		       struct switchdev_trans *trans);
+void dsa_port_set_state_now(struct dsa_port *dp, u8 state);
+int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br);
+void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct switchdev_trans *trans);
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+			 struct switchdev_trans *trans);
+int dsa_port_fdb_add(struct dsa_port *dp,
+		     const struct switchdev_obj_port_fdb *fdb,
+		     struct switchdev_trans *trans);
+int dsa_port_fdb_del(struct dsa_port *dp,
+		     const struct switchdev_obj_port_fdb *fdb);
+int dsa_port_fdb_dump(struct dsa_port *dp, struct switchdev_obj_port_fdb *fdb,
+		      switchdev_obj_dump_cb_t *cb);
+int dsa_port_mdb_add(struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb,
+		     struct switchdev_trans *trans);
+int dsa_port_mdb_del(struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_mdb_dump(struct dsa_port *dp, struct switchdev_obj_port_mdb *mdb,
+		      switchdev_obj_dump_cb_t *cb);
+int dsa_port_vlan_add(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      struct switchdev_trans *trans);
+int dsa_port_vlan_del(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan);
+int dsa_port_vlan_dump(struct dsa_port *dp,
+		       struct switchdev_obj_port_vlan *vlan,
+		       switchdev_obj_dump_cb_t *cb);
+
 /* slave.c */
 extern const struct dsa_device_ops notag_netdev_ops;
 void dsa_slave_mii_bus_init(struct dsa_switch *ds);

net/dsa/port.c

+/*
+ * Handling of a single switch port
+ *
+ * Copyright (c) 2017 Savoir-faire Linux Inc.
+ *	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/if_bridge.h>
+#include <linux/notifier.h>
+
+#include "dsa_priv.h"
+
+static int dsa_port_notify(struct dsa_port *dp, unsigned long e, void *v)
+{
+	struct raw_notifier_head *nh = &dp->ds->dst->nh;
+	int err;
+
+	err = raw_notifier_call_chain(nh, e, v);
+
+	return notifier_to_errno(err);
+}
+
+int dsa_port_set_state(struct dsa_port *dp, u8 state,
+		       struct switchdev_trans *trans)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (switchdev_trans_ph_prepare(trans))
+		return ds->ops->port_stp_state_set ? 0 : -EOPNOTSUPP;
+
+	if (ds->ops->port_stp_state_set)
+		ds->ops->port_stp_state_set(ds, port, state);
+
+	if (ds->ops->port_fast_age) {
+		/* Fast age FDB entries or flush appropriate forwarding database
+		 * for the given port, if we are moving it from Learning or
+		 * Forwarding state, to Disabled or Blocking or Listening state.
+		 */
+
+		if ((dp->stp_state == BR_STATE_LEARNING ||
+		     dp->stp_state == BR_STATE_FORWARDING) &&
+		    (state == BR_STATE_DISABLED ||
+		     state == BR_STATE_BLOCKING ||
+		     state == BR_STATE_LISTENING))
+			ds->ops->port_fast_age(ds, port);
+	}
+
+	dp->stp_state = state;
+
+	return 0;
+}
+
+void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
+{
+	int err;
+
+	err = dsa_port_set_state(dp, state, NULL);
+	if (err)
+		pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
+}
+
+int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
+{
+	struct dsa_notifier_bridge_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.br = br,
+	};
+	int err;
+
+	/* Here the port is already bridged. Reflect the current configuration
+	 * so that drivers can program their chips accordingly.
+	 */
+	dp->bridge_dev = br;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_JOIN, &info);
+
+	/* The bridging is rolled back on error */
+	if (err)
+		dp->bridge_dev = NULL;
+
+	return err;
+}
+
+void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
+{
+	struct dsa_notifier_bridge_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.br = br,
+	};
+	int err;
+
+	/* Here the port is already unbridged. Reflect the current configuration
+	 * so that drivers can program their chips accordingly.
+	 */
+	dp->bridge_dev = NULL;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_LEAVE, &info);
+	if (err)
+		pr_err("DSA: 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
+	 */
+	dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
+}
+
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct switchdev_trans *trans)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	/* bridge skips -EOPNOTSUPP, so skip the prepare phase */
+	if (switchdev_trans_ph_prepare(trans))
+		return 0;
+
+	if (ds->ops->port_vlan_filtering)
+		return ds->ops->port_vlan_filtering(ds, dp->index,
+						    vlan_filtering);
+
+	return 0;
+}
+
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+			 struct switchdev_trans *trans)
+{
+	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
+	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
+	struct dsa_notifier_ageing_time_info info = {
+		.ageing_time = ageing_time,
+		.sw_index = dp->ds->index,
+		.trans = trans,
+	};
+
+	if (switchdev_trans_ph_prepare(trans))
+		return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+
+	dp->ageing_time = ageing_time;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+}
+
+int dsa_port_fdb_add(struct dsa_port *dp,
+		     const struct switchdev_obj_port_fdb *fdb,
+		     struct switchdev_trans *trans)
+{
+	struct dsa_notifier_fdb_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.trans = trans,
+		.fdb = fdb,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_ADD, &info);
+}
+
+int dsa_port_fdb_del(struct dsa_port *dp,
+		     const struct switchdev_obj_port_fdb *fdb)
+{
+	struct dsa_notifier_fdb_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.fdb = fdb,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_DEL, &info);
+}
+
+int dsa_port_fdb_dump(struct dsa_port *dp, struct switchdev_obj_port_fdb *fdb,
+		      switchdev_obj_dump_cb_t *cb)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->port_fdb_dump)
+		return ds->ops->port_fdb_dump(ds, dp->index, fdb, cb);
+
+	return -EOPNOTSUPP;
+}
+
+int dsa_port_mdb_add(struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb,
+		     struct switchdev_trans *trans)
+{
+	struct dsa_notifier_mdb_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.trans = trans,
+		.mdb = mdb,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_ADD, &info);
+}
+
+int dsa_port_mdb_del(struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_notifier_mdb_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.mdb = mdb,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_DEL, &info);
+}
+
+int dsa_port_mdb_dump(struct dsa_port *dp, struct switchdev_obj_port_mdb *mdb,
+		      switchdev_obj_dump_cb_t *cb)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->port_mdb_dump)
+		return ds->ops->port_mdb_dump(ds, dp->index, mdb, cb);
+
+	return -EOPNOTSUPP;
+}
+
+int dsa_port_vlan_add(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      struct switchdev_trans *trans)
+{
+	struct dsa_notifier_vlan_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.trans = trans,
+		.vlan = vlan,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
+}
+
+int dsa_port_vlan_del(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan)
+{
+	struct dsa_notifier_vlan_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.vlan = vlan,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
+}
+
+int dsa_port_vlan_dump(struct dsa_port *dp,
+		       struct switchdev_obj_port_vlan *vlan,
+		       switchdev_obj_dump_cb_t *cb)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->port_vlan_dump)
+		return ds->ops->port_vlan_dump(ds, dp->index, vlan, cb);
+
+	return -EOPNOTSUPP;
+}

net/dsa/switch.c

@@ -12,9 +12,52 @@
 
 #include <linux/netdevice.h>
 #include <linux/notifier.h>
+#include <net/switchdev.h>
 
 #include "dsa_priv.h"
 
+static unsigned int dsa_switch_fastest_ageing_time(struct dsa_switch *ds,
+						   unsigned int ageing_time)
+{
+	int i;
+
+	for (i = 0; i < ds->num_ports; ++i) {
+		struct dsa_port *dp = &ds->ports[i];
+
+		if (dp->ageing_time && dp->ageing_time < ageing_time)
+			ageing_time = dp->ageing_time;
+	}
+
+	return ageing_time;
+}
+
+static int dsa_switch_ageing_time(struct dsa_switch *ds,
+				  struct dsa_notifier_ageing_time_info *info)
+{
+	unsigned int ageing_time = info->ageing_time;
+	struct switchdev_trans *trans = info->trans;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (switchdev_trans_ph_prepare(trans)) {
+		if (ds->ageing_time_min && ageing_time < ds->ageing_time_min)
+			return -ERANGE;
+		if (ds->ageing_time_max && ageing_time > ds->ageing_time_max)
+			return -ERANGE;
+		return 0;
+	}
+
+	/* Program the fastest ageing time in case of multiple bridges */
+	ageing_time = dsa_switch_fastest_ageing_time(ds, ageing_time);
+
+	if (ds->ops->set_ageing_time)
+		return ds->ops->set_ageing_time(ds, ageing_time);
+
+	return 0;
+}
+
 static int dsa_switch_bridge_join(struct dsa_switch *ds,
 				  struct dsa_notifier_bridge_info *info)
 {
@@ -41,6 +84,117 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 	return 0;
 }
 
+static int dsa_switch_fdb_add(struct dsa_switch *ds,
+			      struct dsa_notifier_fdb_info *info)
+{
+	const struct switchdev_obj_port_fdb *fdb = info->fdb;
+	struct switchdev_trans *trans = info->trans;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (switchdev_trans_ph_prepare(trans)) {
+		if (!ds->ops->port_fdb_prepare || !ds->ops->port_fdb_add)
+			return -EOPNOTSUPP;
+
+		return ds->ops->port_fdb_prepare(ds, info->port, fdb, trans);
+	}
+
+	ds->ops->port_fdb_add(ds, info->port, fdb, trans);
+
+	return 0;
+}
+
+static int dsa_switch_fdb_del(struct dsa_switch *ds,
+			      struct dsa_notifier_fdb_info *info)
+{
+	const struct switchdev_obj_port_fdb *fdb = info->fdb;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (!ds->ops->port_fdb_del)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_fdb_del(ds, info->port, fdb);
+}
+
+static int dsa_switch_mdb_add(struct dsa_switch *ds,
+			      struct dsa_notifier_mdb_info *info)
+{
+	const struct switchdev_obj_port_mdb *mdb = info->mdb;
+	struct switchdev_trans *trans = info->trans;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (switchdev_trans_ph_prepare(trans)) {
+		if (!ds->ops->port_mdb_prepare || !ds->ops->port_mdb_add)
+			return -EOPNOTSUPP;
+
+		return ds->ops->port_mdb_prepare(ds, info->port, mdb, trans);
+	}
+
+	ds->ops->port_mdb_add(ds, info->port, mdb, trans);
+
+	return 0;
+}
+
+static int dsa_switch_mdb_del(struct dsa_switch *ds,
+			      struct dsa_notifier_mdb_info *info)
+{
+	const struct switchdev_obj_port_mdb *mdb = info->mdb;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (!ds->ops->port_mdb_del)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_mdb_del(ds, info->port, mdb);
+}
+
+static int dsa_switch_vlan_add(struct dsa_switch *ds,
+			       struct dsa_notifier_vlan_info *info)
+{
+	const struct switchdev_obj_port_vlan *vlan = info->vlan;
+	struct switchdev_trans *trans = info->trans;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (switchdev_trans_ph_prepare(trans)) {
+		if (!ds->ops->port_vlan_prepare || !ds->ops->port_vlan_add)
+			return -EOPNOTSUPP;
+
+		return ds->ops->port_vlan_prepare(ds, info->port, vlan, trans);
+	}
+
+	ds->ops->port_vlan_add(ds, info->port, vlan, trans);
+
+	return 0;
+}
+
+static int dsa_switch_vlan_del(struct dsa_switch *ds,
+			       struct dsa_notifier_vlan_info *info)
+{
+	const struct switchdev_obj_port_vlan *vlan = info->vlan;
+
+	/* Do not care yet about other switch chips of the fabric */
+	if (ds->index != info->sw_index)
+		return 0;
+
+	if (!ds->ops->port_vlan_del)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_vlan_del(ds, info->port, vlan);
+}
+
 static int dsa_switch_event(struct notifier_block *nb,
 			    unsigned long event, void *info)
 {
@@ -48,12 +202,33 @@ static int dsa_switch_event(struct notifier_block *nb,
 	int err;
 
 	switch (event) {
+	case DSA_NOTIFIER_AGEING_TIME:
+		err = dsa_switch_ageing_time(ds, info);
+		break;
 	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;
+	case DSA_NOTIFIER_FDB_ADD:
+		err = dsa_switch_fdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_FDB_DEL:
+		err = dsa_switch_fdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_MDB_ADD:
+		err = dsa_switch_mdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_MDB_DEL:
+		err = dsa_switch_mdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_VLAN_ADD:
+		err = dsa_switch_vlan_add(ds, info);
+		break;
+	case DSA_NOTIFIER_VLAN_DEL:
+		err = dsa_switch_vlan_del(ds, info);
+		break;
 	default:
 		err = -EOPNOTSUPP;
 		break;