ice: Implement basic eswitch bridge setup

With this patch, ice driver is able to track if the port
representors or uplink port were added to the linux bridge in
switchdev mode. Listen for NETDEV_CHANGEUPPER events in order to
detect this. ice_esw_br data structure reflects the linux bridge
and stores all the ports of the bridge (ice_esw_br_port) in
xarray, it's created when the first port is added to the bridge and
freed once the last port is removed. Note that only one bridge is
supported per eswitch.

Bridge port (ice_esw_br_port) can be either a VF port representor
port or uplink port (ice_esw_br_port_type). In both cases bridge port
holds a reference to the VSI, VF's VSI in case of the PR and uplink
VSI in case of the uplink. VSI's index is used as an index to the
xarray in which ports are stored.

Add a check which prevents configuring switchdev mode if uplink is
already added to any bridge. This is needed because we need to listen
for NETDEV_CHANGEUPPER events to record if the uplink was added to
the bridge. Netdevice notifier is registered after eswitch mode
is changed to switchdev.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 384 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_eswitch_br.c b/drivers/net/ethernet/intel/ice/ice_eswitch_br.c
new file mode 100644
index 000000000000..dbc077447ea1
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_eswitch_br.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023, Intel Corporation. */
+
+#include "ice.h"
+#include "ice_eswitch_br.h"
+#include "ice_repr.h"
+
+static bool ice_eswitch_br_is_dev_valid(const struct net_device *dev)
+{
+	/* Accept only PF netdev and PRs */
+	return ice_is_port_repr_netdev(dev) || netif_is_ice(dev);
+}
+
+static struct ice_esw_br_port *
+ice_eswitch_br_netdev_to_port(struct net_device *dev)
+{
+	if (ice_is_port_repr_netdev(dev)) {
+		struct ice_repr *repr = ice_netdev_to_repr(dev);
+
+		return repr->br_port;
+	} else if (netif_is_ice(dev)) {
+		struct ice_pf *pf = ice_netdev_to_pf(dev);
+
+		return pf->br_port;
+	}
+
+	return NULL;
+}
+
+static void
+ice_eswitch_br_port_deinit(struct ice_esw_br *bridge,
+			   struct ice_esw_br_port *br_port)
+{
+	struct ice_vsi *vsi = br_port->vsi;
+
+	if (br_port->type == ICE_ESWITCH_BR_UPLINK_PORT && vsi->back)
+		vsi->back->br_port = NULL;
+	else if (vsi->vf && vsi->vf->repr)
+		vsi->vf->repr->br_port = NULL;
+
+	xa_erase(&bridge->ports, br_port->vsi_idx);
+	kfree(br_port);
+}
+
+static struct ice_esw_br_port *
+ice_eswitch_br_port_init(struct ice_esw_br *bridge)
+{
+	struct ice_esw_br_port *br_port;
+
+	br_port = kzalloc(sizeof(*br_port), GFP_KERNEL);
+	if (!br_port)
+		return ERR_PTR(-ENOMEM);
+
+	br_port->bridge = bridge;
+
+	return br_port;
+}
+
+static int
+ice_eswitch_br_vf_repr_port_init(struct ice_esw_br *bridge,
+				 struct ice_repr *repr)
+{
+	struct ice_esw_br_port *br_port;
+	int err;
+
+	br_port = ice_eswitch_br_port_init(bridge);
+	if (IS_ERR(br_port))
+		return PTR_ERR(br_port);
+
+	br_port->vsi = repr->src_vsi;
+	br_port->vsi_idx = br_port->vsi->idx;
+	br_port->type = ICE_ESWITCH_BR_VF_REPR_PORT;
+	repr->br_port = br_port;
+
+	err = xa_insert(&bridge->ports, br_port->vsi_idx, br_port, GFP_KERNEL);
+	if (err) {
+		ice_eswitch_br_port_deinit(bridge, br_port);
+		return err;
+	}
+
+	return 0;
+}
+
+static int
+ice_eswitch_br_uplink_port_init(struct ice_esw_br *bridge, struct ice_pf *pf)
+{
+	struct ice_vsi *vsi = pf->switchdev.uplink_vsi;
+	struct ice_esw_br_port *br_port;
+	int err;
+
+	br_port = ice_eswitch_br_port_init(bridge);
+	if (IS_ERR(br_port))
+		return PTR_ERR(br_port);
+
+	br_port->vsi = vsi;
+	br_port->vsi_idx = br_port->vsi->idx;
+	br_port->type = ICE_ESWITCH_BR_UPLINK_PORT;
+	pf->br_port = br_port;
+
+	err = xa_insert(&bridge->ports, br_port->vsi_idx, br_port, GFP_KERNEL);
+	if (err) {
+		ice_eswitch_br_port_deinit(bridge, br_port);
+		return err;
+	}
+
+	return 0;
+}
+
+static void
+ice_eswitch_br_ports_flush(struct ice_esw_br *bridge)
+{
+	struct ice_esw_br_port *port;
+	unsigned long i;
+
+	xa_for_each(&bridge->ports, i, port)
+		ice_eswitch_br_port_deinit(bridge, port);
+}
+
+static void
+ice_eswitch_br_deinit(struct ice_esw_br_offloads *br_offloads,
+		      struct ice_esw_br *bridge)
+{
+	if (!bridge)
+		return;
+
+	/* Cleanup all the ports that were added asynchronously
+	 * through NETDEV_CHANGEUPPER event.
+	 */
+	ice_eswitch_br_ports_flush(bridge);
+	WARN_ON(!xa_empty(&bridge->ports));
+	xa_destroy(&bridge->ports);
+	br_offloads->bridge = NULL;
+	kfree(bridge);
+}
+
+static struct ice_esw_br *
+ice_eswitch_br_init(struct ice_esw_br_offloads *br_offloads, int ifindex)
+{
+	struct ice_esw_br *bridge;
+
+	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
+	if (!bridge)
+		return ERR_PTR(-ENOMEM);
+
+	bridge->br_offloads = br_offloads;
+	bridge->ifindex = ifindex;
+	xa_init(&bridge->ports);
+	br_offloads->bridge = bridge;
+
+	return bridge;
+}
+
+static struct ice_esw_br *
+ice_eswitch_br_get(struct ice_esw_br_offloads *br_offloads, int ifindex,
+		   struct netlink_ext_ack *extack)
+{
+	struct ice_esw_br *bridge = br_offloads->bridge;
+
+	if (bridge) {
+		if (bridge->ifindex != ifindex) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Only one bridge is supported per eswitch");
+			return ERR_PTR(-EOPNOTSUPP);
+		}
+		return bridge;
+	}
+
+	/* Create the bridge if it doesn't exist yet */
+	bridge = ice_eswitch_br_init(br_offloads, ifindex);
+	if (IS_ERR(bridge))
+		NL_SET_ERR_MSG_MOD(extack, "Failed to init the bridge");
+
+	return bridge;
+}
+
+static void
+ice_eswitch_br_verify_deinit(struct ice_esw_br_offloads *br_offloads,
+			     struct ice_esw_br *bridge)
+{
+	/* Remove the bridge if it exists and there are no ports left */
+	if (!bridge || !xa_empty(&bridge->ports))
+		return;
+
+	ice_eswitch_br_deinit(br_offloads, bridge);
+}
+
+static int
+ice_eswitch_br_port_unlink(struct ice_esw_br_offloads *br_offloads,
+			   struct net_device *dev, int ifindex,
+			   struct netlink_ext_ack *extack)
+{
+	struct ice_esw_br_port *br_port = ice_eswitch_br_netdev_to_port(dev);
+	struct ice_esw_br *bridge;
+
+	if (!br_port) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Port representor is not attached to any bridge");
+		return -EINVAL;
+	}
+
+	if (br_port->bridge->ifindex != ifindex) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Port representor is attached to another bridge");
+		return -EINVAL;
+	}
+
+	bridge = br_port->bridge;
+
+	ice_eswitch_br_port_deinit(br_port->bridge, br_port);
+	ice_eswitch_br_verify_deinit(br_offloads, bridge);
+
+	return 0;
+}
+
+static int
+ice_eswitch_br_port_link(struct ice_esw_br_offloads *br_offloads,
+			 struct net_device *dev, int ifindex,
+			 struct netlink_ext_ack *extack)
+{
+	struct ice_esw_br *bridge;
+	int err;
+
+	if (ice_eswitch_br_netdev_to_port(dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Port is already attached to the bridge");
+		return -EINVAL;
+	}
+
+	bridge = ice_eswitch_br_get(br_offloads, ifindex, extack);
+	if (IS_ERR(bridge))
+		return PTR_ERR(bridge);
+
+	if (ice_is_port_repr_netdev(dev)) {
+		struct ice_repr *repr = ice_netdev_to_repr(dev);
+
+		err = ice_eswitch_br_vf_repr_port_init(bridge, repr);
+	} else {
+		struct ice_pf *pf = ice_netdev_to_pf(dev);
+
+		err = ice_eswitch_br_uplink_port_init(bridge, pf);
+	}
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to init bridge port");
+		goto err_port_init;
+	}
+
+	return 0;
+
+err_port_init:
+	ice_eswitch_br_verify_deinit(br_offloads, bridge);
+	return err;
+}
+
+static int
+ice_eswitch_br_port_changeupper(struct notifier_block *nb, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct netdev_notifier_changeupper_info *info = ptr;
+	struct ice_esw_br_offloads *br_offloads;
+	struct netlink_ext_ack *extack;
+	struct net_device *upper;
+
+	br_offloads = ice_nb_to_br_offloads(nb, netdev_nb);
+
+	if (!ice_eswitch_br_is_dev_valid(dev))
+		return 0;
+
+	upper = info->upper_dev;
+	if (!netif_is_bridge_master(upper))
+		return 0;
+
+	extack = netdev_notifier_info_to_extack(&info->info);
+
+	if (info->linking)
+		return ice_eswitch_br_port_link(br_offloads, dev,
+						upper->ifindex, extack);
+	else
+		return ice_eswitch_br_port_unlink(br_offloads, dev,
+						  upper->ifindex, extack);
+}
+
+static int
+ice_eswitch_br_port_event(struct notifier_block *nb,
+			  unsigned long event, void *ptr)
+{
+	int err = 0;
+
+	switch (event) {
+	case NETDEV_CHANGEUPPER:
+		err = ice_eswitch_br_port_changeupper(nb, ptr);
+		break;
+	}
+
+	return notifier_from_errno(err);
+}
+
+static void
+ice_eswitch_br_offloads_dealloc(struct ice_pf *pf)
+{
+	struct ice_esw_br_offloads *br_offloads = pf->switchdev.br_offloads;
+
+	ASSERT_RTNL();
+
+	if (!br_offloads)
+		return;
+
+	ice_eswitch_br_deinit(br_offloads, br_offloads->bridge);
+
+	pf->switchdev.br_offloads = NULL;
+	kfree(br_offloads);
+}
+
+static struct ice_esw_br_offloads *
+ice_eswitch_br_offloads_alloc(struct ice_pf *pf)
+{
+	struct ice_esw_br_offloads *br_offloads;
+
+	ASSERT_RTNL();
+
+	if (pf->switchdev.br_offloads)
+		return ERR_PTR(-EEXIST);
+
+	br_offloads = kzalloc(sizeof(*br_offloads), GFP_KERNEL);
+	if (!br_offloads)
+		return ERR_PTR(-ENOMEM);
+
+	pf->switchdev.br_offloads = br_offloads;
+	br_offloads->pf = pf;
+
+	return br_offloads;
+}
+
+void
+ice_eswitch_br_offloads_deinit(struct ice_pf *pf)
+{
+	struct ice_esw_br_offloads *br_offloads;
+
+	br_offloads = pf->switchdev.br_offloads;
+	if (!br_offloads)
+		return;
+
+	unregister_netdevice_notifier(&br_offloads->netdev_nb);
+	/* Although notifier block is unregistered just before,
+	 * so we don't get any new events, some events might be
+	 * already in progress. Hold the rtnl lock and wait for
+	 * them to finished.
+	 */
+	rtnl_lock();
+	ice_eswitch_br_offloads_dealloc(pf);
+	rtnl_unlock();
+}
+
+int
+ice_eswitch_br_offloads_init(struct ice_pf *pf)
+{
+	struct ice_esw_br_offloads *br_offloads;
+	struct device *dev = ice_pf_to_dev(pf);
+	int err;
+
+	rtnl_lock();
+	br_offloads = ice_eswitch_br_offloads_alloc(pf);
+	rtnl_unlock();
+	if (IS_ERR(br_offloads)) {
+		dev_err(dev, "Failed to init eswitch bridge\n");
+		return PTR_ERR(br_offloads);
+	}
+
+	br_offloads->netdev_nb.notifier_call = ice_eswitch_br_port_event;
+	err = register_netdevice_notifier(&br_offloads->netdev_nb);
+	if (err) {
+		dev_err(dev,
+			"Failed to register bridge port event notifier\n");
+		goto err_reg_netdev_nb;
+	}
+
+	return 0;
+
+err_reg_netdev_nb:
+	rtnl_lock();
+	ice_eswitch_br_offloads_dealloc(pf);
+	rtnl_unlock();
+
+	return err;
+}