nfp: flower: offload tunnel decap rules via indirect TC blocks

Previously, TC block tunnel decap rules were only offloaded when a
callback was triggered through registration of the rules egress device.
This meant that the driver had no access to the ingress netdev and so
could not verify it was the same tunnel type that the rule implied.

Register tunnel devices for indirect TC block offloads in NFP, giving
access to new rules based on the ingress device rather than egress. Use
this to verify the netdev type of VXLAN and Geneve based rules and offload
the rules to HW if applicable.

Tunnel registration is done via a netdev notifier. On notifier
registration, this is triggered for already existing netdevs. This means
that NFP can register for offloads from devices that exist before it is
loaded (filter rules will be replayed from the TC core). Similarly, on
notifier unregister, a call is triggered for each currently active netdev.
This allows the driver to unregister any indirect block callbacks that may
still be active.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 133 insertions, 4 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/flower/offload.c b/drivers/net/ethernet/netronome/nfp/flower/offload.c
index 2c32edfc1a9d..222e1a98cf16 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/offload.c
@@ -128,6 +128,7 @@ nfp_flower_calc_opt_layer(struct flow_dissector_key_enc_opts *enc_opts,
 
 static int
 nfp_flower_calculate_key_layers(struct nfp_app *app,
+				struct net_device *netdev,
 				struct nfp_fl_key_ls *ret_key_ls,
 				struct tc_cls_flower_offload *flow,
 				bool egress,
@@ -186,8 +187,6 @@ nfp_flower_calculate_key_layers(struct nfp_app *app,
 			skb_flow_dissector_target(flow->dissector,
 						  FLOW_DISSECTOR_KEY_ENC_CONTROL,
 						  flow->key);
-		if (!egress)
-			return -EOPNOTSUPP;
 
 		if (mask_enc_ctl->addr_type != 0xffff ||
 		    enc_ctl->addr_type != FLOW_DISSECTOR_KEY_IPV4_ADDRS)
@@ -250,6 +249,10 @@ nfp_flower_calculate_key_layers(struct nfp_app *app,
 		default:
 			return -EOPNOTSUPP;
 		}
+
+		/* Ensure the ingress netdev matches the expected tun type. */
+		if (!nfp_fl_netdev_is_tunnel_type(netdev, *tun_type))
+			return -EOPNOTSUPP;
 	} else if (egress) {
 		/* Reject non tunnel matches offloaded to egress repr. */
 		return -EOPNOTSUPP;
@@ -451,8 +454,8 @@ nfp_flower_add_offload(struct nfp_app *app, struct net_device *netdev,
 	if (!key_layer)
 		return -ENOMEM;
 
-	err = nfp_flower_calculate_key_layers(app, key_layer, flow, egress,
-					      &tun_type);
+	err = nfp_flower_calculate_key_layers(app, netdev, key_layer, flow,
+					      egress, &tun_type);
 	if (err)
 		goto err_free_key_ls;
 
@@ -693,3 +696,129 @@ int nfp_flower_setup_tc(struct nfp_app *app, struct net_device *netdev,
 		return -EOPNOTSUPP;
 	}
 }
+
+struct nfp_flower_indr_block_cb_priv {
+	struct net_device *netdev;
+	struct nfp_app *app;
+	struct list_head list;
+};
+
+static struct nfp_flower_indr_block_cb_priv *
+nfp_flower_indr_block_cb_priv_lookup(struct nfp_app *app,
+				     struct net_device *netdev)
+{
+	struct nfp_flower_indr_block_cb_priv *cb_priv;
+	struct nfp_flower_priv *priv = app->priv;
+
+	/* All callback list access should be protected by RTNL. */
+	ASSERT_RTNL();
+
+	list_for_each_entry(cb_priv, &priv->indr_block_cb_priv, list)
+		if (cb_priv->netdev == netdev)
+			return cb_priv;
+
+	return NULL;
+}
+
+static int nfp_flower_setup_indr_block_cb(enum tc_setup_type type,
+					  void *type_data, void *cb_priv)
+{
+	struct nfp_flower_indr_block_cb_priv *priv = cb_priv;
+	struct tc_cls_flower_offload *flower = type_data;
+
+	if (flower->common.chain_index)
+		return -EOPNOTSUPP;
+
+	switch (type) {
+	case TC_SETUP_CLSFLOWER:
+		return nfp_flower_repr_offload(priv->app, priv->netdev,
+					       type_data, false);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+nfp_flower_setup_indr_tc_block(struct net_device *netdev, struct nfp_app *app,
+			       struct tc_block_offload *f)
+{
+	struct nfp_flower_indr_block_cb_priv *cb_priv;
+	struct nfp_flower_priv *priv = app->priv;
+	int err;
+
+	if (f->binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
+		return -EOPNOTSUPP;
+
+	switch (f->command) {
+	case TC_BLOCK_BIND:
+		cb_priv = kmalloc(sizeof(*cb_priv), GFP_KERNEL);
+		if (!cb_priv)
+			return -ENOMEM;
+
+		cb_priv->netdev = netdev;
+		cb_priv->app = app;
+		list_add(&cb_priv->list, &priv->indr_block_cb_priv);
+
+		err = tcf_block_cb_register(f->block,
+					    nfp_flower_setup_indr_block_cb,
+					    netdev, cb_priv, f->extack);
+		if (err) {
+			list_del(&cb_priv->list);
+			kfree(cb_priv);
+		}
+
+		return err;
+	case TC_BLOCK_UNBIND:
+		tcf_block_cb_unregister(f->block,
+					nfp_flower_setup_indr_block_cb, netdev);
+		cb_priv = nfp_flower_indr_block_cb_priv_lookup(app, netdev);
+		if (cb_priv) {
+			list_del(&cb_priv->list);
+			kfree(cb_priv);
+		}
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int
+nfp_flower_indr_setup_tc_cb(struct net_device *netdev, void *cb_priv,
+			    enum tc_setup_type type, void *type_data)
+{
+	switch (type) {
+	case TC_SETUP_BLOCK:
+		return nfp_flower_setup_indr_tc_block(netdev, cb_priv,
+						      type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+int nfp_flower_reg_indir_block_handler(struct nfp_app *app,
+				       struct net_device *netdev,
+				       unsigned long event)
+{
+	int err;
+
+	if (!nfp_fl_is_netdev_to_offload(netdev))
+		return NOTIFY_OK;
+
+	if (event == NETDEV_REGISTER) {
+		err = __tc_indr_block_cb_register(netdev, app,
+						  nfp_flower_indr_setup_tc_cb,
+						  netdev);
+		if (err)
+			nfp_flower_cmsg_warn(app,
+					     "Indirect block reg failed - %s\n",
+					     netdev->name);
+	} else if (event == NETDEV_UNREGISTER) {
+		__tc_indr_block_cb_unregister(netdev,
+					      nfp_flower_indr_setup_tc_cb,
+					      netdev);
+	}
+
+	return NOTIFY_OK;
+}