Merge branch 'nfp-extend-flower-capabilities-for-GRE-tunnel-offload'

Jakub Kicinski says:

====================
nfp: extend flower capabilities for GRE tunnel offload

Pieter says:

This set extends the flower match and action components to offload
GRE decapsulation with classification and encapsulation actions. The
first 3 patches are refactor and cleanup patches for improving
readability and reusability. Patch 4 and 5 implement GRE decap and
encap functionality respectively.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 263 insertions, 89 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/flower/action.c b/drivers/net/ethernet/netronome/nfp/flower/action.c
index 8bea3004d66c..b6bd31fe44b2 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/action.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/action.c
@@ -170,13 +170,36 @@ nfp_fl_output(struct nfp_app *app, struct nfp_fl_output *output,
 	return 0;
 }
 
+static bool
+nfp_flower_tun_is_gre(struct tc_cls_flower_offload *flow, int start_idx)
+{
+	struct flow_action_entry *act = flow->rule->action.entries;
+	int num_act = flow->rule->action.num_entries;
+	int act_idx;
+
+	/* Preparse action list for next mirred or redirect action */
+	for (act_idx = start_idx + 1; act_idx < num_act; act_idx++)
+		if (act[act_idx].id == FLOW_ACTION_REDIRECT ||
+		    act[act_idx].id == FLOW_ACTION_MIRRED)
+			return netif_is_gretap(act[act_idx].dev);
+
+	return false;
+}
+
 static enum nfp_flower_tun_type
-nfp_fl_get_tun_from_act_l4_port(struct nfp_app *app,
-				const struct flow_action_entry *act)
+nfp_fl_get_tun_from_act(struct nfp_app *app,
+			struct tc_cls_flower_offload *flow,
+			const struct flow_action_entry *act, int act_idx)
 {
 	const struct ip_tunnel_info *tun = act->tunnel;
 	struct nfp_flower_priv *priv = app->priv;
 
+	/* Determine the tunnel type based on the egress netdev
+	 * in the mirred action for tunnels without l4.
+	 */
+	if (nfp_flower_tun_is_gre(flow, act_idx))
+		return NFP_FL_TUNNEL_GRE;
+
 	switch (tun->key.tp_dst) {
 	case htons(IANA_VXLAN_UDP_PORT):
 		return NFP_FL_TUNNEL_VXLAN;
@@ -281,15 +304,13 @@ nfp_fl_push_geneve_options(struct nfp_fl_payload *nfp_fl, int *list_len,
 }
 
 static int
-nfp_fl_set_ipv4_udp_tun(struct nfp_app *app,
-			struct nfp_fl_set_ipv4_udp_tun *set_tun,
-			const struct flow_action_entry *act,
-			struct nfp_fl_pre_tunnel *pre_tun,
-			enum nfp_flower_tun_type tun_type,
-			struct net_device *netdev,
-			struct netlink_ext_ack *extack)
+nfp_fl_set_ipv4_tun(struct nfp_app *app, struct nfp_fl_set_ipv4_tun *set_tun,
+		    const struct flow_action_entry *act,
+		    struct nfp_fl_pre_tunnel *pre_tun,
+		    enum nfp_flower_tun_type tun_type,
+		    struct net_device *netdev, struct netlink_ext_ack *extack)
 {
-	size_t act_size = sizeof(struct nfp_fl_set_ipv4_udp_tun);
+	size_t act_size = sizeof(struct nfp_fl_set_ipv4_tun);
 	const struct ip_tunnel_info *ip_tun = act->tunnel;
 	struct nfp_flower_priv *priv = app->priv;
 	u32 tmp_set_ip_tun_type_index = 0;
@@ -843,9 +864,9 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 		       enum nfp_flower_tun_type *tun_type, int *tun_out_cnt,
 		       int *out_cnt, u32 *csum_updated,
 		       struct nfp_flower_pedit_acts *set_act,
-		       struct netlink_ext_ack *extack)
+		       struct netlink_ext_ack *extack, int act_idx)
 {
-	struct nfp_fl_set_ipv4_udp_tun *set_tun;
+	struct nfp_fl_set_ipv4_tun *set_tun;
 	struct nfp_fl_pre_tunnel *pre_tun;
 	struct nfp_fl_push_vlan *psh_v;
 	struct nfp_fl_pop_vlan *pop_v;
@@ -898,7 +919,7 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 	case FLOW_ACTION_TUNNEL_ENCAP: {
 		const struct ip_tunnel_info *ip_tun = act->tunnel;
 
-		*tun_type = nfp_fl_get_tun_from_act_l4_port(app, act);
+		*tun_type = nfp_fl_get_tun_from_act(app, flow, act, act_idx);
 		if (*tun_type == NFP_FL_TUNNEL_NONE) {
 			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: unsupported tunnel type in action list");
 			return -EOPNOTSUPP;
@@ -914,7 +935,7 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 		 * If none, the packet falls back before applying other actions.
 		 */
 		if (*a_len + sizeof(struct nfp_fl_pre_tunnel) +
-		    sizeof(struct nfp_fl_set_ipv4_udp_tun) > NFP_FL_MAX_A_SIZ) {
+		    sizeof(struct nfp_fl_set_ipv4_tun) > NFP_FL_MAX_A_SIZ) {
 			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: maximum allowed action list size exceeded at tunnel encap");
 			return -EOPNOTSUPP;
 		}
@@ -928,11 +949,11 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 			return err;
 
 		set_tun = (void *)&nfp_fl->action_data[*a_len];
-		err = nfp_fl_set_ipv4_udp_tun(app, set_tun, act, pre_tun,
-					      *tun_type, netdev, extack);
+		err = nfp_fl_set_ipv4_tun(app, set_tun, act, pre_tun,
+					  *tun_type, netdev, extack);
 		if (err)
 			return err;
-		*a_len += sizeof(struct nfp_fl_set_ipv4_udp_tun);
+		*a_len += sizeof(struct nfp_fl_set_ipv4_tun);
 		}
 		break;
 	case FLOW_ACTION_TUNNEL_DECAP:
@@ -1024,8 +1045,8 @@ int nfp_flower_compile_action(struct nfp_app *app,
 			memset(&set_act, 0, sizeof(set_act));
 		err = nfp_flower_loop_action(app, act, flow, nfp_flow, &act_len,
 					     netdev, &tun_type, &tun_out_cnt,
-					     &out_cnt, &csum_updated, &set_act,
-					     extack);
+					     &out_cnt, &csum_updated,
+					     &set_act, extack, i);
 		if (err)
 			return err;
 		act_cnt++;
diff --git a/drivers/net/ethernet/netronome/nfp/flower/cmsg.h b/drivers/net/ethernet/netronome/nfp/flower/cmsg.h
index 537f7fc19584..0f1706ae5bfc 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/cmsg.h
+++ b/drivers/net/ethernet/netronome/nfp/flower/cmsg.h
@@ -8,6 +8,7 @@
 #include <linux/skbuff.h>
 #include <linux/types.h>
 #include <net/geneve.h>
+#include <net/gre.h>
 #include <net/vxlan.h>
 
 #include "../nfp_app.h"
@@ -22,6 +23,7 @@
 #define NFP_FLOWER_LAYER_CT		BIT(6)
 #define NFP_FLOWER_LAYER_VXLAN		BIT(7)
 
+#define NFP_FLOWER_LAYER2_GRE		BIT(0)
 #define NFP_FLOWER_LAYER2_GENEVE	BIT(5)
 #define NFP_FLOWER_LAYER2_GENEVE_OP	BIT(6)
 
@@ -37,6 +39,9 @@
 #define NFP_FL_IP_FRAG_FIRST		BIT(7)
 #define NFP_FL_IP_FRAGMENTED		BIT(6)
 
+/* GRE Tunnel flags */
+#define NFP_FL_GRE_FLAG_KEY		BIT(2)
+
 /* Compressed HW representation of TCP Flags */
 #define NFP_FL_TCP_FLAG_URG		BIT(4)
 #define NFP_FL_TCP_FLAG_PSH		BIT(3)
@@ -107,6 +112,7 @@
 
 enum nfp_flower_tun_type {
 	NFP_FL_TUNNEL_NONE =	0,
+	NFP_FL_TUNNEL_GRE =	1,
 	NFP_FL_TUNNEL_VXLAN =	2,
 	NFP_FL_TUNNEL_GENEVE =	4,
 };
@@ -203,7 +209,7 @@ struct nfp_fl_pre_tunnel {
 	__be32 extra[3];
 };
 
-struct nfp_fl_set_ipv4_udp_tun {
+struct nfp_fl_set_ipv4_tun {
 	struct nfp_fl_act_head head;
 	__be16 reserved;
 	__be64 tun_id __packed;
@@ -354,6 +360,16 @@ struct nfp_flower_ipv6 {
 	struct in6_addr ipv6_dst;
 };
 
+struct nfp_flower_tun_ipv4 {
+	__be32 src;
+	__be32 dst;
+};
+
+struct nfp_flower_tun_ip_ext {
+	u8 tos;
+	u8 ttl;
+};
+
 /* Flow Frame IPv4 UDP TUNNEL --> Tunnel details (4W/16B)
  * -----------------------------------------------------------------
  *    3                   2                   1
@@ -371,15 +387,42 @@ struct nfp_flower_ipv6 {
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 struct nfp_flower_ipv4_udp_tun {
-	__be32 ip_src;
-	__be32 ip_dst;
+	struct nfp_flower_tun_ipv4 ipv4;
 	__be16 reserved1;
-	u8 tos;
-	u8 ttl;
+	struct nfp_flower_tun_ip_ext ip_ext;
 	__be32 reserved2;
 	__be32 tun_id;
 };
 
+/* Flow Frame GRE TUNNEL --> Tunnel details (6W/24B)
+ * -----------------------------------------------------------------
+ *    3                   2                   1
+ *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                         ipv4_addr_src                         |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                         ipv4_addr_dst                         |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |           tun_flags           |       tos     |       ttl     |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |            Reserved           |           Ethertype           |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                              Key                              |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                           Reserved                            |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+struct nfp_flower_ipv4_gre_tun {
+	struct nfp_flower_tun_ipv4 ipv4;
+	__be16 tun_flags;
+	struct nfp_flower_tun_ip_ext ip_ext;
+	__be16 reserved1;
+	__be16 ethertype;
+	__be32 tun_key;
+	__be32 reserved2;
+};
+
 struct nfp_flower_geneve_options {
 	u8 data[NFP_FL_MAX_GENEVE_OPT_KEY];
 };
@@ -530,6 +573,8 @@ nfp_fl_netdev_is_tunnel_type(struct net_device *netdev,
 {
 	if (netif_is_vxlan(netdev))
 		return tun_type == NFP_FL_TUNNEL_VXLAN;
+	if (netif_is_gretap(netdev))
+		return tun_type == NFP_FL_TUNNEL_GRE;
 	if (netif_is_geneve(netdev))
 		return tun_type == NFP_FL_TUNNEL_GENEVE;
 
@@ -546,6 +591,8 @@ static inline bool nfp_fl_is_netdev_to_offload(struct net_device *netdev)
 		return true;
 	if (netif_is_geneve(netdev))
 		return true;
+	if (netif_is_gretap(netdev))
+		return true;
 
 	return false;
 }
diff --git a/drivers/net/ethernet/netronome/nfp/flower/match.c b/drivers/net/ethernet/netronome/nfp/flower/match.c
index 371b5be33dc7..c1690de19172 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/match.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/match.c
@@ -281,6 +281,71 @@ nfp_flower_compile_geneve_opt(void *ext, void *msk,
 }
 
 static void
+nfp_flower_compile_tun_ipv4_addrs(struct nfp_flower_tun_ipv4 *ext,
+				  struct nfp_flower_tun_ipv4 *msk,
+				  struct tc_cls_flower_offload *flow)
+{
+	struct flow_rule *rule = tc_cls_flower_offload_flow_rule(flow);
+
+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
+		struct flow_match_ipv4_addrs match;
+
+		flow_rule_match_enc_ipv4_addrs(rule, &match);
+		ext->src = match.key->src;
+		ext->dst = match.key->dst;
+		msk->src = match.mask->src;
+		msk->dst = match.mask->dst;
+	}
+}
+
+static void
+nfp_flower_compile_tun_ip_ext(struct nfp_flower_tun_ip_ext *ext,
+			      struct nfp_flower_tun_ip_ext *msk,
+			      struct tc_cls_flower_offload *flow)
+{
+	struct flow_rule *rule = tc_cls_flower_offload_flow_rule(flow);
+
+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_IP)) {
+		struct flow_match_ip match;
+
+		flow_rule_match_enc_ip(rule, &match);
+		ext->tos = match.key->tos;
+		ext->ttl = match.key->ttl;
+		msk->tos = match.mask->tos;
+		msk->ttl = match.mask->ttl;
+	}
+}
+
+static void
+nfp_flower_compile_ipv4_gre_tun(struct nfp_flower_ipv4_gre_tun *ext,
+				struct nfp_flower_ipv4_gre_tun *msk,
+				struct tc_cls_flower_offload *flow)
+{
+	struct flow_rule *rule = tc_cls_flower_offload_flow_rule(flow);
+
+	memset(ext, 0, sizeof(struct nfp_flower_ipv4_gre_tun));
+	memset(msk, 0, sizeof(struct nfp_flower_ipv4_gre_tun));
+
+	/* NVGRE is the only supported GRE tunnel type */
+	ext->ethertype = cpu_to_be16(ETH_P_TEB);
+	msk->ethertype = cpu_to_be16(~0);
+
+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
+		struct flow_match_enc_keyid match;
+
+		flow_rule_match_enc_keyid(rule, &match);
+		ext->tun_key = match.key->keyid;
+		msk->tun_key = match.mask->keyid;
+
+		ext->tun_flags = cpu_to_be16(NFP_FL_GRE_FLAG_KEY);
+		msk->tun_flags = cpu_to_be16(NFP_FL_GRE_FLAG_KEY);
+	}
+
+	nfp_flower_compile_tun_ipv4_addrs(&ext->ipv4, &msk->ipv4, flow);
+	nfp_flower_compile_tun_ip_ext(&ext->ip_ext, &msk->ip_ext, flow);
+}
+
+static void
 nfp_flower_compile_ipv4_udp_tun(struct nfp_flower_ipv4_udp_tun *ext,
 				struct nfp_flower_ipv4_udp_tun *msk,
 				struct tc_cls_flower_offload *flow)
@@ -301,25 +366,8 @@ nfp_flower_compile_ipv4_udp_tun(struct nfp_flower_ipv4_udp_tun *ext,
 		msk->tun_id = cpu_to_be32(temp_vni);
 	}
 
-	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
-		struct flow_match_ipv4_addrs match;
-
-		flow_rule_match_enc_ipv4_addrs(rule, &match);
-		ext->ip_src = match.key->src;
-		ext->ip_dst = match.key->dst;
-		msk->ip_src = match.mask->src;
-		msk->ip_dst = match.mask->dst;
-	}
-
-	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_IP)) {
-		struct flow_match_ip match;
-
-		flow_rule_match_enc_ip(rule, &match);
-		ext->tos = match.key->tos;
-		ext->ttl = match.key->ttl;
-		msk->tos = match.mask->tos;
-		msk->ttl = match.mask->ttl;
-	}
+	nfp_flower_compile_tun_ipv4_addrs(&ext->ipv4, &msk->ipv4, flow);
+	nfp_flower_compile_tun_ip_ext(&ext->ip_ext, &msk->ip_ext, flow);
 }
 
 int nfp_flower_compile_flow_match(struct nfp_app *app,
@@ -406,12 +454,27 @@ int nfp_flower_compile_flow_match(struct nfp_app *app,
 		msk += sizeof(struct nfp_flower_ipv6);
 	}
 
+	if (key_ls->key_layer_two & NFP_FLOWER_LAYER2_GRE) {
+		__be32 tun_dst;
+
+		nfp_flower_compile_ipv4_gre_tun((void *)ext, (void *)msk, flow);
+		tun_dst = ((struct nfp_flower_ipv4_gre_tun *)ext)->ipv4.dst;
+		ext += sizeof(struct nfp_flower_ipv4_gre_tun);
+		msk += sizeof(struct nfp_flower_ipv4_gre_tun);
+
+		/* Store the tunnel destination in the rule data.
+		 * This must be present and be an exact match.
+		 */
+		nfp_flow->nfp_tun_ipv4_addr = tun_dst;
+		nfp_tunnel_add_ipv4_off(app, tun_dst);
+	}
+
 	if (key_ls->key_layer & NFP_FLOWER_LAYER_VXLAN ||
 	    key_ls->key_layer_two & NFP_FLOWER_LAYER2_GENEVE) {
 		__be32 tun_dst;
 
 		nfp_flower_compile_ipv4_udp_tun((void *)ext, (void *)msk, flow);
-		tun_dst = ((struct nfp_flower_ipv4_udp_tun *)ext)->ip_dst;
+		tun_dst = ((struct nfp_flower_ipv4_udp_tun *)ext)->ipv4.dst;
 		ext += sizeof(struct nfp_flower_ipv4_udp_tun);
 		msk += sizeof(struct nfp_flower_ipv4_udp_tun);
 
diff --git a/drivers/net/ethernet/netronome/nfp/flower/offload.c b/drivers/net/ethernet/netronome/nfp/flower/offload.c
index 39e6599f2bd7..6dbe947269c3 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/offload.c
@@ -52,8 +52,7 @@
 
 #define NFP_FLOWER_WHITELIST_TUN_DISSECTOR_R \
 	(BIT(FLOW_DISSECTOR_KEY_ENC_CONTROL) | \
-	 BIT(FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) | \
-	 BIT(FLOW_DISSECTOR_KEY_ENC_PORTS))
+	 BIT(FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS))
 
 #define NFP_FLOWER_MERGE_FIELDS \
 	(NFP_FLOWER_LAYER_PORT | \
@@ -141,16 +140,16 @@ static bool nfp_flower_check_higher_than_l3(struct tc_cls_flower_offload *f)
 }
 
 static int
-nfp_flower_calc_opt_layer(struct flow_match_enc_opts *enc_opts,
+nfp_flower_calc_opt_layer(struct flow_dissector_key_enc_opts *enc_opts,
 			  u32 *key_layer_two, int *key_size,
 			  struct netlink_ext_ack *extack)
 {
-	if (enc_opts->key->len > NFP_FL_MAX_GENEVE_OPT_KEY) {
+	if (enc_opts->len > NFP_FL_MAX_GENEVE_OPT_KEY) {
 		NL_SET_ERR_MSG_MOD(extack, "unsupported offload: geneve options exceed maximum length");
 		return -EOPNOTSUPP;
 	}
 
-	if (enc_opts->key->len > 0) {
+	if (enc_opts->len > 0) {
 		*key_layer_two |= NFP_FLOWER_LAYER2_GENEVE_OP;
 		*key_size += sizeof(struct nfp_flower_geneve_options);
 	}
@@ -159,6 +158,57 @@ nfp_flower_calc_opt_layer(struct flow_match_enc_opts *enc_opts,
 }
 
 static int
+nfp_flower_calc_udp_tun_layer(struct flow_dissector_key_ports *enc_ports,
+			      struct flow_dissector_key_enc_opts *enc_op,
+			      u32 *key_layer_two, u8 *key_layer, int *key_size,
+			      struct nfp_flower_priv *priv,
+			      enum nfp_flower_tun_type *tun_type,
+			      struct netlink_ext_ack *extack)
+{
+	int err;
+
+	switch (enc_ports->dst) {
+	case htons(IANA_VXLAN_UDP_PORT):
+		*tun_type = NFP_FL_TUNNEL_VXLAN;
+		*key_layer |= NFP_FLOWER_LAYER_VXLAN;
+		*key_size += sizeof(struct nfp_flower_ipv4_udp_tun);
+
+		if (enc_op) {
+			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: encap options not supported on vxlan tunnels");
+			return -EOPNOTSUPP;
+		}
+		break;
+	case htons(GENEVE_UDP_PORT):
+		if (!(priv->flower_ext_feats & NFP_FL_FEATS_GENEVE)) {
+			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: loaded firmware does not support geneve offload");
+			return -EOPNOTSUPP;
+		}
+		*tun_type = NFP_FL_TUNNEL_GENEVE;
+		*key_layer |= NFP_FLOWER_LAYER_EXT_META;
+		*key_size += sizeof(struct nfp_flower_ext_meta);
+		*key_layer_two |= NFP_FLOWER_LAYER2_GENEVE;
+		*key_size += sizeof(struct nfp_flower_ipv4_udp_tun);
+
+		if (!enc_op)
+			break;
+		if (!(priv->flower_ext_feats & NFP_FL_FEATS_GENEVE_OPT)) {
+			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: loaded firmware does not support geneve option offload");
+			return -EOPNOTSUPP;
+		}
+		err = nfp_flower_calc_opt_layer(enc_op, key_layer_two,
+						key_size, extack);
+		if (err)
+			return err;
+		break;
+	default:
+		NL_SET_ERR_MSG_MOD(extack, "unsupported offload: tunnel type unknown");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
 nfp_flower_calculate_key_layers(struct nfp_app *app,
 				struct net_device *netdev,
 				struct nfp_fl_key_ls *ret_key_ls,
@@ -234,58 +284,51 @@ nfp_flower_calculate_key_layers(struct nfp_app *app,
 			return -EOPNOTSUPP;
 		}
 
-		flow_rule_match_enc_ports(rule, &enc_ports);
-		if (enc_ports.mask->dst != cpu_to_be16(~0)) {
-			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: only an exact match L4 destination port is supported");
-			return -EOPNOTSUPP;
-		}
-
 		if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_OPTS))
 			flow_rule_match_enc_opts(rule, &enc_op);
 
-		switch (enc_ports.key->dst) {
-		case htons(IANA_VXLAN_UDP_PORT):
-			*tun_type = NFP_FL_TUNNEL_VXLAN;
-			key_layer |= NFP_FLOWER_LAYER_VXLAN;
-			key_size += sizeof(struct nfp_flower_ipv4_udp_tun);
 
-			if (enc_op.key) {
-				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: encap options not supported on vxlan tunnels");
+		if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
+			/* check if GRE, which has no enc_ports */
+			if (netif_is_gretap(netdev)) {
+				*tun_type = NFP_FL_TUNNEL_GRE;
+				key_layer |= NFP_FLOWER_LAYER_EXT_META;
+				key_size += sizeof(struct nfp_flower_ext_meta);
+				key_layer_two |= NFP_FLOWER_LAYER2_GRE;
+				key_size +=
+					sizeof(struct nfp_flower_ipv4_gre_tun);
+
+				if (enc_op.key) {
+					NL_SET_ERR_MSG_MOD(extack, "unsupported offload: encap options not supported on GRE tunnels");
+					return -EOPNOTSUPP;
+				}
+			} else {
+				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: an exact match on L4 destination port is required for non-GRE tunnels");
 				return -EOPNOTSUPP;
 			}
-			break;
-		case htons(GENEVE_UDP_PORT):
-			if (!(priv->flower_ext_feats & NFP_FL_FEATS_GENEVE)) {
-				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: loaded firmware does not support geneve offload");
+		} else {
+			flow_rule_match_enc_ports(rule, &enc_ports);
+			if (enc_ports.mask->dst != cpu_to_be16(~0)) {
+				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: only an exact match L4 destination port is supported");
 				return -EOPNOTSUPP;
 			}
-			*tun_type = NFP_FL_TUNNEL_GENEVE;
-			key_layer |= NFP_FLOWER_LAYER_EXT_META;
-			key_size += sizeof(struct nfp_flower_ext_meta);
-			key_layer_two |= NFP_FLOWER_LAYER2_GENEVE;
-			key_size += sizeof(struct nfp_flower_ipv4_udp_tun);
 
-			if (!enc_op.key)
-				break;
-			if (!(priv->flower_ext_feats &
-			      NFP_FL_FEATS_GENEVE_OPT)) {
-				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: loaded firmware does not support geneve option offload");
-				return -EOPNOTSUPP;
-			}
-			err = nfp_flower_calc_opt_layer(&enc_op, &key_layer_two,
-							&key_size, extack);
+			err = nfp_flower_calc_udp_tun_layer(enc_ports.key,
+							    enc_op.key,
+							    &key_layer_two,
+							    &key_layer,
+							    &key_size, priv,
+							    tun_type, extack);
 			if (err)
 				return err;
-			break;
-		default:
-			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: tunnel type unknown");
-			return -EOPNOTSUPP;
-		}
 
-		/* Ensure the ingress netdev matches the expected tun type. */
-		if (!nfp_fl_netdev_is_tunnel_type(netdev, *tun_type)) {
-			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: ingress netdev does not match the expected tunnel type");
-			return -EOPNOTSUPP;
+			/* Ensure the ingress netdev matches the expected
+			 * tun type.
+			 */
+			if (!nfp_fl_netdev_is_tunnel_type(netdev, *tun_type)) {
+				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: ingress netdev does not match the expected tunnel type");
+				return -EOPNOTSUPP;
+			}
 		}
 	}