bnxt_en: add support for Flower based vxlan encap/decap offload

This patch adds IPv4 vxlan encap/decap action support to TC-flower
offload.

For vxlan encap, the driver maintains a tunnel encap hash-table.
When a new flow with a tunnel encap action arrives, this table
is looked up; if an encap entry exists, it uses the already
programmed encap_record_handle as the tunnel_handle in the
hwrm_cfa_flow_alloc cmd. Else, a new encap node is added and the
L2 header fields are queried via a route lookup.
hwrm_cfa_encap_record_alloc cmd is used to create a new encap
record and the encap_record_handle is used as the tunnel_handle
while adding the flow.

For vxlan decap, the driver maintains a tunnel decap hash-table.
When a new flow with a tunnel decap action arrives, this table
is looked up; if a decap entry exists, it uses the already
programmed decap_filter_handle as the tunnel_handle in the
hwrm_cfa_flow_alloc cmd. Else, a new decap node is added and
a decap_filter_handle is alloc'd via the hwrm_cfa_decap_filter_alloc
cmd. This handle is used as the tunnel_handle while adding the flow.

The code to issue the HWRM FW cmds is introduced in a follow-up patch.
Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -965,6 +965,15 @@ struct bnxt_tc_info {
 	/* hash table to store L2 keys of TC flows */
 	struct rhashtable		l2_table;
 	struct rhashtable_params	l2_ht_params;
+	/* hash table to store L2 keys for TC tunnel decap */
+	struct rhashtable		decap_l2_table;
+	struct rhashtable_params	decap_l2_ht_params;
+	/* hash table to store tunnel decap entries */
+	struct rhashtable		decap_table;
+	struct rhashtable_params	decap_ht_params;
+	/* hash table to store tunnel encap entries */
+	struct rhashtable		encap_table;
+	struct rhashtable_params	encap_ht_params;
 
 	/* lock to atomically add/del an l2 node when a flow is
 	 * added or deleted.

drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c

@@ -29,7 +29,7 @@ int bnxt_dl_register(struct bnxt *bp)
 	if (!pci_find_ext_capability(bp->pdev, PCI_EXT_CAP_ID_SRIOV))
 		return 0;
 
-	if (bp->hwrm_spec_code < 0x10800) {
+	if (bp->hwrm_spec_code < 0x10803) {
 		netdev_warn(bp->dev, "Firmware does not support SR-IOV E-Switch SWITCHDEV mode.\n");
 		return -ENOTSUPP;
 	}

drivers/net/ethernet/broadcom/bnxt/bnxt_tc.h

@@ -12,6 +12,8 @@
 
 #ifdef CONFIG_BNXT_FLOWER_OFFLOAD
 
+#include <net/ip_tunnels.h>
+
 /* Structs used for storing the filter/actions of the TC cmd.
  */
 struct bnxt_tc_l2_key {
@@ -50,6 +52,13 @@ struct bnxt_tc_l4_key {
 	};
 };
 
+struct bnxt_tc_tunnel_key {
+	struct bnxt_tc_l2_key	l2;
+	struct bnxt_tc_l3_key	l3;
+	struct bnxt_tc_l4_key	l4;
+	__be32			id;
+};
+
 struct bnxt_tc_actions {
 	u32				flags;
 #define BNXT_TC_ACTION_FLAG_FWD			BIT(0)
@@ -57,11 +66,16 @@ struct bnxt_tc_actions {
 #define BNXT_TC_ACTION_FLAG_PUSH_VLAN		BIT(3)
 #define BNXT_TC_ACTION_FLAG_POP_VLAN		BIT(4)
 #define BNXT_TC_ACTION_FLAG_DROP		BIT(5)
+#define BNXT_TC_ACTION_FLAG_TUNNEL_ENCAP	BIT(6)
+#define BNXT_TC_ACTION_FLAG_TUNNEL_DECAP	BIT(7)
 
 	u16				dst_fid;
 	struct net_device		*dst_dev;
 	__be16				push_vlan_tpid;
 	__be16				push_vlan_tci;
+
+	/* tunnel encap */
+	struct ip_tunnel_key		tun_encap_key;
 };
 
 struct bnxt_tc_flow_stats {
@@ -76,6 +90,16 @@ struct bnxt_tc_flow {
 #define BNXT_TC_FLOW_FLAGS_IPV6_ADDRS		BIT(3)
 #define BNXT_TC_FLOW_FLAGS_PORTS		BIT(4)
 #define BNXT_TC_FLOW_FLAGS_ICMP			BIT(5)
+#define BNXT_TC_FLOW_FLAGS_TUNL_ETH_ADDRS	BIT(6)
+#define BNXT_TC_FLOW_FLAGS_TUNL_IPV4_ADDRS	BIT(7)
+#define BNXT_TC_FLOW_FLAGS_TUNL_IPV6_ADDRS	BIT(8)
+#define BNXT_TC_FLOW_FLAGS_TUNL_PORTS		BIT(9)
+#define BNXT_TC_FLOW_FLAGS_TUNL_ID		BIT(10)
+#define BNXT_TC_FLOW_FLAGS_TUNNEL	(BNXT_TC_FLOW_FLAGS_TUNL_ETH_ADDRS | \
+					 BNXT_TC_FLOW_FLAGS_TUNL_IPV4_ADDRS | \
+					 BNXT_TC_FLOW_FLAGS_TUNL_IPV6_ADDRS |\
+					 BNXT_TC_FLOW_FLAGS_TUNL_PORTS |\
+					 BNXT_TC_FLOW_FLAGS_TUNL_ID)
 
 	/* flow applicable to pkts ingressing on this fid */
 	u16				src_fid;
@@ -85,6 +109,8 @@ struct bnxt_tc_flow {
 	struct bnxt_tc_l3_key		l3_mask;
 	struct bnxt_tc_l4_key		l4_key;
 	struct bnxt_tc_l4_key		l4_mask;
+	struct ip_tunnel_key		tun_key;
+	struct ip_tunnel_key		tun_mask;
 
 	struct bnxt_tc_actions		actions;
 
@@ -95,11 +121,33 @@ struct bnxt_tc_flow {
 	unsigned long			lastused; /* jiffies */
 };
 
+/* Tunnel encap/decap hash table
+ * This table is used to maintain a list of flows that use
+ * the same tunnel encap/decap params (ip_daddrs, vni, udp_dport)
+ * and the FW returned handle.
+ * A separate table is maintained for encap and decap
+ */
+struct bnxt_tc_tunnel_node {
+	struct ip_tunnel_key		key;
+	struct rhash_head		node;
+
+	/* tunnel l2 info */
+	struct bnxt_tc_l2_key		l2_info;
+
+#define	INVALID_TUNNEL_HANDLE		cpu_to_le32(0xffffffff)
+	/* tunnel handle returned by FW */
+	__le32				tunnel_handle;
+
+	u32				refcount;
+	struct rcu_head			rcu;
+};
+
 /* L2 hash table
- * This data-struct is used for L2-flow table.
- * The L2 part of a flow is stored in a hash table.
+ * The same data-struct is used for L2-flow table and L2-tunnel table.
+ * The L2 part of a flow or tunnel is stored in a hash table.
  * A flow that shares the same L2 key/mask with an
- * already existing flow must refer to it's flow handle.
+ * already existing flow/tunnel must refer to it's flow handle or
+ * decap_filter_id respectively.
  */
 struct bnxt_tc_l2_node {
 	/* hash key: first 16b of key */
@@ -110,7 +158,7 @@ struct bnxt_tc_l2_node {
 	/* a linked list of flows that share the same l2 key */
 	struct list_head	common_l2_flows;
 
-	/* number of flows sharing the l2 key */
+	/* number of flows/tunnels sharing the l2 key */
 	u16			refcount;
 
 	struct rcu_head		rcu;
@@ -130,6 +178,16 @@ struct bnxt_tc_flow_node {
 	/* for the shared_flows list maintained in l2_node */
 	struct list_head		l2_list_node;
 
+	/* tunnel encap related */
+	struct bnxt_tc_tunnel_node	*encap_node;
+
+	/* tunnel decap related */
+	struct bnxt_tc_tunnel_node	*decap_node;
+	/* L2 node in tunnel-l2 hashtable that shares flow's tunnel l2 key */
+	struct bnxt_tc_l2_node		*decap_l2_node;
+	/* for the shared_flows list maintained in tunnel decap l2_node */
+	struct list_head		decap_l2_list_node;
+
 	struct rcu_head			rcu;
 };