mlxsw: spectrum_router: Introduce loopback RIFs

When offloading L3 tunnels, an adjacency entry is created that loops the
packet back into the underlay router. Loopback interfaces then hold the
corresponding information and are created for IP-in-IP netdevices.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -77,6 +77,7 @@ enum mlxsw_sp_rif_type {
 	MLXSW_SP_RIF_TYPE_SUBPORT,
 	MLXSW_SP_RIF_TYPE_VLAN,
 	MLXSW_SP_RIF_TYPE_FID,
+	MLXSW_SP_RIF_TYPE_IPIP_LB, /* IP-in-IP loopback. */
 	MLXSW_SP_RIF_TYPE_MAX,
 };
 

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

 /*
  * drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
- * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016-2017 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
  * Copyright (c) 2016 Ido Schimmel <idosch@mellanox.com>
  * Copyright (c) 2016 Yotam Gigi <yotamg@mellanox.com>
+ * Copyright (c) 2017 Petr Machata <petrm@mellanox.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -51,6 +52,7 @@
 #include <net/ip_fib.h>
 #include <net/ip6_fib.h>
 #include <net/fib_rules.h>
+#include <net/ip_tunnels.h>
 #include <net/l3mdev.h>
 #include <net/addrconf.h>
 #include <net/ndisc.h>
@@ -131,6 +133,17 @@ struct mlxsw_sp_rif_subport {
 	bool lag;
 };
 
+struct mlxsw_sp_rif_ipip_lb {
+	struct mlxsw_sp_rif common;
+	struct mlxsw_sp_rif_ipip_lb_config lb_config;
+	u16 ul_vr_id; /* Reserved for Spectrum-2. */
+};
+
+struct mlxsw_sp_rif_params_ipip_lb {
+	struct mlxsw_sp_rif_params common;
+	struct mlxsw_sp_rif_ipip_lb_config lb_config;
+};
+
 struct mlxsw_sp_rif_ops {
 	enum mlxsw_sp_rif_type type;
 	size_t rif_size;
@@ -883,6 +896,25 @@ static void mlxsw_sp_vrs_fini(struct mlxsw_sp *mlxsw_sp)
 	kfree(mlxsw_sp->router->vrs);
 }
 
+static struct net_device *
+__mlxsw_sp_ipip_netdev_ul_dev_get(const struct net_device *ol_dev)
+{
+	struct ip_tunnel *tun = netdev_priv(ol_dev);
+	struct net *net = dev_net(ol_dev);
+
+	return __dev_get_by_index(net, tun->parms.link);
+}
+
+static u32 mlxsw_sp_ipip_dev_ul_tb_id(const struct net_device *ol_dev)
+{
+	struct net_device *d = __mlxsw_sp_ipip_netdev_ul_dev_get(ol_dev);
+
+	if (d)
+		return l3mdev_fib_table(d) ? : RT_TABLE_MAIN;
+	else
+		return l3mdev_fib_table(ol_dev) ? : RT_TABLE_MAIN;
+}
+
 struct mlxsw_sp_neigh_key {
 	struct neighbour *n;
 };
@@ -2236,6 +2268,25 @@ static void mlxsw_sp_nexthop_neigh_fini(struct mlxsw_sp *mlxsw_sp,
 	neigh_release(n);
 }
 
+static bool mlxsw_sp_netdev_ipip_type(const struct mlxsw_sp *mlxsw_sp,
+				      const struct net_device *dev,
+				      enum mlxsw_sp_ipip_type *p_type)
+{
+	struct mlxsw_sp_router *router = mlxsw_sp->router;
+	const struct mlxsw_sp_ipip_ops *ipip_ops;
+	enum mlxsw_sp_ipip_type ipipt;
+
+	for (ipipt = 0; ipipt < MLXSW_SP_IPIP_TYPE_MAX; ++ipipt) {
+		ipip_ops = router->ipip_ops_arr[ipipt];
+		if (dev->type == ipip_ops->dev_type) {
+			if (p_type)
+				*p_type = ipipt;
+			return true;
+		}
+	}
+	return false;
+}
+
 static int mlxsw_sp_nexthop4_init(struct mlxsw_sp *mlxsw_sp,
 				  struct mlxsw_sp_nexthop_group *nh_grp,
 				  struct mlxsw_sp_nexthop *nh,
@@ -4374,7 +4425,10 @@ mlxsw_sp_dev_rif_type(const struct mlxsw_sp *mlxsw_sp,
 {
 	enum mlxsw_sp_fid_type type;
 
-	/* RIF type is derived from the type of the underlying FID */
+	if (mlxsw_sp_netdev_ipip_type(mlxsw_sp, dev, NULL))
+		return MLXSW_SP_RIF_TYPE_IPIP_LB;
+
+	/* Otherwise RIF type is derived from the type of the underlying FID. */
 	if (is_vlan_dev(dev) && netif_is_bridge_master(vlan_dev_real_dev(dev)))
 		type = MLXSW_SP_FID_TYPE_8021Q;
 	else if (netif_is_bridge_master(dev) && br_vlan_enabled(dev))
@@ -5164,10 +5218,104 @@ static const struct mlxsw_sp_rif_ops mlxsw_sp_rif_fid_ops = {
 	.fid_get		= mlxsw_sp_rif_fid_fid_get,
 };
 
+static struct mlxsw_sp_rif_ipip_lb *
+mlxsw_sp_rif_ipip_lb_rif(struct mlxsw_sp_rif *rif)
+{
+	return container_of(rif, struct mlxsw_sp_rif_ipip_lb, common);
+}
+
+static void
+mlxsw_sp_rif_ipip_lb_setup(struct mlxsw_sp_rif *rif,
+			   const struct mlxsw_sp_rif_params *params)
+{
+	struct mlxsw_sp_rif_params_ipip_lb *params_lb;
+	struct mlxsw_sp_rif_ipip_lb *rif_lb;
+
+	params_lb = container_of(params, struct mlxsw_sp_rif_params_ipip_lb,
+				 common);
+	rif_lb = mlxsw_sp_rif_ipip_lb_rif(rif);
+	rif_lb->lb_config = params_lb->lb_config;
+}
+
+static int
+mlxsw_sp_rif_ipip_lb_op(struct mlxsw_sp_rif_ipip_lb *lb_rif,
+			struct mlxsw_sp_vr *ul_vr, bool enable)
+{
+	struct mlxsw_sp_rif_ipip_lb_config lb_cf = lb_rif->lb_config;
+	struct mlxsw_sp_rif *rif = &lb_rif->common;
+	struct mlxsw_sp *mlxsw_sp = rif->mlxsw_sp;
+	char ritr_pl[MLXSW_REG_RITR_LEN];
+	u32 saddr4;
+
+	switch (lb_cf.ul_protocol) {
+	case MLXSW_SP_L3_PROTO_IPV4:
+		saddr4 = be32_to_cpu(lb_cf.saddr.addr4);
+		mlxsw_reg_ritr_pack(ritr_pl, enable, MLXSW_REG_RITR_LOOPBACK_IF,
+				    rif->rif_index, rif->vr_id, rif->dev->mtu);
+		mlxsw_reg_ritr_loopback_ipip4_pack(ritr_pl, lb_cf.lb_ipipt,
+			    MLXSW_REG_RITR_LOOPBACK_IPIP_OPTIONS_GRE_KEY_PRESET,
+			    ul_vr->id, saddr4, lb_cf.okey);
+		break;
+
+	case MLXSW_SP_L3_PROTO_IPV6:
+		return -EAFNOSUPPORT;
+	}
+
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(ritr), ritr_pl);
+}
+
+static int
+mlxsw_sp_rif_ipip_lb_configure(struct mlxsw_sp_rif *rif)
+{
+	struct mlxsw_sp_rif_ipip_lb *lb_rif = mlxsw_sp_rif_ipip_lb_rif(rif);
+	u32 ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(rif->dev);
+	struct mlxsw_sp *mlxsw_sp = rif->mlxsw_sp;
+	struct mlxsw_sp_vr *ul_vr;
+	int err;
+
+	ul_vr = mlxsw_sp_vr_get(mlxsw_sp, ul_tb_id);
+	if (IS_ERR(ul_vr))
+		return PTR_ERR(ul_vr);
+
+	err = mlxsw_sp_rif_ipip_lb_op(lb_rif, ul_vr, true);
+	if (err)
+		goto err_loopback_op;
+
+	lb_rif->ul_vr_id = ul_vr->id;
+	++ul_vr->rif_count;
+	return 0;
+
+err_loopback_op:
+	mlxsw_sp_vr_put(ul_vr);
+	return err;
+}
+
+static void mlxsw_sp_rif_ipip_lb_deconfigure(struct mlxsw_sp_rif *rif)
+{
+	struct mlxsw_sp_rif_ipip_lb *lb_rif = mlxsw_sp_rif_ipip_lb_rif(rif);
+	struct mlxsw_sp *mlxsw_sp = rif->mlxsw_sp;
+	struct mlxsw_sp_vr *ul_vr;
+
+	ul_vr = &mlxsw_sp->router->vrs[lb_rif->ul_vr_id];
+	mlxsw_sp_rif_ipip_lb_op(lb_rif, ul_vr, false);
+
+	--ul_vr->rif_count;
+	mlxsw_sp_vr_put(ul_vr);
+}
+
+static const struct mlxsw_sp_rif_ops mlxsw_sp_rif_ipip_lb_ops = {
+	.type			= MLXSW_SP_RIF_TYPE_IPIP_LB,
+	.rif_size		= sizeof(struct mlxsw_sp_rif_ipip_lb),
+	.setup                  = mlxsw_sp_rif_ipip_lb_setup,
+	.configure		= mlxsw_sp_rif_ipip_lb_configure,
+	.deconfigure		= mlxsw_sp_rif_ipip_lb_deconfigure,
+};
+
 static const struct mlxsw_sp_rif_ops *mlxsw_sp_rif_ops_arr[] = {
 	[MLXSW_SP_RIF_TYPE_SUBPORT]	= &mlxsw_sp_rif_subport_ops,
 	[MLXSW_SP_RIF_TYPE_VLAN]	= &mlxsw_sp_rif_vlan_ops,
 	[MLXSW_SP_RIF_TYPE_FID]		= &mlxsw_sp_rif_fid_ops,
+	[MLXSW_SP_RIF_TYPE_IPIP_LB]	= &mlxsw_sp_rif_ipip_lb_ops,
 };
 
 static int mlxsw_sp_rifs_init(struct mlxsw_sp *mlxsw_sp)

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h

@@ -36,12 +36,25 @@
 #define _MLXSW_ROUTER_H_
 
 #include "spectrum.h"
+#include "reg.h"
 
 enum mlxsw_sp_l3proto {
 	MLXSW_SP_L3_PROTO_IPV4,
 	MLXSW_SP_L3_PROTO_IPV6,
 };
 
+union mlxsw_sp_l3addr {
+	__be32 addr4;
+	struct in6_addr addr6;
+};
+
+struct mlxsw_sp_rif_ipip_lb_config {
+	enum mlxsw_reg_ritr_loopback_ipip_type lb_ipipt;
+	u32 okey;
+	enum mlxsw_sp_l3proto ul_protocol; /* Underlay. */
+	union mlxsw_sp_l3addr saddr;
+};
+
 enum mlxsw_sp_rif_counter_dir {
 	MLXSW_SP_RIF_COUNTER_INGRESS,
 	MLXSW_SP_RIF_COUNTER_EGRESS,