[PATCH net-next 10/11] bnge: add aRFS flow steering ndo support

[Vikas Gupta <vikas.gupta@broadcom.com>]

Introduce the ndo_rx_flow_steer callback (bnge_rx_flow_steer) to
support aRFS.
This callback creates an NTUPLE filter that steers matching packets
to the appropriate RX queue. The implementation dissects flow keys
from the SKB, creates an NTUPLE filter with the associated L2 filter,
inserts it into the NTUPLE hash table, and schedules the sp_task
workqueue via BNGE_RX_NTP_FLTR_SP_EVENT to program the filter
in the firmware.
Add bnge_cfg_ntp_filters() called from the periodic timer via sp_task
to handle deferred filter programming and expiration via
rps_may_expire_flow().

Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Dharmender Garg <dharmender.garg@broadcom.com>
---
 .../net/ethernet/broadcom/bnge/bnge_filter.c  |  45 ++++++++
 .../net/ethernet/broadcom/bnge/bnge_filter.h  |   1 +
 .../net/ethernet/broadcom/bnge/bnge_netdev.c  | 101 ++++++++++++++++++
 .../net/ethernet/broadcom/bnge/bnge_netdev.h  |   1 +
 4 files changed, 148 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_filter.c b/drivers/net/ethernet/broadcom/bnge/bnge_filter.c
index f239ec686405..6f75e08a4996 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_filter.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_filter.c
@@ -586,3 +586,48 @@ void bnge_cfg_usr_fltrs(struct bnge_net *bn)
 	list_for_each_entry_safe(usr_fltr, tmp, &bn->usr_fltr_list, list_node)
 		bnge_cfg_one_usr_fltr(bn, usr_fltr);
 }
+
+void bnge_cfg_ntp_filters(struct bnge_net *bn)
+{
+#ifdef CONFIG_RFS_ACCEL
+	struct bnge_ntuple_filter *fltr, *tmp;
+	LIST_HEAD(install_list);
+	LIST_HEAD(expire_list);
+	int i, rc;
+
+	rcu_read_lock();
+	for (i = 0; i < BNGE_NTP_FLTR_HASH_SIZE; i++) {
+		hlist_for_each_entry_rcu(fltr, &bn->ntp_fltr_hash_tbl[i],
+					 base.hlist) {
+			if (test_bit(BNGE_FLTR_VALID, &fltr->base.state)) {
+				if (fltr->base.flags & BNGE_ACT_NO_AGING)
+					continue;
+				if (rps_may_expire_flow(bn->netdev,
+							fltr->base.rxq,
+							fltr->flow_id,
+							fltr->base.sw_id))
+					list_add(&fltr->base.list_node,
+						 &expire_list);
+			} else {
+				list_add(&fltr->base.list_node, &install_list);
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	list_for_each_entry_safe(fltr, tmp, &install_list, base.list_node) {
+		list_del_init(&fltr->base.list_node);
+		rc = bnge_hwrm_cfa_ntuple_filter_alloc(bn->bd, fltr);
+		if (rc)
+			bnge_del_ntp_filter(bn, fltr);
+		else
+			set_bit(BNGE_FLTR_VALID, &fltr->base.state);
+	}
+
+	list_for_each_entry_safe(fltr, tmp, &expire_list, base.list_node) {
+		list_del_init(&fltr->base.list_node);
+		bnge_hwrm_cfa_ntuple_filter_free(bn->bd, fltr);
+		bnge_del_ntp_filter(bn, fltr);
+	}
+#endif
+}
diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_filter.h b/drivers/net/ethernet/broadcom/bnge/bnge_filter.h
index bbe50d404d70..c2f2f754452c 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_filter.h
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_filter.h
@@ -118,4 +118,5 @@ void bnge_del_ntp_filter(struct bnge_net *bn,
 void bnge_del_ntp_filter_rcu(struct bnge_net *bn,
 			     struct bnge_ntuple_filter *fltr);
 void bnge_cfg_usr_fltrs(struct bnge_net *bn);
+void bnge_cfg_ntp_filters(struct bnge_net *bn);
 #endif /* _BNGE_FILTER_H_ */
diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
index 0b0358e30220..fc752fe879b6 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
@@ -303,6 +303,11 @@ static void bnge_timer(struct timer_list *t)
 	if (BNGE_LINK_IS_UP(bd) && bn->stats_coal_ticks)
 		bnge_queue_sp_work(bn, BNGE_PERIODIC_STATS_SP_EVENT);
 
+#ifdef CONFIG_RFS_ACCEL
+	if ((bn->priv_flags & BNGE_NET_EN_NTUPLE) && bn->ntp_fltr_count)
+		bnge_queue_sp_work(bn, BNGE_RX_NTP_FLTR_SP_EVENT);
+#endif
+
 	mod_timer(&bn->timer, jiffies + bn->current_interval);
 }
 
@@ -444,6 +449,9 @@ static void bnge_sp_task(struct work_struct *work)
 			bnge_init_ethtool_link_settings(bn);
 	}
 
+	if (test_and_clear_bit(BNGE_RX_NTP_FLTR_SP_EVENT, &bn->sp_event))
+		bnge_cfg_ntp_filters(bn);
+
 	netdev_unlock(bn->netdev);
 }
 
@@ -3123,6 +3131,96 @@ static const struct netdev_stat_ops bnge_stat_ops = {
 	.get_base_stats		= bnge_get_base_stats,
 };
 
+#ifdef CONFIG_RFS_ACCEL
+static u32 bnge_lookup_l2_filter_from_key(struct bnge_net *bn,
+					  struct bnge_l2_key *key)
+{
+	u32 idx;
+
+	idx = jhash2(&key->filter_key, BNGE_L2_KEY_SIZE, bn->hash_seed) &
+	      BNGE_L2_FLTR_HASH_MASK;
+	return bnge_lookup_l2_filter_rcu(bn, key, idx);
+}
+
+static int bnge_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
+			      u16 rxq_index, u32 flow_id)
+{
+	struct ethhdr *eth = (struct ethhdr *)skb_mac_header(skb);
+	struct bnge_ntuple_filter *fltr, *new_fltr;
+	struct bnge_net *bn = netdev_priv(dev);
+	u32 flags, idx, filter_id;
+	struct flow_keys *fkeys;
+	int rc = 0;
+
+	if (ether_addr_equal(dev->dev_addr, eth->h_dest)) {
+		struct bnge_l2_filter *l2_filter;
+
+		l2_filter = bn->vnic_info[BNGE_VNIC_DEFAULT].l2_filters[0];
+		filter_id = l2_filter->base.filter_id;
+
+	} else {
+		struct bnge_l2_key key;
+
+		ether_addr_copy(key.dst_mac_addr, eth->h_dest);
+		key.vlan = 0;
+
+		filter_id = bnge_lookup_l2_filter_from_key(bn, &key);
+		if (filter_id == BNGE_FLTR_ID_INVALID)
+			return -EINVAL;
+	}
+	new_fltr = kzalloc_obj(*new_fltr, GFP_ATOMIC);
+	if (!new_fltr)
+		return -ENOMEM;
+
+	fkeys = &new_fltr->fkeys;
+	if (!skb_flow_dissect_flow_keys(skb, fkeys, 0)) {
+		rc = -EPROTONOSUPPORT;
+		goto err_free;
+	}
+
+	if ((fkeys->basic.n_proto != htons(ETH_P_IP) &&
+	     fkeys->basic.n_proto != htons(ETH_P_IPV6)) ||
+	    ((fkeys->basic.ip_proto != IPPROTO_TCP) &&
+	     (fkeys->basic.ip_proto != IPPROTO_UDP))) {
+		rc = -EPROTONOSUPPORT;
+		goto err_free;
+	}
+	new_fltr->fmasks = BNGE_FLOW_IPV4_MASK_ALL;
+	if (fkeys->basic.n_proto == htons(ETH_P_IPV6))
+		new_fltr->fmasks = BNGE_FLOW_IPV6_MASK_ALL;
+
+	flags = fkeys->control.flags;
+	if (flags & FLOW_DIS_IS_FRAGMENT) {
+		rc = -EPROTONOSUPPORT;
+		goto err_free;
+	}
+
+	new_fltr->l2_filter_id = filter_id;
+
+	idx = bnge_get_ntp_filter_idx(bn, fkeys, skb);
+	rcu_read_lock();
+	fltr = bnge_lookup_ntp_filter_from_idx(bn, new_fltr, idx);
+	if (fltr) {
+		rc = fltr->base.sw_id;
+		rcu_read_unlock();
+		goto err_free;
+	}
+	rcu_read_unlock();
+
+	new_fltr->flow_id = flow_id;
+	new_fltr->base.rxq = rxq_index;
+	rc = bnge_insert_ntp_filter(bn, new_fltr, idx);
+	if (!rc) {
+		bnge_queue_sp_work(bn, BNGE_RX_NTP_FLTR_SP_EVENT);
+		return new_fltr->base.sw_id;
+	}
+
+err_free:
+	kfree(new_fltr);
+	return rc;
+}
+#endif
+
 static const struct net_device_ops bnge_netdev_ops = {
 	.ndo_open		= bnge_open,
 	.ndo_stop		= bnge_close,
@@ -3130,6 +3228,9 @@ static const struct net_device_ops bnge_netdev_ops = {
 	.ndo_get_stats64	= bnge_get_stats64,
 	.ndo_set_rx_mode_async	= bnge_set_rx_mode,
 	.ndo_features_check	= bnge_features_check,
+#ifdef CONFIG_RFS_ACCEL
+	.ndo_rx_flow_steer	= bnge_rx_flow_steer,
+#endif
 };
 
 static void bnge_init_mac_addr(struct bnge_dev *bd)
diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
index bfd0d9cb871f..3146023621a6 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
@@ -282,6 +282,7 @@ enum bnge_sp_event {
 	BNGE_LINK_CFG_CHANGE_SP_EVENT,
 	BNGE_UPDATE_PHY_SP_EVENT,
 	BNGE_PERIODIC_STATS_SP_EVENT,
+	BNGE_RX_NTP_FLTR_SP_EVENT,
 };
 
 #define BNGE_NTP_FLTR_HASH_SIZE	512
-- 
2.47.1