Subject: [PATCH] net: ethernet: mediatek: mtk_eth_soc: add flow offloading support
From: Felix Fietkau <[email-masked]>
Date: Sun, 11 Oct 2020 22:28:32 +0200

Only supports IPv4 for now

Signed-off-by: Felix Fietkau <[email-masked]>
---
 create mode 100644 drivers/net/ethernet/mediatek/mtk_offload.c
 create mode 100644 drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c

--- a/drivers/net/ethernet/mediatek/Makefile
+++ b/drivers/net/ethernet/mediatek/Makefile
@@ -4,4 +4,4 @@
 #
 
 obj-$(CONFIG_NET_MEDIATEK_SOC)                 += mtk_eth.o
-mtk_eth-y := mtk_eth_soc.o mtk_sgmii.o mtk_eth_path.o mtk_ppe.o
+mtk_eth-y := mtk_eth_soc.o mtk_sgmii.o mtk_eth_path.o mtk_ppe.o mtk_ppe_debugfs.o mtk_offload.o
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -20,6 +20,8 @@
 #include <linux/pinctrl/devinfo.h>
 #include <linux/phylink.h>
 #include <linux/jhash.h>
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_flow_table.h>
 #include <net/dsa.h>
 
 #include "mtk_eth_soc.h"
@@ -1327,8 +1329,12 @@ static int mtk_poll_rx(struct napi_struc
 		    (trxd.rxd2 & RX_DMA_VTAG))
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 					       RX_DMA_VID(trxd.rxd3));
-		skb_record_rx_queue(skb, 0);
-		napi_gro_receive(napi, skb);
+		if (mtk_offload_check_rx(eth, skb, trxd.rxd4) == 0) {
+			skb_record_rx_queue(skb, 0);
+			napi_gro_receive(napi, skb);
+		} else {
+			dev_kfree_skb(skb);
+		}
 
 skip_rx:
 		ring->data[idx] = new_data;
@@ -2861,6 +2867,25 @@ static int mtk_set_rxnfc(struct net_devi
 	return ret;
 }
 
+static int
+mtk_flow_offload(enum flow_offload_type type, struct flow_offload *flow,
+		struct flow_offload_hw_path *src,
+		struct flow_offload_hw_path *dest)
+{
+	struct mtk_mac *mac = netdev_priv(src->dev);
+	struct mtk_eth *eth = mac->hw;
+
+	if (!eth->soc->offload_version)
+		return -EINVAL;
+
+	if (src->dev->base_addr != dest->dev->base_addr)
+		return -EINVAL;
+
+	mac = netdev_priv(src->dev);
+
+	return mtk_flow_offload_add(eth, type, flow, src, dest);
+}
+
 static const struct ethtool_ops mtk_ethtool_ops = {
 	.get_link_ksettings	= mtk_get_link_ksettings,
 	.set_link_ksettings	= mtk_set_link_ksettings,
@@ -2892,6 +2917,7 @@ static const struct net_device_ops mtk_n
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= mtk_poll_controller,
 #endif
+	.ndo_flow_offload       = mtk_flow_offload,
 };
 
 static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
@@ -3157,6 +3183,10 @@ static int mtk_probe(struct platform_dev
 				   eth->base + MTK_ETH_PPE_BASE, 2);
 		if (err)
 			goto err_free_dev;
+
+		err = mtk_flow_offload_init(eth);
+		if (err)
+			goto err_free_dev;
 	}
 
 	for (i = 0; i < MTK_MAX_DEVS; i++) {
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -929,6 +929,7 @@ struct mtk_eth {
 	int				ip_align;
 
 	struct mtk_ppe			ppe;
+	struct flow_offload __rcu       **foe_flow_table;
 };
 
 /* struct mtk_mac -	the structure that holds the info about the MACs of the
@@ -973,4 +974,12 @@ int mtk_gmac_sgmii_path_setup(struct mtk
 int mtk_gmac_gephy_path_setup(struct mtk_eth *eth, int mac_id);
 int mtk_gmac_rgmii_path_setup(struct mtk_eth *eth, int mac_id);
 
+int mtk_flow_offload_init(struct mtk_eth *eth);
+int mtk_flow_offload_add(struct mtk_eth *eth,
+			 enum flow_offload_type type,
+			 struct flow_offload *flow,
+			 struct flow_offload_hw_path *src,
+			 struct flow_offload_hw_path *dest);
+int mtk_offload_check_rx(struct mtk_eth *eth, struct sk_buff *skb, u32 rxd4);
+
 #endif /* MTK_ETH_H */
--- /dev/null
+++ b/drivers/net/ethernet/mediatek/mtk_offload.c
@@ -0,0 +1,146 @@
+/*   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; version 2 of the License
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   Copyright (C) 2018 John Crispin <[email-masked]>
+ */
+
+#include <net/netfilter/nf_flow_table.h>
+#include "mtk_eth_soc.h"
+
+static int
+mtk_offload_prepare_v4(struct mtk_eth *eth, struct mtk_foe_entry *entry,
+		       struct flow_offload_tuple *s_tuple,
+		       struct flow_offload_tuple *d_tuple,
+		       struct flow_offload_hw_path *src,
+		       struct flow_offload_hw_path *dest)
+{
+	int dest_port = 1;
+
+	if (dest->dev == eth->netdev[1])
+	    dest_port = 2;
+
+	mtk_foe_entry_prepare(entry, MTK_PPE_PKT_TYPE_IPV4_HNAPT, s_tuple->l4proto,
+			      dest_port, dest->eth_src, dest->eth_dest);
+	mtk_foe_entry_set_ipv4_tuple(entry, false,
+				     s_tuple->src_v4.s_addr, s_tuple->src_port,
+				     s_tuple->dst_v4.s_addr, s_tuple->dst_port);
+	mtk_foe_entry_set_ipv4_tuple(entry, true,
+				     d_tuple->dst_v4.s_addr, d_tuple->dst_port,
+				     d_tuple->src_v4.s_addr, d_tuple->src_port);
+
+	if (dest->flags & FLOW_OFFLOAD_PATH_PPPOE)
+		mtk_foe_entry_set_pppoe(entry, dest->pppoe_sid);
+
+	if (dest->flags & FLOW_OFFLOAD_PATH_VLAN)
+		mtk_foe_entry_set_vlan(entry, dest->vlan_id);
+
+	if (dest->flags & FLOW_OFFLOAD_PATH_DSA)
+		mtk_foe_entry_set_dsa(entry, dest->dsa_port);
+
+	return 0;
+}
+
+int mtk_flow_offload_add(struct mtk_eth *eth,
+			 enum flow_offload_type type,
+			 struct flow_offload *flow,
+			 struct flow_offload_hw_path *src,
+			 struct flow_offload_hw_path *dest)
+{
+	struct flow_offload_tuple *otuple = &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple;
+	struct flow_offload_tuple *rtuple = &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple;
+	struct mtk_foe_entry orig, reply;
+	u32 ohash, rhash, timestamp;
+
+	if (otuple->l4proto != IPPROTO_TCP && otuple->l4proto != IPPROTO_UDP)
+		return -EINVAL;
+
+	if (type == FLOW_OFFLOAD_DEL) {
+		ohash = (unsigned long)flow->priv;
+		rhash = ohash >> 16;
+		ohash &= 0xffff;
+		mtk_foe_entry_clear(&eth->ppe, ohash);
+		mtk_foe_entry_clear(&eth->ppe, rhash);
+		rcu_assign_pointer(eth->foe_flow_table[ohash], NULL);
+		rcu_assign_pointer(eth->foe_flow_table[rhash], NULL);
+		synchronize_rcu();
+
+		return 0;
+	}
+
+	switch (otuple->l3proto) {
+	case AF_INET:
+		if (mtk_offload_prepare_v4(eth, &orig, otuple, rtuple, src, dest) ||
+		    mtk_offload_prepare_v4(eth, &reply, rtuple, otuple, dest, src))
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	timestamp = mtk_r32(eth, 0x0010);
+
+	ohash = mtk_foe_entry_commit(&eth->ppe, &orig, timestamp);
+	if (ohash < 0)
+		return -EINVAL;
+
+	rhash = mtk_foe_entry_commit(&eth->ppe, &reply, timestamp);
+	if (rhash < 0) {
+		mtk_foe_entry_clear(&eth->ppe, ohash);
+		return -EINVAL;
+	}
+
+	rcu_assign_pointer(eth->foe_flow_table[ohash], flow);
+	rcu_assign_pointer(eth->foe_flow_table[rhash], flow);
+
+	ohash |= rhash << 16;
+	flow->priv = (void *)(unsigned long)ohash;
+
+	return 0;
+}
+
+static void mtk_offload_keepalive(struct mtk_eth *eth, unsigned int hash)
+{
+	struct flow_offload *flow;
+
+	rcu_read_lock();
+	flow = rcu_dereference(eth->foe_flow_table[hash]);
+	if (flow)
+		flow->timeout = jiffies + 30 * HZ;
+	rcu_read_unlock();
+}
+
+int mtk_offload_check_rx(struct mtk_eth *eth, struct sk_buff *skb, u32 rxd4)
+{
+	unsigned int hash;
+
+	switch (FIELD_GET(MTK_RXD4_PPE_CPU_REASON, rxd4)) {
+	case MTK_PPE_CPU_REASON_KEEPALIVE_UC_OLD_HDR:
+	case MTK_PPE_CPU_REASON_KEEPALIVE_MC_NEW_HDR:
+	case MTK_PPE_CPU_REASON_KEEPALIVE_DUP_OLD_HDR:
+		hash = FIELD_GET(MTK_RXD4_FOE_ENTRY, rxd4);
+		mtk_offload_keepalive(eth, hash);
+		return -1;
+	case MTK_PPE_CPU_REASON_PACKET_SAMPLING:
+		return -1;
+	default:
+		return 0;
+	}
+}
+
+int mtk_flow_offload_init(struct mtk_eth *eth)
+{
+	eth->foe_flow_table = devm_kcalloc(eth->dev, MTK_PPE_ENTRIES,
+					   sizeof(*eth->foe_flow_table),
+					   GFP_KERNEL);
+
+	if (!eth->foe_flow_table)
+		return -ENOMEM;
+
+	return 0;
+}
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -375,6 +375,8 @@ int mtk_ppe_init(struct mtk_ppe *ppe, st
 
 	ppe->foe_table = foe;
 
+	mtk_ppe_debugfs_init(ppe);
+
 	return 0;
 }
 
--- a/drivers/net/ethernet/mediatek/mtk_ppe.h
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.h
@@ -271,4 +271,7 @@ int mtk_foe_entry_set_pppoe(struct mtk_f
 int mtk_foe_entry_commit(struct mtk_ppe *ppe, struct mtk_foe_entry *entry,
 			 u16 timestamp);
 
+/* internal */
+int mtk_ppe_debugfs_init(struct mtk_ppe *ppe);
+
 #endif
--- /dev/null
+++ b/drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c
@@ -0,0 +1,114 @@
+/*   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; version 2 of the License
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   Copyright (C) 2014-2016 Sean Wang <[email-masked]>
+ *   Copyright (C) 2016-2017 John Crispin <[email-masked]>
+ *   Copyright (C) 2020 Felix Fietkau <[email-masked]>
+ */
+
+#include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include "mtk_eth_soc.h"
+
+static const char *mtk_foe_entry_state_str[] = {
+	"INVALID",
+	"UNBIND",
+	"BIND",
+	"FIN"
+};
+
+static const char *mtk_foe_packet_type_str[] = {
+	"IPV4_HNAPT",
+	"IPV4_HNAT",
+	"IPV6_1T_ROUTE",
+	"IPV4_DSLITE",
+	"IPV6_3T_ROUTE",
+	"IPV6_5T_ROUTE",
+	"IPV6_6RD",
+};
+
+#define es(entry)		(mtk_foe_entry_state_str[FIELD_GET(MTK_FOE_IB1_STATE, entry->ib1)])
+//#define ei(entry, end)		(MTK_PPE_TBL_SZ - (int)(end - entry))
+#define pt(entry)		(mtk_foe_packet_type_str[FIELD_GET(MTK_FOE_IB1_PACKET_TYPE, entry->ib1)])
+
+static int mtk_ppe_debugfs_foe_show(struct seq_file *m, void *private)
+{
+	struct mtk_ppe *ppe = m->private;
+	int i, count;
+
+	for (i = 0, count = 0; i < MTK_PPE_ENTRIES; i++) {
+		struct mtk_foe_entry *entry = &ppe->foe_table[i];
+
+		if (!FIELD_GET(MTK_FOE_IB1_STATE, entry->ib1))
+			continue;
+
+		if (FIELD_GET(MTK_FOE_IB1_PACKET_TYPE, entry->ib1) ==
+		    MTK_PPE_PKT_TYPE_IPV4_HNAPT) {
+			struct mtk_foe_ipv4 *ip4 = &entry->ipv4;
+			struct mtk_foe_mac_info *l2 = &ip4->l2;
+
+			__be32 saddr = htonl(ip4->orig.src_ip);
+			__be32 daddr = htonl(ip4->orig.dest_ip);
+			__be32 nsaddr = htonl(ip4->new.src_ip);
+			__be32 ndaddr = htonl(ip4->new.dest_ip);
+			unsigned char h_dest[ETH_ALEN];
+			unsigned char h_source[ETH_ALEN];
+
+			*((__be32 *) h_source) = htonl(l2->src_mac_hi);
+			*((__be16*) &h_source[4]) = htons(l2->src_mac_lo);
+			*((__be32*) h_dest) = htonl(l2->dest_mac_hi);
+			*((__be16*) &h_dest[4]) = htons(l2->dest_mac_lo);
+			seq_printf(m,
+				   "(%x)0x%05x|state=%s|type=%s|"
+				   "%pI4:%d->%pI4:%d=>%pI4:%d->%pI4:%d|%pM=>%pM|"
+				   "etype=0x%04x|info1=0x%x|info2=0x%x|"
+				   "vlan1=%d|vlan2=%d\n",
+				   count, i, es(entry), pt(entry),
+				   &saddr, ip4->orig.src_port,
+				   &daddr, ip4->orig.dest_port,
+				   &nsaddr, ip4->new.src_port,
+				   &ndaddr, ip4->new.dest_port,
+				   h_source, h_dest,
+				   ntohs(l2->etype),
+				   entry->ib1,
+				   ip4->ib2,
+				   l2->vlan1,
+				   l2->vlan2);
+			count++;
+		} else
+			seq_printf(m, "0x%05x state=%s\n", count, es(entry));
+	}
+
+	return 0;
+}
+
+static int mtk_ppe_debugfs_foe_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, mtk_ppe_debugfs_foe_show, inode->i_private);
+}
+
+static const struct file_operations mtk_ppe_debugfs_foe_fops = {
+	.open = mtk_ppe_debugfs_foe_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+int mtk_ppe_debugfs_init(struct mtk_ppe *ppe)
+{
+	struct dentry *root;
+
+	root = debugfs_create_dir("mtk_ppe", NULL);
+	if (!root)
+		return -ENOMEM;
+
+	debugfs_create_file("entries", S_IRUGO, root, ppe, &mtk_ppe_debugfs_foe_fops);
+
+	return 0;
+}