rmnet_core: Add support for TSO

This adds support for the new transmit offload header as well as
the handling needed for it in the core driver.

CRs-Fixed: 2810638
Change-Id: I8ce2e0772209faf3d585e7d9d8d56eceb695d586
Signed-off-by: Subash Abhinov Kasiviswanathan <[email protected]>

core/rmnet_config.h

@@ -175,6 +175,8 @@ struct rmnet_priv_stats {
 	u64 csum_hw;
 	struct rmnet_coal_stats coal;
 	u64 ul_prio;
+	u64 tso_pkts;
+	u64 tso_arriv_errs;
 };
 
 struct rmnet_priv {

core/rmnet_handlers.c

@@ -325,7 +325,7 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 				    struct rmnet_port *port, u8 mux_id,
 				    struct net_device *orig_dev)
 {
-	int required_headroom, additional_header_len, csum_type;
+	int required_headroom, additional_header_len, csum_type, tso = 0;
 	struct rmnet_map_header *map_header;
 
 	additional_header_len = 0;
@@ -351,6 +351,20 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 	if (port->data_format & RMNET_INGRESS_FORMAT_PS)
 		qmi_rmnet_work_maybe_restart(port);
 
+	if (csum_type &&
+	    (skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_L4 | SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) &&
+	     skb_shinfo(skb)->gso_size) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&port->agg_lock, flags);
+		rmnet_map_send_agg_skb(port, flags);
+
+		if (rmnet_map_add_tso_header(skb, port, orig_dev))
+			return -EINVAL;
+		csum_type = 0;
+		tso = 1;
+	}
+
 	if (csum_type)
 		rmnet_map_checksum_uplink_packet(skb, port, orig_dev,
 						 csum_type);
@@ -363,7 +377,7 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 	map_header->mux_id = mux_id;
 
 	if (port->data_format & RMNET_EGRESS_FORMAT_AGGREGATION) {
-		if (rmnet_map_tx_agg_skip(skb, required_headroom))
+		if (rmnet_map_tx_agg_skip(skb, required_headroom) || tso)
 			goto done;
 
 		rmnet_map_tx_aggregate(skb, port);
@@ -467,7 +481,7 @@ void rmnet_egress_handler(struct sk_buff *skb)
 
 	skb_len = skb->len;
 	err = rmnet_map_egress_handler(skb, port, mux_id, orig_dev);
-	if (err == -ENOMEM) {
+	if (err == -ENOMEM || err == -EINVAL) {
 		goto drop;
 	} else if (err == -EINPROGRESS) {
 		rmnet_vnd_tx_fixup(orig_dev, skb_len);

core/rmnet_map.h

@@ -48,6 +48,7 @@ enum rmnet_map_v5_header_type {
 	RMNET_MAP_HEADER_TYPE_UNKNOWN,
 	RMNET_MAP_HEADER_TYPE_COALESCING = 0x1,
 	RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD = 0x2,
+	RMNET_MAP_HEADER_TYPE_TSO = 0x3,
 	RMNET_MAP_HEADER_TYPE_ENUM_LENGTH
 };
 
@@ -111,6 +112,16 @@ struct rmnet_map_v5_coal_header {
 	struct rmnet_map_v5_nl_pair nl_pairs[RMNET_MAP_V5_MAX_NLOS];
 } __aligned(1);
 
+struct rmnet_map_v5_tso_header {
+	u8  next_hdr:1;
+	u8  header_type:7;
+	u8  hw_reserved:5;
+	u8  priority:1;
+	u8  zero_csum:1;
+	u8  ip_id_cfg:1;
+	__be16 segment_size;
+} __aligned(1);
+
 /* QMAP v4 headers */
 struct rmnet_map_dl_csum_trailer {
 	u8  reserved1;
@@ -280,4 +291,7 @@ int rmnet_map_dl_ind_register(struct rmnet_port *port,
 int rmnet_map_dl_ind_deregister(struct rmnet_port *port,
 				struct rmnet_map_dl_ind *dl_ind);
 void rmnet_map_cmd_exit(struct rmnet_port *port);
+void rmnet_map_send_agg_skb(struct rmnet_port *port, unsigned long flags);
+int rmnet_map_add_tso_header(struct sk_buff *skb, struct rmnet_port *port,
+			      struct net_device *orig_dev);
 #endif /* _RMNET_MAP_H_ */

core/rmnet_map_data.c

@@ -1423,7 +1423,7 @@ static struct sk_buff *rmnet_map_build_skb(struct rmnet_port *port)
 	return skb;
 }
 
-static void rmnet_map_send_agg_skb(struct rmnet_port *port, unsigned long flags)
+void rmnet_map_send_agg_skb(struct rmnet_port *port, unsigned long flags)
 {
 	struct sk_buff *agg_skb;
 
@@ -1621,3 +1621,38 @@ void rmnet_map_tx_qmap_cmd(struct sk_buff *qmap_skb)
 	dev_queue_xmit(qmap_skb);
 }
 EXPORT_SYMBOL(rmnet_map_tx_qmap_cmd);
+
+int rmnet_map_add_tso_header(struct sk_buff *skb, struct rmnet_port *port,
+			      struct net_device *orig_dev)
+{
+	struct rmnet_priv *priv = netdev_priv(orig_dev);
+	struct rmnet_map_v5_tso_header *ul_header;
+
+	if (!(orig_dev->features & (NETIF_F_ALL_TSO | NETIF_F_GSO_UDP_L4))) {
+		priv->stats.tso_arriv_errs++;
+		return -EINVAL;
+	}
+
+	ul_header = (struct rmnet_map_v5_tso_header *)
+		    skb_push(skb, sizeof(*ul_header));
+	memset(ul_header, 0, sizeof(*ul_header));
+	ul_header->header_type = RMNET_MAP_HEADER_TYPE_TSO;
+
+	if (port->data_format & RMNET_EGRESS_FORMAT_PRIORITY)
+		rmnet_map_v5_check_priority(skb, orig_dev,
+					    (struct rmnet_map_v5_csum_header *)ul_header);
+
+	ul_header->segment_size = htons(skb_shinfo(skb)->gso_size);
+
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID)
+		ul_header->ip_id_cfg = 1;
+
+	skb->ip_summed = CHECKSUM_NONE;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_segs = 0;
+	skb_shinfo(skb)->gso_type = 0;
+
+	priv->stats.tso_pkts++;
+
+	return 0;
+}

core/rmnet_vnd.c

@@ -257,6 +257,8 @@ static const char rmnet_gstrings_stats[][ETH_GSTRING_LEN] = {
 	"Coalescing UDP frames",
 	"Coalescing UDP bytes",
 	"Uplink priority packets",
+	"TSO packets",
+	"TSO packets arriving incorrectly",
 };
 
 static const char rmnet_port_gstrings_stats[][ETH_GSTRING_LEN] = {
@@ -390,9 +392,13 @@ int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 	rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
 	rmnet_dev->hw_features |= NETIF_F_SG;
 	rmnet_dev->hw_features |= NETIF_F_GRO_HW;
+	rmnet_dev->hw_features |= NETIF_F_GSO_UDP_L4;
+	rmnet_dev->hw_features |= NETIF_F_ALL_TSO;
 
 	priv->real_dev = real_dev;
 
+	rmnet_dev->gso_max_size = 64000;
+
 	rc = register_netdevice(rmnet_dev);
 	if (!rc) {
 		ep->egress_dev = rmnet_dev;