1 files changed, 80 insertions, 9 deletions

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
index d58b51d277f1..2adcf24848a4 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
@@ -58,9 +58,30 @@ static netdev_tx_t rmnet_vnd_start_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 }
 
+static int rmnet_vnd_headroom(struct rmnet_port *port)
+{
+	u32 headroom;
+
+	headroom = sizeof(struct rmnet_map_header);
+
+	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
+		headroom += sizeof(struct rmnet_map_ul_csum_header);
+
+	return headroom;
+}
+
 static int rmnet_vnd_change_mtu(struct net_device *rmnet_dev, int new_mtu)
 {
-	if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE)
+	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
+	struct rmnet_port *port;
+	u32 headroom;
+
+	port = rmnet_get_port_rtnl(priv->real_dev);
+
+	headroom = rmnet_vnd_headroom(port);
+
+	if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE ||
+	    new_mtu > (priv->real_dev->mtu - headroom))
 		return -EINVAL;
 
 	rmnet_dev->mtu = new_mtu;
@@ -104,24 +125,24 @@ static void rmnet_get_stats64(struct net_device *dev,
 			      struct rtnl_link_stats64 *s)
 {
 	struct rmnet_priv *priv = netdev_priv(dev);
-	struct rmnet_vnd_stats total_stats;
+	struct rmnet_vnd_stats total_stats = { };
 	struct rmnet_pcpu_stats *pcpu_ptr;
+	struct rmnet_vnd_stats snapshot;
 	unsigned int cpu, start;
 
-	memset(&total_stats, 0, sizeof(struct rmnet_vnd_stats));
-
 	for_each_possible_cpu(cpu) {
 		pcpu_ptr = per_cpu_ptr(priv->pcpu_stats, cpu);
 
 		do {
 			start = u64_stats_fetch_begin_irq(&pcpu_ptr->syncp);
-			total_stats.rx_pkts += pcpu_ptr->stats.rx_pkts;
-			total_stats.rx_bytes += pcpu_ptr->stats.rx_bytes;
-			total_stats.tx_pkts += pcpu_ptr->stats.tx_pkts;
-			total_stats.tx_bytes += pcpu_ptr->stats.tx_bytes;
+			snapshot = pcpu_ptr->stats;	/* struct assignment */
 		} while (u64_stats_fetch_retry_irq(&pcpu_ptr->syncp, start));
 
-		total_stats.tx_drops += pcpu_ptr->stats.tx_drops;
+		total_stats.rx_pkts += snapshot.rx_pkts;
+		total_stats.rx_bytes += snapshot.rx_bytes;
+		total_stats.tx_pkts += snapshot.tx_pkts;
+		total_stats.tx_bytes += snapshot.tx_bytes;
+		total_stats.tx_drops += snapshot.tx_drops;
 	}
 
 	s->rx_packets = total_stats.rx_pkts;
@@ -229,6 +250,7 @@ int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 
 {
 	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
+	u32 headroom;
 	int rc;
 
 	if (rmnet_get_endpoint(port, id)) {
@@ -242,6 +264,13 @@ int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 
 	priv->real_dev = real_dev;
 
+	headroom = rmnet_vnd_headroom(port);
+
+	if (rmnet_vnd_change_mtu(rmnet_dev, real_dev->mtu - headroom)) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid MTU on real dev");
+		return -EINVAL;
+	}
+
 	rc = register_netdevice(rmnet_dev);
 	if (!rc) {
 		ep->egress_dev = rmnet_dev;
@@ -283,3 +312,45 @@ int rmnet_vnd_do_flow_control(struct net_device *rmnet_dev, int enable)
 
 	return 0;
 }
+
+int rmnet_vnd_validate_real_dev_mtu(struct net_device *real_dev)
+{
+	struct hlist_node *tmp_ep;
+	struct rmnet_endpoint *ep;
+	struct rmnet_port *port;
+	unsigned long bkt_ep;
+	u32 headroom;
+
+	port = rmnet_get_port_rtnl(real_dev);
+
+	headroom = rmnet_vnd_headroom(port);
+
+	hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
+		if (ep->egress_dev->mtu > (real_dev->mtu - headroom))
+			return -1;
+	}
+
+	return 0;
+}
+
+int rmnet_vnd_update_dev_mtu(struct rmnet_port *port,
+			     struct net_device *real_dev)
+{
+	struct hlist_node *tmp_ep;
+	struct rmnet_endpoint *ep;
+	unsigned long bkt_ep;
+	u32 headroom;
+
+	headroom = rmnet_vnd_headroom(port);
+
+	hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
+		if (ep->egress_dev->mtu <= (real_dev->mtu - headroom))
+			continue;
+
+		if (rmnet_vnd_change_mtu(ep->egress_dev,
+					 real_dev->mtu - headroom))
+			return -1;
+	}
+
+	return 0;
+}