Merge branch 'rmnet-next'

Subash Abhinov Kasiviswanathan says:

====================
net: qualcomm: rmnet: Updates 2018-05-14

Patch 1 adds tx_drops counter to more places.
Patch 2 adds ethtool private stats support to make it easy to debug
the checksum offload path.
Patch 3 is a cleanup in command packet processing path.

v1->v2: Fix the incorrect if / else statement in
rmnet_map_checksum_downlink_packet() and define rmnet_ethtool_ops
as static as mentioned by kbuild test robot.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h

@@ -54,11 +54,24 @@ struct rmnet_pcpu_stats {
 	struct u64_stats_sync syncp;
 };
 
+struct rmnet_priv_stats {
+	u64 csum_ok;
+	u64 csum_valid_unset;
+	u64 csum_validation_failed;
+	u64 csum_err_bad_buffer;
+	u64 csum_err_invalid_ip_version;
+	u64 csum_err_invalid_transport;
+	u64 csum_fragmented_pkt;
+	u64 csum_skipped;
+	u64 csum_sw;
+};
+
 struct rmnet_priv {
 	u8 mux_id;
 	struct net_device *real_dev;
 	struct rmnet_pcpu_stats __percpu *pcpu_stats;
 	struct gro_cells gro_cells;
+	struct rmnet_priv_stats stats;
 };
 
 struct rmnet_port *rmnet_get_port(struct net_device *real_dev);

drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

@@ -148,7 +148,7 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 
 	if (skb_headroom(skb) < required_headroom) {
 		if (pskb_expand_head(skb, required_headroom, 0, GFP_KERNEL))
-			goto fail;
+			return -ENOMEM;
 	}
 
 	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
@@ -156,17 +156,13 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 
 	map_header = rmnet_map_add_map_header(skb, additional_header_len, 0);
 	if (!map_header)
-		goto fail;
+		return -ENOMEM;
 
 	map_header->mux_id = mux_id;
 
 	skb->protocol = htons(ETH_P_MAP);
 
 	return 0;
-
-fail:
-	kfree_skb(skb);
-	return -ENOMEM;
 }
 
 static void
@@ -228,15 +224,18 @@ void rmnet_egress_handler(struct sk_buff *skb)
 	mux_id = priv->mux_id;
 
 	port = rmnet_get_port(skb->dev);
-	if (!port) {
-		kfree_skb(skb);
-		return;
-	}
+	if (!port)
+		goto drop;
 
 	if (rmnet_map_egress_handler(skb, port, mux_id, orig_dev))
-		return;
+		goto drop;
 
 	rmnet_vnd_tx_fixup(skb, orig_dev);
 
 	dev_queue_xmit(skb);
+	return;
+
+drop:
+	this_cpu_inc(priv->pcpu_stats->stats.tx_drops);
+	kfree_skb(skb);
 }

drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c

@@ -69,17 +69,9 @@ static void rmnet_map_send_ack(struct sk_buff *skb,
 	struct rmnet_map_control_command *cmd;
 	int xmit_status;
 
-	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {
-		if (skb->len < sizeof(struct rmnet_map_header) +
-		    RMNET_MAP_GET_LENGTH(skb) +
-		    sizeof(struct rmnet_map_dl_csum_trailer)) {
-			kfree_skb(skb);
-			return;
-		}
-
-		skb_trim(skb, skb->len -
-			 sizeof(struct rmnet_map_dl_csum_trailer));
-	}
+	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
+		skb_trim(skb,
+			 skb->len - sizeof(struct rmnet_map_dl_csum_trailer));
 
 	skb->protocol = htons(ETH_P_MAP);
 

drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

@@ -48,7 +48,8 @@ static __sum16 *rmnet_map_get_csum_field(unsigned char protocol,
 
 static int
 rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb,
-			       struct rmnet_map_dl_csum_trailer *csum_trailer)
+			       struct rmnet_map_dl_csum_trailer *csum_trailer,
+			       struct rmnet_priv *priv)
 {
 	__sum16 *csum_field, csum_temp, pseudo_csum, hdr_csum, ip_payload_csum;
 	u16 csum_value, csum_value_final;
@@ -58,19 +59,25 @@ rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb,
 
 	ip4h = (struct iphdr *)(skb->data);
 	if ((ntohs(ip4h->frag_off) & IP_MF) ||
-	    ((ntohs(ip4h->frag_off) & IP_OFFSET) > 0))
+	    ((ntohs(ip4h->frag_off) & IP_OFFSET) > 0)) {
+		priv->stats.csum_fragmented_pkt++;
 		return -EOPNOTSUPP;
+	}
 
 	txporthdr = skb->data + ip4h->ihl * 4;
 
 	csum_field = rmnet_map_get_csum_field(ip4h->protocol, txporthdr);
 
-	if (!csum_field)
+	if (!csum_field) {
+		priv->stats.csum_err_invalid_transport++;
 		return -EPROTONOSUPPORT;
+	}
 
 	/* RFC 768 - Skip IPv4 UDP packets where sender checksum field is 0 */
-	if (*csum_field == 0 && ip4h->protocol == IPPROTO_UDP)
+	if (*csum_field == 0 && ip4h->protocol == IPPROTO_UDP) {
+		priv->stats.csum_skipped++;
 		return 0;
+	}
 
 	csum_value = ~ntohs(csum_trailer->csum_value);
 	hdr_csum = ~ip_fast_csum(ip4h, (int)ip4h->ihl);
@@ -102,16 +109,20 @@ rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb,
 		}
 	}
 
-	if (csum_value_final == ntohs((__force __be16)*csum_field))
+	if (csum_value_final == ntohs((__force __be16)*csum_field)) {
+		priv->stats.csum_ok++;
 		return 0;
-	else
+	} else {
+		priv->stats.csum_validation_failed++;
 		return -EINVAL;
+	}
 }
 
 #if IS_ENABLED(CONFIG_IPV6)
 static int
 rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb,
-			       struct rmnet_map_dl_csum_trailer *csum_trailer)
+			       struct rmnet_map_dl_csum_trailer *csum_trailer,
+			       struct rmnet_priv *priv)
 {
 	__sum16 *csum_field, ip6_payload_csum, pseudo_csum, csum_temp;
 	u16 csum_value, csum_value_final;
@@ -125,8 +136,10 @@ rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb,
 	txporthdr = skb->data + sizeof(struct ipv6hdr);
 	csum_field = rmnet_map_get_csum_field(ip6h->nexthdr, txporthdr);
 
-	if (!csum_field)
+	if (!csum_field) {
+		priv->stats.csum_err_invalid_transport++;
 		return -EPROTONOSUPPORT;
+	}
 
 	csum_value = ~ntohs(csum_trailer->csum_value);
 	ip6_hdr_csum = (__force __be16)
@@ -164,10 +177,13 @@ rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb,
 		}
 	}
 
-	if (csum_value_final == ntohs((__force __be16)*csum_field))
+	if (csum_value_final == ntohs((__force __be16)*csum_field)) {
+		priv->stats.csum_ok++;
 		return 0;
-	else
+	} else {
+		priv->stats.csum_validation_failed++;
 		return -EINVAL;
+	}
 }
 #endif
 
@@ -339,24 +355,34 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
  */
 int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len)
 {
+	struct rmnet_priv *priv = netdev_priv(skb->dev);
 	struct rmnet_map_dl_csum_trailer *csum_trailer;
 
-	if (unlikely(!(skb->dev->features & NETIF_F_RXCSUM)))
+	if (unlikely(!(skb->dev->features & NETIF_F_RXCSUM))) {
+		priv->stats.csum_sw++;
 		return -EOPNOTSUPP;
+	}
 
 	csum_trailer = (struct rmnet_map_dl_csum_trailer *)(skb->data + len);
 
-	if (!csum_trailer->valid)
+	if (!csum_trailer->valid) {
+		priv->stats.csum_valid_unset++;
 		return -EINVAL;
+	}
 
-	if (skb->protocol == htons(ETH_P_IP))
-		return rmnet_map_ipv4_dl_csum_trailer(skb, csum_trailer);
-	else if (skb->protocol == htons(ETH_P_IPV6))
+	if (skb->protocol == htons(ETH_P_IP)) {
+		return rmnet_map_ipv4_dl_csum_trailer(skb, csum_trailer, priv);
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
 #if IS_ENABLED(CONFIG_IPV6)
-		return rmnet_map_ipv6_dl_csum_trailer(skb, csum_trailer);
+		return rmnet_map_ipv6_dl_csum_trailer(skb, csum_trailer, priv);
 #else
+		priv->stats.csum_err_invalid_ip_version++;
 		return -EPROTONOSUPPORT;
 #endif
+	} else {
+		priv->stats.csum_err_invalid_ip_version++;
+		return -EPROTONOSUPPORT;
+	}
 
 	return 0;
 }
@@ -367,6 +393,7 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len)
 void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 				      struct net_device *orig_dev)
 {
+	struct rmnet_priv *priv = netdev_priv(orig_dev);
 	struct rmnet_map_ul_csum_header *ul_header;
 	void *iphdr;
 
@@ -389,8 +416,11 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 			rmnet_map_ipv6_ul_csum_header(iphdr, ul_header, skb);
 			return;
 #else
+			priv->stats.csum_err_invalid_ip_version++;
 			goto sw_csum;
 #endif
+		} else {
+			priv->stats.csum_err_invalid_ip_version++;
 		}
 	}
 
@@ -399,4 +429,6 @@ sw_csum:
 	ul_header->csum_insert_offset = 0;
 	ul_header->csum_enabled = 0;
 	ul_header->udp_ip4_ind = 0;
+
+	priv->stats.csum_sw++;
 }

drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c

@@ -152,6 +152,56 @@ static const struct net_device_ops rmnet_vnd_ops = {
 	.ndo_get_stats64 = rmnet_get_stats64,
 };
 
+static const char rmnet_gstrings_stats[][ETH_GSTRING_LEN] = {
+	"Checksum ok",
+	"Checksum valid bit not set",
+	"Checksum validation failed",
+	"Checksum error bad buffer",
+	"Checksum error bad ip version",
+	"Checksum error bad transport",
+	"Checksum skipped on ip fragment",
+	"Checksum skipped",
+	"Checksum computed in software",
+};
+
+static void rmnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+	switch (stringset) {
+	case ETH_SS_STATS:
+		memcpy(buf, &rmnet_gstrings_stats,
+		       sizeof(rmnet_gstrings_stats));
+		break;
+	}
+}
+
+static int rmnet_get_sset_count(struct net_device *dev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(rmnet_gstrings_stats);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void rmnet_get_ethtool_stats(struct net_device *dev,
+				    struct ethtool_stats *stats, u64 *data)
+{
+	struct rmnet_priv *priv = netdev_priv(dev);
+	struct rmnet_priv_stats *st = &priv->stats;
+
+	if (!data)
+		return;
+
+	memcpy(data, st, ARRAY_SIZE(rmnet_gstrings_stats) * sizeof(u64));
+}
+
+static const struct ethtool_ops rmnet_ethtool_ops = {
+	.get_ethtool_stats = rmnet_get_ethtool_stats,
+	.get_strings = rmnet_get_strings,
+	.get_sset_count = rmnet_get_sset_count,
+};
+
 /* Called by kernel whenever a new rmnet<n> device is created. Sets MTU,
  * flags, ARP type, needed headroom, etc...
  */
@@ -170,6 +220,7 @@ void rmnet_vnd_setup(struct net_device *rmnet_dev)
 	rmnet_dev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
 
 	rmnet_dev->needs_free_netdev = true;
+	rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
 }
 
 /* Exposed API */