nfp: support TX VLAN ctag insert in NFDK

Add support for TX VLAN ctag insert
which may be configured via ethtool.
e.g.
     # ethtool -K $DEV tx-vlan-offload on

The NIC supplies VLAN insert information as packet metadata.
The fields of this VLAN metadata including vlan_proto and vlan tag.

Configuration control bit NFP_NET_CFG_CTRL_TXVLAN_V2 is to
signal availability of ctag-insert features of the firmware.

NFDK is used to communicate via PCIE to NFP-3800 based NICs
while NFD3 is used for other NICs supported by the NFP driver.
This features is currently implemented only for NFD3 and
this patch adds support for it with NFDK.
Signed-off-by: Diana Wang <na.wang@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220711093048.1911698-1-simon.horman@corigine.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/netronome/nfp/nfdk/dp.c

@@ -169,49 +169,52 @@ nfp_nfdk_tx_maybe_close_block(struct nfp_net_tx_ring *tx_ring,
 	return 0;
 }
 
-static int nfp_nfdk_prep_port_id(struct sk_buff *skb)
+static int
+nfp_nfdk_prep_tx_meta(struct nfp_net_dp *dp, struct nfp_app *app,
+		      struct sk_buff *skb)
 {
 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 	unsigned char *data;
+	bool vlan_insert;
+	u32 meta_id = 0;
+	int md_bytes;
 
-	if (likely(!md_dst))
-		return 0;
-	if (unlikely(md_dst->type != METADATA_HW_PORT_MUX))
-		return 0;
-
-	if (unlikely(skb_cow_head(skb, sizeof(md_dst->u.port_info.port_id))))
-		return -ENOMEM;
-
-	data = skb_push(skb, sizeof(md_dst->u.port_info.port_id));
-	put_unaligned_be32(md_dst->u.port_info.port_id, data);
+	if (unlikely(md_dst && md_dst->type != METADATA_HW_PORT_MUX))
+		md_dst = NULL;
 
-	return sizeof(md_dst->u.port_info.port_id);
-}
+	vlan_insert = skb_vlan_tag_present(skb) && (dp->ctrl & NFP_NET_CFG_CTRL_TXVLAN_V2);
 
-static int
-nfp_nfdk_prep_tx_meta(struct nfp_app *app, struct sk_buff *skb,
-		      struct nfp_net_r_vector *r_vec)
-{
-	unsigned char *data;
-	int res, md_bytes;
-	u32 meta_id = 0;
-
-	res = nfp_nfdk_prep_port_id(skb);
-	if (unlikely(res <= 0))
-		return res;
+	if (!(md_dst || vlan_insert))
+		return 0;
 
-	md_bytes = res;
-	meta_id = NFP_NET_META_PORTID;
+	md_bytes = sizeof(meta_id) +
+		   !!md_dst * NFP_NET_META_PORTID_SIZE +
+		   vlan_insert * NFP_NET_META_VLAN_SIZE;
 
-	if (unlikely(skb_cow_head(skb, sizeof(meta_id))))
+	if (unlikely(skb_cow_head(skb, md_bytes)))
 		return -ENOMEM;
 
-	md_bytes += sizeof(meta_id);
+	data = skb_push(skb, md_bytes) + md_bytes;
+	if (md_dst) {
+		data -= NFP_NET_META_PORTID_SIZE;
+		put_unaligned_be32(md_dst->u.port_info.port_id, data);
+		meta_id = NFP_NET_META_PORTID;
+	}
+	if (vlan_insert) {
+		data -= NFP_NET_META_VLAN_SIZE;
+		/* data type of skb->vlan_proto is __be16
+		 * so it fills metadata without calling put_unaligned_be16
+		 */
+		memcpy(data, &skb->vlan_proto, sizeof(skb->vlan_proto));
+		put_unaligned_be16(skb_vlan_tag_get(skb), data + sizeof(skb->vlan_proto));
+		meta_id <<= NFP_NET_META_FIELD_SIZE;
+		meta_id |= NFP_NET_META_VLAN;
+	}
 
 	meta_id = FIELD_PREP(NFDK_META_LEN, md_bytes) |
 		  FIELD_PREP(NFDK_META_FIELDS, meta_id);
 
-	data = skb_push(skb, sizeof(meta_id));
+	data -= sizeof(meta_id);
 	put_unaligned_be32(meta_id, data);
 
 	return NFDK_DESC_TX_CHAIN_META;
@@ -259,7 +262,7 @@ netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev)
 		return NETDEV_TX_BUSY;
 	}
 
-	metadata = nfp_nfdk_prep_tx_meta(nn->app, skb, r_vec);
+	metadata = nfp_nfdk_prep_tx_meta(dp, nn->app, skb);
 	if (unlikely((int)metadata < 0))
 		goto err_flush;
 

drivers/net/ethernet/netronome/nfp/nfdk/rings.c

@@ -169,6 +169,7 @@ nfp_nfdk_print_tx_descs(struct seq_file *file,
 	 NFP_NET_CFG_CTRL_RXCSUM | NFP_NET_CFG_CTRL_TXCSUM |		\
 	 NFP_NET_CFG_CTRL_RXVLAN |					\
 	 NFP_NET_CFG_CTRL_RXVLAN_V2 | NFP_NET_CFG_CTRL_RXQINQ |		\
+	 NFP_NET_CFG_CTRL_TXVLAN_V2 |					\
 	 NFP_NET_CFG_CTRL_GATHER | NFP_NET_CFG_CTRL_LSO |		\
 	 NFP_NET_CFG_CTRL_CTAG_FILTER | NFP_NET_CFG_CTRL_CMSG_DATA |	\
 	 NFP_NET_CFG_CTRL_RINGCFG | NFP_NET_CFG_CTRL_IRQMOD |		\

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -2104,7 +2104,7 @@ void nfp_net_info(struct nfp_net *nn)
 		nn->cap & NFP_NET_CFG_CTRL_TXVLAN   ? "TXVLAN "   : "",
 		nn->cap & NFP_NET_CFG_CTRL_RXQINQ   ? "RXQINQ "   : "",
 		nn->cap & NFP_NET_CFG_CTRL_RXVLAN_V2 ? "RXVLANv2 "   : "",
-		nn->cap & NFP_NET_CFG_CTRL_TXVLAN_V2   ? "TXVLAN2 "   : "",
+		nn->cap & NFP_NET_CFG_CTRL_TXVLAN_V2   ? "TXVLANv2 "   : "",
 		nn->cap & NFP_NET_CFG_CTRL_SCATTER  ? "SCATTER "  : "",
 		nn->cap & NFP_NET_CFG_CTRL_GATHER   ? "GATHER "   : "",
 		nn->cap & NFP_NET_CFG_CTRL_LSO      ? "TSO1 "     : "",