[xdp-hints] [RFC bpf-next v2 10/24] ice: Implement VLAN tag hint

[Larysa Zaremba <larysa.zaremba@intel.com>]

Implement .xmo_rx_vlan_tag callback to allow XDP code to read
packet's VLAN tag.

At the same time, use vlan_tci instead of vlan_tag in touched code,
because VLAN tag often refers to VLAN proto and VLAN TCI combined,
while in the code we clearly store only VLAN TCI.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_main.c     | 20 ++++++++++++++
 drivers/net/ethernet/intel/ice/ice_txrx.c     |  6 ++---
 drivers/net/ethernet/intel/ice/ice_txrx.h     |  1 +
 drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 26 +++++++++++++++++++
 drivers/net/ethernet/intel/ice/ice_txrx_lib.h |  4 +--
 drivers/net/ethernet/intel/ice/ice_xsk.c      |  6 ++---
 6 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 2153e27642eb..47e8920e1727 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -6014,6 +6014,23 @@ ice_fix_features(struct net_device *netdev, netdev_features_t features)
 	return features;
 }
 
+/**
+ * ice_set_rx_rings_vlan_proto - update rings with new stripped VLAN proto
+ * @vsi: PF's VSI
+ * @vlan_ethertype: VLAN ethertype (802.1Q or 802.1ad) in network byte order
+ *
+ * Store current stripped VLAN proto in ring packet context,
+ * so it can be accessed more efficiently by packet processing code.
+ */
+static void
+ice_set_rx_rings_vlan_proto(struct ice_vsi *vsi, __be16 vlan_ethertype)
+{
+	u16 i;
+
+	ice_for_each_alloc_rxq(vsi, i)
+		vsi->rx_rings[i]->pkt_ctx.vlan_proto = vlan_ethertype;
+}
+
 /**
  * ice_set_vlan_offload_features - set VLAN offload features for the PF VSI
  * @vsi: PF's VSI
@@ -6056,6 +6073,9 @@ ice_set_vlan_offload_features(struct ice_vsi *vsi, netdev_features_t features)
 	if (strip_err || insert_err)
 		return -EIO;
 
+	ice_set_rx_rings_vlan_proto(vsi, enable_stripping ?
+				    htons(vlan_ethertype) : 0);
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 4e6546d9cf85..4fd7614f243d 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -1183,7 +1183,7 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
 		struct sk_buff *skb;
 		unsigned int size;
 		u16 stat_err_bits;
-		u16 vlan_tag = 0;
+		u16 vlan_tci;
 
 		/* get the Rx desc from Rx ring based on 'next_to_clean' */
 		rx_desc = ICE_RX_DESC(rx_ring, ntc);
@@ -1278,7 +1278,7 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
 			continue;
 		}
 
-		vlan_tag = ice_get_vlan_tag_from_rx_desc(rx_desc);
+		vlan_tci = ice_get_vlan_tci(rx_desc);
 
 		/* pad the skb if needed, to make a valid ethernet frame */
 		if (eth_skb_pad(skb))
@@ -1292,7 +1292,7 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
 
 		ice_trace(clean_rx_irq_indicate, rx_ring, rx_desc, skb);
 		/* send completed skb up the stack */
-		ice_receive_skb(rx_ring, skb, vlan_tag);
+		ice_receive_skb(rx_ring, skb, vlan_tci);
 
 		/* update budget accounting */
 		total_rx_pkts++;
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index 4237702a58a9..41e0b14e6643 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -260,6 +260,7 @@ enum ice_rx_dtype {
 struct ice_pkt_ctx {
 	const union ice_32b_rx_flex_desc *eop_desc;
 	u64 cached_phctime;
+	__be16 vlan_proto;
 };
 
 struct ice_xdp_buff {
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
index 574a119aecf5..fa138f66e1c4 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
@@ -626,7 +626,33 @@ static int ice_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
 	return 0;
 }
 
+/**
+ * ice_xdp_rx_vlan_tag - VLAN tag XDP hint handler
+ * @ctx: XDP buff pointer
+ * @vlan_proto: destination address for VLAN protocol
+ * @vlan_tci: destination address for VLAN TCI
+ *
+ * Copy VLAN tag (if was stripped) and corresponding protocol
+ * to the destination address.
+ */
+static int ice_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
+			       u16 *vlan_tci)
+{
+	const struct ice_xdp_buff *xdp_ext = (void *)ctx;
+
+	*vlan_proto = xdp_ext->pkt_ctx.vlan_proto;
+	if (!*vlan_proto)
+		return -ENODATA;
+
+	*vlan_tci = ice_get_vlan_tci(xdp_ext->pkt_ctx.eop_desc);
+	if (!*vlan_tci)
+		return -ENODATA;
+
+	return 0;
+}
+
 const struct xdp_metadata_ops ice_xdp_md_ops = {
 	.xmo_rx_timestamp		= ice_xdp_rx_hw_ts,
 	.xmo_rx_hash			= ice_xdp_rx_hash,
+	.xmo_rx_vlan_tag		= ice_xdp_rx_vlan_tag,
 };
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.h b/drivers/net/ethernet/intel/ice/ice_txrx_lib.h
index 145883eec129..b7205826fea8 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.h
@@ -84,7 +84,7 @@ ice_build_ctob(u64 td_cmd, u64 td_offset, unsigned int size, u64 td_tag)
 }
 
 /**
- * ice_get_vlan_tag_from_rx_desc - get VLAN from Rx flex descriptor
+ * ice_get_vlan_tci - get VLAN TCI from Rx flex descriptor
  * @rx_desc: Rx 32b flex descriptor with RXDID=2
  *
  * The OS and current PF implementation only support stripping a single VLAN tag
@@ -92,7 +92,7 @@ ice_build_ctob(u64 td_cmd, u64 td_offset, unsigned int size, u64 td_tag)
  * one is found return the tag, else return 0 to mean no VLAN tag was found.
  */
 static inline u16
-ice_get_vlan_tag_from_rx_desc(union ice_32b_rx_flex_desc *rx_desc)
+ice_get_vlan_tci(const union ice_32b_rx_flex_desc *rx_desc)
 {
 	u16 stat_err_bits;
 
diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 6ca620b2fbdd..39775bb6cec1 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -898,7 +898,7 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
 		struct xdp_buff *xdp;
 		struct sk_buff *skb;
 		u16 stat_err_bits;
-		u16 vlan_tag = 0;
+		u16 vlan_tci;
 
 		rx_desc = ICE_RX_DESC(rx_ring, ntc);
 
@@ -977,10 +977,10 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
 		total_rx_bytes += skb->len;
 		total_rx_packets++;
 
-		vlan_tag = ice_get_vlan_tag_from_rx_desc(rx_desc);
+		vlan_tci = ice_get_vlan_tci(rx_desc);
 
 		ice_process_skb_fields(rx_ring, rx_desc, skb);
-		ice_receive_skb(rx_ring, skb, vlan_tag);
+		ice_receive_skb(rx_ring, skb, vlan_tci);
 	}
 
 	rx_ring->next_to_clean = ntc;
-- 
2.41.0