[PATCH net-next v5 05/12] net/mlx5e: Remove jumbo_remove step from TX path

[Alice Mikityanska <alice.kernel@fastmail.im>]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the mlx5e and mlx5i TX path, that used to check
and remove HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_tx.c   | 75 +++----------------
 1 file changed, 12 insertions(+), 63 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index a01ee656a1e7..9f0272649fa1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -152,12 +152,11 @@ mlx5e_txwqe_build_eseg_csum(struct mlx5e_txqsq *sq, struct sk_buff *skb,
  * to inline later in the transmit descriptor
  */
 static inline u16
-mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb, int *hopbyhop)
+mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb)
 {
 	struct mlx5e_sq_stats *stats = sq->stats;
 	u16 ihs;
 
-	*hopbyhop = 0;
 	if (skb->encapsulation) {
 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 			ihs = skb_inner_transport_offset(skb) +
@@ -167,17 +166,12 @@ mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb, int *hopbyhop)
 		stats->tso_inner_packets++;
 		stats->tso_inner_bytes += skb->len - ihs;
 	} else {
-		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 			ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
-		} else {
+		else
 			ihs = skb_tcp_all_headers(skb);
-			if (ipv6_has_hopopt_jumbo(skb)) {
-				*hopbyhop = sizeof(struct hop_jumbo_hdr);
-				ihs -= sizeof(struct hop_jumbo_hdr);
-			}
-		}
 		stats->tso_packets++;
-		stats->tso_bytes += skb->len - ihs - *hopbyhop;
+		stats->tso_bytes += skb->len - ihs;
 	}
 
 	return ihs;
@@ -239,7 +233,6 @@ struct mlx5e_tx_attr {
 	__be16 mss;
 	u16 insz;
 	u8 opcode;
-	u8 hopbyhop;
 };
 
 struct mlx5e_tx_wqe_attr {
@@ -275,16 +268,14 @@ static void mlx5e_sq_xmit_prepare(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	struct mlx5e_sq_stats *stats = sq->stats;
 
 	if (skb_is_gso(skb)) {
-		int hopbyhop;
-		u16 ihs = mlx5e_tx_get_gso_ihs(sq, skb, &hopbyhop);
+		u16 ihs = mlx5e_tx_get_gso_ihs(sq, skb);
 
 		*attr = (struct mlx5e_tx_attr) {
 			.opcode    = MLX5_OPCODE_LSO,
 			.mss       = cpu_to_be16(skb_shinfo(skb)->gso_size),
 			.ihs       = ihs,
 			.num_bytes = skb->len + (skb_shinfo(skb)->gso_segs - 1) * ihs,
-			.headlen   = skb_headlen(skb) - ihs - hopbyhop,
-			.hopbyhop  = hopbyhop,
+			.headlen   = skb_headlen(skb) - ihs,
 		};
 
 		stats->packets += skb_shinfo(skb)->gso_segs;
@@ -439,7 +430,6 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	struct mlx5_wqe_data_seg *dseg;
 	struct mlx5e_tx_wqe_info *wi;
 	u16 ihs = attr->ihs;
-	struct ipv6hdr *h6;
 	struct mlx5e_sq_stats *stats = sq->stats;
 	int num_dma;
 
@@ -456,28 +446,7 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	if (ihs) {
 		u8 *start = eseg->inline_hdr.start;
 
-		if (unlikely(attr->hopbyhop)) {
-			/* remove the HBH header.
-			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
-			 */
-			if (skb_vlan_tag_present(skb)) {
-				mlx5e_insert_vlan(start, skb, ETH_HLEN + sizeof(*h6));
-				ihs += VLAN_HLEN;
-				h6 = (struct ipv6hdr *)(start + sizeof(struct vlan_ethhdr));
-			} else {
-				unsafe_memcpy(start, skb->data,
-					      ETH_HLEN + sizeof(*h6),
-					      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-				h6 = (struct ipv6hdr *)(start + ETH_HLEN);
-			}
-			h6->nexthdr = IPPROTO_TCP;
-			/* Copy the TCP header after the IPv6 one */
-			memcpy(h6 + 1,
-			       skb->data + ETH_HLEN + sizeof(*h6) +
-					sizeof(struct hop_jumbo_hdr),
-			       tcp_hdrlen(skb));
-			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
-		} else if (skb_vlan_tag_present(skb)) {
+		if (skb_vlan_tag_present(skb)) {
 			mlx5e_insert_vlan(start, skb, ihs);
 			ihs += VLAN_HLEN;
 			stats->added_vlan_packets++;
@@ -491,7 +460,7 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	}
 
 	dseg += wqe_attr->ds_cnt_ids;
-	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr->ihs + attr->hopbyhop,
+	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr->ihs,
 					  attr->headlen, dseg);
 	if (unlikely(num_dma < 0))
 		goto err_drop;
@@ -1019,34 +988,14 @@ void mlx5i_sq_xmit(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	eseg->mss = attr.mss;
 
 	if (attr.ihs) {
-		if (unlikely(attr.hopbyhop)) {
-			struct ipv6hdr *h6;
-
-			/* remove the HBH header.
-			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
-			 */
-			unsafe_memcpy(eseg->inline_hdr.start, skb->data,
-				      ETH_HLEN + sizeof(*h6),
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-			h6 = (struct ipv6hdr *)((char *)eseg->inline_hdr.start + ETH_HLEN);
-			h6->nexthdr = IPPROTO_TCP;
-			/* Copy the TCP header after the IPv6 one */
-			unsafe_memcpy(h6 + 1,
-				      skb->data + ETH_HLEN + sizeof(*h6) +
-						  sizeof(struct hop_jumbo_hdr),
-				      tcp_hdrlen(skb),
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
-		} else {
-			unsafe_memcpy(eseg->inline_hdr.start, skb->data,
-				      attr.ihs,
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-		}
+		unsafe_memcpy(eseg->inline_hdr.start, skb->data,
+			      attr.ihs,
+			      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
 		eseg->inline_hdr.sz = cpu_to_be16(attr.ihs);
 		dseg += wqe_attr.ds_cnt_inl;
 	}
 
-	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr.ihs + attr.hopbyhop,
+	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr.ihs,
 					  attr.headlen, dseg);
 	if (unlikely(num_dma < 0))
 		goto err_drop;
-- 
2.52.0