net/mlx5e: Return bool from TLS and IPSEC offloads

TLS and IPSEC offloads currently return struct sk_buff *, but the value
is either NULL or the same skb that was passed as a parameter. Return
bool instead to provide stronger guarantees to the calling code (it
won't need to support handling a different SKB that could be potentially
returned before this change) and to simplify restructuring this code in
the following commits.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h

@@ -102,8 +102,7 @@ mlx5e_udp_gso_handle_tx_skb(struct sk_buff *skb)
 	udp_hdr(skb)->len = htons(payload_len);
 }
 
-static inline struct sk_buff *
-mlx5e_accel_handle_tx(struct sk_buff *skb,
+static inline bool mlx5e_accel_handle_tx(struct sk_buff *skb,
 					 struct mlx5e_txqsq *sq,
 					 struct net_device *dev,
 					 struct mlx5e_tx_wqe **wqe,
@@ -111,24 +110,22 @@ mlx5e_accel_handle_tx(struct sk_buff *skb,
 {
 #ifdef CONFIG_MLX5_EN_TLS
 	if (test_bit(MLX5E_SQ_STATE_TLS, &sq->state)) {
-		skb = mlx5e_tls_handle_tx_skb(dev, sq, skb, wqe, pi);
-		if (unlikely(!skb))
-			return NULL;
+		if (unlikely(!mlx5e_tls_handle_tx_skb(dev, sq, skb, wqe, pi)))
+			return false;
 	}
 #endif
 
 #ifdef CONFIG_MLX5_EN_IPSEC
 	if (test_bit(MLX5E_SQ_STATE_IPSEC, &sq->state)) {
-		skb = mlx5e_ipsec_handle_tx_skb(dev, *wqe, skb);
-		if (unlikely(!skb))
-			return NULL;
+		if (unlikely(!mlx5e_ipsec_handle_tx_skb(dev, *wqe, skb)))
+			return false;
 	}
 #endif
 
 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 		mlx5e_udp_gso_handle_tx_skb(skb);
 
-	return skb;
+	return true;
 }
 
 #endif /* __MLX5E_EN_ACCEL_H__ */

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c

@@ -233,7 +233,7 @@ static void mlx5e_ipsec_set_metadata(struct sk_buff *skb,
 		   ntohs(mdata->content.tx.seq));
 }
 
-struct sk_buff *mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
+bool mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
 			       struct mlx5e_tx_wqe *wqe,
 			       struct sk_buff *skb)
 {
@@ -245,7 +245,7 @@ struct sk_buff *mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
 	struct sec_path *sp;
 
 	if (!xo)
-		return skb;
+		return true;
 
 	sp = skb_sec_path(skb);
 	if (unlikely(sp->len != 1)) {
@@ -281,11 +281,11 @@ struct sk_buff *mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
 	sa_entry->set_iv_op(skb, x, xo);
 	mlx5e_ipsec_set_metadata(skb, mdata, xo);
 
-	return skb;
+	return true;
 
 drop:
 	kfree_skb(skb);
-	return NULL;
+	return false;
 }
 
 static inline struct xfrm_state *

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h

@@ -52,7 +52,7 @@ void mlx5e_ipsec_set_iv_esn(struct sk_buff *skb, struct xfrm_state *x,
 			    struct xfrm_offload *xo);
 void mlx5e_ipsec_set_iv(struct sk_buff *skb, struct xfrm_state *x,
 			struct xfrm_offload *xo);
-struct sk_buff *mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
+bool mlx5e_ipsec_handle_tx_skb(struct net_device *netdev,
 			       struct mlx5e_tx_wqe *wqe,
 			       struct sk_buff *skb);
 

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls.h

@@ -95,10 +95,9 @@ mlx5e_get_ktls_tx_priv_ctx(struct tls_context *tls_ctx)
 void mlx5e_ktls_build_netdev(struct mlx5e_priv *priv);
 void mlx5e_ktls_tx_offload_set_pending(struct mlx5e_ktls_offload_context_tx *priv_tx);
 
-struct sk_buff *mlx5e_ktls_handle_tx_skb(struct net_device *netdev,
-					 struct mlx5e_txqsq *sq,
-					 struct sk_buff *skb,
-					 struct mlx5e_tx_wqe **wqe, u16 *pi);
+bool mlx5e_ktls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
+			      struct sk_buff *skb, struct mlx5e_tx_wqe **wqe,
+			      u16 *pi);
 void mlx5e_ktls_tx_handle_resync_dump_comp(struct mlx5e_txqsq *sq,
 					   struct mlx5e_tx_wqe_info *wi,
 					   u32 *dma_fifo_cc);

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c

@@ -413,10 +413,9 @@ mlx5e_ktls_tx_handle_ooo(struct mlx5e_ktls_offload_context_tx *priv_tx,
 	return MLX5E_KTLS_SYNC_FAIL;
 }
 
-struct sk_buff *mlx5e_ktls_handle_tx_skb(struct net_device *netdev,
-					 struct mlx5e_txqsq *sq,
-					 struct sk_buff *skb,
-					 struct mlx5e_tx_wqe **wqe, u16 *pi)
+bool mlx5e_ktls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
+			      struct sk_buff *skb, struct mlx5e_tx_wqe **wqe,
+			      u16 *pi)
 {
 	struct mlx5e_ktls_offload_context_tx *priv_tx;
 	struct mlx5e_sq_stats *stats = sq->stats;
@@ -474,9 +473,9 @@ struct sk_buff *mlx5e_ktls_handle_tx_skb(struct net_device *netdev,
 	stats->tls_encrypted_bytes   += datalen;
 
 out:
-	return skb;
+	return true;
 
 err_out:
 	dev_kfree_skb_any(skb);
-	return NULL;
+	return false;
 }

drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls_rxtx.c

@@ -184,11 +184,9 @@ static void mlx5e_tls_complete_sync_skb(struct sk_buff *skb,
 	nskb->queue_mapping = skb->queue_mapping;
 }
 
-static struct sk_buff *
-mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx *context,
+static bool mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx *context,
 				 struct mlx5e_txqsq *sq, struct sk_buff *skb,
-		     struct mlx5e_tx_wqe **wqe,
-		     u16 *pi,
+				 struct mlx5e_tx_wqe **wqe, u16 *pi,
 				 struct mlx5e_tls *tls)
 {
 	u32 tcp_seq = ntohl(tcp_hdr(skb)->seq);
@@ -217,7 +215,7 @@ mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx *context,
 		if (likely(payload <= -info.sync_len))
 			/* SKB payload doesn't require offload
 			 */
-			return skb;
+			return true;
 
 		atomic64_inc(&tls->sw_stats.tx_tls_drop_bypass_required);
 		goto err_out;
@@ -250,17 +248,15 @@ mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx *context,
 	mlx5e_sq_xmit(sq, nskb, *wqe, *pi, true);
 	*pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc);
 	*wqe = MLX5E_TX_FETCH_WQE(sq, *pi);
-	return skb;
+	return true;
 
 err_out:
 	dev_kfree_skb_any(skb);
-	return NULL;
+	return false;
 }
 
-struct sk_buff *mlx5e_tls_handle_tx_skb(struct net_device *netdev,
-					struct mlx5e_txqsq *sq,
-					struct sk_buff *skb,
-					struct mlx5e_tx_wqe **wqe,
+bool mlx5e_tls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
+			     struct sk_buff *skb, struct mlx5e_tx_wqe **wqe,
 			     u16 *pi)
 {
 	struct mlx5e_priv *priv = netdev_priv(netdev);
@@ -270,41 +266,35 @@ struct sk_buff *mlx5e_tls_handle_tx_skb(struct net_device *netdev,
 	int datalen;
 	u32 skb_seq;
 
-	if (MLX5_CAP_GEN(sq->channel->mdev, tls_tx)) {
-		skb = mlx5e_ktls_handle_tx_skb(netdev, sq, skb, wqe, pi);
-		goto out;
-	}
+	if (MLX5_CAP_GEN(sq->channel->mdev, tls_tx))
+		return mlx5e_ktls_handle_tx_skb(netdev, sq, skb, wqe, pi);
 
 	if (!skb->sk || !tls_is_sk_tx_device_offloaded(skb->sk))
-		goto out;
+		return true;
 
 	datalen = skb->len - (skb_transport_offset(skb) + tcp_hdrlen(skb));
 	if (!datalen)
-		goto out;
+		return true;
 
 	tls_ctx = tls_get_ctx(skb->sk);
 	if (unlikely(tls_ctx->netdev != netdev))
-		goto out;
+		return true;
 
 	skb_seq = ntohl(tcp_hdr(skb)->seq);
 	context = mlx5e_get_tls_tx_context(tls_ctx);
 	expected_seq = context->expected_seq;
 
-	if (unlikely(expected_seq != skb_seq)) {
-		skb = mlx5e_tls_handle_ooo(context, sq, skb, wqe, pi, priv->tls);
-		goto out;
-	}
+	if (unlikely(expected_seq != skb_seq))
+		return mlx5e_tls_handle_ooo(context, sq, skb, wqe, pi, priv->tls);
 
 	if (unlikely(mlx5e_tls_add_metadata(skb, context->swid))) {
 		atomic64_inc(&priv->tls->sw_stats.tx_tls_drop_metadata);
 		dev_kfree_skb_any(skb);
-		skb = NULL;
-		goto out;
+		return false;
 	}
 
 	context->expected_seq = skb_seq + datalen;
-out:
-	return skb;
+	return true;
 }
 
 static int tls_update_resync_sn(struct net_device *netdev,

drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls_rxtx.h

@@ -40,10 +40,8 @@
 #include "en.h"
 #include "en/txrx.h"
 
-struct sk_buff *mlx5e_tls_handle_tx_skb(struct net_device *netdev,
-					struct mlx5e_txqsq *sq,
-					struct sk_buff *skb,
-					struct mlx5e_tx_wqe **wqe,
+bool mlx5e_tls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
+			     struct sk_buff *skb, struct mlx5e_tx_wqe **wqe,
 			     u16 *pi);
 
 void mlx5e_tls_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,

drivers/net/ethernet/mellanox/mlx5/core/en_tx.c

@@ -394,8 +394,7 @@ netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev)
 	wqe = MLX5E_TX_FETCH_WQE(sq, pi);
 
 	/* might send skbs and update wqe and pi */
-	skb = mlx5e_accel_handle_tx(skb, sq, dev, &wqe, &pi);
-	if (unlikely(!skb))
+	if (unlikely(!mlx5e_accel_handle_tx(skb, sq, dev, &wqe, &pi)))
 		return NETDEV_TX_OK;
 
 	return mlx5e_sq_xmit(sq, skb, wqe, pi, netdev_xmit_more());