net/mlx5e: kTLS, Improve rx handler function call

Prior to this patch mlx5e tls rx handler was called unconditionally on
all rx frames and the decision whether a frame is a valid tls record
is done inside that function.  A function call can be expensive especially
for regular rx packet rate.  To avoid this, check the tls validity before
jumping into the tls rx handler.

While at it, split between kTLS device offload rx handler and FPGA tls rx
handler using a similar method.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>

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

@@ -263,6 +263,7 @@ enum {
 	MLX5E_RQ_STATE_AM,
 	MLX5E_RQ_STATE_NO_CSUM_COMPLETE,
 	MLX5E_RQ_STATE_CSUM_FULL, /* cqe_csum_full hw bit is set */
+	MLX5E_RQ_STATE_FPGA_TLS, /* FPGA TLS enabled */
 };
 
 struct mlx5e_cq {

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

@@ -517,15 +517,9 @@ void mlx5e_ktls_rx_resync(struct net_device *netdev, struct sock *sk,
 void mlx5e_ktls_handle_rx_skb(struct mlx5e_rq *rq, struct sk_buff *skb,
 			      struct mlx5_cqe64 *cqe, u32 *cqe_bcnt)
 {
-	u8 tls_offload = get_cqe_tls_offload(cqe);
-	struct mlx5e_rq_stats *stats;
+	struct mlx5e_rq_stats *stats = rq->stats;
 
-	if (likely(tls_offload == CQE_TLS_OFFLOAD_NOT_DECRYPTED))
-		return;
-
-	stats = rq->stats;
-
-	switch (tls_offload) {
+	switch (get_cqe_tls_offload(cqe)) {
 	case CQE_TLS_OFFLOAD_DECRYPTED:
 		skb->decrypted = 1;
 		stats->tls_decrypted_packets++;

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

@@ -87,6 +87,11 @@ mlx5e_get_tls_rx_context(struct tls_context *tls_ctx)
 			    base);
 }
 
+static inline bool mlx5e_is_tls_on(struct mlx5e_priv *priv)
+{
+	return priv->tls;
+}
+
 void mlx5e_tls_build_netdev(struct mlx5e_priv *priv);
 int mlx5e_tls_init(struct mlx5e_priv *priv);
 void mlx5e_tls_cleanup(struct mlx5e_priv *priv);
@@ -103,6 +108,7 @@ static inline void mlx5e_tls_build_netdev(struct mlx5e_priv *priv)
 		mlx5e_ktls_build_netdev(priv);
 }
 
+static inline bool mlx5e_is_tls_on(struct mlx5e_priv *priv) { return false; }
 static inline int mlx5e_tls_init(struct mlx5e_priv *priv) { return 0; }
 static inline void mlx5e_tls_cleanup(struct mlx5e_priv *priv) { }
 static inline int mlx5e_tls_get_count(struct mlx5e_priv *priv) { return 0; }

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

@@ -355,19 +355,13 @@ static int tls_update_resync_sn(struct net_device *netdev,
 	return 0;
 }
 
-void mlx5e_tls_handle_rx_skb(struct mlx5e_rq *rq, struct sk_buff *skb,
-			     struct mlx5_cqe64 *cqe, u32 *cqe_bcnt)
+/* FPGA tls rx handler */
+void mlx5e_tls_handle_rx_skb_metadata(struct mlx5e_rq *rq, struct sk_buff *skb,
+				      u32 *cqe_bcnt)
 {
 	struct mlx5e_tls_metadata *mdata;
 	struct mlx5e_priv *priv;
 
-	if (likely(mlx5_accel_is_ktls_rx(rq->mdev)))
-		return mlx5e_ktls_handle_rx_skb(rq, skb, cqe, cqe_bcnt);
-
-	/* FPGA */
-	if (!is_metadata_hdr_valid(skb))
-		return;
-
 	/* Use the metadata */
 	mdata = (struct mlx5e_tls_metadata *)(skb->data + ETH_HLEN);
 	switch (mdata->content.recv.syndrome) {

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

@@ -34,6 +34,7 @@
 #ifndef __MLX5E_TLS_RXTX_H__
 #define __MLX5E_TLS_RXTX_H__
 
+#include "accel/accel.h"
 #include "en_accel/ktls_txrx.h"
 
 #ifdef CONFIG_MLX5_EN_TLS
@@ -49,11 +50,27 @@ bool mlx5e_tls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
 void mlx5e_tls_handle_tx_wqe(struct mlx5e_txqsq *sq, struct mlx5_wqe_ctrl_seg *cseg,
 			     struct mlx5e_accel_tx_tls_state *state);
 
-void mlx5e_tls_handle_rx_skb(struct mlx5e_rq *rq, struct sk_buff *skb,
-			     struct mlx5_cqe64 *cqe, u32 *cqe_bcnt);
+void mlx5e_tls_handle_rx_skb_metadata(struct mlx5e_rq *rq, struct sk_buff *skb,
+				      u32 *cqe_bcnt);
+
+static inline void
+mlx5e_tls_handle_rx_skb(struct mlx5e_rq *rq, struct sk_buff *skb,
+			struct mlx5_cqe64 *cqe, u32 *cqe_bcnt)
+{
+	if (unlikely(get_cqe_tls_offload(cqe))) /* cqe bit indicates a TLS device */
+		return mlx5e_ktls_handle_rx_skb(rq, skb, cqe, cqe_bcnt);
+
+	if (unlikely(test_bit(MLX5E_RQ_STATE_FPGA_TLS, &rq->state) && is_metadata_hdr_valid(skb)))
+		return mlx5e_tls_handle_rx_skb_metadata(rq, skb, cqe_bcnt);
+}
 
 #else
 
+static inline bool
+mlx5e_accel_is_tls(struct mlx5_cqe64 *cqe, struct sk_buff *skb) { return false; }
+static inline void
+mlx5e_tls_handle_rx_skb(struct mlx5e_rq *rq, struct sk_buff *skb,
+			struct mlx5_cqe64 *cqe, u32 *cqe_bcnt) {}
 static inline u16 mlx5e_tls_get_stop_room(struct mlx5e_txqsq *sq)
 {
 	return 0;

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

@@ -873,6 +873,9 @@ int mlx5e_open_rq(struct mlx5e_channel *c, struct mlx5e_params *params,
 	if (err)
 		goto err_destroy_rq;
 
+	if (mlx5e_is_tls_on(c->priv) && !mlx5_accel_is_ktls_device(c->mdev))
+		__set_bit(MLX5E_RQ_STATE_FPGA_TLS, &c->rq.state); /* must be FPGA */
+
 	if (MLX5_CAP_ETH(c->mdev, cqe_checksum_full))
 		__set_bit(MLX5E_RQ_STATE_CSUM_FULL, &c->rq.state);
 

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

@@ -1019,9 +1019,7 @@ static inline void mlx5e_build_rx_skb(struct mlx5_cqe64 *cqe,
 
 	skb->mac_len = ETH_HLEN;
 
-#ifdef CONFIG_MLX5_EN_TLS
 	mlx5e_tls_handle_rx_skb(rq, skb, cqe, &cqe_bcnt);
-#endif
 
 	if (lro_num_seg > 1) {
 		mlx5e_lro_update_hdr(skb, cqe, cqe_bcnt);