net/mlx4_en: Support RX XDP metadata

RX timestamp and hash for now. Tested using the prog from the next
patch.

Also enabling xdp metadata support; don't see why it's disabled,
there is enough headroom..

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-14-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

drivers/net/ethernet/mellanox/mlx4/en_clock.c

@@ -58,9 +58,7 @@ u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
 	return hi | lo;
 }
 
-void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
-			    struct skb_shared_hwtstamps *hwts,
-			    u64 timestamp)
+u64 mlx4_en_get_hwtstamp(struct mlx4_en_dev *mdev, u64 timestamp)
 {
 	unsigned int seq;
 	u64 nsec;
@@ -70,8 +68,15 @@ void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
 		nsec = timecounter_cyc2time(&mdev->clock, timestamp);
 	} while (read_seqretry(&mdev->clock_lock, seq));
 
+	return ns_to_ktime(nsec);
+}
+
+void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
+			    struct skb_shared_hwtstamps *hwts,
+			    u64 timestamp)
+{
 	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
-	hwts->hwtstamp = ns_to_ktime(nsec);
+	hwts->hwtstamp = mlx4_en_get_hwtstamp(mdev, timestamp);
 }
 
 /**

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -2889,6 +2889,11 @@ static const struct net_device_ops mlx4_netdev_ops_master = {
 	.ndo_bpf		= mlx4_xdp,
 };
 
+static const struct xdp_metadata_ops mlx4_xdp_metadata_ops = {
+	.xmo_rx_timestamp		= mlx4_en_xdp_rx_timestamp,
+	.xmo_rx_hash			= mlx4_en_xdp_rx_hash,
+};
+
 struct mlx4_en_bond {
 	struct work_struct work;
 	struct mlx4_en_priv *priv;
@@ -3310,6 +3315,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 		dev->netdev_ops = &mlx4_netdev_ops_master;
 	else
 		dev->netdev_ops = &mlx4_netdev_ops;
+	dev->xdp_metadata_ops = &mlx4_xdp_metadata_ops;
 	dev->watchdog_timeo = MLX4_EN_WATCHDOG_TIMEOUT;
 	netif_set_real_num_tx_queues(dev, priv->tx_ring_num[TX]);
 	netif_set_real_num_rx_queues(dev, priv->rx_ring_num);

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -663,8 +663,35 @@ static int check_csum(struct mlx4_cqe *cqe, struct sk_buff *skb, void *va,
 
 struct mlx4_en_xdp_buff {
 	struct xdp_buff xdp;
+	struct mlx4_cqe *cqe;
+	struct mlx4_en_dev *mdev;
+	struct mlx4_en_rx_ring *ring;
+	struct net_device *dev;
 };
 
+int mlx4_en_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
+{
+	struct mlx4_en_xdp_buff *_ctx = (void *)ctx;
+
+	if (unlikely(_ctx->ring->hwtstamp_rx_filter != HWTSTAMP_FILTER_ALL))
+		return -EOPNOTSUPP;
+
+	*timestamp = mlx4_en_get_hwtstamp(_ctx->mdev,
+					  mlx4_en_get_cqe_ts(_ctx->cqe));
+	return 0;
+}
+
+int mlx4_en_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
+{
+	struct mlx4_en_xdp_buff *_ctx = (void *)ctx;
+
+	if (unlikely(!(_ctx->dev->features & NETIF_F_RXHASH)))
+		return -EOPNOTSUPP;
+
+	*hash = be32_to_cpu(_ctx->cqe->immed_rss_invalid);
+	return 0;
+}
+
 int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int budget)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
@@ -781,8 +808,12 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 						DMA_FROM_DEVICE);
 
 			xdp_prepare_buff(&mxbuf.xdp, va - frags[0].page_offset,
-					 frags[0].page_offset, length, false);
+					 frags[0].page_offset, length, true);
 			orig_data = mxbuf.xdp.data;
+			mxbuf.cqe = cqe;
+			mxbuf.mdev = priv->mdev;
+			mxbuf.ring = ring;
+			mxbuf.dev = dev;
 
 			act = bpf_prog_run_xdp(xdp_prog, &mxbuf.xdp);
 

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

@@ -796,10 +796,15 @@ void mlx4_en_update_pfc_stats_bitmap(struct mlx4_dev *dev,
 int mlx4_en_netdev_event(struct notifier_block *this,
 			 unsigned long event, void *ptr);
 
+struct xdp_md;
+int mlx4_en_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp);
+int mlx4_en_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash);
+
 /*
  * Functions for time stamping
  */
 u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe);
+u64 mlx4_en_get_hwtstamp(struct mlx4_en_dev *mdev, u64 timestamp);
 void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
 			    struct skb_shared_hwtstamps *hwts,
 			    u64 timestamp);