net/mlx4_en: Add HW timestamping (TS) support

The patch allows to enable/disable HW timestamping for incoming and/or
outgoing packets. It adds and initializes all structs and callbacks
needed by kernel TS API.
To enable/disable HW timestamping appropriate ioctl should be used.
Currently HWTSTAMP_FILTER_ALL/NONE and HWTSAMP_TX_ON/OFF only are
supported.
When enabling TS on receive flow - VLAN stripping will be disabled.
Also were made all relevant changes in RX/TX flows to consider TS request
and plant HW timestamps into relevant structures.
mlx4_ib was fixed to compile with new mlx4_cq_alloc() signature.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 3 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 49308cc65ee..b0a2d2b96e4 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -118,6 +118,8 @@ int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
 	} else
 		ring->bf_enabled = true;
 
+	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
+
 	return 0;
 
 err_map:
@@ -192,8 +194,9 @@ void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
 
 static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
 				struct mlx4_en_tx_ring *ring,
-				int index, u8 owner)
+				int index, u8 owner, u64 timestamp)
 {
+	struct mlx4_en_dev *mdev = priv->mdev;
 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
@@ -204,6 +207,12 @@ static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
 	int i;
 	__be32 *ptr = (__be32 *)tx_desc;
 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
+	struct skb_shared_hwtstamps hwts;
+
+	if (timestamp) {
+		mlx4_en_fill_hwtstamps(mdev, &hwts, timestamp);
+		skb_tstamp_tx(skb, &hwts);
+	}
 
 	/* Optimize the common case when there are no wraparounds */
 	if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
@@ -289,7 +298,7 @@ int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
 	while (ring->cons != ring->prod) {
 		ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
 						ring->cons & ring->size_mask,
-						!!(ring->cons & ring->size));
+						!!(ring->cons & ring->size), 0);
 		ring->cons += ring->last_nr_txbb;
 		cnt++;
 	}
@@ -318,6 +327,7 @@ static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq)
 	u32 packets = 0;
 	u32 bytes = 0;
 	int factor = priv->cqe_factor;
+	u64 timestamp = 0;
 
 	if (!priv->port_up)
 		return;
@@ -341,11 +351,14 @@ static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq)
 		do {
 			txbbs_skipped += ring->last_nr_txbb;
 			ring_index = (ring_index + ring->last_nr_txbb) & size_mask;
+			if (ring->tx_info[ring_index].ts_requested)
+				timestamp = mlx4_en_get_cqe_ts(cqe);
+
 			/* free next descriptor */
 			ring->last_nr_txbb = mlx4_en_free_tx_desc(
 					priv, ring, ring_index,
 					!!((ring->cons + txbbs_skipped) &
-							ring->size));
+					ring->size), timestamp);
 			packets++;
 			bytes += ring->tx_info[ring_index].nr_bytes;
 		} while (ring_index != new_index);
@@ -629,6 +642,16 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 	tx_info->skb = skb;
 	tx_info->nr_txbb = nr_txbb;
 
+	/*
+	 * For timestamping add flag to skb_shinfo and
+	 * set flag for further reference
+	 */
+	if (ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
+	    skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+		tx_info->ts_requested = 1;
+	}
+
 	/* Prepare ctrl segement apart opcode+ownership, which depends on
 	 * whether LSO is used */
 	tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag);