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>
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index b8d0854..1e6c594 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -77,6 +77,7 @@
 	struct mlx4_en_dev *mdev = priv->mdev;
 	int err = 0;
 	char name[25];
+	int timestamp_en = 0;
 	struct cpu_rmap *rmap =
 #ifdef CONFIG_RFS_ACCEL
 		priv->dev->rx_cpu_rmap;
@@ -123,8 +124,13 @@
 	if (!cq->is_tx)
 		cq->size = priv->rx_ring[cq->ring].actual_size;
 
-	err = mlx4_cq_alloc(mdev->dev, cq->size, &cq->wqres.mtt, &mdev->priv_uar,
-			    cq->wqres.db.dma, &cq->mcq, cq->vector, 0);
+	if ((cq->is_tx && priv->hwtstamp_config.tx_type) ||
+	    (!cq->is_tx && priv->hwtstamp_config.rx_filter))
+		timestamp_en = 1;
+
+	err = mlx4_cq_alloc(mdev->dev, cq->size, &cq->wqres.mtt,
+			    &mdev->priv_uar, cq->wqres.db.dma, &cq->mcq,
+			    cq->vector, 0, timestamp_en);
 	if (err)
 		return err;