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Commit 58d52291 authored by Achiad Shochat's avatar Achiad Shochat Committed by David S. Miller
Browse files

net/mlx5e: Support TX packet copy into WQE 



AKA inline WQE.
A TX latency optimization to save data gather DMA reads.
Controlled by ETHTOOL_TX_COPYBREAK.

Signed-off-by: default avatarAchiad Shochat <achiad@mellanox.com>
Signed-off-by: default avatarAmir Vadai <amirv@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 311c7c71

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

+2 −0
Original line number Diff line number Diff line
@@ -196,6 +196,7 @@ struct mlx5e_params { 
	bool lro_en;

	u32 lro_wqe_sz;

	u8  rss_hfunc;

	u16 tx_max_inline;

};



enum {
@@ -520,3 +521,4 @@ static inline void mlx5e_cq_arm(struct mlx5e_cq *cq) 
}



extern const struct ethtool_ops mlx5e_ethtool_ops;

u16 mlx5e_get_max_inline_cap(struct mlx5_core_dev *mdev);

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

+53 −0
Original line number Diff line number Diff line
@@ -699,6 +699,57 @@ static int mlx5e_set_rxfh(struct net_device *netdev, const u32 *indir, 
	return err;

}



static int mlx5e_get_tunable(struct net_device *dev,

			     const struct ethtool_tunable *tuna,

			     void *data)

{

	const struct mlx5e_priv *priv = netdev_priv(dev);

	int err = 0;



	switch (tuna->id) {

	case ETHTOOL_TX_COPYBREAK:

		*(u32 *)data = priv->params.tx_max_inline;

		break;

	default:

		err = -EINVAL;

		break;

	}



	return err;

}



static int mlx5e_set_tunable(struct net_device *dev,

			     const struct ethtool_tunable *tuna,

			     const void *data)

{

	struct mlx5e_priv *priv = netdev_priv(dev);

	struct mlx5_core_dev *mdev = priv->mdev;

	struct mlx5e_params new_params;

	u32 val;

	int err = 0;



	switch (tuna->id) {

	case ETHTOOL_TX_COPYBREAK:

		val = *(u32 *)data;

		if (val > mlx5e_get_max_inline_cap(mdev)) {

			err = -EINVAL;

			break;

		}



		mutex_lock(&priv->state_lock);

		new_params = priv->params;

		new_params.tx_max_inline = val;

		err = mlx5e_update_priv_params(priv, &new_params);

		mutex_unlock(&priv->state_lock);

		break;

	default:

		err = -EINVAL;

		break;

	}



	return err;

}



const struct ethtool_ops mlx5e_ethtool_ops = {

	.get_drvinfo       = mlx5e_get_drvinfo,

	.get_link          = ethtool_op_get_link,
@@ -715,4 +766,6 @@ const struct ethtool_ops mlx5e_ethtool_ops = { 
	.set_settings      = mlx5e_set_settings,

	.get_rxfh          = mlx5e_get_rxfh,

	.set_rxfh          = mlx5e_set_rxfh,

	.get_tunable       = mlx5e_get_tunable,

	.set_tunable       = mlx5e_set_tunable,

};

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

+13 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ struct mlx5e_rq_param { 
struct mlx5e_sq_param {

	u32                        sqc[MLX5_ST_SZ_DW(sqc)];

	struct mlx5_wq_param       wq;

	u16                        max_inline;

};



struct mlx5e_cq_param {
@@ -514,6 +515,7 @@ static int mlx5e_create_sq(struct mlx5e_channel *c, 
	sq->wq.db       = &sq->wq.db[MLX5_SND_DBR];

	sq->uar_map     = sq->uar.map;

	sq->bf_buf_size = (1 << MLX5_CAP_GEN(mdev, log_bf_reg_size)) / 2;

	sq->max_inline  = param->max_inline;



	err = mlx5e_alloc_sq_db(sq, cpu_to_node(c->cpu));

	if (err)
@@ -1020,6 +1022,7 @@ static void mlx5e_build_sq_param(struct mlx5e_priv *priv, 
	MLX5_SET(wq, wq, pd,            priv->pdn);



	param->wq.buf_numa_node = dev_to_node(&priv->mdev->pdev->dev);

	param->max_inline = priv->params.tx_max_inline;

}



static void mlx5e_build_common_cq_param(struct mlx5e_priv *priv,
@@ -1703,6 +1706,15 @@ static int mlx5e_check_required_hca_cap(struct mlx5_core_dev *mdev) 
	return 0;

}



u16 mlx5e_get_max_inline_cap(struct mlx5_core_dev *mdev)

{

	int bf_buf_size = (1 << MLX5_CAP_GEN(mdev, log_bf_reg_size)) / 2;



	return bf_buf_size -

	       sizeof(struct mlx5e_tx_wqe) +

	       2 /*sizeof(mlx5e_tx_wqe.inline_hdr_start)*/;

}



static void mlx5e_build_netdev_priv(struct mlx5_core_dev *mdev,

				    struct net_device *netdev,

				    int num_comp_vectors)
@@ -1721,6 +1733,7 @@ static void mlx5e_build_netdev_priv(struct mlx5_core_dev *mdev, 
		MLX5E_PARAMS_DEFAULT_TX_CQ_MODERATION_USEC;

	priv->params.tx_cq_moderation_pkts =

		MLX5E_PARAMS_DEFAULT_TX_CQ_MODERATION_PKTS;

	priv->params.tx_max_inline         = mlx5e_get_max_inline_cap(mdev);

	priv->params.min_rx_wqes           =

		MLX5E_PARAMS_DEFAULT_MIN_RX_WQES;

	priv->params.rx_hash_log_tbl_sz    =

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

+9 −1
Original line number Diff line number Diff line
@@ -112,7 +112,15 @@ u16 mlx5e_select_queue(struct net_device *dev, struct sk_buff *skb, 
static inline u16 mlx5e_get_inline_hdr_size(struct mlx5e_sq *sq,

					    struct sk_buff *skb)

{

#define MLX5E_MIN_INLINE 16 /* eth header with vlan (w/o next ethertype) */

	/* Some NIC TX decisions, e.g loopback, are based on the packet

	 * headers and occur before the data gather.

	 * Therefore these headers must be copied into the WQE

	 */

#define MLX5E_MIN_INLINE (ETH_HLEN + 2/*vlan tag*/)



	if (skb_headlen(skb) <= sq->max_inline)

		return skb_headlen(skb);



	return MLX5E_MIN_INLINE;

}