Commit 58a51894 authored by Aya Levin's avatar Aya Levin Committed by Saeed Mahameed
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net/mlx5e: Add resiliency for PTP TX port timestamp 



PTP TX port timestamp relies on receiving 2 CQEs for each outgoing
packet (WQE). The regular CQE has a less accurate timestamp than the
wire CQE. On link change, the wire CQE may get lost. Let the driver
detect and restore the relation between the CQEs, and re-sync after
timeout.

Add resiliency for this as follows: add id (producer counter)
into the WQE's metadata. This id will be received in the wire
CQE (in wqe_counter field). On handling the wire CQE, if there is no
match, replay the PTP application with the time-stamp from the regular
CQE and restore the sync between the CQEs and their SKBs. This patch
adds 2 ptp counters:
1) ptp_cq0_resync_event: number of times a mismatch was detected between
   the regular CQE and the wire CQE.
2) ptp_cq0_resync_cqe: total amount of missing wire CQEs.

Signed-off-by: default avatarAya Levin <ayal@nvidia.com>
Reviewed-by: default avatarTariq Toukan <tariqt@nvidia.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
parent 2e5e4185

drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c

+35 −2
Original line number Diff line number Diff line
@@ -79,19 +79,49 @@ void mlx5e_skb_cb_hwtstamp_handler(struct sk_buff *skb, int hwtstamp_type, 
	memset(skb->cb, 0, sizeof(struct mlx5e_skb_cb_hwtstamp));

}



#define PTP_WQE_CTR2IDX(val) ((val) & ptpsq->ts_cqe_ctr_mask)



static bool mlx5e_ptp_ts_cqe_drop(struct mlx5e_ptpsq *ptpsq, u16 skb_cc, u16 skb_id)

{

	return (ptpsq->ts_cqe_ctr_mask && (skb_cc != skb_id));

}



static void mlx5e_ptp_skb_fifo_ts_cqe_resync(struct mlx5e_ptpsq *ptpsq, u16 skb_cc, u16 skb_id)

{

	struct skb_shared_hwtstamps hwts = {};

	struct sk_buff *skb;



	ptpsq->cq_stats->resync_event++;



	while (skb_cc != skb_id) {

		skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo);

		hwts.hwtstamp = mlx5e_skb_cb_get_hwts(skb)->cqe_hwtstamp;

		skb_tstamp_tx(skb, &hwts);

		ptpsq->cq_stats->resync_cqe++;

		skb_cc = PTP_WQE_CTR2IDX(ptpsq->skb_fifo_cc);

	}

}



static void mlx5e_ptp_handle_ts_cqe(struct mlx5e_ptpsq *ptpsq,

				    struct mlx5_cqe64 *cqe,

				    int budget)

{

	struct sk_buff *skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo);

	u16 skb_id = PTP_WQE_CTR2IDX(be16_to_cpu(cqe->wqe_counter));

	u16 skb_cc = PTP_WQE_CTR2IDX(ptpsq->skb_fifo_cc);

	struct mlx5e_txqsq *sq = &ptpsq->txqsq;

	struct sk_buff *skb;

	ktime_t hwtstamp;



	if (unlikely(MLX5E_RX_ERR_CQE(cqe))) {

		skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo);

		ptpsq->cq_stats->err_cqe++;

		goto out;

	}



	if (mlx5e_ptp_ts_cqe_drop(ptpsq, skb_cc, skb_id))

		mlx5e_ptp_skb_fifo_ts_cqe_resync(ptpsq, skb_cc, skb_id);



	skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo);

	hwtstamp = mlx5e_cqe_ts_to_ns(sq->ptp_cyc2time, sq->clock, get_cqe_ts(cqe));

	mlx5e_skb_cb_hwtstamp_handler(skb, MLX5E_SKB_CB_PORT_HWTSTAMP,

				      hwtstamp, ptpsq->cq_stats);
@@ -241,6 +271,7 @@ static void mlx5e_ptp_destroy_sq(struct mlx5_core_dev *mdev, u32 sqn) 
static int mlx5e_ptp_alloc_traffic_db(struct mlx5e_ptpsq *ptpsq, int numa)

{

	int wq_sz = mlx5_wq_cyc_get_size(&ptpsq->txqsq.wq);

	struct mlx5_core_dev *mdev = ptpsq->txqsq.mdev;



	ptpsq->skb_fifo.fifo = kvzalloc_node(array_size(wq_sz, sizeof(*ptpsq->skb_fifo.fifo)),

					     GFP_KERNEL, numa);
@@ -250,7 +281,9 @@ static int mlx5e_ptp_alloc_traffic_db(struct mlx5e_ptpsq *ptpsq, int numa) 
	ptpsq->skb_fifo.pc   = &ptpsq->skb_fifo_pc;

	ptpsq->skb_fifo.cc   = &ptpsq->skb_fifo_cc;

	ptpsq->skb_fifo.mask = wq_sz - 1;



	if (MLX5_CAP_GEN_2(mdev, ts_cqe_metadata_size2wqe_counter))

		ptpsq->ts_cqe_ctr_mask =

			(1 << MLX5_CAP_GEN_2(mdev, ts_cqe_metadata_size2wqe_counter)) - 1;

	return 0;

}

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

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ struct mlx5e_ptpsq { 
	u16                      skb_fifo_pc;

	struct mlx5e_skb_fifo    skb_fifo;

	struct mlx5e_ptp_cq_stats *cq_stats;

	u16                      ts_cqe_ctr_mask;

};



enum {

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

+2 −0
Original line number Diff line number Diff line
@@ -2100,6 +2100,8 @@ static const struct counter_desc ptp_cq_stats_desc[] = { 
	{ MLX5E_DECLARE_PTP_CQ_STAT(struct mlx5e_ptp_cq_stats, err_cqe) },

	{ MLX5E_DECLARE_PTP_CQ_STAT(struct mlx5e_ptp_cq_stats, abort) },

	{ MLX5E_DECLARE_PTP_CQ_STAT(struct mlx5e_ptp_cq_stats, abort_abs_diff_ns) },

	{ MLX5E_DECLARE_PTP_CQ_STAT(struct mlx5e_ptp_cq_stats, resync_cqe) },

	{ MLX5E_DECLARE_PTP_CQ_STAT(struct mlx5e_ptp_cq_stats, resync_event) },

};



static const struct counter_desc ptp_rq_stats_desc[] = {

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

+2 −0
Original line number Diff line number Diff line
@@ -453,6 +453,8 @@ struct mlx5e_ptp_cq_stats { 
	u64 err_cqe;

	u64 abort;

	u64 abort_abs_diff_ns;

	u64 resync_cqe;

	u64 resync_event;

};



struct mlx5e_stats {

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

+10 −0
Original line number Diff line number Diff line
@@ -631,12 +631,22 @@ void mlx5e_tx_mpwqe_ensure_complete(struct mlx5e_txqsq *sq) 
		mlx5e_tx_mpwqe_session_complete(sq);

}



static void mlx5e_cqe_ts_id_eseg(struct mlx5e_ptpsq *ptpsq, struct sk_buff *skb,

				 struct mlx5_wqe_eth_seg *eseg)

{

	if (ptpsq->ts_cqe_ctr_mask && unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))

		eseg->flow_table_metadata = cpu_to_be32(ptpsq->skb_fifo_pc &

							ptpsq->ts_cqe_ctr_mask);

}



static void mlx5e_txwqe_build_eseg(struct mlx5e_priv *priv, struct mlx5e_txqsq *sq,

				   struct sk_buff *skb, struct mlx5e_accel_tx_state *accel,

				   struct mlx5_wqe_eth_seg *eseg, u16 ihs)

{

	mlx5e_accel_tx_eseg(priv, skb, eseg, ihs);

	mlx5e_txwqe_build_eseg_csum(sq, skb, accel, eseg);

	if (unlikely(sq->ptpsq))

		mlx5e_cqe_ts_id_eseg(sq->ptpsq, skb, eseg);

}



netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev)