Commit 1347b419 authored by Song Yoong Siang's avatar Song Yoong Siang Committed by Alexei Starovoitov
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net: stmmac: Add Tx HWTS support to XDP ZC 



This patch enables transmit hardware timestamp support to XDP zero copy
via XDP Tx metadata framework.

This patchset is tested with tools/testing/selftests/bpf/xdp_hw_metadata
on Intel Tiger Lake platform. Below are the test steps and results.

Command on DUT:
sudo ./xdp_hw_metadata <interface name>
sudo hwstamp_ctl -i <interface name> -t 1 -r 1

Command on Link Partner:
echo -n xdp | nc -u -q1 <destination IPv4 addr> 9091

Result:
xsk_ring_cons__peek: 1
0x55bbbf08b6d0: rx_desc[2]->addr=8c100 addr=8c100 comp_addr=8c100 EoP
No rx_hash err=-95
rx_timestamp:  1677762688429141540 (sec:1677762688.4291)
HW RX-time:   1677762688429141540 (sec:1677762688.4291) delta to User RX-time sec:0.0003 (250.665 usec)
XDP RX-time:   1677762688429375597 (sec:1677762688.4294) delta to User RX-time sec:0.0000 (16.608 usec)
0x55bbbf08b6d0: ping-pong with csum=561c (want f488) csum_start=34 csum_offset=6
0x55bbbf08b6d0: complete tx idx=2 addr=2008
tx_timestamp:  1677762688431127273 (sec:1677762688.4311)
HW TX-complete-time:   1677762688431127273 (sec:1677762688.4311) delta to User TX-complete-time sec:0.0083 (8331.655 usec)
XDP RX-time:   1677762688429375597 (sec:1677762688.4294) delta to User TX-complete-time sec:0.0101 (10083.331 usec)
HW RX-time:   1677762688429141540 (sec:1677762688.4291) delta to HW TX-complete-time sec:0.0020 (1985.733 usec)
0x55bbbf08b6d0: complete rx idx=130 addr=8c100

Signed-off-by: default avatarSong Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20231127190319.1190813-6-sdf@google.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ec706a86

drivers/net/ethernet/stmicro/stmmac/stmmac.h

+12 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct stmmac_tx_info { 
	bool last_segment;

	bool is_jumbo;

	enum stmmac_txbuf_type buf_type;

	struct xsk_tx_metadata_compl xsk_meta;

};



#define STMMAC_TBS_AVAIL	BIT(0)
@@ -100,6 +101,17 @@ struct stmmac_xdp_buff { 
	struct dma_desc *ndesc;

};



struct stmmac_metadata_request {

	struct stmmac_priv *priv;

	struct dma_desc *tx_desc;

	bool *set_ic;

};



struct stmmac_xsk_tx_complete {

	struct stmmac_priv *priv;

	struct dma_desc *desc;

};



struct stmmac_rx_queue {

	u32 rx_count_frames;

	u32 queue_index;

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

+63 −1
Original line number Diff line number Diff line
@@ -2430,6 +2430,46 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv) 
	}

}



static void stmmac_xsk_request_timestamp(void *_priv)

{

	struct stmmac_metadata_request *meta_req = _priv;



	stmmac_enable_tx_timestamp(meta_req->priv, meta_req->tx_desc);

	*meta_req->set_ic = true;

}



static u64 stmmac_xsk_fill_timestamp(void *_priv)

{

	struct stmmac_xsk_tx_complete *tx_compl = _priv;

	struct stmmac_priv *priv = tx_compl->priv;

	struct dma_desc *desc = tx_compl->desc;

	bool found = false;

	u64 ns = 0;



	if (!priv->hwts_tx_en)

		return 0;



	/* check tx tstamp status */

	if (stmmac_get_tx_timestamp_status(priv, desc)) {

		stmmac_get_timestamp(priv, desc, priv->adv_ts, &ns);

		found = true;

	} else if (!stmmac_get_mac_tx_timestamp(priv, priv->hw, &ns)) {

		found = true;

	}



	if (found) {

		ns -= priv->plat->cdc_error_adj;

		return ns_to_ktime(ns);

	}



	return 0;

}



static const struct xsk_tx_metadata_ops stmmac_xsk_tx_metadata_ops = {

	.tmo_request_timestamp		= stmmac_xsk_request_timestamp,

	.tmo_fill_timestamp		= stmmac_xsk_fill_timestamp,

};



static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget)

{

	struct netdev_queue *nq = netdev_get_tx_queue(priv->dev, queue);
@@ -2449,6 +2489,8 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) 
	budget = min(budget, stmmac_tx_avail(priv, queue));



	while (budget-- > 0) {

		struct stmmac_metadata_request meta_req;

		struct xsk_tx_metadata *meta = NULL;

		dma_addr_t dma_addr;

		bool set_ic;
@@ -2472,6 +2514,7 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) 
			tx_desc = tx_q->dma_tx + entry;



		dma_addr = xsk_buff_raw_get_dma(pool, xdp_desc.addr);

		meta = xsk_buff_get_metadata(pool, xdp_desc.addr);

		xsk_buff_raw_dma_sync_for_device(pool, dma_addr, xdp_desc.len);



		tx_q->tx_skbuff_dma[entry].buf_type = STMMAC_TXBUF_T_XSK_TX;
@@ -2499,6 +2542,11 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) 
		else

			set_ic = false;



		meta_req.priv = priv;

		meta_req.tx_desc = tx_desc;

		meta_req.set_ic = &set_ic;

		xsk_tx_metadata_request(meta, &stmmac_xsk_tx_metadata_ops,

					&meta_req);

		if (set_ic) {

			tx_q->tx_count_frames = 0;

			stmmac_set_tx_ic(priv, tx_desc);
@@ -2511,6 +2559,9 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) 


		stmmac_enable_dma_transmission(priv, priv->ioaddr);



		xsk_tx_metadata_to_compl(meta,

					 &tx_q->tx_skbuff_dma[entry].xsk_meta);



		tx_q->cur_tx = STMMAC_GET_ENTRY(tx_q->cur_tx, priv->dma_conf.dma_tx_size);

		entry = tx_q->cur_tx;

	}
@@ -2620,8 +2671,18 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue, 
			} else {

				tx_packets++;

			}

			if (skb)

			if (skb) {

				stmmac_get_tx_hwtstamp(priv, p, skb);

			} else {

				struct stmmac_xsk_tx_complete tx_compl = {

					.priv = priv,

					.desc = p,

				};



				xsk_tx_metadata_complete(&tx_q->tx_skbuff_dma[entry].xsk_meta,

							 &stmmac_xsk_tx_metadata_ops,

							 &tx_compl);

			}

		}



		if (likely(tx_q->tx_skbuff_dma[entry].buf &&
@@ -7464,6 +7525,7 @@ int stmmac_dvr_probe(struct device *device, 
	ndev->netdev_ops = &stmmac_netdev_ops;



	ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;

	ndev->xsk_tx_metadata_ops = &stmmac_xsk_tx_metadata_ops;



	ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |

			    NETIF_F_RXCSUM;