Commit 9c840d5f authored by Baowen Zheng's avatar Baowen Zheng Committed by David S. Miller
Browse files

nfp: fix issue of skb segments exceeds descriptor limitation 



TCP packets will be dropped if the segments number in the tx skb
exceeds limitation when sending iperf3 traffic with --zerocopy option.

we make the following changes:

Get nr_frags in nfp_nfdk_tx_maybe_close_block instead of passing from
outside because it will be changed after skb_linearize operation.

Fill maximum dma_len in first tx descriptor to make sure the whole
head is included in the first descriptor.

Fixes: c10d12e3 ("nfp: add support for NFDK data path")
Signed-off-by: default avatarBaowen Zheng <baowen.zheng@corigine.com>
Reviewed-by: default avatarLouis Peens <louis.peens@corigine.com>
Signed-off-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6676d727

drivers/net/ethernet/netronome/nfp/nfdk/dp.c

+25 −8
Original line number Diff line number Diff line
@@ -125,17 +125,18 @@ nfp_nfdk_tx_csum(struct nfp_net_dp *dp, struct nfp_net_r_vector *r_vec, 


static int

nfp_nfdk_tx_maybe_close_block(struct nfp_net_tx_ring *tx_ring,

			      unsigned int nr_frags, struct sk_buff *skb)

			      struct sk_buff *skb)

{

	unsigned int n_descs, wr_p, nop_slots;

	const skb_frag_t *frag, *fend;

	struct nfp_nfdk_tx_desc *txd;

	unsigned int nr_frags;

	unsigned int wr_idx;

	int err;



recount_descs:

	n_descs = nfp_nfdk_headlen_to_segs(skb_headlen(skb));



	nr_frags = skb_shinfo(skb)->nr_frags;

	frag = skb_shinfo(skb)->frags;

	fend = frag + nr_frags;

	for (; frag < fend; frag++)
@@ -281,10 +282,13 @@ netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev) 
	if (unlikely((int)metadata < 0))

		goto err_flush;



	nr_frags = skb_shinfo(skb)->nr_frags;

	if (nfp_nfdk_tx_maybe_close_block(tx_ring, nr_frags, skb))

	if (nfp_nfdk_tx_maybe_close_block(tx_ring, skb))

		goto err_flush;



	/* nr_frags will change after skb_linearize so we get nr_frags after

	 * nfp_nfdk_tx_maybe_close_block function

	 */

	nr_frags = skb_shinfo(skb)->nr_frags;

	/* DMA map all */

	wr_idx = D_IDX(tx_ring, tx_ring->wr_p);

	txd = &tx_ring->ktxds[wr_idx];
@@ -310,7 +314,16 @@ netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev) 


	/* FIELD_PREP() implicitly truncates to chunk */

	dma_len -= 1;

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD, dma_len) |



	/* We will do our best to pass as much data as we can in descriptor

	 * and we need to make sure the first descriptor includes whole head

	 * since there is limitation in firmware side. Sometimes the value of

	 * dma_len bitwise and NFDK_DESC_TX_DMA_LEN_HEAD will less than

	 * headlen.

	 */

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,

			       dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?

			       NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |

		    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);



	txd->dma_len_type = cpu_to_le16(dlen_type);
@@ -925,7 +938,9 @@ nfp_nfdk_tx_xdp_buf(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring, 


	/* FIELD_PREP() implicitly truncates to chunk */

	dma_len -= 1;

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD, dma_len) |

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,

			       dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?

			       NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |

		    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);



	txd->dma_len_type = cpu_to_le16(dlen_type);
@@ -1303,7 +1318,7 @@ nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec, 
				   skb_push(skb, 4));

	}



	if (nfp_nfdk_tx_maybe_close_block(tx_ring, 0, skb))

	if (nfp_nfdk_tx_maybe_close_block(tx_ring, skb))

		goto err_free;



	/* DMA map all */
@@ -1328,7 +1343,9 @@ nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec, 
	txbuf++;



	dma_len -= 1;

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD, dma_len) |

	dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,

			       dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?

			       NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |

		    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);



	txd->dma_len_type = cpu_to_le16(dlen_type);