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nfp: fix issue of skb segments exceeds descriptor limitation

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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: c10d12e3dc ("nfp: add support for NFDK data path")
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Baowen Zheng 2022-07-08 11:07:18 +01:00 committed by David S. Miller
parent 6676d7270c
commit 9c840d5f9a
1 changed files with 25 additions and 8 deletions
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33
drivers/net/ethernet/netronome/nfp/nfdk/dp.c
View File

@ -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);