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net: fec: improve XDP_TX performance

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As suggested by Jesper and Alexander, we can avoid converting xdp_buff
to xdp_frame in case of XDP_TX to save a bunch of CPU cycles, so that
we can further improve the XDP_TX performance.

Before this patch on i.MX8MP-EVK board, the performance shows as follows.
root@imx8mpevk:~# ./xdp2 eth0
proto 17:     353918 pkt/s
proto 17:     352923 pkt/s
proto 17:     353900 pkt/s
proto 17:     352672 pkt/s
proto 17:     353912 pkt/s
proto 17:     354219 pkt/s

After applying this patch, the performance is improved.
root@imx8mpevk:~# ./xdp2 eth0
proto 17:     369261 pkt/s
proto 17:     369267 pkt/s
proto 17:     369206 pkt/s
proto 17:     369214 pkt/s
proto 17:     369126 pkt/s
proto 17:     369272 pkt/s

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Suggested-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Fang 2023-08-15 13:19:55 +08:00 committed by David S. Miller
parent f601899e43
commit af6f479138
2 changed files with 77 additions and 72 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
drivers/net/ethernet/freescale/fec.h
View file

@ -552,10 +552,7 @@ enum fec_txbuf_type {
};
struct fec_tx_buffer {
union {
struct sk_buff *skb;
struct xdp_frame *xdp;
};
void *buf_p;
enum fec_txbuf_type type;
};

144
drivers/net/ethernet/freescale/fec_main.c
View file

@ -400,7 +400,7 @@ static void fec_dump(struct net_device *ndev)
fec16_to_cpu(bdp->cbd_sc),
fec32_to_cpu(bdp->cbd_bufaddr),
fec16_to_cpu(bdp->cbd_datlen),
txq->tx_buf[index].skb);
txq->tx_buf[index].buf_p);
bdp = fec_enet_get_nextdesc(bdp, &txq->bd);
index++;
} while (bdp != txq->bd.base);
@ -657,7 +657,7 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq,
index = fec_enet_get_bd_index(last_bdp, &txq->bd);
/* Save skb pointer */
txq->tx_buf[index].skb = skb;
txq->tx_buf[index].buf_p = skb;
/* Make sure the updates to rest of the descriptor are performed before
* transferring ownership.
@ -863,7 +863,7 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq,
}
/* Save skb pointer */
txq->tx_buf[index].skb = skb;
txq->tx_buf[index].buf_p = skb;
skb_tx_timestamp(skb);
txq->bd.cur = bdp;
@ -960,27 +960,27 @@ static void fec_enet_bd_init(struct net_device *dev)
fec32_to_cpu(bdp->cbd_bufaddr),
fec16_to_cpu(bdp->cbd_datlen),
DMA_TO_DEVICE);
if (txq->tx_buf[i].skb) {
dev_kfree_skb_any(txq->tx_buf[i].skb);
txq->tx_buf[i].skb = NULL;
}
} else {
if (bdp->cbd_bufaddr &&
txq->tx_buf[i].type == FEC_TXBUF_T_XDP_NDO)
if (txq->tx_buf[i].buf_p)
dev_kfree_skb_any(txq->tx_buf[i].buf_p);
} else if (txq->tx_buf[i].type == FEC_TXBUF_T_XDP_NDO) {
if (bdp->cbd_bufaddr)
dma_unmap_single(&fep->pdev->dev,
fec32_to_cpu(bdp->cbd_bufaddr),
fec16_to_cpu(bdp->cbd_datlen),
DMA_TO_DEVICE);
if (txq->tx_buf[i].xdp) {
xdp_return_frame(txq->tx_buf[i].xdp);
txq->tx_buf[i].xdp = NULL;
}
if (txq->tx_buf[i].buf_p)
xdp_return_frame(txq->tx_buf[i].buf_p);
} else {
struct page *page = txq->tx_buf[i].buf_p;
/* restore default tx buffer type: FEC_TXBUF_T_SKB */
txq->tx_buf[i].type = FEC_TXBUF_T_SKB;
if (page)
page_pool_put_page(page->pp, page, 0, false);
}
txq->tx_buf[i].buf_p = NULL;
/* restore default tx buffer type: FEC_TXBUF_T_SKB */
txq->tx_buf[i].type = FEC_TXBUF_T_SKB;
bdp->cbd_bufaddr = cpu_to_fec32(0);
bdp = fec_enet_get_nextdesc(bdp, &txq->bd);
}
@ -1387,6 +1387,8 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget)
struct netdev_queue *nq;
int index = 0;
int entries_free;
struct page *page;
int frame_len;
fep = netdev_priv(ndev);
@ -1408,8 +1410,7 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget)
index = fec_enet_get_bd_index(bdp, &txq->bd);
if (txq->tx_buf[index].type == FEC_TXBUF_T_SKB) {
skb = txq->tx_buf[index].skb;
txq->tx_buf[index].skb = NULL;
skb = txq->tx_buf[index].buf_p;
if (bdp->cbd_bufaddr &&
!IS_TSO_HEADER(txq, fec32_to_cpu(bdp->cbd_bufaddr)))
dma_unmap_single(&fep->pdev->dev,
@ -1428,18 +1429,24 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget)
if (unlikely(!budget))
break;
xdpf = txq->tx_buf[index].xdp;
if (bdp->cbd_bufaddr &&
txq->tx_buf[index].type == FEC_TXBUF_T_XDP_NDO)
dma_unmap_single(&fep->pdev->dev,
fec32_to_cpu(bdp->cbd_bufaddr),
fec16_to_cpu(bdp->cbd_datlen),
DMA_TO_DEVICE);
if (txq->tx_buf[index].type == FEC_TXBUF_T_XDP_NDO) {
xdpf = txq->tx_buf[index].buf_p;
if (bdp->cbd_bufaddr)
dma_unmap_single(&fep->pdev->dev,
fec32_to_cpu(bdp->cbd_bufaddr),
fec16_to_cpu(bdp->cbd_datlen),
DMA_TO_DEVICE);
} else {
page = txq->tx_buf[index].buf_p;
}
bdp->cbd_bufaddr = cpu_to_fec32(0);
if (unlikely(!xdpf)) {
if (unlikely(!txq->tx_buf[index].buf_p)) {
txq->tx_buf[index].type = FEC_TXBUF_T_SKB;
goto tx_buf_done;
}
frame_len = fec16_to_cpu(bdp->cbd_datlen);
}
/* Check for errors. */
@ -1463,7 +1470,7 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget)
if (txq->tx_buf[index].type == FEC_TXBUF_T_SKB)
ndev->stats.tx_bytes += skb->len;
else
ndev->stats.tx_bytes += xdpf->len;
ndev->stats.tx_bytes += frame_len;
}
/* Deferred means some collisions occurred during transmit,
@ -1488,23 +1495,17 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget)
/* Free the sk buffer associated with this last transmit */
dev_kfree_skb_any(skb);
} else {
if (txq->tx_buf[index].type == FEC_TXBUF_T_XDP_NDO) {
xdp_return_frame_rx_napi(xdpf);
} else { /* recycle pages of XDP_TX frames */
struct page *page = virt_to_head_page(xdpf->data);
/* The dma_sync_size = 0 as XDP_TX has already
* synced DMA for_device.
*/
page_pool_put_page(page->pp, page, 0, true);
}
txq->tx_buf[index].xdp = NULL;
/* restore default tx buffer type: FEC_TXBUF_T_SKB */
txq->tx_buf[index].type = FEC_TXBUF_T_SKB;
} else if (txq->tx_buf[index].type == FEC_TXBUF_T_XDP_NDO) {
xdp_return_frame_rx_napi(xdpf);
} else { /* recycle pages of XDP_TX frames */
/* The dma_sync_size = 0 as XDP_TX has already synced DMA for_device */
page_pool_put_page(page->pp, page, 0, true);
}
txq->tx_buf[index].buf_p = NULL;
/* restore default tx buffer type: FEC_TXBUF_T_SKB */
txq->tx_buf[index].type = FEC_TXBUF_T_SKB;
tx_buf_done:
/* Make sure the update to bdp and tx_buf are performed
* before dirty_tx
@ -3234,7 +3235,6 @@ static void fec_enet_free_buffers(struct net_device *ndev)
{
struct fec_enet_private *fep = netdev_priv(ndev);
unsigned int i;
struct sk_buff *skb;
struct fec_enet_priv_tx_q *txq;
struct fec_enet_priv_rx_q *rxq;
unsigned int q;
@ -3259,18 +3259,23 @@ static void fec_enet_free_buffers(struct net_device *ndev)
kfree(txq->tx_bounce[i]);
txq->tx_bounce[i] = NULL;
if (txq->tx_buf[i].type == FEC_TXBUF_T_SKB) {
skb = txq->tx_buf[i].skb;
txq->tx_buf[i].skb = NULL;
dev_kfree_skb(skb);
} else {
if (txq->tx_buf[i].xdp) {
xdp_return_frame(txq->tx_buf[i].xdp);
txq->tx_buf[i].xdp = NULL;
}
if (!txq->tx_buf[i].buf_p) {
txq->tx_buf[i].type = FEC_TXBUF_T_SKB;
continue;
}
if (txq->tx_buf[i].type == FEC_TXBUF_T_SKB) {
dev_kfree_skb(txq->tx_buf[i].buf_p);
} else if (txq->tx_buf[i].type == FEC_TXBUF_T_XDP_NDO) {
xdp_return_frame(txq->tx_buf[i].buf_p);
} else {
struct page *page = txq->tx_buf[i].buf_p;
page_pool_put_page(page->pp, page, 0, false);
}
txq->tx_buf[i].buf_p = NULL;
txq->tx_buf[i].type = FEC_TXBUF_T_SKB;
}
}
}
@ -3793,13 +3798,14 @@ fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int index)
static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
struct fec_enet_priv_tx_q *txq,
struct xdp_frame *frame,
u32 dma_sync_len, bool ndo_xmit)
void *frame, u32 dma_sync_len,
bool ndo_xmit)
{
unsigned int index, status, estatus;
struct bufdesc *bdp;
dma_addr_t dma_addr;
int entries_free;
u16 frame_len;
entries_free = fec_enet_get_free_txdesc_num(txq);
if (entries_free < MAX_SKB_FRAGS + 1) {
@ -3815,30 +3821,36 @@ static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
index = fec_enet_get_bd_index(bdp, &txq->bd);
if (ndo_xmit) {
dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
frame->len, DMA_TO_DEVICE);
struct xdp_frame *xdpf = frame;
dma_addr = dma_map_single(&fep->pdev->dev, xdpf->data,
xdpf->len, DMA_TO_DEVICE);
if (dma_mapping_error(&fep->pdev->dev, dma_addr))
return -ENOMEM;
frame_len = xdpf->len;
txq->tx_buf[index].buf_p = xdpf;
txq->tx_buf[index].type = FEC_TXBUF_T_XDP_NDO;
} else {
struct page *page = virt_to_page(frame->data);
struct xdp_buff *xdpb = frame;
struct page *page;
dma_addr = page_pool_get_dma_addr(page) + sizeof(*frame) +
frame->headroom;
page = virt_to_page(xdpb->data);
dma_addr = page_pool_get_dma_addr(page) +
(xdpb->data - xdpb->data_hard_start);
dma_sync_single_for_device(&fep->pdev->dev, dma_addr,
dma_sync_len, DMA_BIDIRECTIONAL);
frame_len = xdpb->data_end - xdpb->data;
txq->tx_buf[index].buf_p = page;
txq->tx_buf[index].type = FEC_TXBUF_T_XDP_TX;
}
txq->tx_buf[index].xdp = frame;
status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
if (fep->bufdesc_ex)
estatus = BD_ENET_TX_INT;
bdp->cbd_bufaddr = cpu_to_fec32(dma_addr);
bdp->cbd_datlen = cpu_to_fec16(frame->len);
bdp->cbd_datlen = cpu_to_fec16(frame_len);
if (fep->bufdesc_ex) {
struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
@ -3879,14 +3891,10 @@ static int fec_enet_xdp_tx_xmit(struct fec_enet_private *fep,
int cpu, struct xdp_buff *xdp,
u32 dma_sync_len)
{
struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
struct fec_enet_priv_tx_q *txq;
struct netdev_queue *nq;
int queue, ret;
if (unlikely(!xdpf))
return -EFAULT;
queue = fec_enet_xdp_get_tx_queue(fep, cpu);
txq = fep->tx_queue[queue];
nq = netdev_get_tx_queue(fep->netdev, queue);
@ -3895,7 +3903,7 @@ static int fec_enet_xdp_tx_xmit(struct fec_enet_private *fep,
/* Avoid tx timeout as XDP shares the queue with kernel stack */
txq_trans_cond_update(nq);
ret = fec_enet_txq_xmit_frame(fep, txq, xdpf, dma_sync_len, false);
ret = fec_enet_txq_xmit_frame(fep, txq, xdp, dma_sync_len, false);
__netif_tx_unlock(nq);