[PATCH V2 net 2/4] net: fec: recycle pages for transmitted XDP frames
From: wei . fang
Date: Thu Jul 06 2023 - 04:17:06 EST
From: Wei Fang <wei.fang@xxxxxxx>
Once the XDP frames have been successfully transmitted through the
ndo_xdp_xmit() interface, it's the driver responsibility to free
the frames so that the page_pool can recycle the pages and reuse
them. However, this action is not implemented in the fec driver.
This leads to a user-visible problem that the console will print
the following warning log.
[ 157.568851] page_pool_release_retry() stalled pool shutdown 1389 inflight 60 sec
[ 217.983446] page_pool_release_retry() stalled pool shutdown 1389 inflight 120 sec
[ 278.399006] page_pool_release_retry() stalled pool shutdown 1389 inflight 181 sec
[ 338.812885] page_pool_release_retry() stalled pool shutdown 1389 inflight 241 sec
[ 399.226946] page_pool_release_retry() stalled pool shutdown 1389 inflight 302 sec
Therefore, to solve this issue, we free XDP frames via xdp_return_frame()
while cleaning the tx BD ring.
Fixes: 6d6b39f180b8 ("net: fec: add initial XDP support")
Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
V2 change:
No change.
---
drivers/net/ethernet/freescale/fec.h | 15 ++-
drivers/net/ethernet/freescale/fec_main.c | 148 +++++++++++++++-------
2 files changed, 115 insertions(+), 48 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 9939ccafb556..8c0226d061fe 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -544,10 +544,23 @@ enum {
XDP_STATS_TOTAL,
};
+enum fec_txbuf_type {
+ FEC_TXBUF_T_SKB,
+ FEC_TXBUF_T_XDP_NDO,
+};
+
+struct fec_tx_buffer {
+ union {
+ struct sk_buff *skb;
+ struct xdp_frame *xdp;
+ };
+ enum fec_txbuf_type type;
+};
+
struct fec_enet_priv_tx_q {
struct bufdesc_prop bd;
unsigned char *tx_bounce[TX_RING_SIZE];
- struct sk_buff *tx_skbuff[TX_RING_SIZE];
+ struct fec_tx_buffer tx_buf[TX_RING_SIZE];
unsigned short tx_stop_threshold;
unsigned short tx_wake_threshold;
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 9ce0319b33c3..940d3afe1d24 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -397,7 +397,7 @@ 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_skbuff[index]);
+ txq->tx_buf[index].skb);
bdp = fec_enet_get_nextdesc(bdp, &txq->bd);
index++;
} while (bdp != txq->bd.base);
@@ -654,7 +654,7 @@ 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_skbuff[index] = skb;
+ txq->tx_buf[index].skb = skb;
/* Make sure the updates to rest of the descriptor are performed before
* transferring ownership.
@@ -672,9 +672,7 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq,
skb_tx_timestamp(skb);
- /* Make sure the update to bdp and tx_skbuff are performed before
- * txq->bd.cur.
- */
+ /* Make sure the update to bdp is performed before txq->bd.cur. */
wmb();
txq->bd.cur = bdp;
@@ -862,7 +860,7 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq,
}
/* Save skb pointer */
- txq->tx_skbuff[index] = skb;
+ txq->tx_buf[index].skb = skb;
skb_tx_timestamp(skb);
txq->bd.cur = bdp;
@@ -952,16 +950,33 @@ static void fec_enet_bd_init(struct net_device *dev)
for (i = 0; i < txq->bd.ring_size; i++) {
/* Initialize the BD for every fragment in the page. */
bdp->cbd_sc = cpu_to_fec16(0);
- if (bdp->cbd_bufaddr &&
- !IS_TSO_HEADER(txq, fec32_to_cpu(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_skbuff[i]) {
- dev_kfree_skb_any(txq->tx_skbuff[i]);
- txq->tx_skbuff[i] = NULL;
+ if (txq->tx_buf[i].type == FEC_TXBUF_T_SKB) {
+ if (bdp->cbd_bufaddr &&
+ !IS_TSO_HEADER(txq, fec32_to_cpu(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].skb) {
+ dev_kfree_skb_any(txq->tx_buf[i].skb);
+ txq->tx_buf[i].skb = NULL;
+ }
+ } else {
+ 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;
+ }
+
+ /* 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);
}
@@ -1360,6 +1375,7 @@ static void
fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)
{
struct fec_enet_private *fep;
+ struct xdp_frame *xdpf;
struct bufdesc *bdp;
unsigned short status;
struct sk_buff *skb;
@@ -1387,16 +1403,31 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)
index = fec_enet_get_bd_index(bdp, &txq->bd);
- skb = txq->tx_skbuff[index];
- txq->tx_skbuff[index] = NULL;
- if (!IS_TSO_HEADER(txq, fec32_to_cpu(bdp->cbd_bufaddr)))
- dma_unmap_single(&fep->pdev->dev,
- fec32_to_cpu(bdp->cbd_bufaddr),
- fec16_to_cpu(bdp->cbd_datlen),
- DMA_TO_DEVICE);
- bdp->cbd_bufaddr = cpu_to_fec32(0);
- if (!skb)
- goto skb_done;
+ if (txq->tx_buf[index].type == FEC_TXBUF_T_SKB) {
+ skb = txq->tx_buf[index].skb;
+ txq->tx_buf[index].skb = NULL;
+ if (bdp->cbd_bufaddr &&
+ !IS_TSO_HEADER(txq, fec32_to_cpu(bdp->cbd_bufaddr)))
+ dma_unmap_single(&fep->pdev->dev,
+ fec32_to_cpu(bdp->cbd_bufaddr),
+ fec16_to_cpu(bdp->cbd_datlen),
+ DMA_TO_DEVICE);
+ bdp->cbd_bufaddr = cpu_to_fec32(0);
+ if (!skb)
+ goto tx_buf_done;
+ } else {
+ xdpf = txq->tx_buf[index].xdp;
+ 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);
+ bdp->cbd_bufaddr = cpu_to_fec32(0);
+ if (!xdpf) {
+ txq->tx_buf[index].type = FEC_TXBUF_T_SKB;
+ goto tx_buf_done;
+ }
+ }
/* Check for errors. */
if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC |
@@ -1415,21 +1446,11 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)
ndev->stats.tx_carrier_errors++;
} else {
ndev->stats.tx_packets++;
- ndev->stats.tx_bytes += skb->len;
- }
- /* NOTE: SKBTX_IN_PROGRESS being set does not imply it's we who
- * are to time stamp the packet, so we still need to check time
- * stamping enabled flag.
- */
- if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS &&
- fep->hwts_tx_en) &&
- fep->bufdesc_ex) {
- struct skb_shared_hwtstamps shhwtstamps;
- struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
-
- fec_enet_hwtstamp(fep, fec32_to_cpu(ebdp->ts), &shhwtstamps);
- skb_tstamp_tx(skb, &shhwtstamps);
+ if (txq->tx_buf[index].type == FEC_TXBUF_T_SKB)
+ ndev->stats.tx_bytes += skb->len;
+ else
+ ndev->stats.tx_bytes += xdpf->len;
}
/* Deferred means some collisions occurred during transmit,
@@ -1438,10 +1459,32 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)
if (status & BD_ENET_TX_DEF)
ndev->stats.collisions++;
- /* Free the sk buffer associated with this last transmit */
- dev_kfree_skb_any(skb);
-skb_done:
- /* Make sure the update to bdp and tx_skbuff are performed
+ if (txq->tx_buf[index].type == FEC_TXBUF_T_SKB) {
+ /* NOTE: SKBTX_IN_PROGRESS being set does not imply it's we who
+ * are to time stamp the packet, so we still need to check time
+ * stamping enabled flag.
+ */
+ if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS &&
+ fep->hwts_tx_en) && fep->bufdesc_ex) {
+ struct skb_shared_hwtstamps shhwtstamps;
+ struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
+
+ fec_enet_hwtstamp(fep, fec32_to_cpu(ebdp->ts), &shhwtstamps);
+ skb_tstamp_tx(skb, &shhwtstamps);
+ }
+
+ /* Free the sk buffer associated with this last transmit */
+ dev_kfree_skb_any(skb);
+ } else {
+ xdp_return_frame(xdpf);
+
+ txq->tx_buf[index].xdp = 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
*/
wmb();
@@ -3249,9 +3292,19 @@ static void fec_enet_free_buffers(struct net_device *ndev)
for (i = 0; i < txq->bd.ring_size; i++) {
kfree(txq->tx_bounce[i]);
txq->tx_bounce[i] = NULL;
- skb = txq->tx_skbuff[i];
- txq->tx_skbuff[i] = NULL;
- dev_kfree_skb(skb);
+
+ 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;
+ }
+
+ txq->tx_buf[i].type = FEC_TXBUF_T_SKB;
+ }
}
}
}
@@ -3817,7 +3870,8 @@ static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
ebdp->cbd_esc = cpu_to_fec32(estatus);
}
- txq->tx_skbuff[index] = NULL;
+ txq->tx_buf[index].type = FEC_TXBUF_T_XDP_NDO;
+ txq->tx_buf[index].xdp = frame;
/* Make sure the updates to rest of the descriptor are performed before
* transferring ownership.
--
2.25.1