From: Wei Fang wei.fang@nxp.com
[ Upstream commit 15cec633fc7bfe4cd69aa012c3b35b31acfc86f2 ]
According to the clarification [1] in the latest napi.rst, the tx processing cannot call any XDP (or page pool) APIs if the "budget" is 0. Because NAPI is called with the budget of 0 (such as netpoll) indicates we may be in an IRQ context, however, we cannot use the page pool from IRQ context.
[1] https://lore.kernel.org/all/20230720161323.2025379-1-kuba@kernel.org/
Fixes: 20f797399035 ("net: fec: recycle pages for transmitted XDP frames") Signed-off-by: Wei Fang wei.fang@nxp.com Suggested-by: Jakub Kicinski kuba@kernel.org Link: https://lore.kernel.org/r/20230725074148.2936402-1-wei.fang@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/fec_main.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index a1b0abe54a0e5..92410f30ad241 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1372,7 +1372,7 @@ fec_enet_hwtstamp(struct fec_enet_private *fep, unsigned ts, }
static void -fec_enet_tx_queue(struct net_device *ndev, u16 queue_id) +fec_enet_tx_queue(struct net_device *ndev, u16 queue_id, int budget) { struct fec_enet_private *fep; struct xdp_frame *xdpf; @@ -1416,6 +1416,14 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id) if (!skb) goto tx_buf_done; } else { + /* Tx processing cannot call any XDP (or page pool) APIs if + * the "budget" is 0. Because NAPI is called with budget of + * 0 (such as netpoll) indicates we may be in an IRQ context, + * however, we can't use the page pool from IRQ context. + */ + if (unlikely(!budget)) + break; + xdpf = txq->tx_buf[index].xdp; if (bdp->cbd_bufaddr) dma_unmap_single(&fep->pdev->dev, @@ -1508,14 +1516,14 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id) writel(0, txq->bd.reg_desc_active); }
-static void fec_enet_tx(struct net_device *ndev) +static void fec_enet_tx(struct net_device *ndev, int budget) { struct fec_enet_private *fep = netdev_priv(ndev); int i;
/* Make sure that AVB queues are processed first. */ for (i = fep->num_tx_queues - 1; i >= 0; i--) - fec_enet_tx_queue(ndev, i); + fec_enet_tx_queue(ndev, i, budget); }
static void fec_enet_update_cbd(struct fec_enet_priv_rx_q *rxq, @@ -1858,7 +1866,7 @@ static int fec_enet_rx_napi(struct napi_struct *napi, int budget)
do { done += fec_enet_rx(ndev, budget - done); - fec_enet_tx(ndev); + fec_enet_tx(ndev, budget); } while ((done < budget) && fec_enet_collect_events(fep));
if (done < budget) {