From 37b61cda9c1606cd8b6445d900ca9dc03185e8b6 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 28 Jul 2023 13:50:20 -0700 Subject: [PATCH] bnxt: don't handle XDP in netpoll Similarly to other recently fixed drivers make sure we don't try to access XDP or page pool APIs when NAPI budget is 0. NAPI budget of 0 may mean that we are in netpoll. This may result in running software IRQs in hard IRQ context, leading to deadlocks or crashes. To make sure bnapi->tx_pkts don't get wiped without handling the events, move clearing the field into the handler itself. Remember to clear tx_pkts after reset (bnxt_enable_napi()) as it's technically possible that netpoll will accumulate some tx_pkts and then a reset will happen, leaving tx_pkts out of sync with reality. Fixes: 322b87ca55f2 ("bnxt_en: add page_pool support") Reviewed-by: Andy Gospodarek Reviewed-by: Michael Chan Link: https://lore.kernel.org/r/20230728205020.2784844-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 26 +++++++++++++++----------- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 +- drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 8 +++++++- drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h | 2 +- 4 files changed, 24 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index e5b54e6..06b238b 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -633,12 +633,13 @@ tx_kick_pending: return NETDEV_TX_OK; } -static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) +static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) { struct bnxt_tx_ring_info *txr = bnapi->tx_ring; struct netdev_queue *txq = netdev_get_tx_queue(bp->dev, txr->txq_index); u16 cons = txr->tx_cons; struct pci_dev *pdev = bp->pdev; + int nr_pkts = bnapi->tx_pkts; int i; unsigned int tx_bytes = 0; @@ -688,6 +689,7 @@ next_tx_int: dev_kfree_skb_any(skb); } + bnapi->tx_pkts = 0; WRITE_ONCE(txr->tx_cons, cons); __netif_txq_completed_wake(txq, nr_pkts, tx_bytes, @@ -2569,12 +2571,11 @@ static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr, return rx_pkts; } -static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi) +static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi, + int budget) { - if (bnapi->tx_pkts) { - bnapi->tx_int(bp, bnapi, bnapi->tx_pkts); - bnapi->tx_pkts = 0; - } + if (bnapi->tx_pkts) + bnapi->tx_int(bp, bnapi, budget); if ((bnapi->events & BNXT_RX_EVENT) && !(bnapi->in_reset)) { struct bnxt_rx_ring_info *rxr = bnapi->rx_ring; @@ -2603,7 +2604,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr, */ bnxt_db_cq(bp, &cpr->cp_db, cpr->cp_raw_cons); - __bnxt_poll_work_done(bp, bnapi); + __bnxt_poll_work_done(bp, bnapi, budget); return rx_pkts; } @@ -2734,7 +2735,7 @@ static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) } static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi, - u64 dbr_type) + u64 dbr_type, int budget) { struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring; int i; @@ -2750,7 +2751,7 @@ static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi, cpr2->had_work_done = 0; } } - __bnxt_poll_work_done(bp, bnapi); + __bnxt_poll_work_done(bp, bnapi, budget); } static int bnxt_poll_p5(struct napi_struct *napi, int budget) @@ -2780,7 +2781,8 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget) if (cpr->has_more_work) break; - __bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ_ARMALL); + __bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ_ARMALL, + budget); cpr->cp_raw_cons = raw_cons; if (napi_complete_done(napi, work_done)) BNXT_DB_NQ_ARM_P5(&cpr->cp_db, @@ -2810,7 +2812,7 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget) } raw_cons = NEXT_RAW_CMP(raw_cons); } - __bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ); + __bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ, budget); if (raw_cons != cpr->cp_raw_cons) { cpr->cp_raw_cons = raw_cons; BNXT_DB_NQ_P5(&cpr->cp_db, raw_cons); @@ -9429,6 +9431,8 @@ static void bnxt_enable_napi(struct bnxt *bp) cpr->sw_stats.rx.rx_resets++; bnapi->in_reset = false; + bnapi->tx_pkts = 0; + if (bnapi->rx_ring) { INIT_WORK(&cpr->dim.work, bnxt_dim_work); cpr->dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 080e734..bb95c3d 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -1005,7 +1005,7 @@ struct bnxt_napi { struct bnxt_tx_ring_info *tx_ring; void (*tx_int)(struct bnxt *, struct bnxt_napi *, - int); + int budget); int tx_pkts; u8 events; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c index 4efa5fe..7f2f9a3 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c @@ -125,16 +125,20 @@ static void __bnxt_xmit_xdp_redirect(struct bnxt *bp, dma_unmap_len_set(tx_buf, len, 0); } -void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) +void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) { struct bnxt_tx_ring_info *txr = bnapi->tx_ring; struct bnxt_rx_ring_info *rxr = bnapi->rx_ring; bool rx_doorbell_needed = false; + int nr_pkts = bnapi->tx_pkts; struct bnxt_sw_tx_bd *tx_buf; u16 tx_cons = txr->tx_cons; u16 last_tx_cons = tx_cons; int i, j, frags; + if (!budget) + return; + for (i = 0; i < nr_pkts; i++) { tx_buf = &txr->tx_buf_ring[tx_cons]; @@ -161,6 +165,8 @@ void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) } tx_cons = NEXT_TX(tx_cons); } + + bnapi->tx_pkts = 0; WRITE_ONCE(txr->tx_cons, tx_cons); if (rx_doorbell_needed) { tx_buf = &txr->tx_buf_ring[last_tx_cons]; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h index ea430d6..5e412c5 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h @@ -16,7 +16,7 @@ struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp, struct bnxt_tx_ring_info *txr, dma_addr_t mapping, u32 len, struct xdp_buff *xdp); -void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts); +void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int budget); bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons, struct xdp_buff xdp, struct page *page, u8 **data_ptr, unsigned int *len, u8 *event); -- 2.7.4