[PATCH net] bnxt: don't handle XDP in netpoll
From: Jakub Kicinski <kuba@kernel.org>
Date: 2023-07-27 17:05:09
Subsystem:
broadcom bnxt_en 50 gigabit ethernet driver, networking drivers, the rest, xdp (express data path) · Maintainers:
Michael Chan, Pavan Chebbi, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Alexei Starovoitov, Daniel Borkmann, David S. Miller, Jesper Dangaard Brouer, John Fastabend
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.
Fixes: 322b87ca55f2 ("bnxt_en: add page_pool support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: michael.chan@broadcom.com
CC: gospo@broadcom.com
Side note - having to plumb the "budget" everywhere really makes
me wonder if we shouldn't have had those APIs accept a pointer
to napi_struct instead :S
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 19 +++++++++++--------
drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 +-
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 6 +++++-
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h | 3 ++-
4 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index a3bbd13c070f..fe1d645c39d0 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c@@ -687,7 +687,8 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 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 nr_pkts, + int budget) { struct bnxt_tx_ring_info *txr = bnapi->tx_ring; struct netdev_queue *txq = netdev_get_tx_queue(bp->dev, txr->txq_index);
@@ -2595,10 +2596,11 @@ 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_fault) { - bnapi->tx_int(bp, bnapi, bnapi->tx_pkts); + bnapi->tx_int(bp, bnapi, bnapi->tx_pkts, budget); bnapi->tx_pkts = 0; }
@@ -2629,7 +2631,7 @@ 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; }
@@ -2760,7 +2762,7 @@ 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;
@@ -2776,7 +2778,7 @@ 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)
@@ -2806,7 +2808,8 @@ 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,
@@ -2836,7 +2839,7 @@ 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);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 9d16757e27fe..bd44a5701e5f 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 tx_pkts, int budget); int tx_pkts; u8 events; u8 tx_fault:1;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index 5b6fbdc4dc40..33b7eddfbf41 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c@@ -125,7 +125,8 @@ 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 nr_pkts, + int budget) { struct bnxt_tx_ring_info *txr = bnapi->tx_ring; struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
@@ -135,6 +136,9 @@ void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) 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];
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
index ea430d6961df..3ab47ae2f26d 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h@@ -16,7 +16,8 @@ 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 nr_pkts, + 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);
--
2.41.0