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Code Issues Releases Wiki Activity

bnxt: don't handle XDP in netpoll

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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: 322b87ca55 ("bnxt_en: add page_pool support")
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20230728205020.2784844-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2023-07-28 13:50:20 -07:00
parent 4b31fd4d77
commit 37b61cda9c
4 changed files with 24 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
drivers/net/ethernet/broadcom/bnxt/bnxt.c
View file

@ -633,12 +633,13 @@ 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 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 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
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;

2
drivers/net/ethernet/broadcom/bnxt/bnxt.h
View file

@ -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;

8
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
View file

@ -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];

2
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
View file

@ -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);