6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 0c53cdb95eb4a604062e326636971d96dd9b1b26 ]
ocelot_get_txtstamp() is a threaded IRQ handler, requested explicitly as such by both ocelot_ptp_rdy_irq_handler() and vsc9959_irq_handler().
As such, it runs with IRQs enabled, and not in hardirq context. Thus, ocelot_port_add_txtstamp_skb() has no reason to turn off IRQs, it cannot be preempted by ocelot_get_txtstamp(). For the same reason, dev_kfree_skb_any_reason() will always evaluate as kfree_skb_reason() in this calling context, so just simplify the dev_kfree_skb_any() call to kfree_skb().
Also, ocelot_port_txtstamp_request() runs from NET_TX softirq context, not with hardirqs enabled. Thus, ocelot_get_txtstamp() which shares the ocelot_port->tx_skbs.lock lock with it, has no reason to disable hardirqs.
This is part of a larger rework of the TX timestamping procedure. A logical subportion of the rework has been split into a separate change.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Link: https://patch.msgid.link/20241205145519.1236778-4-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: b454abfab525 ("net: mscc: ocelot: be resilient to loss of PTP packets during transmission") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot_ptp.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot_ptp.c b/drivers/net/ethernet/mscc/ocelot_ptp.c index 1386fb2ff4a9..c54e96ff3976 100644 --- a/drivers/net/ethernet/mscc/ocelot_ptp.c +++ b/drivers/net/ethernet/mscc/ocelot_ptp.c @@ -611,13 +611,12 @@ static int ocelot_port_add_txtstamp_skb(struct ocelot *ocelot, int port, struct sk_buff *clone) { struct ocelot_port *ocelot_port = ocelot->ports[port]; - unsigned long flags;
- spin_lock_irqsave(&ocelot->ts_id_lock, flags); + spin_lock(&ocelot->ts_id_lock);
if (ocelot_port->ptp_skbs_in_flight == OCELOT_MAX_PTP_ID || ocelot->ptp_skbs_in_flight == OCELOT_PTP_FIFO_SIZE) { - spin_unlock_irqrestore(&ocelot->ts_id_lock, flags); + spin_unlock(&ocelot->ts_id_lock); return -EBUSY; }
@@ -634,7 +633,7 @@ static int ocelot_port_add_txtstamp_skb(struct ocelot *ocelot, int port,
skb_queue_tail(&ocelot_port->tx_skbs, clone);
- spin_unlock_irqrestore(&ocelot->ts_id_lock, flags); + spin_unlock(&ocelot->ts_id_lock);
return 0; } @@ -753,7 +752,6 @@ void ocelot_get_txtstamp(struct ocelot *ocelot) u32 val, id, seqid, txport; struct ocelot_port *port; struct timespec64 ts; - unsigned long flags;
val = ocelot_read(ocelot, SYS_PTP_STATUS);
@@ -777,7 +775,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
/* Retrieve its associated skb */ try_again: - spin_lock_irqsave(&port->tx_skbs.lock, flags); + spin_lock(&port->tx_skbs.lock);
skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) { if (OCELOT_SKB_CB(skb)->ts_id != id) @@ -787,7 +785,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot) break; }
- spin_unlock_irqrestore(&port->tx_skbs.lock, flags); + spin_unlock(&port->tx_skbs.lock);
if (WARN_ON(!skb_match)) goto next_ts; @@ -796,7 +794,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot) dev_err_ratelimited(ocelot->dev, "port %d received stale TX timestamp for seqid %d, discarding\n", txport, seqid); - dev_kfree_skb_any(skb); + kfree_skb(skb); goto try_again; }