This is a note to let you know that I've just added the patch titled
net: mscc: ocelot: ocelot->ts_id_lock and ocelot_port->tx_skbs.lock are IRQ-safe
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mscc-ocelot-ocelot-ts_id_lock-and-ocelot_port-tx.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 976d718b186835557e242963e90aa25f5536f205
Author: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Thu Dec 5 16:55:17 2024 +0200
net: mscc: ocelot: ocelot->ts_id_lock and ocelot_port->tx_skbs.lock are IRQ-safe
[ 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@xxxxxxx>
Link: https://patch.msgid.link/20241205145519.1236778-4-vladimir.oltean@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Stable-dep-of: b454abfab525 ("net: mscc: ocelot: be resilient to loss of PTP packets during transmission")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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;
}
