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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-10-12 14:40:36 +0300
committerJakub Kicinski <kuba@kernel.org>2021-10-12 17:35:17 -0700
commit52849bcf0029ccc553be304e4f804938a39112e2 (patch)
tree164fb20ac0bac33fbf83ae0139fc9953db90a897 /drivers
parentc57fe0037a4e3863d9b740f8c14df9c51ac31aa1 (diff)
net: mscc: ocelot: avoid overflowing the PTP timestamp FIFO
PTP packets with 2-step TX timestamp requests are matched to packets based on the egress port number and a 6-bit timestamp identifier. All PTP timestamps are held in a common FIFO that is 128 entry deep. This patch ensures that back-to-back timestamping requests cannot exceed the hardware FIFO capacity. If that happens, simply send the packets without requesting a TX timestamp to be taken (in the case of felix, since the DSA API has a void return code in ds->ops->port_txtstamp) or drop them (in the case of ocelot). I've moved the ts_id_lock from a per-port basis to a per-switch basis, because we need separate accounting for both numbers of PTP frames in flight. And since we need locking to inc/dec the per-switch counter, that also offers protection for the per-port counter and hence there is no reason to have a per-port counter anymore. Fixes: 4e3b0468e6d7 ("net: mscc: PTP Hardware Clock (PHC) support") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/dsa/ocelot/felix.c6
-rw-r--r--drivers/net/ethernet/mscc/ocelot.c37
2 files changed, 35 insertions, 8 deletions
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index a3a9636430d6..50ef20724958 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1291,8 +1291,12 @@ static void felix_txtstamp(struct dsa_switch *ds, int port,
if (!ocelot->ptp)
return;
- if (ocelot_port_txtstamp_request(ocelot, port, skb, &clone))
+ if (ocelot_port_txtstamp_request(ocelot, port, skb, &clone)) {
+ dev_err_ratelimited(ds->dev,
+ "port %d delivering skb without TX timestamp\n",
+ port);
return;
+ }
if (clone)
OCELOT_SKB_CB(skb)->clone = clone;
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index c43c8f53faaf..9c62f1d13adc 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -569,22 +569,36 @@ void ocelot_phylink_mac_link_up(struct ocelot *ocelot, int port,
}
EXPORT_SYMBOL_GPL(ocelot_phylink_mac_link_up);
-static void ocelot_port_add_txtstamp_skb(struct ocelot *ocelot, int port,
- struct sk_buff *clone)
+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_port->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);
+ return -EBUSY;
+ }
skb_shinfo(clone)->tx_flags |= SKBTX_IN_PROGRESS;
/* Store timestamp ID in OCELOT_SKB_CB(clone)->ts_id */
OCELOT_SKB_CB(clone)->ts_id = ocelot_port->ts_id;
+
ocelot_port->ts_id++;
if (ocelot_port->ts_id == OCELOT_MAX_PTP_ID)
ocelot_port->ts_id = 0;
+
+ ocelot_port->ptp_skbs_in_flight++;
+ ocelot->ptp_skbs_in_flight++;
+
skb_queue_tail(&ocelot_port->tx_skbs, clone);
- spin_unlock(&ocelot_port->ts_id_lock);
+ spin_unlock_irqrestore(&ocelot->ts_id_lock, flags);
+
+ return 0;
}
u32 ocelot_ptp_rew_op(struct sk_buff *skb)
@@ -633,6 +647,7 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
{
struct ocelot_port *ocelot_port = ocelot->ports[port];
u8 ptp_cmd = ocelot_port->ptp_cmd;
+ int err;
/* Store ptp_cmd in OCELOT_SKB_CB(skb)->ptp_cmd */
if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) {
@@ -650,7 +665,10 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
if (!(*clone))
return -ENOMEM;
- ocelot_port_add_txtstamp_skb(ocelot, port, *clone);
+ err = ocelot_port_add_txtstamp_skb(ocelot, port, *clone);
+ if (err)
+ return err;
+
OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
}
@@ -709,9 +727,14 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
id = SYS_PTP_STATUS_PTP_MESS_ID_X(val);
txport = SYS_PTP_STATUS_PTP_MESS_TXPORT_X(val);
- /* Retrieve its associated skb */
port = ocelot->ports[txport];
+ spin_lock(&ocelot->ts_id_lock);
+ port->ptp_skbs_in_flight--;
+ ocelot->ptp_skbs_in_flight--;
+ spin_unlock(&ocelot->ts_id_lock);
+
+ /* Retrieve its associated skb */
spin_lock_irqsave(&port->tx_skbs.lock, flags);
skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
@@ -1950,7 +1973,6 @@ void ocelot_init_port(struct ocelot *ocelot, int port)
struct ocelot_port *ocelot_port = ocelot->ports[port];
skb_queue_head_init(&ocelot_port->tx_skbs);
- spin_lock_init(&ocelot_port->ts_id_lock);
/* Basic L2 initialization */
@@ -2083,6 +2105,7 @@ int ocelot_init(struct ocelot *ocelot)
mutex_init(&ocelot->stats_lock);
mutex_init(&ocelot->ptp_lock);
spin_lock_init(&ocelot->ptp_clock_lock);
+ spin_lock_init(&ocelot->ts_id_lock);
snprintf(queue_name, sizeof(queue_name), "%s-stats",
dev_name(ocelot->dev));
ocelot->stats_queue = create_singlethread_workqueue(queue_name);