The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 52849bcf0029ccc553be304e4f804938a39112e2 Mon Sep 17 00:00:00 2001
From: Vladimir Oltean vladimir.oltean@nxp.com Date: Tue, 12 Oct 2021 14:40:36 +0300 Subject: [PATCH] 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
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); diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index 06706a9fd5b1..b0ece85d9a76 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -603,10 +603,10 @@ struct ocelot_port { /* The VLAN ID that will be transmitted as untagged, on egress */ struct ocelot_vlan native_vlan;
+ unsigned int ptp_skbs_in_flight; u8 ptp_cmd; struct sk_buff_head tx_skbs; u8 ts_id; - spinlock_t ts_id_lock;
phy_interface_t phy_mode;
@@ -680,6 +680,9 @@ struct ocelot { struct ptp_clock *ptp_clock; struct ptp_clock_info ptp_info; struct hwtstamp_config hwtstamp_config; + unsigned int ptp_skbs_in_flight; + /* Protects the 2-step TX timestamp ID logic */ + spinlock_t ts_id_lock; /* Protects the PTP interface state */ struct mutex ptp_lock; /* Protects the PTP clock */ diff --git a/include/soc/mscc/ocelot_ptp.h b/include/soc/mscc/ocelot_ptp.h index 6e54442b49ad..f085884b1fa2 100644 --- a/include/soc/mscc/ocelot_ptp.h +++ b/include/soc/mscc/ocelot_ptp.h @@ -14,6 +14,7 @@ #include <soc/mscc/ocelot.h>
#define OCELOT_MAX_PTP_ID 63 +#define OCELOT_PTP_FIFO_SIZE 128
#define PTP_PIN_CFG_RSZ 0x20 #define PTP_PIN_TOD_SEC_MSB_RSZ PTP_PIN_CFG_RSZ