From 3b4241817601a2f59beea471baa51763d7262232 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
Git-commit: 52849bcf0029ccc553be304e4f804938a39112e2
Patch-mainline: v5.15-rc6
References: stable-5.14.14
commit 52849bcf0029ccc553be304e4f804938a39112e2 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/dsa/ocelot/felix.c | 6 ++++-
drivers/net/ethernet/mscc/ocelot.c | 37 ++++++++++++++++++++++++------
include/soc/mscc/ocelot.h | 5 +++-
include/soc/mscc/ocelot_ptp.h | 1 +
4 files changed, 40 insertions(+), 9 deletions(-)
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index a2a15919b960..42d64a6a0a65 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1406,8 +1406,12 @@ 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 51a236622f57..87ac24a7e003 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -536,22 +536,36 @@ void ocelot_port_disable(struct ocelot *ocelot, int port)
}
EXPORT_SYMBOL(ocelot_port_disable);
-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)
@@ -600,6 +614,7 @@ 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) {
@@ -617,7 +632,10 @@ 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;
}
@@ -676,9 +694,14 @@ 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) {
@@ -1917,7 +1940,6 @@ 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 */
@@ -2041,6 +2063,7 @@ 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 2f5ce4d4fdbf..33b1e78eab24 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -600,10 +600,10 @@ 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;
@@ -677,6 +677,9 @@ 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
--
2.26.2