diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2020-09-18 04:07:24 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-09-18 13:52:33 -0700 |
| commit | 6565243c0677aa2befa5a953cf11bc7b4a6f0a47 (patch) | |
| tree | 2b57ec438bfe55b8e25f47f4a7df5e7aae959545 /drivers/net/ethernet | |
| parent | 9dda66acddcbcd5c9e94a1292c679738ba999345 (diff) | |
net: mscc: ocelot: add locking for the port TX timestamp ID
The ocelot_port->ts_id is used to:
(a) populate skb->cb[0] for matching the TX timestamp in the PTP IRQ
with an skb.
(b) populate the REW_OP from the injection header of the ongoing skb.
Only then is ocelot_port->ts_id incremented.
This is a problem because, at least theoretically, another timestampable
skb might use the same ocelot_port->ts_id before that is incremented.
Normally all transmit calls are serialized by the netdev transmit
spinlock, but in this case, ocelot_port_add_txtstamp_skb() is also
called by DSA, which has started declaring the NETIF_F_LLTX feature
since commit 2b86cb829976 ("net: dsa: declare lockless TX feature for
slave ports"). So the logic of using and incrementing the timestamp id
should be atomic per port.
The solution is to use the global ocelot_port->ts_id only while
protected by the associated ocelot_port->ts_id_lock. That's where we
populate skb->cb[0]. Note that for ocelot, ocelot_port_add_txtstamp_skb
is called for the actual skb, but for felix, it is called for the skb's
clone. That is something which will also be changed in the future.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet')
| -rw-r--r-- | drivers/net/ethernet/mscc/ocelot.c | 8 | ||||
| -rw-r--r-- | drivers/net/ethernet/mscc/ocelot_net.c | 6 |
2 files changed, 9 insertions, 5 deletions
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 5abb7d2b0a9e..83eb7c325061 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -421,10 +421,15 @@ int ocelot_port_add_txtstamp_skb(struct ocelot_port *ocelot_port, if (ocelot->ptp && shinfo->tx_flags & SKBTX_HW_TSTAMP && ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) { + spin_lock(&ocelot_port->ts_id_lock); + shinfo->tx_flags |= SKBTX_IN_PROGRESS; /* Store timestamp ID in cb[0] of sk_buff */ - skb->cb[0] = ocelot_port->ts_id % 4; + skb->cb[0] = ocelot_port->ts_id; + ocelot_port->ts_id = (ocelot_port->ts_id + 1) % 4; skb_queue_tail(&ocelot_port->tx_skbs, skb); + + spin_unlock(&ocelot_port->ts_id_lock); return 0; } return -ENODATA; @@ -1300,6 +1305,7 @@ 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 */ diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c index cacabc23215a..8490e42e9e2d 100644 --- a/drivers/net/ethernet/mscc/ocelot_net.c +++ b/drivers/net/ethernet/mscc/ocelot_net.c @@ -349,10 +349,8 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev) if (ocelot->ptp && shinfo->tx_flags & SKBTX_HW_TSTAMP) { info.rew_op = ocelot_port->ptp_cmd; - if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) { - info.rew_op |= (ocelot_port->ts_id % 4) << 3; - ocelot_port->ts_id++; - } + if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) + info.rew_op |= skb->cb[0] << 3; } ocelot_gen_ifh(ifh, &info); |