net: dsa: convert to ndo_hwtstamp_get() and ndo_hwtstamp_set()

New timestamping API was introduced in commit 66f7223039c0 ("net: add
NDOs for configuring hardware timestamping") from kernel v6.6. It is
time to convert DSA to the new API, so that the ndo_eth_ioctl() path can
be removed completely.

Move the ds->ops->port_hwtstamp_get() and ds->ops->port_hwtstamp_set()
calls from dsa_user_ioctl() to dsa_user_hwtstamp_get() and
dsa_user_hwtstamp_set().

Due to the fact that the underlying ifreq type changes to
kernel_hwtstamp_config, the drivers and the Ocelot switchdev front-end,
all hooked up directly or indirectly, must also be converted all at once.

The conversion also updates the comment from dsa_port_supports_hwtstamp(),
which is no longer true because kernel_hwtstamp_config is kernel memory
and does not need copy_to_user(). I've deliberated whether it is
necessary to also update "err != -EOPNOTSUPP" to a more general "!err",
but all drivers now either return 0 or -EOPNOTSUPP.

The existing logic from the ocelot_ioctl() function, to avoid
configuring timestamping if the PHY supports the operation, is obsoleted
by more advanced core logic in dev_set_hwtstamp_phylib().

This is only a partial preparation for proper PHY timestamping support.
None of these switch driver currently sets up PTP traps for PHY
timestamping, so setting dev->see_all_hwtstamp_requests is not yet
necessary and the conversion is relatively trivial.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # felix, sja1105, mv88e6xxx
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20250508095236.887789-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 30 insertions, 21 deletions

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 5c9d1798e830..082573ae6864 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -116,19 +116,15 @@ static bool dsa_port_can_configure_learning(struct dsa_port *dp)
 
 bool dsa_port_supports_hwtstamp(struct dsa_port *dp)
 {
+	struct kernel_hwtstamp_config config = {};
 	struct dsa_switch *ds = dp->ds;
-	struct ifreq ifr = {};
 	int err;
 
 	if (!ds->ops->port_hwtstamp_get || !ds->ops->port_hwtstamp_set)
 		return false;
 
-	/* "See through" shim implementations of the "get" method.
-	 * Since we can't cook up a complete ioctl request structure, this will
-	 * fail in copy_to_user() with -EFAULT, which hopefully is enough to
-	 * detect a valid implementation.
-	 */
-	err = ds->ops->port_hwtstamp_get(ds, dp->index, &ifr);
+	/* "See through" shim implementations of the "get" method. */
+	err = ds->ops->port_hwtstamp_get(ds, dp->index, &config);
 	return err != -EOPNOTSUPP;
 }
 
diff --git a/net/dsa/user.c b/net/dsa/user.c
index 804dc7dac4f2..e9334520c54a 100644
--- a/net/dsa/user.c
+++ b/net/dsa/user.c
@@ -578,20 +578,6 @@ dsa_user_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 static int dsa_user_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
 	struct dsa_user_priv *p = netdev_priv(dev);
-	struct dsa_switch *ds = p->dp->ds;
-	int port = p->dp->index;
-
-	/* Pass through to switch driver if it supports timestamping */
-	switch (cmd) {
-	case SIOCGHWTSTAMP:
-		if (ds->ops->port_hwtstamp_get)
-			return ds->ops->port_hwtstamp_get(ds, port, ifr);
-		break;
-	case SIOCSHWTSTAMP:
-		if (ds->ops->port_hwtstamp_set)
-			return ds->ops->port_hwtstamp_set(ds, port, ifr);
-		break;
-	}
 
 	return phylink_mii_ioctl(p->dp->pl, ifr, cmd);
 }
@@ -2574,6 +2560,31 @@ static int dsa_user_fill_forward_path(struct net_device_path_ctx *ctx,
 	return 0;
 }
 
+static int dsa_user_hwtstamp_get(struct net_device *dev,
+				 struct kernel_hwtstamp_config *cfg)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_hwtstamp_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_hwtstamp_get(ds, dp->index, cfg);
+}
+
+static int dsa_user_hwtstamp_set(struct net_device *dev,
+				 struct kernel_hwtstamp_config *cfg,
+				 struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_hwtstamp_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_hwtstamp_set(ds, dp->index, cfg, extack);
+}
+
 static const struct net_device_ops dsa_user_netdev_ops = {
 	.ndo_open		= dsa_user_open,
 	.ndo_stop		= dsa_user_close,
@@ -2595,6 +2606,8 @@ static const struct net_device_ops dsa_user_netdev_ops = {
 	.ndo_vlan_rx_kill_vid	= dsa_user_vlan_rx_kill_vid,
 	.ndo_change_mtu		= dsa_user_change_mtu,
 	.ndo_fill_forward_path	= dsa_user_fill_forward_path,
+	.ndo_hwtstamp_get	= dsa_user_hwtstamp_get,
+	.ndo_hwtstamp_set	= dsa_user_hwtstamp_set,
 };
 
 static const struct device_type dsa_type = {