net: dsa: propagate extack to ds->ops->port_hsr_join()

Drivers can provide meaningful error messages which state a reason why
they can't perform an offload, and dsa_slave_changeupper() already has
the infrastructure to propagate these over netlink rather than printing
to the kernel log. So pass the extack argument and modify the xrs700x
driver's port_hsr_join() prototype.

Also take the opportunity and use the extack for the 2 -EOPNOTSUPP cases
from xrs700x_hsr_join().

Signed-off-by: Vladimir Oltean <[e-mail]>
Signed-off-by: Lukasz Majewski <[e-mail]>
Reviewed-by: Florian Fainelli <[e-mail]>
Reviewed-by: Vladimir Oltean <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/net/dsa/xrs700x/xrs700x.c

···
 }
 
 static int xrs700x_hsr_join(struct dsa_switch *ds, int port,
-			    struct net_device *hsr)
+			    struct net_device *hsr,
+			    struct netlink_ext_ack *extack)
 {
 	unsigned int val = XRS_HSR_CFG_HSR_PRP;
 	struct dsa_port *partner = NULL, *dp;
···
 	if (ret)
 		return ret;
 
-	/* Only ports 1 and 2 can be HSR/PRP redundant ports. */
-	if (port != 1 && port != 2)
+	if (port != 1 && port != 2) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only ports 1 and 2 can offload HSR/PRP");
 		return -EOPNOTSUPP;
+	}
 
-	if (ver == HSR_V1)
+	if (ver == HSR_V1) {
 		val |= XRS_HSR_CFG_HSR;
-	else if (ver == PRP_V1)
+	} else if (ver == PRP_V1) {
 		val |= XRS_HSR_CFG_PRP;
-	else
+	} else {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only HSR v1 and PRP v1 can be offloaded");
 		return -EOPNOTSUPP;
+	}
 
 	dsa_hsr_foreach_port(dp, ds, hsr) {
 		if (dp->index != port) {

include/net/dsa.h

···
 	 * HSR integration
 	 */
 	int	(*port_hsr_join)(struct dsa_switch *ds, int port,
-				 struct net_device *hsr);
+				 struct net_device *hsr,
+				 struct netlink_ext_ack *extack);
 	int	(*port_hsr_leave)(struct dsa_switch *ds, int port,
 				  struct net_device *hsr);
 

net/dsa/port.c

···
 		dsa_shared_port_setup_phy_of(dp, false);
 }
 
-int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr)
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
+		      struct netlink_ext_ack *extack)
 {
 	struct dsa_switch *ds = dp->ds;
 	int err;
···
 
 	dp->hsr_dev = hsr;
 
-	err = ds->ops->port_hsr_join(ds, dp->index, hsr);
+	err = ds->ops->port_hsr_join(ds, dp->index, hsr, extack);
 	if (err)
 		dp->hsr_dev = NULL;
 

net/dsa/port.h

···
 void dsa_port_phylink_destroy(struct dsa_port *dp);
 int dsa_shared_port_link_register_of(struct dsa_port *dp);
 void dsa_shared_port_link_unregister_of(struct dsa_port *dp);
-int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr);
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
+		      struct netlink_ext_ack *extack);
 void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr);
 int dsa_port_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid, bool broadcast);
 void dsa_port_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid, bool broadcast);

net/dsa/slave.c

···
 		}
 	} else if (is_hsr_master(info->upper_dev)) {
 		if (info->linking) {
-			err = dsa_port_hsr_join(dp, info->upper_dev);
+			err = dsa_port_hsr_join(dp, info->upper_dev, extack);
 			if (err == -EOPNOTSUPP) {
 				NL_SET_ERR_MSG_WEAK_MOD(extack,
 							"Offloading not supported");