xref: /openbmc/linux/net/dsa/port.c (revision 08720988)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Handling of a single switch port
4  *
5  * Copyright (c) 2017 Savoir-faire Linux Inc.
6  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
7  */
8 
9 #include <linux/if_bridge.h>
10 #include <linux/notifier.h>
11 #include <linux/of_mdio.h>
12 #include <linux/of_net.h>
13 
14 #include "dsa_priv.h"
15 
16 static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)
17 {
18 	struct raw_notifier_head *nh = &dp->ds->dst->nh;
19 	int err;
20 
21 	err = raw_notifier_call_chain(nh, e, v);
22 
23 	return notifier_to_errno(err);
24 }
25 
26 int dsa_port_set_state(struct dsa_port *dp, u8 state,
27 		       struct switchdev_trans *trans)
28 {
29 	struct dsa_switch *ds = dp->ds;
30 	int port = dp->index;
31 
32 	if (switchdev_trans_ph_prepare(trans))
33 		return ds->ops->port_stp_state_set ? 0 : -EOPNOTSUPP;
34 
35 	if (ds->ops->port_stp_state_set)
36 		ds->ops->port_stp_state_set(ds, port, state);
37 
38 	if (ds->ops->port_fast_age) {
39 		/* Fast age FDB entries or flush appropriate forwarding database
40 		 * for the given port, if we are moving it from Learning or
41 		 * Forwarding state, to Disabled or Blocking or Listening state.
42 		 */
43 
44 		if ((dp->stp_state == BR_STATE_LEARNING ||
45 		     dp->stp_state == BR_STATE_FORWARDING) &&
46 		    (state == BR_STATE_DISABLED ||
47 		     state == BR_STATE_BLOCKING ||
48 		     state == BR_STATE_LISTENING))
49 			ds->ops->port_fast_age(ds, port);
50 	}
51 
52 	dp->stp_state = state;
53 
54 	return 0;
55 }
56 
57 static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
58 {
59 	int err;
60 
61 	err = dsa_port_set_state(dp, state, NULL);
62 	if (err)
63 		pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
64 }
65 
66 int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
67 {
68 	struct dsa_switch *ds = dp->ds;
69 	int port = dp->index;
70 	int err;
71 
72 	if (ds->ops->port_enable) {
73 		err = ds->ops->port_enable(ds, port, phy);
74 		if (err)
75 			return err;
76 	}
77 
78 	if (!dp->bridge_dev)
79 		dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
80 
81 	return 0;
82 }
83 
84 void dsa_port_disable(struct dsa_port *dp)
85 {
86 	struct dsa_switch *ds = dp->ds;
87 	int port = dp->index;
88 
89 	if (!dp->bridge_dev)
90 		dsa_port_set_state_now(dp, BR_STATE_DISABLED);
91 
92 	if (ds->ops->port_disable)
93 		ds->ops->port_disable(ds, port);
94 }
95 
96 int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
97 {
98 	struct dsa_notifier_bridge_info info = {
99 		.sw_index = dp->ds->index,
100 		.port = dp->index,
101 		.br = br,
102 	};
103 	int err;
104 
105 	/* Set the flooding mode before joining the port in the switch */
106 	err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD, NULL);
107 	if (err)
108 		return err;
109 
110 	/* Here the interface is already bridged. Reflect the current
111 	 * configuration so that drivers can program their chips accordingly.
112 	 */
113 	dp->bridge_dev = br;
114 
115 	err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_JOIN, &info);
116 
117 	/* The bridging is rolled back on error */
118 	if (err) {
119 		dsa_port_bridge_flags(dp, 0, NULL);
120 		dp->bridge_dev = NULL;
121 	}
122 
123 	return err;
124 }
125 
126 void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
127 {
128 	struct dsa_notifier_bridge_info info = {
129 		.sw_index = dp->ds->index,
130 		.port = dp->index,
131 		.br = br,
132 	};
133 	int err;
134 
135 	/* Here the port is already unbridged. Reflect the current configuration
136 	 * so that drivers can program their chips accordingly.
137 	 */
138 	dp->bridge_dev = NULL;
139 
140 	err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_LEAVE, &info);
141 	if (err)
142 		pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");
143 
144 	/* Port is leaving the bridge, disable flooding */
145 	dsa_port_bridge_flags(dp, 0, NULL);
146 
147 	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
148 	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
149 	 */
150 	dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
151 }
152 
153 static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
154 					      bool vlan_filtering)
155 {
156 	struct dsa_switch *ds = dp->ds;
157 	int i;
158 
159 	if (!ds->vlan_filtering_is_global)
160 		return true;
161 
162 	/* For cases where enabling/disabling VLAN awareness is global to the
163 	 * switch, we need to handle the case where multiple bridges span
164 	 * different ports of the same switch device and one of them has a
165 	 * different setting than what is being requested.
166 	 */
167 	for (i = 0; i < ds->num_ports; i++) {
168 		struct net_device *other_bridge;
169 
170 		other_bridge = dsa_to_port(ds, i)->bridge_dev;
171 		if (!other_bridge)
172 			continue;
173 		/* If it's the same bridge, it also has same
174 		 * vlan_filtering setting => no need to check
175 		 */
176 		if (other_bridge == dp->bridge_dev)
177 			continue;
178 		if (br_vlan_enabled(other_bridge) != vlan_filtering) {
179 			dev_err(ds->dev, "VLAN filtering is a global setting\n");
180 			return false;
181 		}
182 	}
183 	return true;
184 }
185 
186 int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
187 			    struct switchdev_trans *trans)
188 {
189 	struct dsa_switch *ds = dp->ds;
190 	int err;
191 
192 	/* bridge skips -EOPNOTSUPP, so skip the prepare phase */
193 	if (switchdev_trans_ph_prepare(trans))
194 		return 0;
195 
196 	if (!ds->ops->port_vlan_filtering)
197 		return 0;
198 
199 	if (!dsa_port_can_apply_vlan_filtering(dp, vlan_filtering))
200 		return -EINVAL;
201 
202 	if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
203 		return 0;
204 
205 	err = ds->ops->port_vlan_filtering(ds, dp->index,
206 					   vlan_filtering);
207 	if (err)
208 		return err;
209 
210 	if (ds->vlan_filtering_is_global)
211 		ds->vlan_filtering = vlan_filtering;
212 	else
213 		dp->vlan_filtering = vlan_filtering;
214 	return 0;
215 }
216 
217 int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
218 			 struct switchdev_trans *trans)
219 {
220 	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
221 	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
222 	struct dsa_notifier_ageing_time_info info = {
223 		.ageing_time = ageing_time,
224 		.trans = trans,
225 	};
226 
227 	if (switchdev_trans_ph_prepare(trans))
228 		return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
229 
230 	dp->ageing_time = ageing_time;
231 
232 	return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
233 }
234 
235 int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
236 			      struct switchdev_trans *trans)
237 {
238 	struct dsa_switch *ds = dp->ds;
239 
240 	if (!ds->ops->port_egress_floods ||
241 	    (flags & ~(BR_FLOOD | BR_MCAST_FLOOD)))
242 		return -EINVAL;
243 
244 	return 0;
245 }
246 
247 int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
248 			  struct switchdev_trans *trans)
249 {
250 	struct dsa_switch *ds = dp->ds;
251 	int port = dp->index;
252 	int err = 0;
253 
254 	if (switchdev_trans_ph_prepare(trans))
255 		return 0;
256 
257 	if (ds->ops->port_egress_floods)
258 		err = ds->ops->port_egress_floods(ds, port, flags & BR_FLOOD,
259 						  flags & BR_MCAST_FLOOD);
260 
261 	return err;
262 }
263 
264 int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
265 		     struct switchdev_trans *trans)
266 {
267 	struct dsa_switch *ds = dp->ds;
268 	int port = dp->index;
269 
270 	if (switchdev_trans_ph_prepare(trans))
271 		return ds->ops->port_egress_floods ? 0 : -EOPNOTSUPP;
272 
273 	return ds->ops->port_egress_floods(ds, port, true, mrouter);
274 }
275 
276 int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
277 		     u16 vid)
278 {
279 	struct dsa_notifier_fdb_info info = {
280 		.sw_index = dp->ds->index,
281 		.port = dp->index,
282 		.addr = addr,
283 		.vid = vid,
284 	};
285 
286 	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_ADD, &info);
287 }
288 
289 int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
290 		     u16 vid)
291 {
292 	struct dsa_notifier_fdb_info info = {
293 		.sw_index = dp->ds->index,
294 		.port = dp->index,
295 		.addr = addr,
296 		.vid = vid,
297 
298 	};
299 
300 	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_DEL, &info);
301 }
302 
303 int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data)
304 {
305 	struct dsa_switch *ds = dp->ds;
306 	int port = dp->index;
307 
308 	if (!ds->ops->port_fdb_dump)
309 		return -EOPNOTSUPP;
310 
311 	return ds->ops->port_fdb_dump(ds, port, cb, data);
312 }
313 
314 int dsa_port_mdb_add(const struct dsa_port *dp,
315 		     const struct switchdev_obj_port_mdb *mdb,
316 		     struct switchdev_trans *trans)
317 {
318 	struct dsa_notifier_mdb_info info = {
319 		.sw_index = dp->ds->index,
320 		.port = dp->index,
321 		.trans = trans,
322 		.mdb = mdb,
323 	};
324 
325 	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_ADD, &info);
326 }
327 
328 int dsa_port_mdb_del(const struct dsa_port *dp,
329 		     const struct switchdev_obj_port_mdb *mdb)
330 {
331 	struct dsa_notifier_mdb_info info = {
332 		.sw_index = dp->ds->index,
333 		.port = dp->index,
334 		.mdb = mdb,
335 	};
336 
337 	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_DEL, &info);
338 }
339 
340 int dsa_port_vlan_add(struct dsa_port *dp,
341 		      const struct switchdev_obj_port_vlan *vlan,
342 		      struct switchdev_trans *trans)
343 {
344 	struct dsa_notifier_vlan_info info = {
345 		.sw_index = dp->ds->index,
346 		.port = dp->index,
347 		.trans = trans,
348 		.vlan = vlan,
349 	};
350 
351 	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
352 }
353 
354 int dsa_port_vlan_del(struct dsa_port *dp,
355 		      const struct switchdev_obj_port_vlan *vlan)
356 {
357 	struct dsa_notifier_vlan_info info = {
358 		.sw_index = dp->ds->index,
359 		.port = dp->index,
360 		.vlan = vlan,
361 	};
362 
363 	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
364 }
365 
366 int dsa_port_vid_add(struct dsa_port *dp, u16 vid, u16 flags)
367 {
368 	struct switchdev_obj_port_vlan vlan = {
369 		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
370 		.flags = flags,
371 		.vid_begin = vid,
372 		.vid_end = vid,
373 	};
374 	struct switchdev_trans trans;
375 	int err;
376 
377 	trans.ph_prepare = true;
378 	err = dsa_port_vlan_add(dp, &vlan, &trans);
379 	if (err)
380 		return err;
381 
382 	trans.ph_prepare = false;
383 	return dsa_port_vlan_add(dp, &vlan, &trans);
384 }
385 EXPORT_SYMBOL(dsa_port_vid_add);
386 
387 int dsa_port_vid_del(struct dsa_port *dp, u16 vid)
388 {
389 	struct switchdev_obj_port_vlan vlan = {
390 		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
391 		.vid_begin = vid,
392 		.vid_end = vid,
393 	};
394 
395 	return dsa_port_vlan_del(dp, &vlan);
396 }
397 EXPORT_SYMBOL(dsa_port_vid_del);
398 
399 static struct phy_device *dsa_port_get_phy_device(struct dsa_port *dp)
400 {
401 	struct device_node *phy_dn;
402 	struct phy_device *phydev;
403 
404 	phy_dn = of_parse_phandle(dp->dn, "phy-handle", 0);
405 	if (!phy_dn)
406 		return NULL;
407 
408 	phydev = of_phy_find_device(phy_dn);
409 	if (!phydev) {
410 		of_node_put(phy_dn);
411 		return ERR_PTR(-EPROBE_DEFER);
412 	}
413 
414 	of_node_put(phy_dn);
415 	return phydev;
416 }
417 
418 static void dsa_port_phylink_validate(struct phylink_config *config,
419 				      unsigned long *supported,
420 				      struct phylink_link_state *state)
421 {
422 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
423 	struct dsa_switch *ds = dp->ds;
424 
425 	if (!ds->ops->phylink_validate)
426 		return;
427 
428 	ds->ops->phylink_validate(ds, dp->index, supported, state);
429 }
430 
431 static void dsa_port_phylink_mac_pcs_get_state(struct phylink_config *config,
432 					       struct phylink_link_state *state)
433 {
434 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
435 	struct dsa_switch *ds = dp->ds;
436 
437 	/* Only called for inband modes */
438 	if (!ds->ops->phylink_mac_link_state) {
439 		state->link = 0;
440 		return;
441 	}
442 
443 	if (ds->ops->phylink_mac_link_state(ds, dp->index, state) < 0)
444 		state->link = 0;
445 }
446 
447 static void dsa_port_phylink_mac_config(struct phylink_config *config,
448 					unsigned int mode,
449 					const struct phylink_link_state *state)
450 {
451 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
452 	struct dsa_switch *ds = dp->ds;
453 
454 	if (!ds->ops->phylink_mac_config)
455 		return;
456 
457 	ds->ops->phylink_mac_config(ds, dp->index, mode, state);
458 }
459 
460 static void dsa_port_phylink_mac_an_restart(struct phylink_config *config)
461 {
462 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
463 	struct dsa_switch *ds = dp->ds;
464 
465 	if (!ds->ops->phylink_mac_an_restart)
466 		return;
467 
468 	ds->ops->phylink_mac_an_restart(ds, dp->index);
469 }
470 
471 static void dsa_port_phylink_mac_link_down(struct phylink_config *config,
472 					   unsigned int mode,
473 					   phy_interface_t interface)
474 {
475 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
476 	struct phy_device *phydev = NULL;
477 	struct dsa_switch *ds = dp->ds;
478 
479 	if (dsa_is_user_port(ds, dp->index))
480 		phydev = dp->slave->phydev;
481 
482 	if (!ds->ops->phylink_mac_link_down) {
483 		if (ds->ops->adjust_link && phydev)
484 			ds->ops->adjust_link(ds, dp->index, phydev);
485 		return;
486 	}
487 
488 	ds->ops->phylink_mac_link_down(ds, dp->index, mode, interface);
489 }
490 
491 static void dsa_port_phylink_mac_link_up(struct phylink_config *config,
492 					 unsigned int mode,
493 					 phy_interface_t interface,
494 					 struct phy_device *phydev)
495 {
496 	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
497 	struct dsa_switch *ds = dp->ds;
498 
499 	if (!ds->ops->phylink_mac_link_up) {
500 		if (ds->ops->adjust_link && phydev)
501 			ds->ops->adjust_link(ds, dp->index, phydev);
502 		return;
503 	}
504 
505 	ds->ops->phylink_mac_link_up(ds, dp->index, mode, interface, phydev);
506 }
507 
508 const struct phylink_mac_ops dsa_port_phylink_mac_ops = {
509 	.validate = dsa_port_phylink_validate,
510 	.mac_pcs_get_state = dsa_port_phylink_mac_pcs_get_state,
511 	.mac_config = dsa_port_phylink_mac_config,
512 	.mac_an_restart = dsa_port_phylink_mac_an_restart,
513 	.mac_link_down = dsa_port_phylink_mac_link_down,
514 	.mac_link_up = dsa_port_phylink_mac_link_up,
515 };
516 
517 static int dsa_port_setup_phy_of(struct dsa_port *dp, bool enable)
518 {
519 	struct dsa_switch *ds = dp->ds;
520 	struct phy_device *phydev;
521 	int port = dp->index;
522 	int err = 0;
523 
524 	phydev = dsa_port_get_phy_device(dp);
525 	if (!phydev)
526 		return 0;
527 
528 	if (IS_ERR(phydev))
529 		return PTR_ERR(phydev);
530 
531 	if (enable) {
532 		err = genphy_resume(phydev);
533 		if (err < 0)
534 			goto err_put_dev;
535 
536 		err = genphy_read_status(phydev);
537 		if (err < 0)
538 			goto err_put_dev;
539 	} else {
540 		err = genphy_suspend(phydev);
541 		if (err < 0)
542 			goto err_put_dev;
543 	}
544 
545 	if (ds->ops->adjust_link)
546 		ds->ops->adjust_link(ds, port, phydev);
547 
548 	dev_dbg(ds->dev, "enabled port's phy: %s", phydev_name(phydev));
549 
550 err_put_dev:
551 	put_device(&phydev->mdio.dev);
552 	return err;
553 }
554 
555 static int dsa_port_fixed_link_register_of(struct dsa_port *dp)
556 {
557 	struct device_node *dn = dp->dn;
558 	struct dsa_switch *ds = dp->ds;
559 	struct phy_device *phydev;
560 	int port = dp->index;
561 	phy_interface_t mode;
562 	int err;
563 
564 	err = of_phy_register_fixed_link(dn);
565 	if (err) {
566 		dev_err(ds->dev,
567 			"failed to register the fixed PHY of port %d\n",
568 			port);
569 		return err;
570 	}
571 
572 	phydev = of_phy_find_device(dn);
573 
574 	err = of_get_phy_mode(dn, &mode);
575 	if (err)
576 		mode = PHY_INTERFACE_MODE_NA;
577 	phydev->interface = mode;
578 
579 	genphy_read_status(phydev);
580 
581 	if (ds->ops->adjust_link)
582 		ds->ops->adjust_link(ds, port, phydev);
583 
584 	put_device(&phydev->mdio.dev);
585 
586 	return 0;
587 }
588 
589 static int dsa_port_phylink_register(struct dsa_port *dp)
590 {
591 	struct dsa_switch *ds = dp->ds;
592 	struct device_node *port_dn = dp->dn;
593 	phy_interface_t mode;
594 	int err;
595 
596 	err = of_get_phy_mode(port_dn, &mode);
597 	if (err)
598 		mode = PHY_INTERFACE_MODE_NA;
599 
600 	dp->pl_config.dev = ds->dev;
601 	dp->pl_config.type = PHYLINK_DEV;
602 	dp->pl_config.pcs_poll = ds->pcs_poll;
603 
604 	dp->pl = phylink_create(&dp->pl_config, of_fwnode_handle(port_dn),
605 				mode, &dsa_port_phylink_mac_ops);
606 	if (IS_ERR(dp->pl)) {
607 		pr_err("error creating PHYLINK: %ld\n", PTR_ERR(dp->pl));
608 		return PTR_ERR(dp->pl);
609 	}
610 
611 	err = phylink_of_phy_connect(dp->pl, port_dn, 0);
612 	if (err && err != -ENODEV) {
613 		pr_err("could not attach to PHY: %d\n", err);
614 		goto err_phy_connect;
615 	}
616 
617 	rtnl_lock();
618 	phylink_start(dp->pl);
619 	rtnl_unlock();
620 
621 	return 0;
622 
623 err_phy_connect:
624 	phylink_destroy(dp->pl);
625 	return err;
626 }
627 
628 int dsa_port_link_register_of(struct dsa_port *dp)
629 {
630 	struct dsa_switch *ds = dp->ds;
631 
632 	if (!ds->ops->adjust_link)
633 		return dsa_port_phylink_register(dp);
634 
635 	dev_warn(ds->dev,
636 		 "Using legacy PHYLIB callbacks. Please migrate to PHYLINK!\n");
637 
638 	if (of_phy_is_fixed_link(dp->dn))
639 		return dsa_port_fixed_link_register_of(dp);
640 	else
641 		return dsa_port_setup_phy_of(dp, true);
642 }
643 
644 void dsa_port_link_unregister_of(struct dsa_port *dp)
645 {
646 	struct dsa_switch *ds = dp->ds;
647 
648 	if (!ds->ops->adjust_link) {
649 		rtnl_lock();
650 		phylink_disconnect_phy(dp->pl);
651 		rtnl_unlock();
652 		phylink_destroy(dp->pl);
653 		return;
654 	}
655 
656 	if (of_phy_is_fixed_link(dp->dn))
657 		of_phy_deregister_fixed_link(dp->dn);
658 	else
659 		dsa_port_setup_phy_of(dp, false);
660 }
661 
662 int dsa_port_get_phy_strings(struct dsa_port *dp, uint8_t *data)
663 {
664 	struct phy_device *phydev;
665 	int ret = -EOPNOTSUPP;
666 
667 	if (of_phy_is_fixed_link(dp->dn))
668 		return ret;
669 
670 	phydev = dsa_port_get_phy_device(dp);
671 	if (IS_ERR_OR_NULL(phydev))
672 		return ret;
673 
674 	ret = phy_ethtool_get_strings(phydev, data);
675 	put_device(&phydev->mdio.dev);
676 
677 	return ret;
678 }
679 EXPORT_SYMBOL_GPL(dsa_port_get_phy_strings);
680 
681 int dsa_port_get_ethtool_phy_stats(struct dsa_port *dp, uint64_t *data)
682 {
683 	struct phy_device *phydev;
684 	int ret = -EOPNOTSUPP;
685 
686 	if (of_phy_is_fixed_link(dp->dn))
687 		return ret;
688 
689 	phydev = dsa_port_get_phy_device(dp);
690 	if (IS_ERR_OR_NULL(phydev))
691 		return ret;
692 
693 	ret = phy_ethtool_get_stats(phydev, NULL, data);
694 	put_device(&phydev->mdio.dev);
695 
696 	return ret;
697 }
698 EXPORT_SYMBOL_GPL(dsa_port_get_ethtool_phy_stats);
699 
700 int dsa_port_get_phy_sset_count(struct dsa_port *dp)
701 {
702 	struct phy_device *phydev;
703 	int ret = -EOPNOTSUPP;
704 
705 	if (of_phy_is_fixed_link(dp->dn))
706 		return ret;
707 
708 	phydev = dsa_port_get_phy_device(dp);
709 	if (IS_ERR_OR_NULL(phydev))
710 		return ret;
711 
712 	ret = phy_ethtool_get_sset_count(phydev);
713 	put_device(&phydev->mdio.dev);
714 
715 	return ret;
716 }
717 EXPORT_SYMBOL_GPL(dsa_port_get_phy_sset_count);
718