xref: /linux/drivers/net/dsa/dsa_loop.c (revision e2683c8868d03382da7e1ce8453b543a043066d1)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Distributed Switch Architecture loopback driver
4  *
5  * Copyright (C) 2016, Florian Fainelli <f.fainelli@gmail.com>
6  */
7 
8 #include <linux/platform_device.h>
9 #include <linux/netdevice.h>
10 #include <linux/phy.h>
11 #include <linux/phy_fixed.h>
12 #include <linux/export.h>
13 #include <linux/ethtool.h>
14 #include <linux/workqueue.h>
15 #include <linux/module.h>
16 #include <linux/if_bridge.h>
17 #include <linux/if_vlan.h>
18 #include <linux/types.h>
19 #include <net/dsa.h>
20 
21 #define DSA_LOOP_NUM_PORTS	6
22 #define DSA_LOOP_CPU_PORT	(DSA_LOOP_NUM_PORTS - 1)
23 #define NUM_FIXED_PHYS		(DSA_LOOP_NUM_PORTS - 2)
24 
25 struct dsa_loop_vlan {
26 	u16 members;
27 	u16 untagged;
28 };
29 
30 struct dsa_loop_mib_entry {
31 	char name[ETH_GSTRING_LEN];
32 	unsigned long val;
33 };
34 
35 enum dsa_loop_mib_counters {
36 	DSA_LOOP_PHY_READ_OK,
37 	DSA_LOOP_PHY_READ_ERR,
38 	DSA_LOOP_PHY_WRITE_OK,
39 	DSA_LOOP_PHY_WRITE_ERR,
40 	__DSA_LOOP_CNT_MAX,
41 };
42 
43 struct dsa_loop_port {
44 	struct dsa_loop_mib_entry mib[__DSA_LOOP_CNT_MAX];
45 	u16 pvid;
46 	int mtu;
47 };
48 
49 struct dsa_loop_priv {
50 	struct mii_bus	*bus;
51 	unsigned int	port_base;
52 	struct dsa_loop_vlan vlans[VLAN_N_VID];
53 	struct net_device *netdev;
54 	struct dsa_loop_port ports[DSA_MAX_PORTS];
55 };
56 
57 struct dsa_loop_pdata {
58 	/* Must be first, such that dsa_register_switch() can access this
59 	 * without gory pointer manipulations
60 	 */
61 	struct dsa_chip_data cd;
62 	const char *name;
63 	unsigned int enabled_ports;
64 	const char *netdev;
65 };
66 
67 static struct dsa_loop_mib_entry dsa_loop_mibs[] = {
68 	[DSA_LOOP_PHY_READ_OK]	= { "phy_read_ok", },
69 	[DSA_LOOP_PHY_READ_ERR]	= { "phy_read_err", },
70 	[DSA_LOOP_PHY_WRITE_OK] = { "phy_write_ok", },
71 	[DSA_LOOP_PHY_WRITE_ERR] = { "phy_write_err", },
72 };
73 
74 static struct phy_device *phydevs[PHY_MAX_ADDR];
75 static struct mdio_device *switch_mdiodev;
76 
77 enum dsa_loop_devlink_resource_id {
78 	DSA_LOOP_DEVLINK_PARAM_ID_VTU,
79 };
80 
81 static u64 dsa_loop_devlink_vtu_get(void *priv)
82 {
83 	struct dsa_loop_priv *ps = priv;
84 	unsigned int i, count = 0;
85 	struct dsa_loop_vlan *vl;
86 
87 	for (i = 0; i < ARRAY_SIZE(ps->vlans); i++) {
88 		vl = &ps->vlans[i];
89 		if (vl->members)
90 			count++;
91 	}
92 
93 	return count;
94 }
95 
96 static int dsa_loop_setup_devlink_resources(struct dsa_switch *ds)
97 {
98 	struct devlink_resource_size_params size_params;
99 	struct dsa_loop_priv *ps = ds->priv;
100 	int err;
101 
102 	devlink_resource_size_params_init(&size_params, ARRAY_SIZE(ps->vlans),
103 					  ARRAY_SIZE(ps->vlans),
104 					  1, DEVLINK_RESOURCE_UNIT_ENTRY);
105 
106 	err = dsa_devlink_resource_register(ds, "VTU", ARRAY_SIZE(ps->vlans),
107 					    DSA_LOOP_DEVLINK_PARAM_ID_VTU,
108 					    DEVLINK_RESOURCE_ID_PARENT_TOP,
109 					    &size_params);
110 	if (err)
111 		goto out;
112 
113 	dsa_devlink_resource_occ_get_register(ds,
114 					      DSA_LOOP_DEVLINK_PARAM_ID_VTU,
115 					      dsa_loop_devlink_vtu_get, ps);
116 
117 	return 0;
118 
119 out:
120 	dsa_devlink_resources_unregister(ds);
121 	return err;
122 }
123 
124 static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds,
125 						   int port,
126 						   enum dsa_tag_protocol mp)
127 {
128 	dev_dbg(ds->dev, "%s: port: %d\n", __func__, port);
129 
130 	return DSA_TAG_PROTO_NONE;
131 }
132 
133 static int dsa_loop_setup(struct dsa_switch *ds)
134 {
135 	struct dsa_loop_priv *ps = ds->priv;
136 	unsigned int i;
137 
138 	for (i = 0; i < ds->num_ports; i++)
139 		memcpy(ps->ports[i].mib, dsa_loop_mibs,
140 		       sizeof(dsa_loop_mibs));
141 
142 	dev_dbg(ds->dev, "%s\n", __func__);
143 
144 	return dsa_loop_setup_devlink_resources(ds);
145 }
146 
147 static void dsa_loop_teardown(struct dsa_switch *ds)
148 {
149 	dsa_devlink_resources_unregister(ds);
150 }
151 
152 static int dsa_loop_get_sset_count(struct dsa_switch *ds, int port, int sset)
153 {
154 	if (sset != ETH_SS_STATS && sset != ETH_SS_PHY_STATS)
155 		return 0;
156 
157 	return __DSA_LOOP_CNT_MAX;
158 }
159 
160 static void dsa_loop_get_strings(struct dsa_switch *ds, int port,
161 				 u32 stringset, uint8_t *data)
162 {
163 	struct dsa_loop_priv *ps = ds->priv;
164 	unsigned int i;
165 
166 	if (stringset != ETH_SS_STATS && stringset != ETH_SS_PHY_STATS)
167 		return;
168 
169 	for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
170 		ethtool_puts(&data, ps->ports[port].mib[i].name);
171 }
172 
173 static void dsa_loop_get_ethtool_stats(struct dsa_switch *ds, int port,
174 				       uint64_t *data)
175 {
176 	struct dsa_loop_priv *ps = ds->priv;
177 	unsigned int i;
178 
179 	for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
180 		data[i] = ps->ports[port].mib[i].val;
181 }
182 
183 static int dsa_loop_phy_read(struct dsa_switch *ds, int port, int regnum)
184 {
185 	struct dsa_loop_priv *ps = ds->priv;
186 	struct mii_bus *bus = ps->bus;
187 	int ret;
188 
189 	ret = mdiobus_read_nested(bus, ps->port_base + port, regnum);
190 	if (ret < 0)
191 		ps->ports[port].mib[DSA_LOOP_PHY_READ_ERR].val++;
192 	else
193 		ps->ports[port].mib[DSA_LOOP_PHY_READ_OK].val++;
194 
195 	return ret;
196 }
197 
198 static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
199 			      int regnum, u16 value)
200 {
201 	struct dsa_loop_priv *ps = ds->priv;
202 	struct mii_bus *bus = ps->bus;
203 	int ret;
204 
205 	ret = mdiobus_write_nested(bus, ps->port_base + port, regnum, value);
206 	if (ret < 0)
207 		ps->ports[port].mib[DSA_LOOP_PHY_WRITE_ERR].val++;
208 	else
209 		ps->ports[port].mib[DSA_LOOP_PHY_WRITE_OK].val++;
210 
211 	return ret;
212 }
213 
214 static int dsa_loop_port_bridge_join(struct dsa_switch *ds, int port,
215 				     struct dsa_bridge bridge,
216 				     bool *tx_fwd_offload,
217 				     struct netlink_ext_ack *extack)
218 {
219 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
220 		__func__, port, bridge.dev->name);
221 
222 	return 0;
223 }
224 
225 static void dsa_loop_port_bridge_leave(struct dsa_switch *ds, int port,
226 				       struct dsa_bridge bridge)
227 {
228 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
229 		__func__, port, bridge.dev->name);
230 }
231 
232 static void dsa_loop_port_stp_state_set(struct dsa_switch *ds, int port,
233 					u8 state)
234 {
235 	dev_dbg(ds->dev, "%s: port: %d, state: %d\n",
236 		__func__, port, state);
237 }
238 
239 static int dsa_loop_port_vlan_filtering(struct dsa_switch *ds, int port,
240 					bool vlan_filtering,
241 					struct netlink_ext_ack *extack)
242 {
243 	dev_dbg(ds->dev, "%s: port: %d, vlan_filtering: %d\n",
244 		__func__, port, vlan_filtering);
245 
246 	return 0;
247 }
248 
249 static int dsa_loop_port_vlan_add(struct dsa_switch *ds, int port,
250 				  const struct switchdev_obj_port_vlan *vlan,
251 				  struct netlink_ext_ack *extack)
252 {
253 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
254 	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
255 	struct dsa_loop_priv *ps = ds->priv;
256 	struct mii_bus *bus = ps->bus;
257 	struct dsa_loop_vlan *vl;
258 
259 	if (vlan->vid >= ARRAY_SIZE(ps->vlans))
260 		return -ERANGE;
261 
262 	/* Just do a sleeping operation to make lockdep checks effective */
263 	mdiobus_read(bus, ps->port_base + port, MII_BMSR);
264 
265 	vl = &ps->vlans[vlan->vid];
266 
267 	vl->members |= BIT(port);
268 	if (untagged)
269 		vl->untagged |= BIT(port);
270 	else
271 		vl->untagged &= ~BIT(port);
272 
273 	dev_dbg(ds->dev, "%s: port: %d vlan: %d, %stagged, pvid: %d\n",
274 		__func__, port, vlan->vid, untagged ? "un" : "", pvid);
275 
276 	if (pvid)
277 		ps->ports[port].pvid = vlan->vid;
278 
279 	return 0;
280 }
281 
282 static int dsa_loop_port_vlan_del(struct dsa_switch *ds, int port,
283 				  const struct switchdev_obj_port_vlan *vlan)
284 {
285 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
286 	struct dsa_loop_priv *ps = ds->priv;
287 	u16 pvid = ps->ports[port].pvid;
288 	struct mii_bus *bus = ps->bus;
289 	struct dsa_loop_vlan *vl;
290 
291 	/* Just do a sleeping operation to make lockdep checks effective */
292 	mdiobus_read(bus, ps->port_base + port, MII_BMSR);
293 
294 	vl = &ps->vlans[vlan->vid];
295 
296 	vl->members &= ~BIT(port);
297 	if (untagged)
298 		vl->untagged &= ~BIT(port);
299 
300 	if (pvid == vlan->vid)
301 		pvid = 1;
302 
303 	dev_dbg(ds->dev, "%s: port: %d vlan: %d, %stagged, pvid: %d\n",
304 		__func__, port, vlan->vid, untagged ? "un" : "", pvid);
305 	ps->ports[port].pvid = pvid;
306 
307 	return 0;
308 }
309 
310 static int dsa_loop_port_change_mtu(struct dsa_switch *ds, int port,
311 				    int new_mtu)
312 {
313 	struct dsa_loop_priv *priv = ds->priv;
314 
315 	priv->ports[port].mtu = new_mtu;
316 
317 	return 0;
318 }
319 
320 static int dsa_loop_port_max_mtu(struct dsa_switch *ds, int port)
321 {
322 	return ETH_MAX_MTU;
323 }
324 
325 static void dsa_loop_phylink_get_caps(struct dsa_switch *dsa, int port,
326 				      struct phylink_config *config)
327 {
328 	bitmap_fill(config->supported_interfaces, PHY_INTERFACE_MODE_MAX);
329 	__clear_bit(PHY_INTERFACE_MODE_NA, config->supported_interfaces);
330 	config->mac_capabilities = ~0;
331 }
332 
333 static const struct dsa_switch_ops dsa_loop_driver = {
334 	.get_tag_protocol	= dsa_loop_get_protocol,
335 	.setup			= dsa_loop_setup,
336 	.teardown		= dsa_loop_teardown,
337 	.get_strings		= dsa_loop_get_strings,
338 	.get_ethtool_stats	= dsa_loop_get_ethtool_stats,
339 	.get_sset_count		= dsa_loop_get_sset_count,
340 	.get_ethtool_phy_stats	= dsa_loop_get_ethtool_stats,
341 	.phy_read		= dsa_loop_phy_read,
342 	.phy_write		= dsa_loop_phy_write,
343 	.port_bridge_join	= dsa_loop_port_bridge_join,
344 	.port_bridge_leave	= dsa_loop_port_bridge_leave,
345 	.port_stp_state_set	= dsa_loop_port_stp_state_set,
346 	.port_vlan_filtering	= dsa_loop_port_vlan_filtering,
347 	.port_vlan_add		= dsa_loop_port_vlan_add,
348 	.port_vlan_del		= dsa_loop_port_vlan_del,
349 	.port_change_mtu	= dsa_loop_port_change_mtu,
350 	.port_max_mtu		= dsa_loop_port_max_mtu,
351 	.phylink_get_caps	= dsa_loop_phylink_get_caps,
352 };
353 
354 static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
355 {
356 	struct dsa_loop_pdata *pdata = mdiodev->dev.platform_data;
357 	struct dsa_loop_priv *ps;
358 	struct dsa_switch *ds;
359 	int ret;
360 
361 	if (!pdata)
362 		return -ENODEV;
363 
364 	ds = devm_kzalloc(&mdiodev->dev, sizeof(*ds), GFP_KERNEL);
365 	if (!ds)
366 		return -ENOMEM;
367 
368 	ds->dev = &mdiodev->dev;
369 	ds->num_ports = DSA_LOOP_NUM_PORTS;
370 
371 	ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
372 	if (!ps)
373 		return -ENOMEM;
374 
375 	ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
376 	if (!ps->netdev)
377 		return -EPROBE_DEFER;
378 
379 	pdata->cd.netdev[DSA_LOOP_CPU_PORT] = &ps->netdev->dev;
380 
381 	ds->dev = &mdiodev->dev;
382 	ds->ops = &dsa_loop_driver;
383 	ds->priv = ps;
384 	ps->bus = mdiodev->bus;
385 
386 	dev_set_drvdata(&mdiodev->dev, ds);
387 
388 	ret = dsa_register_switch(ds);
389 	if (!ret)
390 		dev_info(&mdiodev->dev, "%s: 0x%0x\n",
391 			 pdata->name, pdata->enabled_ports);
392 
393 	return ret;
394 }
395 
396 static void dsa_loop_drv_remove(struct mdio_device *mdiodev)
397 {
398 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
399 	struct dsa_loop_priv *ps;
400 
401 	if (!ds)
402 		return;
403 
404 	ps = ds->priv;
405 
406 	dsa_unregister_switch(ds);
407 	dev_put(ps->netdev);
408 }
409 
410 static void dsa_loop_drv_shutdown(struct mdio_device *mdiodev)
411 {
412 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
413 
414 	if (!ds)
415 		return;
416 
417 	dsa_switch_shutdown(ds);
418 
419 	dev_set_drvdata(&mdiodev->dev, NULL);
420 }
421 
422 static struct mdio_driver dsa_loop_drv = {
423 	.mdiodrv.driver	= {
424 		.name	= "dsa-loop",
425 	},
426 	.probe	= dsa_loop_drv_probe,
427 	.remove	= dsa_loop_drv_remove,
428 	.shutdown = dsa_loop_drv_shutdown,
429 };
430 
431 static int dsa_loop_bus_match(struct device *dev,
432 			      const struct device_driver *drv)
433 {
434 	return drv == &dsa_loop_drv.mdiodrv.driver;
435 }
436 
437 static void dsa_loop_phydevs_unregister(void)
438 {
439 	for (int i = 0; i < NUM_FIXED_PHYS; i++) {
440 		if (!IS_ERR(phydevs[i]))
441 			fixed_phy_unregister(phydevs[i]);
442 	}
443 }
444 
445 static int __init dsa_loop_create_switch_mdiodev(void)
446 {
447 	static struct dsa_loop_pdata dsa_loop_pdata = {
448 		.cd = {
449 			.port_names[0] = "lan1",
450 			.port_names[1] = "lan2",
451 			.port_names[2] = "lan3",
452 			.port_names[3] = "lan4",
453 			.port_names[DSA_LOOP_CPU_PORT] = "cpu",
454 		},
455 		.name = "DSA mockup driver",
456 		.enabled_ports = 0x1f,
457 		.netdev = "eth0",
458 	};
459 	struct mii_bus *bus;
460 	int ret = -ENODEV;
461 
462 	bus = mdio_find_bus("fixed-0");
463 	if (WARN_ON(!bus))
464 		return ret;
465 
466 	switch_mdiodev = mdio_device_create(bus, 31);
467 	if (IS_ERR(switch_mdiodev))
468 		goto out;
469 
470 	switch_mdiodev->bus_match = dsa_loop_bus_match;
471 	switch_mdiodev->dev.platform_data = &dsa_loop_pdata;
472 
473 	ret = mdio_device_register(switch_mdiodev);
474 	if (ret)
475 		mdio_device_free(switch_mdiodev);
476 out:
477 	put_device(&bus->dev);
478 	return ret;
479 }
480 
481 static int __init dsa_loop_init(void)
482 {
483 	unsigned int i;
484 	int ret;
485 
486 	ret = dsa_loop_create_switch_mdiodev();
487 	if (ret)
488 		return ret;
489 
490 	for (i = 0; i < NUM_FIXED_PHYS; i++)
491 		phydevs[i] = fixed_phy_register_100fd();
492 
493 	ret = mdio_driver_register(&dsa_loop_drv);
494 	if (ret) {
495 		dsa_loop_phydevs_unregister();
496 		mdio_device_remove(switch_mdiodev);
497 		mdio_device_free(switch_mdiodev);
498 	}
499 
500 	return ret;
501 }
502 module_init(dsa_loop_init);
503 
504 static void __exit dsa_loop_exit(void)
505 {
506 	mdio_driver_unregister(&dsa_loop_drv);
507 	dsa_loop_phydevs_unregister();
508 	mdio_device_remove(switch_mdiodev);
509 	mdio_device_free(switch_mdiodev);
510 }
511 module_exit(dsa_loop_exit);
512 
513 MODULE_LICENSE("GPL");
514 MODULE_AUTHOR("Florian Fainelli");
515 MODULE_DESCRIPTION("DSA loopback driver");
516