xref: /linux/drivers/net/dsa/dsa_loop.c (revision 4b99990cdf9560e8a071640baf19f312e6ae02f4)
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_NONE,  /* DEVLINK_RESOURCE_ID_PARENT_TOP */
79 	DSA_LOOP_DEVLINK_PARAM_ID_VTU,
80 };
81 
82 static u64 dsa_loop_devlink_vtu_get(void *priv)
83 {
84 	struct dsa_loop_priv *ps = priv;
85 	unsigned int i, count = 0;
86 	struct dsa_loop_vlan *vl;
87 
88 	for (i = 0; i < ARRAY_SIZE(ps->vlans); i++) {
89 		vl = &ps->vlans[i];
90 		if (vl->members)
91 			count++;
92 	}
93 
94 	return count;
95 }
96 
97 static int dsa_loop_setup_devlink_resources(struct dsa_switch *ds)
98 {
99 	struct devlink_resource_size_params size_params;
100 	struct dsa_loop_priv *ps = ds->priv;
101 	int err;
102 
103 	devlink_resource_size_params_init(&size_params, ARRAY_SIZE(ps->vlans),
104 					  ARRAY_SIZE(ps->vlans),
105 					  1, DEVLINK_RESOURCE_UNIT_ENTRY);
106 
107 	err = dsa_devlink_resource_register(ds, "VTU", ARRAY_SIZE(ps->vlans),
108 					    DSA_LOOP_DEVLINK_PARAM_ID_VTU,
109 					    DEVLINK_RESOURCE_ID_PARENT_TOP,
110 					    &size_params);
111 	if (err)
112 		goto out;
113 
114 	dsa_devlink_resource_occ_get_register(ds,
115 					      DSA_LOOP_DEVLINK_PARAM_ID_VTU,
116 					      dsa_loop_devlink_vtu_get, ps);
117 
118 	return 0;
119 
120 out:
121 	dsa_devlink_resources_unregister(ds);
122 	return err;
123 }
124 
125 static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds,
126 						   int port,
127 						   enum dsa_tag_protocol mp)
128 {
129 	dev_dbg(ds->dev, "%s: port: %d\n", __func__, port);
130 
131 	return DSA_TAG_PROTO_NONE;
132 }
133 
134 static int dsa_loop_setup(struct dsa_switch *ds)
135 {
136 	struct dsa_loop_priv *ps = ds->priv;
137 	unsigned int i;
138 
139 	for (i = 0; i < ds->num_ports; i++)
140 		memcpy(ps->ports[i].mib, dsa_loop_mibs,
141 		       sizeof(dsa_loop_mibs));
142 
143 	dev_dbg(ds->dev, "%s\n", __func__);
144 
145 	return dsa_loop_setup_devlink_resources(ds);
146 }
147 
148 static void dsa_loop_teardown(struct dsa_switch *ds)
149 {
150 	dsa_devlink_resources_unregister(ds);
151 }
152 
153 static int dsa_loop_get_sset_count(struct dsa_switch *ds, int port, int sset)
154 {
155 	if (sset != ETH_SS_STATS && sset != ETH_SS_PHY_STATS)
156 		return 0;
157 
158 	return __DSA_LOOP_CNT_MAX;
159 }
160 
161 static void dsa_loop_get_strings(struct dsa_switch *ds, int port,
162 				 u32 stringset, uint8_t *data)
163 {
164 	struct dsa_loop_priv *ps = ds->priv;
165 	unsigned int i;
166 
167 	if (stringset != ETH_SS_STATS && stringset != ETH_SS_PHY_STATS)
168 		return;
169 
170 	for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
171 		ethtool_puts(&data, ps->ports[port].mib[i].name);
172 }
173 
174 static void dsa_loop_get_ethtool_stats(struct dsa_switch *ds, int port,
175 				       uint64_t *data)
176 {
177 	struct dsa_loop_priv *ps = ds->priv;
178 	unsigned int i;
179 
180 	for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
181 		data[i] = ps->ports[port].mib[i].val;
182 }
183 
184 static int dsa_loop_phy_read(struct dsa_switch *ds, int port, int regnum)
185 {
186 	struct dsa_loop_priv *ps = ds->priv;
187 	struct mii_bus *bus = ps->bus;
188 	int ret;
189 
190 	ret = mdiobus_read_nested(bus, ps->port_base + port, regnum);
191 	if (ret < 0)
192 		ps->ports[port].mib[DSA_LOOP_PHY_READ_ERR].val++;
193 	else
194 		ps->ports[port].mib[DSA_LOOP_PHY_READ_OK].val++;
195 
196 	return ret;
197 }
198 
199 static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
200 			      int regnum, u16 value)
201 {
202 	struct dsa_loop_priv *ps = ds->priv;
203 	struct mii_bus *bus = ps->bus;
204 	int ret;
205 
206 	ret = mdiobus_write_nested(bus, ps->port_base + port, regnum, value);
207 	if (ret < 0)
208 		ps->ports[port].mib[DSA_LOOP_PHY_WRITE_ERR].val++;
209 	else
210 		ps->ports[port].mib[DSA_LOOP_PHY_WRITE_OK].val++;
211 
212 	return ret;
213 }
214 
215 static int dsa_loop_port_bridge_join(struct dsa_switch *ds, int port,
216 				     struct dsa_bridge bridge,
217 				     bool *tx_fwd_offload,
218 				     struct netlink_ext_ack *extack)
219 {
220 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
221 		__func__, port, bridge.dev->name);
222 
223 	return 0;
224 }
225 
226 static void dsa_loop_port_bridge_leave(struct dsa_switch *ds, int port,
227 				       struct dsa_bridge bridge)
228 {
229 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
230 		__func__, port, bridge.dev->name);
231 }
232 
233 static void dsa_loop_port_stp_state_set(struct dsa_switch *ds, int port,
234 					u8 state)
235 {
236 	dev_dbg(ds->dev, "%s: port: %d, state: %d\n",
237 		__func__, port, state);
238 }
239 
240 static int dsa_loop_port_vlan_filtering(struct dsa_switch *ds, int port,
241 					bool vlan_filtering,
242 					struct netlink_ext_ack *extack)
243 {
244 	dev_dbg(ds->dev, "%s: port: %d, vlan_filtering: %d\n",
245 		__func__, port, vlan_filtering);
246 
247 	return 0;
248 }
249 
250 static int dsa_loop_port_vlan_add(struct dsa_switch *ds, int port,
251 				  const struct switchdev_obj_port_vlan *vlan,
252 				  struct netlink_ext_ack *extack)
253 {
254 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
255 	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
256 	struct dsa_loop_priv *ps = ds->priv;
257 	struct mii_bus *bus = ps->bus;
258 	struct dsa_loop_vlan *vl;
259 
260 	if (vlan->vid >= ARRAY_SIZE(ps->vlans))
261 		return -ERANGE;
262 
263 	/* Just do a sleeping operation to make lockdep checks effective */
264 	mdiobus_read(bus, ps->port_base + port, MII_BMSR);
265 
266 	vl = &ps->vlans[vlan->vid];
267 
268 	vl->members |= BIT(port);
269 	if (untagged)
270 		vl->untagged |= BIT(port);
271 	else
272 		vl->untagged &= ~BIT(port);
273 
274 	dev_dbg(ds->dev, "%s: port: %d vlan: %d, %stagged, pvid: %d\n",
275 		__func__, port, vlan->vid, untagged ? "un" : "", pvid);
276 
277 	if (pvid)
278 		ps->ports[port].pvid = vlan->vid;
279 
280 	return 0;
281 }
282 
283 static int dsa_loop_port_vlan_del(struct dsa_switch *ds, int port,
284 				  const struct switchdev_obj_port_vlan *vlan)
285 {
286 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
287 	struct dsa_loop_priv *ps = ds->priv;
288 	u16 pvid = ps->ports[port].pvid;
289 	struct mii_bus *bus = ps->bus;
290 	struct dsa_loop_vlan *vl;
291 
292 	/* Just do a sleeping operation to make lockdep checks effective */
293 	mdiobus_read(bus, ps->port_base + port, MII_BMSR);
294 
295 	vl = &ps->vlans[vlan->vid];
296 
297 	vl->members &= ~BIT(port);
298 	if (untagged)
299 		vl->untagged &= ~BIT(port);
300 
301 	if (pvid == vlan->vid)
302 		pvid = 1;
303 
304 	dev_dbg(ds->dev, "%s: port: %d vlan: %d, %stagged, pvid: %d\n",
305 		__func__, port, vlan->vid, untagged ? "un" : "", pvid);
306 	ps->ports[port].pvid = pvid;
307 
308 	return 0;
309 }
310 
311 static int dsa_loop_port_change_mtu(struct dsa_switch *ds, int port,
312 				    int new_mtu)
313 {
314 	struct dsa_loop_priv *priv = ds->priv;
315 
316 	priv->ports[port].mtu = new_mtu;
317 
318 	return 0;
319 }
320 
321 static int dsa_loop_port_max_mtu(struct dsa_switch *ds, int port)
322 {
323 	return ETH_MAX_MTU;
324 }
325 
326 static void dsa_loop_phylink_get_caps(struct dsa_switch *dsa, int port,
327 				      struct phylink_config *config)
328 {
329 	bitmap_fill(config->supported_interfaces, PHY_INTERFACE_MODE_MAX);
330 	__clear_bit(PHY_INTERFACE_MODE_NA, config->supported_interfaces);
331 	config->mac_capabilities = ~0;
332 }
333 
334 static const struct dsa_switch_ops dsa_loop_driver = {
335 	.get_tag_protocol	= dsa_loop_get_protocol,
336 	.setup			= dsa_loop_setup,
337 	.teardown		= dsa_loop_teardown,
338 	.get_strings		= dsa_loop_get_strings,
339 	.get_ethtool_stats	= dsa_loop_get_ethtool_stats,
340 	.get_sset_count		= dsa_loop_get_sset_count,
341 	.get_ethtool_phy_stats	= dsa_loop_get_ethtool_stats,
342 	.phy_read		= dsa_loop_phy_read,
343 	.phy_write		= dsa_loop_phy_write,
344 	.port_bridge_join	= dsa_loop_port_bridge_join,
345 	.port_bridge_leave	= dsa_loop_port_bridge_leave,
346 	.port_stp_state_set	= dsa_loop_port_stp_state_set,
347 	.port_vlan_filtering	= dsa_loop_port_vlan_filtering,
348 	.port_vlan_add		= dsa_loop_port_vlan_add,
349 	.port_vlan_del		= dsa_loop_port_vlan_del,
350 	.port_change_mtu	= dsa_loop_port_change_mtu,
351 	.port_max_mtu		= dsa_loop_port_max_mtu,
352 	.phylink_get_caps	= dsa_loop_phylink_get_caps,
353 };
354 
355 static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
356 {
357 	struct dsa_loop_pdata *pdata = mdiodev->dev.platform_data;
358 	struct dsa_loop_priv *ps;
359 	struct dsa_switch *ds;
360 	int ret;
361 
362 	if (!pdata)
363 		return -ENODEV;
364 
365 	ds = devm_kzalloc(&mdiodev->dev, sizeof(*ds), GFP_KERNEL);
366 	if (!ds)
367 		return -ENOMEM;
368 
369 	ds->dev = &mdiodev->dev;
370 	ds->num_ports = DSA_LOOP_NUM_PORTS;
371 
372 	ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
373 	if (!ps)
374 		return -ENOMEM;
375 
376 	ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
377 	if (!ps->netdev)
378 		return -EPROBE_DEFER;
379 
380 	pdata->cd.netdev[DSA_LOOP_CPU_PORT] = &ps->netdev->dev;
381 
382 	ds->dev = &mdiodev->dev;
383 	ds->ops = &dsa_loop_driver;
384 	ds->priv = ps;
385 	ps->bus = mdiodev->bus;
386 
387 	dev_set_drvdata(&mdiodev->dev, ds);
388 
389 	ret = dsa_register_switch(ds);
390 	if (!ret)
391 		dev_info(&mdiodev->dev, "%s: 0x%0x\n",
392 			 pdata->name, pdata->enabled_ports);
393 
394 	return ret;
395 }
396 
397 static void dsa_loop_drv_remove(struct mdio_device *mdiodev)
398 {
399 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
400 	struct dsa_loop_priv *ps;
401 
402 	if (!ds)
403 		return;
404 
405 	ps = ds->priv;
406 
407 	dsa_unregister_switch(ds);
408 	dev_put(ps->netdev);
409 }
410 
411 static void dsa_loop_drv_shutdown(struct mdio_device *mdiodev)
412 {
413 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
414 
415 	if (!ds)
416 		return;
417 
418 	dsa_switch_shutdown(ds);
419 
420 	dev_set_drvdata(&mdiodev->dev, NULL);
421 }
422 
423 static struct mdio_driver dsa_loop_drv = {
424 	.mdiodrv.driver	= {
425 		.name	= "dsa-loop",
426 	},
427 	.probe	= dsa_loop_drv_probe,
428 	.remove	= dsa_loop_drv_remove,
429 	.shutdown = dsa_loop_drv_shutdown,
430 };
431 
432 static int dsa_loop_bus_match(struct device *dev,
433 			      const struct device_driver *drv)
434 {
435 	return drv == &dsa_loop_drv.mdiodrv.driver;
436 }
437 
438 static void dsa_loop_phydevs_unregister(void)
439 {
440 	for (int i = 0; i < NUM_FIXED_PHYS; i++) {
441 		if (!IS_ERR(phydevs[i]))
442 			fixed_phy_unregister(phydevs[i]);
443 	}
444 }
445 
446 static int __init dsa_loop_create_switch_mdiodev(void)
447 {
448 	static struct dsa_loop_pdata dsa_loop_pdata = {
449 		.cd = {
450 			.port_names[0] = "lan1",
451 			.port_names[1] = "lan2",
452 			.port_names[2] = "lan3",
453 			.port_names[3] = "lan4",
454 			.port_names[DSA_LOOP_CPU_PORT] = "cpu",
455 		},
456 		.name = "DSA mockup driver",
457 		.enabled_ports = 0x1f,
458 		.netdev = "eth0",
459 	};
460 	struct mii_bus *bus;
461 	int ret = -ENODEV;
462 
463 	bus = mdio_find_bus("fixed-0");
464 	if (WARN_ON(!bus))
465 		return ret;
466 
467 	switch_mdiodev = mdio_device_create(bus, 31);
468 	if (IS_ERR(switch_mdiodev))
469 		goto out;
470 
471 	switch_mdiodev->bus_match = dsa_loop_bus_match;
472 	switch_mdiodev->dev.platform_data = &dsa_loop_pdata;
473 
474 	ret = mdio_device_register(switch_mdiodev);
475 	if (ret)
476 		mdio_device_free(switch_mdiodev);
477 out:
478 	put_device(&bus->dev);
479 	return ret;
480 }
481 
482 static int __init dsa_loop_init(void)
483 {
484 	unsigned int i;
485 	int ret;
486 
487 	ret = dsa_loop_create_switch_mdiodev();
488 	if (ret)
489 		return ret;
490 
491 	for (i = 0; i < NUM_FIXED_PHYS; i++)
492 		phydevs[i] = fixed_phy_register_100fd();
493 
494 	ret = mdio_driver_register(&dsa_loop_drv);
495 	if (ret) {
496 		dsa_loop_phydevs_unregister();
497 		mdio_device_remove(switch_mdiodev);
498 		mdio_device_free(switch_mdiodev);
499 	}
500 
501 	return ret;
502 }
503 module_init(dsa_loop_init);
504 
505 static void __exit dsa_loop_exit(void)
506 {
507 	mdio_driver_unregister(&dsa_loop_drv);
508 	dsa_loop_phydevs_unregister();
509 	mdio_device_remove(switch_mdiodev);
510 	mdio_device_free(switch_mdiodev);
511 }
512 module_exit(dsa_loop_exit);
513 
514 MODULE_LICENSE("GPL");
515 MODULE_AUTHOR("Florian Fainelli");
516 MODULE_DESCRIPTION("DSA loopback driver");
517