xref: /kernel/linux/linux-5.10/net/dsa/dsa.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/dsa/dsa.c - Hardware switch handling
4 * Copyright (c) 2008-2009 Marvell Semiconductor
5 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
6 */
7
8#include <linux/device.h>
9#include <linux/list.h>
10#include <linux/platform_device.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13#include <linux/notifier.h>
14#include <linux/of.h>
15#include <linux/of_mdio.h>
16#include <linux/of_platform.h>
17#include <linux/of_net.h>
18#include <linux/netdevice.h>
19#include <linux/sysfs.h>
20#include <linux/phy_fixed.h>
21#include <linux/ptp_classify.h>
22#include <linux/etherdevice.h>
23
24#include "dsa_priv.h"
25
26static LIST_HEAD(dsa_tag_drivers_list);
27static DEFINE_MUTEX(dsa_tag_drivers_lock);
28
29static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
30					    struct net_device *dev)
31{
32	/* Just return the original SKB */
33	return skb;
34}
35
36static const struct dsa_device_ops none_ops = {
37	.name	= "none",
38	.proto	= DSA_TAG_PROTO_NONE,
39	.xmit	= dsa_slave_notag_xmit,
40	.rcv	= NULL,
41};
42
43DSA_TAG_DRIVER(none_ops);
44
45static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
46				    struct module *owner)
47{
48	dsa_tag_driver->owner = owner;
49
50	mutex_lock(&dsa_tag_drivers_lock);
51	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
52	mutex_unlock(&dsa_tag_drivers_lock);
53}
54
55void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
56			      unsigned int count, struct module *owner)
57{
58	unsigned int i;
59
60	for (i = 0; i < count; i++)
61		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
62}
63
64static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
65{
66	mutex_lock(&dsa_tag_drivers_lock);
67	list_del(&dsa_tag_driver->list);
68	mutex_unlock(&dsa_tag_drivers_lock);
69}
70EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
71
72void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
73				unsigned int count)
74{
75	unsigned int i;
76
77	for (i = 0; i < count; i++)
78		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
79}
80EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
81
82const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
83{
84	return ops->name;
85};
86
87const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
88{
89	struct dsa_tag_driver *dsa_tag_driver;
90	const struct dsa_device_ops *ops;
91	bool found = false;
92
93	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
94
95	mutex_lock(&dsa_tag_drivers_lock);
96	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
97		ops = dsa_tag_driver->ops;
98		if (ops->proto == tag_protocol) {
99			found = true;
100			break;
101		}
102	}
103
104	if (found) {
105		if (!try_module_get(dsa_tag_driver->owner))
106			ops = ERR_PTR(-ENOPROTOOPT);
107	} else {
108		ops = ERR_PTR(-ENOPROTOOPT);
109	}
110
111	mutex_unlock(&dsa_tag_drivers_lock);
112
113	return ops;
114}
115
116void dsa_tag_driver_put(const struct dsa_device_ops *ops)
117{
118	struct dsa_tag_driver *dsa_tag_driver;
119
120	mutex_lock(&dsa_tag_drivers_lock);
121	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
122		if (dsa_tag_driver->ops == ops) {
123			module_put(dsa_tag_driver->owner);
124			break;
125		}
126	}
127	mutex_unlock(&dsa_tag_drivers_lock);
128}
129
130static int dev_is_class(struct device *dev, void *class)
131{
132	if (dev->class != NULL && !strcmp(dev->class->name, class))
133		return 1;
134
135	return 0;
136}
137
138static struct device *dev_find_class(struct device *parent, char *class)
139{
140	if (dev_is_class(parent, class)) {
141		get_device(parent);
142		return parent;
143	}
144
145	return device_find_child(parent, class, dev_is_class);
146}
147
148struct net_device *dsa_dev_to_net_device(struct device *dev)
149{
150	struct device *d;
151
152	d = dev_find_class(dev, "net");
153	if (d != NULL) {
154		struct net_device *nd;
155
156		nd = to_net_dev(d);
157		dev_hold(nd);
158		put_device(d);
159
160		return nd;
161	}
162
163	return NULL;
164}
165EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
166
167/* Determine if we should defer delivery of skb until we have a rx timestamp.
168 *
169 * Called from dsa_switch_rcv. For now, this will only work if tagging is
170 * enabled on the switch. Normally the MAC driver would retrieve the hardware
171 * timestamp when it reads the packet out of the hardware. However in a DSA
172 * switch, the DSA driver owning the interface to which the packet is
173 * delivered is never notified unless we do so here.
174 */
175static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
176				       struct sk_buff *skb)
177{
178	struct dsa_switch *ds = p->dp->ds;
179	unsigned int type;
180
181	if (skb_headroom(skb) < ETH_HLEN)
182		return false;
183
184	__skb_push(skb, ETH_HLEN);
185
186	type = ptp_classify_raw(skb);
187
188	__skb_pull(skb, ETH_HLEN);
189
190	if (type == PTP_CLASS_NONE)
191		return false;
192
193	if (likely(ds->ops->port_rxtstamp))
194		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
195
196	return false;
197}
198
199static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
200			  struct packet_type *pt, struct net_device *unused)
201{
202	struct dsa_port *cpu_dp = dev->dsa_ptr;
203	struct sk_buff *nskb = NULL;
204	struct pcpu_sw_netstats *s;
205	struct dsa_slave_priv *p;
206
207	if (unlikely(!cpu_dp)) {
208		kfree_skb(skb);
209		return 0;
210	}
211
212	skb = skb_unshare(skb, GFP_ATOMIC);
213	if (!skb)
214		return 0;
215
216	nskb = cpu_dp->rcv(skb, dev, pt);
217	if (!nskb) {
218		kfree_skb(skb);
219		return 0;
220	}
221
222	skb = nskb;
223	p = netdev_priv(skb->dev);
224	skb_push(skb, ETH_HLEN);
225	skb->pkt_type = PACKET_HOST;
226	skb->protocol = eth_type_trans(skb, skb->dev);
227
228	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
229		nskb = dsa_untag_bridge_pvid(skb);
230		if (!nskb) {
231			kfree_skb(skb);
232			return 0;
233		}
234		skb = nskb;
235	}
236
237	s = this_cpu_ptr(p->stats64);
238	u64_stats_update_begin(&s->syncp);
239	s->rx_packets++;
240	s->rx_bytes += skb->len;
241	u64_stats_update_end(&s->syncp);
242
243	if (dsa_skb_defer_rx_timestamp(p, skb))
244		return 0;
245
246	gro_cells_receive(&p->gcells, skb);
247
248	return 0;
249}
250
251#ifdef CONFIG_PM_SLEEP
252static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
253{
254	const struct dsa_port *dp = dsa_to_port(ds, p);
255
256	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
257}
258
259int dsa_switch_suspend(struct dsa_switch *ds)
260{
261	int i, ret = 0;
262
263	/* Suspend slave network devices */
264	for (i = 0; i < ds->num_ports; i++) {
265		if (!dsa_is_port_initialized(ds, i))
266			continue;
267
268		ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
269		if (ret)
270			return ret;
271	}
272
273	if (ds->ops->suspend)
274		ret = ds->ops->suspend(ds);
275
276	return ret;
277}
278EXPORT_SYMBOL_GPL(dsa_switch_suspend);
279
280int dsa_switch_resume(struct dsa_switch *ds)
281{
282	int i, ret = 0;
283
284	if (ds->ops->resume)
285		ret = ds->ops->resume(ds);
286
287	if (ret)
288		return ret;
289
290	/* Resume slave network devices */
291	for (i = 0; i < ds->num_ports; i++) {
292		if (!dsa_is_port_initialized(ds, i))
293			continue;
294
295		ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
296		if (ret)
297			return ret;
298	}
299
300	return 0;
301}
302EXPORT_SYMBOL_GPL(dsa_switch_resume);
303#endif
304
305static struct packet_type dsa_pack_type __read_mostly = {
306	.type	= cpu_to_be16(ETH_P_XDSA),
307	.func	= dsa_switch_rcv,
308};
309
310static struct workqueue_struct *dsa_owq;
311
312bool dsa_schedule_work(struct work_struct *work)
313{
314	return queue_work(dsa_owq, work);
315}
316
317static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
318
319int register_dsa_notifier(struct notifier_block *nb)
320{
321	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
322}
323EXPORT_SYMBOL_GPL(register_dsa_notifier);
324
325int unregister_dsa_notifier(struct notifier_block *nb)
326{
327	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
328}
329EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
330
331int call_dsa_notifiers(unsigned long val, struct net_device *dev,
332		       struct dsa_notifier_info *info)
333{
334	info->dev = dev;
335	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
336}
337EXPORT_SYMBOL_GPL(call_dsa_notifiers);
338
339int dsa_devlink_param_get(struct devlink *dl, u32 id,
340			  struct devlink_param_gset_ctx *ctx)
341{
342	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
343
344	if (!ds->ops->devlink_param_get)
345		return -EOPNOTSUPP;
346
347	return ds->ops->devlink_param_get(ds, id, ctx);
348}
349EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
350
351int dsa_devlink_param_set(struct devlink *dl, u32 id,
352			  struct devlink_param_gset_ctx *ctx)
353{
354	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
355
356	if (!ds->ops->devlink_param_set)
357		return -EOPNOTSUPP;
358
359	return ds->ops->devlink_param_set(ds, id, ctx);
360}
361EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
362
363int dsa_devlink_params_register(struct dsa_switch *ds,
364				const struct devlink_param *params,
365				size_t params_count)
366{
367	return devlink_params_register(ds->devlink, params, params_count);
368}
369EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
370
371void dsa_devlink_params_unregister(struct dsa_switch *ds,
372				   const struct devlink_param *params,
373				   size_t params_count)
374{
375	devlink_params_unregister(ds->devlink, params, params_count);
376}
377EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
378
379int dsa_devlink_resource_register(struct dsa_switch *ds,
380				  const char *resource_name,
381				  u64 resource_size,
382				  u64 resource_id,
383				  u64 parent_resource_id,
384				  const struct devlink_resource_size_params *size_params)
385{
386	return devlink_resource_register(ds->devlink, resource_name,
387					 resource_size, resource_id,
388					 parent_resource_id,
389					 size_params);
390}
391EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
392
393void dsa_devlink_resources_unregister(struct dsa_switch *ds)
394{
395	devlink_resources_unregister(ds->devlink, NULL);
396}
397EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
398
399void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
400					   u64 resource_id,
401					   devlink_resource_occ_get_t *occ_get,
402					   void *occ_get_priv)
403{
404	return devlink_resource_occ_get_register(ds->devlink, resource_id,
405						 occ_get, occ_get_priv);
406}
407EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
408
409void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
410					     u64 resource_id)
411{
412	devlink_resource_occ_get_unregister(ds->devlink, resource_id);
413}
414EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
415
416struct devlink_region *
417dsa_devlink_region_create(struct dsa_switch *ds,
418			  const struct devlink_region_ops *ops,
419			  u32 region_max_snapshots, u64 region_size)
420{
421	return devlink_region_create(ds->devlink, ops, region_max_snapshots,
422				     region_size);
423}
424EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
425
426struct devlink_region *
427dsa_devlink_port_region_create(struct dsa_switch *ds,
428			       int port,
429			       const struct devlink_port_region_ops *ops,
430			       u32 region_max_snapshots, u64 region_size)
431{
432	struct dsa_port *dp = dsa_to_port(ds, port);
433
434	return devlink_port_region_create(&dp->devlink_port, ops,
435					  region_max_snapshots,
436					  region_size);
437}
438EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
439
440void dsa_devlink_region_destroy(struct devlink_region *region)
441{
442	devlink_region_destroy(region);
443}
444EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
445
446struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
447{
448	if (!netdev || !dsa_slave_dev_check(netdev))
449		return ERR_PTR(-ENODEV);
450
451	return dsa_slave_to_port(netdev);
452}
453EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
454
455static int __init dsa_init_module(void)
456{
457	int rc;
458
459	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
460					  WQ_MEM_RECLAIM);
461	if (!dsa_owq)
462		return -ENOMEM;
463
464	rc = dsa_slave_register_notifier();
465	if (rc)
466		goto register_notifier_fail;
467
468	dev_add_pack(&dsa_pack_type);
469
470	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
471				THIS_MODULE);
472
473	return 0;
474
475register_notifier_fail:
476	destroy_workqueue(dsa_owq);
477
478	return rc;
479}
480module_init(dsa_init_module);
481
482static void __exit dsa_cleanup_module(void)
483{
484	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
485
486	dsa_slave_unregister_notifier();
487	dev_remove_pack(&dsa_pack_type);
488	destroy_workqueue(dsa_owq);
489}
490module_exit(dsa_cleanup_module);
491
492MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
493MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
494MODULE_LICENSE("GPL");
495MODULE_ALIAS("platform:dsa");
496