1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
4 * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
5 */
6
7#include <net/genetlink.h>
8#define CREATE_TRACE_POINTS
9#include <trace/events/devlink.h>
10
11#include "devl_internal.h"
12
13EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwmsg);
14EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwerr);
15EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_trap_report);
16
17DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
18
19static struct devlink *devlinks_xa_get(unsigned long index)
20{
21 struct devlink *devlink;
22
23 rcu_read_lock();
24 devlink = xa_find(xa: &devlinks, index: &index, max: index, DEVLINK_REGISTERED);
25 if (!devlink || !devlink_try_get(devlink))
26 devlink = NULL;
27 rcu_read_unlock();
28 return devlink;
29}
30
31/* devlink_rels xarray contains 1:1 relationships between
32 * devlink object and related nested devlink instance.
33 * The xarray index is used to get the nested object from
34 * the nested-in object code.
35 */
36static DEFINE_XARRAY_FLAGS(devlink_rels, XA_FLAGS_ALLOC1);
37
38#define DEVLINK_REL_IN_USE XA_MARK_0
39
40struct devlink_rel {
41 u32 index;
42 refcount_t refcount;
43 u32 devlink_index;
44 struct {
45 u32 devlink_index;
46 u32 obj_index;
47 devlink_rel_notify_cb_t *notify_cb;
48 devlink_rel_cleanup_cb_t *cleanup_cb;
49 struct delayed_work notify_work;
50 } nested_in;
51};
52
53static void devlink_rel_free(struct devlink_rel *rel)
54{
55 xa_erase(&devlink_rels, index: rel->index);
56 kfree(objp: rel);
57}
58
59static void __devlink_rel_get(struct devlink_rel *rel)
60{
61 refcount_inc(r: &rel->refcount);
62}
63
64static void __devlink_rel_put(struct devlink_rel *rel)
65{
66 if (refcount_dec_and_test(r: &rel->refcount))
67 devlink_rel_free(rel);
68}
69
70static void devlink_rel_nested_in_notify_work(struct work_struct *work)
71{
72 struct devlink_rel *rel = container_of(work, struct devlink_rel,
73 nested_in.notify_work.work);
74 struct devlink *devlink;
75
76 devlink = devlinks_xa_get(index: rel->nested_in.devlink_index);
77 if (!devlink)
78 goto rel_put;
79 if (!devl_trylock(devlink)) {
80 devlink_put(devlink);
81 goto reschedule_work;
82 }
83 if (!devl_is_registered(devlink)) {
84 devl_unlock(devlink);
85 devlink_put(devlink);
86 goto rel_put;
87 }
88 if (!xa_get_mark(&devlink_rels, index: rel->index, DEVLINK_REL_IN_USE))
89 rel->nested_in.cleanup_cb(devlink, rel->nested_in.obj_index, rel->index);
90 rel->nested_in.notify_cb(devlink, rel->nested_in.obj_index);
91 devl_unlock(devlink);
92 devlink_put(devlink);
93
94rel_put:
95 __devlink_rel_put(rel);
96 return;
97
98reschedule_work:
99 schedule_delayed_work(dwork: &rel->nested_in.notify_work, delay: 1);
100}
101
102static void devlink_rel_nested_in_notify_work_schedule(struct devlink_rel *rel)
103{
104 __devlink_rel_get(rel);
105 schedule_delayed_work(dwork: &rel->nested_in.notify_work, delay: 0);
106}
107
108static struct devlink_rel *devlink_rel_alloc(void)
109{
110 struct devlink_rel *rel;
111 static u32 next;
112 int err;
113
114 rel = kzalloc(sizeof(*rel), GFP_KERNEL);
115 if (!rel)
116 return ERR_PTR(error: -ENOMEM);
117
118 err = xa_alloc_cyclic(xa: &devlink_rels, id: &rel->index, entry: rel,
119 xa_limit_32b, next: &next, GFP_KERNEL);
120 if (err < 0) {
121 kfree(objp: rel);
122 return ERR_PTR(error: err);
123 }
124
125 refcount_set(r: &rel->refcount, n: 1);
126 INIT_DELAYED_WORK(&rel->nested_in.notify_work,
127 &devlink_rel_nested_in_notify_work);
128 return rel;
129}
130
131static void devlink_rel_put(struct devlink *devlink)
132{
133 struct devlink_rel *rel = devlink->rel;
134
135 if (!rel)
136 return;
137 xa_clear_mark(&devlink_rels, index: rel->index, DEVLINK_REL_IN_USE);
138 devlink_rel_nested_in_notify_work_schedule(rel);
139 __devlink_rel_put(rel);
140 devlink->rel = NULL;
141}
142
143void devlink_rel_nested_in_clear(u32 rel_index)
144{
145 xa_clear_mark(&devlink_rels, index: rel_index, DEVLINK_REL_IN_USE);
146}
147
148int devlink_rel_nested_in_add(u32 *rel_index, u32 devlink_index,
149 u32 obj_index, devlink_rel_notify_cb_t *notify_cb,
150 devlink_rel_cleanup_cb_t *cleanup_cb,
151 struct devlink *devlink)
152{
153 struct devlink_rel *rel = devlink_rel_alloc();
154
155 ASSERT_DEVLINK_NOT_REGISTERED(devlink);
156
157 if (IS_ERR(ptr: rel))
158 return PTR_ERR(ptr: rel);
159
160 rel->devlink_index = devlink->index;
161 rel->nested_in.devlink_index = devlink_index;
162 rel->nested_in.obj_index = obj_index;
163 rel->nested_in.notify_cb = notify_cb;
164 rel->nested_in.cleanup_cb = cleanup_cb;
165 *rel_index = rel->index;
166 xa_set_mark(&devlink_rels, index: rel->index, DEVLINK_REL_IN_USE);
167 devlink->rel = rel;
168 return 0;
169}
170
171/**
172 * devlink_rel_nested_in_notify - Notify the object this devlink
173 * instance is nested in.
174 * @devlink: devlink
175 *
176 * This is called upon network namespace change of devlink instance.
177 * In case this devlink instance is nested in another devlink object,
178 * a notification of a change of this object should be sent
179 * over netlink. The parent devlink instance lock needs to be
180 * taken during the notification preparation.
181 * However, since the devlink lock of nested instance is held here,
182 * we would end with wrong devlink instance lock ordering and
183 * deadlock. Therefore the work is utilized to avoid that.
184 */
185void devlink_rel_nested_in_notify(struct devlink *devlink)
186{
187 struct devlink_rel *rel = devlink->rel;
188
189 if (!rel)
190 return;
191 devlink_rel_nested_in_notify_work_schedule(rel);
192}
193
194static struct devlink_rel *devlink_rel_find(unsigned long rel_index)
195{
196 return xa_find(xa: &devlink_rels, index: &rel_index, max: rel_index,
197 DEVLINK_REL_IN_USE);
198}
199
200static struct devlink *devlink_rel_devlink_get(u32 rel_index)
201{
202 struct devlink_rel *rel;
203 u32 devlink_index;
204
205 if (!rel_index)
206 return NULL;
207 xa_lock(&devlink_rels);
208 rel = devlink_rel_find(rel_index);
209 if (rel)
210 devlink_index = rel->devlink_index;
211 xa_unlock(&devlink_rels);
212 if (!rel)
213 return NULL;
214 return devlinks_xa_get(index: devlink_index);
215}
216
217int devlink_rel_devlink_handle_put(struct sk_buff *msg, struct devlink *devlink,
218 u32 rel_index, int attrtype,
219 bool *msg_updated)
220{
221 struct net *net = devlink_net(devlink);
222 struct devlink *rel_devlink;
223 int err;
224
225 rel_devlink = devlink_rel_devlink_get(rel_index);
226 if (!rel_devlink)
227 return 0;
228 err = devlink_nl_put_nested_handle(msg, net, devlink: rel_devlink, attrtype);
229 devlink_put(devlink: rel_devlink);
230 if (!err && msg_updated)
231 *msg_updated = true;
232 return err;
233}
234
235void *devlink_priv(struct devlink *devlink)
236{
237 return &devlink->priv;
238}
239EXPORT_SYMBOL_GPL(devlink_priv);
240
241struct devlink *priv_to_devlink(void *priv)
242{
243 return container_of(priv, struct devlink, priv);
244}
245EXPORT_SYMBOL_GPL(priv_to_devlink);
246
247struct device *devlink_to_dev(const struct devlink *devlink)
248{
249 return devlink->dev;
250}
251EXPORT_SYMBOL_GPL(devlink_to_dev);
252
253struct net *devlink_net(const struct devlink *devlink)
254{
255 return read_pnet(pnet: &devlink->_net);
256}
257EXPORT_SYMBOL_GPL(devlink_net);
258
259void devl_assert_locked(struct devlink *devlink)
260{
261 lockdep_assert_held(&devlink->lock);
262}
263EXPORT_SYMBOL_GPL(devl_assert_locked);
264
265#ifdef CONFIG_LOCKDEP
266/* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
267bool devl_lock_is_held(struct devlink *devlink)
268{
269 return lockdep_is_held(&devlink->lock);
270}
271EXPORT_SYMBOL_GPL(devl_lock_is_held);
272#endif
273
274void devl_lock(struct devlink *devlink)
275{
276 mutex_lock(&devlink->lock);
277}
278EXPORT_SYMBOL_GPL(devl_lock);
279
280int devl_trylock(struct devlink *devlink)
281{
282 return mutex_trylock(&devlink->lock);
283}
284EXPORT_SYMBOL_GPL(devl_trylock);
285
286void devl_unlock(struct devlink *devlink)
287{
288 mutex_unlock(lock: &devlink->lock);
289}
290EXPORT_SYMBOL_GPL(devl_unlock);
291
292/**
293 * devlink_try_get() - try to obtain a reference on a devlink instance
294 * @devlink: instance to reference
295 *
296 * Obtain a reference on a devlink instance. A reference on a devlink instance
297 * only implies that it's safe to take the instance lock. It does not imply
298 * that the instance is registered, use devl_is_registered() after taking
299 * the instance lock to check registration status.
300 */
301struct devlink *__must_check devlink_try_get(struct devlink *devlink)
302{
303 if (refcount_inc_not_zero(r: &devlink->refcount))
304 return devlink;
305 return NULL;
306}
307
308static void devlink_release(struct work_struct *work)
309{
310 struct devlink *devlink;
311
312 devlink = container_of(to_rcu_work(work), struct devlink, rwork);
313
314 mutex_destroy(lock: &devlink->lock);
315 lockdep_unregister_key(key: &devlink->lock_key);
316 put_device(dev: devlink->dev);
317 kvfree(addr: devlink);
318}
319
320void devlink_put(struct devlink *devlink)
321{
322 if (refcount_dec_and_test(r: &devlink->refcount))
323 queue_rcu_work(wq: system_wq, rwork: &devlink->rwork);
324}
325
326struct devlink *devlinks_xa_find_get(struct net *net, unsigned long *indexp)
327{
328 struct devlink *devlink = NULL;
329
330 rcu_read_lock();
331retry:
332 devlink = xa_find(xa: &devlinks, index: indexp, ULONG_MAX, DEVLINK_REGISTERED);
333 if (!devlink)
334 goto unlock;
335
336 if (!devlink_try_get(devlink))
337 goto next;
338 if (!net_eq(net1: devlink_net(devlink), net2: net)) {
339 devlink_put(devlink);
340 goto next;
341 }
342unlock:
343 rcu_read_unlock();
344 return devlink;
345
346next:
347 (*indexp)++;
348 goto retry;
349}
350
351/**
352 * devl_register - Register devlink instance
353 * @devlink: devlink
354 */
355int devl_register(struct devlink *devlink)
356{
357 ASSERT_DEVLINK_NOT_REGISTERED(devlink);
358 devl_assert_locked(devlink);
359
360 xa_set_mark(&devlinks, index: devlink->index, DEVLINK_REGISTERED);
361 devlink_notify_register(devlink);
362 devlink_rel_nested_in_notify(devlink);
363
364 return 0;
365}
366EXPORT_SYMBOL_GPL(devl_register);
367
368void devlink_register(struct devlink *devlink)
369{
370 devl_lock(devlink);
371 devl_register(devlink);
372 devl_unlock(devlink);
373}
374EXPORT_SYMBOL_GPL(devlink_register);
375
376/**
377 * devl_unregister - Unregister devlink instance
378 * @devlink: devlink
379 */
380void devl_unregister(struct devlink *devlink)
381{
382 ASSERT_DEVLINK_REGISTERED(devlink);
383 devl_assert_locked(devlink);
384
385 devlink_notify_unregister(devlink);
386 xa_clear_mark(&devlinks, index: devlink->index, DEVLINK_REGISTERED);
387 devlink_rel_put(devlink);
388}
389EXPORT_SYMBOL_GPL(devl_unregister);
390
391void devlink_unregister(struct devlink *devlink)
392{
393 devl_lock(devlink);
394 devl_unregister(devlink);
395 devl_unlock(devlink);
396}
397EXPORT_SYMBOL_GPL(devlink_unregister);
398
399/**
400 * devlink_alloc_ns - Allocate new devlink instance resources
401 * in specific namespace
402 *
403 * @ops: ops
404 * @priv_size: size of user private data
405 * @net: net namespace
406 * @dev: parent device
407 *
408 * Allocate new devlink instance resources, including devlink index
409 * and name.
410 */
411struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
412 size_t priv_size, struct net *net,
413 struct device *dev)
414{
415 struct devlink *devlink;
416 static u32 last_id;
417 int ret;
418
419 WARN_ON(!ops || !dev);
420 if (!devlink_reload_actions_valid(ops))
421 return NULL;
422
423 devlink = kvzalloc(struct_size(devlink, priv, priv_size), GFP_KERNEL);
424 if (!devlink)
425 return NULL;
426
427 ret = xa_alloc_cyclic(xa: &devlinks, id: &devlink->index, entry: devlink, xa_limit_31b,
428 next: &last_id, GFP_KERNEL);
429 if (ret < 0)
430 goto err_xa_alloc;
431
432 devlink->dev = get_device(dev);
433 devlink->ops = ops;
434 xa_init_flags(xa: &devlink->ports, XA_FLAGS_ALLOC);
435 xa_init_flags(xa: &devlink->params, XA_FLAGS_ALLOC);
436 xa_init_flags(xa: &devlink->snapshot_ids, XA_FLAGS_ALLOC);
437 xa_init_flags(xa: &devlink->nested_rels, XA_FLAGS_ALLOC);
438 write_pnet(pnet: &devlink->_net, net);
439 INIT_LIST_HEAD(list: &devlink->rate_list);
440 INIT_LIST_HEAD(list: &devlink->linecard_list);
441 INIT_LIST_HEAD(list: &devlink->sb_list);
442 INIT_LIST_HEAD_RCU(list: &devlink->dpipe_table_list);
443 INIT_LIST_HEAD(list: &devlink->resource_list);
444 INIT_LIST_HEAD(list: &devlink->region_list);
445 INIT_LIST_HEAD(list: &devlink->reporter_list);
446 INIT_LIST_HEAD(list: &devlink->trap_list);
447 INIT_LIST_HEAD(list: &devlink->trap_group_list);
448 INIT_LIST_HEAD(list: &devlink->trap_policer_list);
449 INIT_RCU_WORK(&devlink->rwork, devlink_release);
450 lockdep_register_key(key: &devlink->lock_key);
451 mutex_init(&devlink->lock);
452 lockdep_set_class(&devlink->lock, &devlink->lock_key);
453 refcount_set(r: &devlink->refcount, n: 1);
454
455 return devlink;
456
457err_xa_alloc:
458 kvfree(addr: devlink);
459 return NULL;
460}
461EXPORT_SYMBOL_GPL(devlink_alloc_ns);
462
463/**
464 * devlink_free - Free devlink instance resources
465 *
466 * @devlink: devlink
467 */
468void devlink_free(struct devlink *devlink)
469{
470 ASSERT_DEVLINK_NOT_REGISTERED(devlink);
471
472 WARN_ON(!list_empty(&devlink->trap_policer_list));
473 WARN_ON(!list_empty(&devlink->trap_group_list));
474 WARN_ON(!list_empty(&devlink->trap_list));
475 WARN_ON(!list_empty(&devlink->reporter_list));
476 WARN_ON(!list_empty(&devlink->region_list));
477 WARN_ON(!list_empty(&devlink->resource_list));
478 WARN_ON(!list_empty(&devlink->dpipe_table_list));
479 WARN_ON(!list_empty(&devlink->sb_list));
480 WARN_ON(!list_empty(&devlink->rate_list));
481 WARN_ON(!list_empty(&devlink->linecard_list));
482 WARN_ON(!xa_empty(&devlink->ports));
483
484 xa_destroy(&devlink->nested_rels);
485 xa_destroy(&devlink->snapshot_ids);
486 xa_destroy(&devlink->params);
487 xa_destroy(&devlink->ports);
488
489 xa_erase(&devlinks, index: devlink->index);
490
491 devlink_put(devlink);
492}
493EXPORT_SYMBOL_GPL(devlink_free);
494
495static void __net_exit devlink_pernet_pre_exit(struct net *net)
496{
497 struct devlink *devlink;
498 u32 actions_performed;
499 unsigned long index;
500 int err;
501
502 /* In case network namespace is getting destroyed, reload
503 * all devlink instances from this namespace into init_net.
504 */
505 devlinks_xa_for_each_registered_get(net, index, devlink) {
506 devl_dev_lock(devlink, dev_lock: true);
507 err = 0;
508 if (devl_is_registered(devlink))
509 err = devlink_reload(devlink, dest_net: &init_net,
510 action: DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
511 limit: DEVLINK_RELOAD_LIMIT_UNSPEC,
512 actions_performed: &actions_performed, NULL);
513 devl_dev_unlock(devlink, dev_lock: true);
514 devlink_put(devlink);
515 if (err && err != -EOPNOTSUPP)
516 pr_warn("Failed to reload devlink instance into init_net\n");
517 }
518}
519
520static struct pernet_operations devlink_pernet_ops __net_initdata = {
521 .pre_exit = devlink_pernet_pre_exit,
522};
523
524static struct notifier_block devlink_port_netdevice_nb = {
525 .notifier_call = devlink_port_netdevice_event,
526};
527
528static int __init devlink_init(void)
529{
530 int err;
531
532 err = register_pernet_subsys(&devlink_pernet_ops);
533 if (err)
534 goto out;
535 err = genl_register_family(family: &devlink_nl_family);
536 if (err)
537 goto out_unreg_pernet_subsys;
538 err = register_netdevice_notifier(nb: &devlink_port_netdevice_nb);
539 if (!err)
540 return 0;
541
542 genl_unregister_family(family: &devlink_nl_family);
543
544out_unreg_pernet_subsys:
545 unregister_pernet_subsys(&devlink_pernet_ops);
546out:
547 WARN_ON(err);
548 return err;
549}
550
551subsys_initcall(devlink_init);
552

source code of linux/net/devlink/core.c

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