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
13 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwmsg);
14 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwerr);
15 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_trap_report);
16
17 DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
18
19 static struct devlink *devlinks_xa_get(unsigned long index)
20 {
21 struct devlink *devlink;
22
23 rcu_read_lock();
24 devlink = xa_find(&devlinks, &index, 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 */
36 static DEFINE_XARRAY_FLAGS(devlink_rels, XA_FLAGS_ALLOC1);
37
38 #define DEVLINK_REL_IN_USE XA_MARK_0
39
40 struct 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
53 static void devlink_rel_free(struct devlink_rel *rel)
54 {
55 xa_erase(&devlink_rels, rel->index);
56 kfree(rel);
57 }
58
59 static void __devlink_rel_get(struct devlink_rel *rel)
60 {
61 refcount_inc(&rel->refcount);
62 }
63
64 static void __devlink_rel_put(struct devlink_rel *rel)
65 {
66 if (refcount_dec_and_test(&rel->refcount))
67 devlink_rel_free(rel);
68 }
69
70 static 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(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, 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
94 rel_put:
95 __devlink_rel_put(rel);
96 return;
97
98 reschedule_work:
99 schedule_delayed_work(&rel->nested_in.notify_work, 1);
100 }
101
102 static void devlink_rel_nested_in_notify_work_schedule(struct devlink_rel *rel)
103 {
104 __devlink_rel_get(rel);
105 schedule_delayed_work(&rel->nested_in.notify_work, 0);
106 }
107
108 static 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(-ENOMEM);
117
118 err = xa_alloc_cyclic(&devlink_rels, &rel->index, rel,
119 xa_limit_32b, &next, GFP_KERNEL);
120 if (err) {
121 kfree(rel);
122 return ERR_PTR(err);
123 }
124
125 refcount_set(&rel->refcount, 1);
126 INIT_DELAYED_WORK(&rel->nested_in.notify_work,
127 &devlink_rel_nested_in_notify_work);
128 return rel;
129 }
130
131 static 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, 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
143 void devlink_rel_nested_in_clear(u32 rel_index)
144 {
145 xa_clear_mark(&devlink_rels, rel_index, DEVLINK_REL_IN_USE);
146 }
147
148 int 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(rel))
158 return PTR_ERR(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, 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 */
185 void 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
194 static struct devlink_rel *devlink_rel_find(unsigned long rel_index)
195 {
196 return xa_find(&devlink_rels, &rel_index, rel_index,
197 DEVLINK_REL_IN_USE);
198 }
199
200 static 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(devlink_index);
215 }
216
217 int 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, rel_devlink, attrtype);
229 devlink_put(rel_devlink);
230 if (!err && msg_updated)
231 *msg_updated = true;
232 return err;
233 }
234
235 void *devlink_priv(struct devlink *devlink)
236 {
237 return &devlink->priv;
238 }
239 EXPORT_SYMBOL_GPL(devlink_priv);
240
241 struct devlink *priv_to_devlink(void *priv)
242 {
243 return container_of(priv, struct devlink, priv);
244 }
245 EXPORT_SYMBOL_GPL(priv_to_devlink);
246
247 struct device *devlink_to_dev(const struct devlink *devlink)
248 {
249 return devlink->dev;
250 }
251 EXPORT_SYMBOL_GPL(devlink_to_dev);
252
253 struct net *devlink_net(const struct devlink *devlink)
254 {
255 return read_pnet(&devlink->_net);
256 }
257 EXPORT_SYMBOL_GPL(devlink_net);
258
259 void devl_assert_locked(struct devlink *devlink)
260 {
261 lockdep_assert_held(&devlink->lock);
262 }
263 EXPORT_SYMBOL_GPL(devl_assert_locked);
264
265 #ifdef CONFIG_LOCKDEP
266 /* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
267 bool devl_lock_is_held(struct devlink *devlink)
268 {
269 return lockdep_is_held(&devlink->lock);
270 }
271 EXPORT_SYMBOL_GPL(devl_lock_is_held);
272 #endif
273
274 void devl_lock(struct devlink *devlink)
275 {
276 mutex_lock(&devlink->lock);
277 }
278 EXPORT_SYMBOL_GPL(devl_lock);
279
280 int devl_trylock(struct devlink *devlink)
281 {
282 return mutex_trylock(&devlink->lock);
283 }
284 EXPORT_SYMBOL_GPL(devl_trylock);
285
286 void devl_unlock(struct devlink *devlink)
287 {
288 mutex_unlock(&devlink->lock);
289 }
290 EXPORT_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 */
301 struct devlink *__must_check devlink_try_get(struct devlink *devlink)
302 {
303 if (refcount_inc_not_zero(&devlink->refcount))
304 return devlink;
305 return NULL;
306 }
307
308 static 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(&devlink->lock);
315 lockdep_unregister_key(&devlink->lock_key);
316 put_device(devlink->dev);
317 kvfree(devlink);
318 }
319
320 void devlink_put(struct devlink *devlink)
321 {
322 if (refcount_dec_and_test(&devlink->refcount))
323 queue_rcu_work(system_wq, &devlink->rwork);
324 }
325
326 struct devlink *devlinks_xa_find_get(struct net *net, unsigned long *indexp)
327 {
328 struct devlink *devlink = NULL;
329
330 rcu_read_lock();
331 retry:
332 devlink = xa_find(&devlinks, 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(devlink_net(devlink), net)) {
339 devlink_put(devlink);
340 goto next;
341 }
342 unlock:
343 rcu_read_unlock();
344 return devlink;
345
346 next:
347 (*indexp)++;
348 goto retry;
349 }
350
351 /**
352 * devl_register - Register devlink instance
353 * @devlink: devlink
354 */
355 int devl_register(struct devlink *devlink)
356 {
357 ASSERT_DEVLINK_NOT_REGISTERED(devlink);
358 devl_assert_locked(devlink);
359
360 xa_set_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
361 devlink_notify_register(devlink);
362 devlink_rel_nested_in_notify(devlink);
363
364 return 0;
365 }
366 EXPORT_SYMBOL_GPL(devl_register);
367
368 void devlink_register(struct devlink *devlink)
369 {
370 devl_lock(devlink);
371 devl_register(devlink);
372 devl_unlock(devlink);
373 }
374 EXPORT_SYMBOL_GPL(devlink_register);
375
376 /**
377 * devl_unregister - Unregister devlink instance
378 * @devlink: devlink
379 */
380 void 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, devlink->index, DEVLINK_REGISTERED);
387 devlink_rel_put(devlink);
388 }
389 EXPORT_SYMBOL_GPL(devl_unregister);
390
391 void devlink_unregister(struct devlink *devlink)
392 {
393 devl_lock(devlink);
394 devl_unregister(devlink);
395 devl_unlock(devlink);
396 }
397 EXPORT_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 */
411 struct 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(&devlinks, &devlink->index, devlink, xa_limit_31b,
428 &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(&devlink->ports, XA_FLAGS_ALLOC);
435 xa_init_flags(&devlink->params, XA_FLAGS_ALLOC);
436 xa_init_flags(&devlink->snapshot_ids, XA_FLAGS_ALLOC);
437 xa_init_flags(&devlink->nested_rels, XA_FLAGS_ALLOC);
438 write_pnet(&devlink->_net, net);
439 INIT_LIST_HEAD(&devlink->rate_list);
440 INIT_LIST_HEAD(&devlink->linecard_list);
441 INIT_LIST_HEAD(&devlink->sb_list);
442 INIT_LIST_HEAD_RCU(&devlink->dpipe_table_list);
443 INIT_LIST_HEAD(&devlink->resource_list);
444 INIT_LIST_HEAD(&devlink->region_list);
445 INIT_LIST_HEAD(&devlink->reporter_list);
446 INIT_LIST_HEAD(&devlink->trap_list);
447 INIT_LIST_HEAD(&devlink->trap_group_list);
448 INIT_LIST_HEAD(&devlink->trap_policer_list);
449 INIT_RCU_WORK(&devlink->rwork, devlink_release);
450 lockdep_register_key(&devlink->lock_key);
451 mutex_init(&devlink->lock);
452 lockdep_set_class(&devlink->lock, &devlink->lock_key);
453 refcount_set(&devlink->refcount, 1);
454
455 return devlink;
456
457 err_xa_alloc:
458 kvfree(devlink);
459 return NULL;
460 }
461 EXPORT_SYMBOL_GPL(devlink_alloc_ns);
462
463 /**
464 * devlink_free - Free devlink instance resources
465 *
466 * @devlink: devlink
467 */
468 void 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, devlink->index);
490
491 devlink_put(devlink);
492 }
493 EXPORT_SYMBOL_GPL(devlink_free);
494
495 static 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, true);
507 err = 0;
508 if (devl_is_registered(devlink))
509 err = devlink_reload(devlink, &init_net,
510 DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
511 DEVLINK_RELOAD_LIMIT_UNSPEC,
512 &actions_performed, NULL);
513 devl_dev_unlock(devlink, 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
520 static struct pernet_operations devlink_pernet_ops __net_initdata = {
521 .pre_exit = devlink_pernet_pre_exit,
522 };
523
524 static struct notifier_block devlink_port_netdevice_nb = {
525 .notifier_call = devlink_port_netdevice_event,
526 };
527
528 static 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(&devlink_nl_family);
536 if (err)
537 goto out_unreg_pernet_subsys;
538 err = register_netdevice_notifier(&devlink_port_netdevice_nb);
539 if (!err)
540 return 0;
541
542 genl_unregister_family(&devlink_nl_family);
543
544 out_unreg_pernet_subsys:
545 unregister_pernet_subsys(&devlink_pernet_ops);
546 out:
547 WARN_ON(err);
548 return err;
549 }
550
551 subsys_initcall(devlink_init);
552
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