xref: /openbmc/linux/drivers/infiniband/core/cache.c (revision 5c816641)
1 /*
2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005 Intel Corporation. All rights reserved.
4  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
5  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
6  *
7  * This software is available to you under a choice of one of two
8  * licenses.  You may choose to be licensed under the terms of the GNU
9  * General Public License (GPL) Version 2, available from the file
10  * COPYING in the main directory of this source tree, or the
11  * OpenIB.org BSD license below:
12  *
13  *     Redistribution and use in source and binary forms, with or
14  *     without modification, are permitted provided that the following
15  *     conditions are met:
16  *
17  *      - Redistributions of source code must retain the above
18  *        copyright notice, this list of conditions and the following
19  *        disclaimer.
20  *
21  *      - Redistributions in binary form must reproduce the above
22  *        copyright notice, this list of conditions and the following
23  *        disclaimer in the documentation and/or other materials
24  *        provided with the distribution.
25  *
26  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
30  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
31  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
32  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33  * SOFTWARE.
34  */
35 
36 #include <linux/if_vlan.h>
37 #include <linux/module.h>
38 #include <linux/errno.h>
39 #include <linux/slab.h>
40 #include <linux/workqueue.h>
41 #include <linux/netdevice.h>
42 #include <net/addrconf.h>
43 
44 #include <rdma/ib_cache.h>
45 
46 #include "core_priv.h"
47 
48 struct ib_pkey_cache {
49 	int             table_len;
50 	u16             table[];
51 };
52 
53 struct ib_update_work {
54 	struct work_struct work;
55 	struct ib_event event;
56 	bool enforce_security;
57 };
58 
59 union ib_gid zgid;
60 EXPORT_SYMBOL(zgid);
61 
62 enum gid_attr_find_mask {
63 	GID_ATTR_FIND_MASK_GID          = 1UL << 0,
64 	GID_ATTR_FIND_MASK_NETDEV	= 1UL << 1,
65 	GID_ATTR_FIND_MASK_DEFAULT	= 1UL << 2,
66 	GID_ATTR_FIND_MASK_GID_TYPE	= 1UL << 3,
67 };
68 
69 enum gid_table_entry_state {
70 	GID_TABLE_ENTRY_INVALID		= 1,
71 	GID_TABLE_ENTRY_VALID		= 2,
72 	/*
73 	 * Indicates that entry is pending to be removed, there may
74 	 * be active users of this GID entry.
75 	 * When last user of the GID entry releases reference to it,
76 	 * GID entry is detached from the table.
77 	 */
78 	GID_TABLE_ENTRY_PENDING_DEL	= 3,
79 };
80 
81 struct roce_gid_ndev_storage {
82 	struct rcu_head rcu_head;
83 	struct net_device *ndev;
84 };
85 
86 struct ib_gid_table_entry {
87 	struct kref			kref;
88 	struct work_struct		del_work;
89 	struct ib_gid_attr		attr;
90 	void				*context;
91 	/* Store the ndev pointer to release reference later on in
92 	 * call_rcu context because by that time gid_table_entry
93 	 * and attr might be already freed. So keep a copy of it.
94 	 * ndev_storage is freed by rcu callback.
95 	 */
96 	struct roce_gid_ndev_storage	*ndev_storage;
97 	enum gid_table_entry_state	state;
98 };
99 
100 struct ib_gid_table {
101 	int				sz;
102 	/* In RoCE, adding a GID to the table requires:
103 	 * (a) Find if this GID is already exists.
104 	 * (b) Find a free space.
105 	 * (c) Write the new GID
106 	 *
107 	 * Delete requires different set of operations:
108 	 * (a) Find the GID
109 	 * (b) Delete it.
110 	 *
111 	 **/
112 	/* Any writer to data_vec must hold this lock and the write side of
113 	 * rwlock. Readers must hold only rwlock. All writers must be in a
114 	 * sleepable context.
115 	 */
116 	struct mutex			lock;
117 	/* rwlock protects data_vec[ix]->state and entry pointer.
118 	 */
119 	rwlock_t			rwlock;
120 	struct ib_gid_table_entry	**data_vec;
121 	/* bit field, each bit indicates the index of default GID */
122 	u32				default_gid_indices;
123 };
124 
125 static void dispatch_gid_change_event(struct ib_device *ib_dev, u32 port)
126 {
127 	struct ib_event event;
128 
129 	event.device		= ib_dev;
130 	event.element.port_num	= port;
131 	event.event		= IB_EVENT_GID_CHANGE;
132 
133 	ib_dispatch_event_clients(&event);
134 }
135 
136 static const char * const gid_type_str[] = {
137 	/* IB/RoCE v1 value is set for IB_GID_TYPE_IB and IB_GID_TYPE_ROCE for
138 	 * user space compatibility reasons.
139 	 */
140 	[IB_GID_TYPE_IB]	= "IB/RoCE v1",
141 	[IB_GID_TYPE_ROCE]	= "IB/RoCE v1",
142 	[IB_GID_TYPE_ROCE_UDP_ENCAP]	= "RoCE v2",
143 };
144 
145 const char *ib_cache_gid_type_str(enum ib_gid_type gid_type)
146 {
147 	if (gid_type < ARRAY_SIZE(gid_type_str) && gid_type_str[gid_type])
148 		return gid_type_str[gid_type];
149 
150 	return "Invalid GID type";
151 }
152 EXPORT_SYMBOL(ib_cache_gid_type_str);
153 
154 /** rdma_is_zero_gid - Check if given GID is zero or not.
155  * @gid:	GID to check
156  * Returns true if given GID is zero, returns false otherwise.
157  */
158 bool rdma_is_zero_gid(const union ib_gid *gid)
159 {
160 	return !memcmp(gid, &zgid, sizeof(*gid));
161 }
162 EXPORT_SYMBOL(rdma_is_zero_gid);
163 
164 /** is_gid_index_default - Check if a given index belongs to
165  * reserved default GIDs or not.
166  * @table:	GID table pointer
167  * @index:	Index to check in GID table
168  * Returns true if index is one of the reserved default GID index otherwise
169  * returns false.
170  */
171 static bool is_gid_index_default(const struct ib_gid_table *table,
172 				 unsigned int index)
173 {
174 	return index < 32 && (BIT(index) & table->default_gid_indices);
175 }
176 
177 int ib_cache_gid_parse_type_str(const char *buf)
178 {
179 	unsigned int i;
180 	size_t len;
181 	int err = -EINVAL;
182 
183 	len = strlen(buf);
184 	if (len == 0)
185 		return -EINVAL;
186 
187 	if (buf[len - 1] == '\n')
188 		len--;
189 
190 	for (i = 0; i < ARRAY_SIZE(gid_type_str); ++i)
191 		if (gid_type_str[i] && !strncmp(buf, gid_type_str[i], len) &&
192 		    len == strlen(gid_type_str[i])) {
193 			err = i;
194 			break;
195 		}
196 
197 	return err;
198 }
199 EXPORT_SYMBOL(ib_cache_gid_parse_type_str);
200 
201 static struct ib_gid_table *rdma_gid_table(struct ib_device *device, u32 port)
202 {
203 	return device->port_data[port].cache.gid;
204 }
205 
206 static bool is_gid_entry_free(const struct ib_gid_table_entry *entry)
207 {
208 	return !entry;
209 }
210 
211 static bool is_gid_entry_valid(const struct ib_gid_table_entry *entry)
212 {
213 	return entry && entry->state == GID_TABLE_ENTRY_VALID;
214 }
215 
216 static void schedule_free_gid(struct kref *kref)
217 {
218 	struct ib_gid_table_entry *entry =
219 			container_of(kref, struct ib_gid_table_entry, kref);
220 
221 	queue_work(ib_wq, &entry->del_work);
222 }
223 
224 static void put_gid_ndev(struct rcu_head *head)
225 {
226 	struct roce_gid_ndev_storage *storage =
227 		container_of(head, struct roce_gid_ndev_storage, rcu_head);
228 
229 	WARN_ON(!storage->ndev);
230 	/* At this point its safe to release netdev reference,
231 	 * as all callers working on gid_attr->ndev are done
232 	 * using this netdev.
233 	 */
234 	dev_put(storage->ndev);
235 	kfree(storage);
236 }
237 
238 static void free_gid_entry_locked(struct ib_gid_table_entry *entry)
239 {
240 	struct ib_device *device = entry->attr.device;
241 	u32 port_num = entry->attr.port_num;
242 	struct ib_gid_table *table = rdma_gid_table(device, port_num);
243 
244 	dev_dbg(&device->dev, "%s port=%u index=%u gid %pI6\n", __func__,
245 		port_num, entry->attr.index, entry->attr.gid.raw);
246 
247 	write_lock_irq(&table->rwlock);
248 
249 	/*
250 	 * The only way to avoid overwriting NULL in table is
251 	 * by comparing if it is same entry in table or not!
252 	 * If new entry in table is added by the time we free here,
253 	 * don't overwrite the table entry.
254 	 */
255 	if (entry == table->data_vec[entry->attr.index])
256 		table->data_vec[entry->attr.index] = NULL;
257 	/* Now this index is ready to be allocated */
258 	write_unlock_irq(&table->rwlock);
259 
260 	if (entry->ndev_storage)
261 		call_rcu(&entry->ndev_storage->rcu_head, put_gid_ndev);
262 	kfree(entry);
263 }
264 
265 static void free_gid_entry(struct kref *kref)
266 {
267 	struct ib_gid_table_entry *entry =
268 			container_of(kref, struct ib_gid_table_entry, kref);
269 
270 	free_gid_entry_locked(entry);
271 }
272 
273 /**
274  * free_gid_work - Release reference to the GID entry
275  * @work: Work structure to refer to GID entry which needs to be
276  * deleted.
277  *
278  * free_gid_work() frees the entry from the HCA's hardware table
279  * if provider supports it. It releases reference to netdevice.
280  */
281 static void free_gid_work(struct work_struct *work)
282 {
283 	struct ib_gid_table_entry *entry =
284 		container_of(work, struct ib_gid_table_entry, del_work);
285 	struct ib_device *device = entry->attr.device;
286 	u32 port_num = entry->attr.port_num;
287 	struct ib_gid_table *table = rdma_gid_table(device, port_num);
288 
289 	mutex_lock(&table->lock);
290 	free_gid_entry_locked(entry);
291 	mutex_unlock(&table->lock);
292 }
293 
294 static struct ib_gid_table_entry *
295 alloc_gid_entry(const struct ib_gid_attr *attr)
296 {
297 	struct ib_gid_table_entry *entry;
298 	struct net_device *ndev;
299 
300 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
301 	if (!entry)
302 		return NULL;
303 
304 	ndev = rcu_dereference_protected(attr->ndev, 1);
305 	if (ndev) {
306 		entry->ndev_storage = kzalloc(sizeof(*entry->ndev_storage),
307 					      GFP_KERNEL);
308 		if (!entry->ndev_storage) {
309 			kfree(entry);
310 			return NULL;
311 		}
312 		dev_hold(ndev);
313 		entry->ndev_storage->ndev = ndev;
314 	}
315 	kref_init(&entry->kref);
316 	memcpy(&entry->attr, attr, sizeof(*attr));
317 	INIT_WORK(&entry->del_work, free_gid_work);
318 	entry->state = GID_TABLE_ENTRY_INVALID;
319 	return entry;
320 }
321 
322 static void store_gid_entry(struct ib_gid_table *table,
323 			    struct ib_gid_table_entry *entry)
324 {
325 	entry->state = GID_TABLE_ENTRY_VALID;
326 
327 	dev_dbg(&entry->attr.device->dev, "%s port=%u index=%u gid %pI6\n",
328 		__func__, entry->attr.port_num, entry->attr.index,
329 		entry->attr.gid.raw);
330 
331 	lockdep_assert_held(&table->lock);
332 	write_lock_irq(&table->rwlock);
333 	table->data_vec[entry->attr.index] = entry;
334 	write_unlock_irq(&table->rwlock);
335 }
336 
337 static void get_gid_entry(struct ib_gid_table_entry *entry)
338 {
339 	kref_get(&entry->kref);
340 }
341 
342 static void put_gid_entry(struct ib_gid_table_entry *entry)
343 {
344 	kref_put(&entry->kref, schedule_free_gid);
345 }
346 
347 static void put_gid_entry_locked(struct ib_gid_table_entry *entry)
348 {
349 	kref_put(&entry->kref, free_gid_entry);
350 }
351 
352 static int add_roce_gid(struct ib_gid_table_entry *entry)
353 {
354 	const struct ib_gid_attr *attr = &entry->attr;
355 	int ret;
356 
357 	if (!attr->ndev) {
358 		dev_err(&attr->device->dev, "%s NULL netdev port=%u index=%u\n",
359 			__func__, attr->port_num, attr->index);
360 		return -EINVAL;
361 	}
362 	if (rdma_cap_roce_gid_table(attr->device, attr->port_num)) {
363 		ret = attr->device->ops.add_gid(attr, &entry->context);
364 		if (ret) {
365 			dev_err(&attr->device->dev,
366 				"%s GID add failed port=%u index=%u\n",
367 				__func__, attr->port_num, attr->index);
368 			return ret;
369 		}
370 	}
371 	return 0;
372 }
373 
374 /**
375  * del_gid - Delete GID table entry
376  *
377  * @ib_dev:	IB device whose GID entry to be deleted
378  * @port:	Port number of the IB device
379  * @table:	GID table of the IB device for a port
380  * @ix:		GID entry index to delete
381  *
382  */
383 static void del_gid(struct ib_device *ib_dev, u32 port,
384 		    struct ib_gid_table *table, int ix)
385 {
386 	struct roce_gid_ndev_storage *ndev_storage;
387 	struct ib_gid_table_entry *entry;
388 
389 	lockdep_assert_held(&table->lock);
390 
391 	dev_dbg(&ib_dev->dev, "%s port=%u index=%d gid %pI6\n", __func__, port,
392 		ix, table->data_vec[ix]->attr.gid.raw);
393 
394 	write_lock_irq(&table->rwlock);
395 	entry = table->data_vec[ix];
396 	entry->state = GID_TABLE_ENTRY_PENDING_DEL;
397 	/*
398 	 * For non RoCE protocol, GID entry slot is ready to use.
399 	 */
400 	if (!rdma_protocol_roce(ib_dev, port))
401 		table->data_vec[ix] = NULL;
402 	write_unlock_irq(&table->rwlock);
403 
404 	ndev_storage = entry->ndev_storage;
405 	if (ndev_storage) {
406 		entry->ndev_storage = NULL;
407 		rcu_assign_pointer(entry->attr.ndev, NULL);
408 		call_rcu(&ndev_storage->rcu_head, put_gid_ndev);
409 	}
410 
411 	if (rdma_cap_roce_gid_table(ib_dev, port))
412 		ib_dev->ops.del_gid(&entry->attr, &entry->context);
413 
414 	put_gid_entry_locked(entry);
415 }
416 
417 /**
418  * add_modify_gid - Add or modify GID table entry
419  *
420  * @table:	GID table in which GID to be added or modified
421  * @attr:	Attributes of the GID
422  *
423  * Returns 0 on success or appropriate error code. It accepts zero
424  * GID addition for non RoCE ports for HCA's who report them as valid
425  * GID. However such zero GIDs are not added to the cache.
426  */
427 static int add_modify_gid(struct ib_gid_table *table,
428 			  const struct ib_gid_attr *attr)
429 {
430 	struct ib_gid_table_entry *entry;
431 	int ret = 0;
432 
433 	/*
434 	 * Invalidate any old entry in the table to make it safe to write to
435 	 * this index.
436 	 */
437 	if (is_gid_entry_valid(table->data_vec[attr->index]))
438 		del_gid(attr->device, attr->port_num, table, attr->index);
439 
440 	/*
441 	 * Some HCA's report multiple GID entries with only one valid GID, and
442 	 * leave other unused entries as the zero GID. Convert zero GIDs to
443 	 * empty table entries instead of storing them.
444 	 */
445 	if (rdma_is_zero_gid(&attr->gid))
446 		return 0;
447 
448 	entry = alloc_gid_entry(attr);
449 	if (!entry)
450 		return -ENOMEM;
451 
452 	if (rdma_protocol_roce(attr->device, attr->port_num)) {
453 		ret = add_roce_gid(entry);
454 		if (ret)
455 			goto done;
456 	}
457 
458 	store_gid_entry(table, entry);
459 	return 0;
460 
461 done:
462 	put_gid_entry(entry);
463 	return ret;
464 }
465 
466 /* rwlock should be read locked, or lock should be held */
467 static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
468 		    const struct ib_gid_attr *val, bool default_gid,
469 		    unsigned long mask, int *pempty)
470 {
471 	int i = 0;
472 	int found = -1;
473 	int empty = pempty ? -1 : 0;
474 
475 	while (i < table->sz && (found < 0 || empty < 0)) {
476 		struct ib_gid_table_entry *data = table->data_vec[i];
477 		struct ib_gid_attr *attr;
478 		int curr_index = i;
479 
480 		i++;
481 
482 		/* find_gid() is used during GID addition where it is expected
483 		 * to return a free entry slot which is not duplicate.
484 		 * Free entry slot is requested and returned if pempty is set,
485 		 * so lookup free slot only if requested.
486 		 */
487 		if (pempty && empty < 0) {
488 			if (is_gid_entry_free(data) &&
489 			    default_gid ==
490 				is_gid_index_default(table, curr_index)) {
491 				/*
492 				 * Found an invalid (free) entry; allocate it.
493 				 * If default GID is requested, then our
494 				 * found slot must be one of the DEFAULT
495 				 * reserved slots or we fail.
496 				 * This ensures that only DEFAULT reserved
497 				 * slots are used for default property GIDs.
498 				 */
499 				empty = curr_index;
500 			}
501 		}
502 
503 		/*
504 		 * Additionally find_gid() is used to find valid entry during
505 		 * lookup operation; so ignore the entries which are marked as
506 		 * pending for removal and the entries which are marked as
507 		 * invalid.
508 		 */
509 		if (!is_gid_entry_valid(data))
510 			continue;
511 
512 		if (found >= 0)
513 			continue;
514 
515 		attr = &data->attr;
516 		if (mask & GID_ATTR_FIND_MASK_GID_TYPE &&
517 		    attr->gid_type != val->gid_type)
518 			continue;
519 
520 		if (mask & GID_ATTR_FIND_MASK_GID &&
521 		    memcmp(gid, &data->attr.gid, sizeof(*gid)))
522 			continue;
523 
524 		if (mask & GID_ATTR_FIND_MASK_NETDEV &&
525 		    attr->ndev != val->ndev)
526 			continue;
527 
528 		if (mask & GID_ATTR_FIND_MASK_DEFAULT &&
529 		    is_gid_index_default(table, curr_index) != default_gid)
530 			continue;
531 
532 		found = curr_index;
533 	}
534 
535 	if (pempty)
536 		*pempty = empty;
537 
538 	return found;
539 }
540 
541 static void make_default_gid(struct  net_device *dev, union ib_gid *gid)
542 {
543 	gid->global.subnet_prefix = cpu_to_be64(0xfe80000000000000LL);
544 	addrconf_ifid_eui48(&gid->raw[8], dev);
545 }
546 
547 static int __ib_cache_gid_add(struct ib_device *ib_dev, u32 port,
548 			      union ib_gid *gid, struct ib_gid_attr *attr,
549 			      unsigned long mask, bool default_gid)
550 {
551 	struct ib_gid_table *table;
552 	int ret = 0;
553 	int empty;
554 	int ix;
555 
556 	/* Do not allow adding zero GID in support of
557 	 * IB spec version 1.3 section 4.1.1 point (6) and
558 	 * section 12.7.10 and section 12.7.20
559 	 */
560 	if (rdma_is_zero_gid(gid))
561 		return -EINVAL;
562 
563 	table = rdma_gid_table(ib_dev, port);
564 
565 	mutex_lock(&table->lock);
566 
567 	ix = find_gid(table, gid, attr, default_gid, mask, &empty);
568 	if (ix >= 0)
569 		goto out_unlock;
570 
571 	if (empty < 0) {
572 		ret = -ENOSPC;
573 		goto out_unlock;
574 	}
575 	attr->device = ib_dev;
576 	attr->index = empty;
577 	attr->port_num = port;
578 	attr->gid = *gid;
579 	ret = add_modify_gid(table, attr);
580 	if (!ret)
581 		dispatch_gid_change_event(ib_dev, port);
582 
583 out_unlock:
584 	mutex_unlock(&table->lock);
585 	if (ret)
586 		pr_warn("%s: unable to add gid %pI6 error=%d\n",
587 			__func__, gid->raw, ret);
588 	return ret;
589 }
590 
591 int ib_cache_gid_add(struct ib_device *ib_dev, u32 port,
592 		     union ib_gid *gid, struct ib_gid_attr *attr)
593 {
594 	unsigned long mask = GID_ATTR_FIND_MASK_GID |
595 			     GID_ATTR_FIND_MASK_GID_TYPE |
596 			     GID_ATTR_FIND_MASK_NETDEV;
597 
598 	return __ib_cache_gid_add(ib_dev, port, gid, attr, mask, false);
599 }
600 
601 static int
602 _ib_cache_gid_del(struct ib_device *ib_dev, u32 port,
603 		  union ib_gid *gid, struct ib_gid_attr *attr,
604 		  unsigned long mask, bool default_gid)
605 {
606 	struct ib_gid_table *table;
607 	int ret = 0;
608 	int ix;
609 
610 	table = rdma_gid_table(ib_dev, port);
611 
612 	mutex_lock(&table->lock);
613 
614 	ix = find_gid(table, gid, attr, default_gid, mask, NULL);
615 	if (ix < 0) {
616 		ret = -EINVAL;
617 		goto out_unlock;
618 	}
619 
620 	del_gid(ib_dev, port, table, ix);
621 	dispatch_gid_change_event(ib_dev, port);
622 
623 out_unlock:
624 	mutex_unlock(&table->lock);
625 	if (ret)
626 		pr_debug("%s: can't delete gid %pI6 error=%d\n",
627 			 __func__, gid->raw, ret);
628 	return ret;
629 }
630 
631 int ib_cache_gid_del(struct ib_device *ib_dev, u32 port,
632 		     union ib_gid *gid, struct ib_gid_attr *attr)
633 {
634 	unsigned long mask = GID_ATTR_FIND_MASK_GID	  |
635 			     GID_ATTR_FIND_MASK_GID_TYPE |
636 			     GID_ATTR_FIND_MASK_DEFAULT  |
637 			     GID_ATTR_FIND_MASK_NETDEV;
638 
639 	return _ib_cache_gid_del(ib_dev, port, gid, attr, mask, false);
640 }
641 
642 int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u32 port,
643 				     struct net_device *ndev)
644 {
645 	struct ib_gid_table *table;
646 	int ix;
647 	bool deleted = false;
648 
649 	table = rdma_gid_table(ib_dev, port);
650 
651 	mutex_lock(&table->lock);
652 
653 	for (ix = 0; ix < table->sz; ix++) {
654 		if (is_gid_entry_valid(table->data_vec[ix]) &&
655 		    table->data_vec[ix]->attr.ndev == ndev) {
656 			del_gid(ib_dev, port, table, ix);
657 			deleted = true;
658 		}
659 	}
660 
661 	mutex_unlock(&table->lock);
662 
663 	if (deleted)
664 		dispatch_gid_change_event(ib_dev, port);
665 
666 	return 0;
667 }
668 
669 /**
670  * rdma_find_gid_by_port - Returns the GID entry attributes when it finds
671  * a valid GID entry for given search parameters. It searches for the specified
672  * GID value in the local software cache.
673  * @ib_dev: The device to query.
674  * @gid: The GID value to search for.
675  * @gid_type: The GID type to search for.
676  * @port: The port number of the device where the GID value should be searched.
677  * @ndev: In RoCE, the net device of the device. NULL means ignore.
678  *
679  * Returns sgid attributes if the GID is found with valid reference or
680  * returns ERR_PTR for the error.
681  * The caller must invoke rdma_put_gid_attr() to release the reference.
682  */
683 const struct ib_gid_attr *
684 rdma_find_gid_by_port(struct ib_device *ib_dev,
685 		      const union ib_gid *gid,
686 		      enum ib_gid_type gid_type,
687 		      u32 port, struct net_device *ndev)
688 {
689 	int local_index;
690 	struct ib_gid_table *table;
691 	unsigned long mask = GID_ATTR_FIND_MASK_GID |
692 			     GID_ATTR_FIND_MASK_GID_TYPE;
693 	struct ib_gid_attr val = {.ndev = ndev, .gid_type = gid_type};
694 	const struct ib_gid_attr *attr;
695 	unsigned long flags;
696 
697 	if (!rdma_is_port_valid(ib_dev, port))
698 		return ERR_PTR(-ENOENT);
699 
700 	table = rdma_gid_table(ib_dev, port);
701 
702 	if (ndev)
703 		mask |= GID_ATTR_FIND_MASK_NETDEV;
704 
705 	read_lock_irqsave(&table->rwlock, flags);
706 	local_index = find_gid(table, gid, &val, false, mask, NULL);
707 	if (local_index >= 0) {
708 		get_gid_entry(table->data_vec[local_index]);
709 		attr = &table->data_vec[local_index]->attr;
710 		read_unlock_irqrestore(&table->rwlock, flags);
711 		return attr;
712 	}
713 
714 	read_unlock_irqrestore(&table->rwlock, flags);
715 	return ERR_PTR(-ENOENT);
716 }
717 EXPORT_SYMBOL(rdma_find_gid_by_port);
718 
719 /**
720  * rdma_find_gid_by_filter - Returns the GID table attribute where a
721  * specified GID value occurs
722  * @ib_dev: The device to query.
723  * @gid: The GID value to search for.
724  * @port: The port number of the device where the GID value could be
725  *   searched.
726  * @filter: The filter function is executed on any matching GID in the table.
727  *   If the filter function returns true, the corresponding index is returned,
728  *   otherwise, we continue searching the GID table. It's guaranteed that
729  *   while filter is executed, ndev field is valid and the structure won't
730  *   change. filter is executed in an atomic context. filter must not be NULL.
731  * @context: Private data to pass into the call-back.
732  *
733  * rdma_find_gid_by_filter() searches for the specified GID value
734  * of which the filter function returns true in the port's GID table.
735  *
736  */
737 const struct ib_gid_attr *rdma_find_gid_by_filter(
738 	struct ib_device *ib_dev, const union ib_gid *gid, u32 port,
739 	bool (*filter)(const union ib_gid *gid, const struct ib_gid_attr *,
740 		       void *),
741 	void *context)
742 {
743 	const struct ib_gid_attr *res = ERR_PTR(-ENOENT);
744 	struct ib_gid_table *table;
745 	unsigned long flags;
746 	unsigned int i;
747 
748 	if (!rdma_is_port_valid(ib_dev, port))
749 		return ERR_PTR(-EINVAL);
750 
751 	table = rdma_gid_table(ib_dev, port);
752 
753 	read_lock_irqsave(&table->rwlock, flags);
754 	for (i = 0; i < table->sz; i++) {
755 		struct ib_gid_table_entry *entry = table->data_vec[i];
756 
757 		if (!is_gid_entry_valid(entry))
758 			continue;
759 
760 		if (memcmp(gid, &entry->attr.gid, sizeof(*gid)))
761 			continue;
762 
763 		if (filter(gid, &entry->attr, context)) {
764 			get_gid_entry(entry);
765 			res = &entry->attr;
766 			break;
767 		}
768 	}
769 	read_unlock_irqrestore(&table->rwlock, flags);
770 	return res;
771 }
772 
773 static struct ib_gid_table *alloc_gid_table(int sz)
774 {
775 	struct ib_gid_table *table = kzalloc(sizeof(*table), GFP_KERNEL);
776 
777 	if (!table)
778 		return NULL;
779 
780 	table->data_vec = kcalloc(sz, sizeof(*table->data_vec), GFP_KERNEL);
781 	if (!table->data_vec)
782 		goto err_free_table;
783 
784 	mutex_init(&table->lock);
785 
786 	table->sz = sz;
787 	rwlock_init(&table->rwlock);
788 	return table;
789 
790 err_free_table:
791 	kfree(table);
792 	return NULL;
793 }
794 
795 static void release_gid_table(struct ib_device *device,
796 			      struct ib_gid_table *table)
797 {
798 	bool leak = false;
799 	int i;
800 
801 	if (!table)
802 		return;
803 
804 	for (i = 0; i < table->sz; i++) {
805 		if (is_gid_entry_free(table->data_vec[i]))
806 			continue;
807 		if (kref_read(&table->data_vec[i]->kref) > 1) {
808 			dev_err(&device->dev,
809 				"GID entry ref leak for index %d ref=%u\n", i,
810 				kref_read(&table->data_vec[i]->kref));
811 			leak = true;
812 		}
813 	}
814 	if (leak)
815 		return;
816 
817 	mutex_destroy(&table->lock);
818 	kfree(table->data_vec);
819 	kfree(table);
820 }
821 
822 static void cleanup_gid_table_port(struct ib_device *ib_dev, u32 port,
823 				   struct ib_gid_table *table)
824 {
825 	int i;
826 
827 	if (!table)
828 		return;
829 
830 	mutex_lock(&table->lock);
831 	for (i = 0; i < table->sz; ++i) {
832 		if (is_gid_entry_valid(table->data_vec[i]))
833 			del_gid(ib_dev, port, table, i);
834 	}
835 	mutex_unlock(&table->lock);
836 }
837 
838 void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u32 port,
839 				  struct net_device *ndev,
840 				  unsigned long gid_type_mask,
841 				  enum ib_cache_gid_default_mode mode)
842 {
843 	union ib_gid gid = { };
844 	struct ib_gid_attr gid_attr;
845 	unsigned int gid_type;
846 	unsigned long mask;
847 
848 	mask = GID_ATTR_FIND_MASK_GID_TYPE |
849 	       GID_ATTR_FIND_MASK_DEFAULT |
850 	       GID_ATTR_FIND_MASK_NETDEV;
851 	memset(&gid_attr, 0, sizeof(gid_attr));
852 	gid_attr.ndev = ndev;
853 
854 	for (gid_type = 0; gid_type < IB_GID_TYPE_SIZE; ++gid_type) {
855 		if (1UL << gid_type & ~gid_type_mask)
856 			continue;
857 
858 		gid_attr.gid_type = gid_type;
859 
860 		if (mode == IB_CACHE_GID_DEFAULT_MODE_SET) {
861 			make_default_gid(ndev, &gid);
862 			__ib_cache_gid_add(ib_dev, port, &gid,
863 					   &gid_attr, mask, true);
864 		} else if (mode == IB_CACHE_GID_DEFAULT_MODE_DELETE) {
865 			_ib_cache_gid_del(ib_dev, port, &gid,
866 					  &gid_attr, mask, true);
867 		}
868 	}
869 }
870 
871 static void gid_table_reserve_default(struct ib_device *ib_dev, u32 port,
872 				      struct ib_gid_table *table)
873 {
874 	unsigned int i;
875 	unsigned long roce_gid_type_mask;
876 	unsigned int num_default_gids;
877 
878 	roce_gid_type_mask = roce_gid_type_mask_support(ib_dev, port);
879 	num_default_gids = hweight_long(roce_gid_type_mask);
880 	/* Reserve starting indices for default GIDs */
881 	for (i = 0; i < num_default_gids && i < table->sz; i++)
882 		table->default_gid_indices |= BIT(i);
883 }
884 
885 
886 static void gid_table_release_one(struct ib_device *ib_dev)
887 {
888 	u32 p;
889 
890 	rdma_for_each_port (ib_dev, p) {
891 		release_gid_table(ib_dev, ib_dev->port_data[p].cache.gid);
892 		ib_dev->port_data[p].cache.gid = NULL;
893 	}
894 }
895 
896 static int _gid_table_setup_one(struct ib_device *ib_dev)
897 {
898 	struct ib_gid_table *table;
899 	u32 rdma_port;
900 
901 	rdma_for_each_port (ib_dev, rdma_port) {
902 		table = alloc_gid_table(
903 			ib_dev->port_data[rdma_port].immutable.gid_tbl_len);
904 		if (!table)
905 			goto rollback_table_setup;
906 
907 		gid_table_reserve_default(ib_dev, rdma_port, table);
908 		ib_dev->port_data[rdma_port].cache.gid = table;
909 	}
910 	return 0;
911 
912 rollback_table_setup:
913 	gid_table_release_one(ib_dev);
914 	return -ENOMEM;
915 }
916 
917 static void gid_table_cleanup_one(struct ib_device *ib_dev)
918 {
919 	u32 p;
920 
921 	rdma_for_each_port (ib_dev, p)
922 		cleanup_gid_table_port(ib_dev, p,
923 				       ib_dev->port_data[p].cache.gid);
924 }
925 
926 static int gid_table_setup_one(struct ib_device *ib_dev)
927 {
928 	int err;
929 
930 	err = _gid_table_setup_one(ib_dev);
931 
932 	if (err)
933 		return err;
934 
935 	rdma_roce_rescan_device(ib_dev);
936 
937 	return err;
938 }
939 
940 /**
941  * rdma_query_gid - Read the GID content from the GID software cache
942  * @device:		Device to query the GID
943  * @port_num:		Port number of the device
944  * @index:		Index of the GID table entry to read
945  * @gid:		Pointer to GID where to store the entry's GID
946  *
947  * rdma_query_gid() only reads the GID entry content for requested device,
948  * port and index. It reads for IB, RoCE and iWarp link layers.  It doesn't
949  * hold any reference to the GID table entry in the HCA or software cache.
950  *
951  * Returns 0 on success or appropriate error code.
952  *
953  */
954 int rdma_query_gid(struct ib_device *device, u32 port_num,
955 		   int index, union ib_gid *gid)
956 {
957 	struct ib_gid_table *table;
958 	unsigned long flags;
959 	int res;
960 
961 	if (!rdma_is_port_valid(device, port_num))
962 		return -EINVAL;
963 
964 	table = rdma_gid_table(device, port_num);
965 	read_lock_irqsave(&table->rwlock, flags);
966 
967 	if (index < 0 || index >= table->sz) {
968 		res = -EINVAL;
969 		goto done;
970 	}
971 
972 	if (!is_gid_entry_valid(table->data_vec[index])) {
973 		res = -ENOENT;
974 		goto done;
975 	}
976 
977 	memcpy(gid, &table->data_vec[index]->attr.gid, sizeof(*gid));
978 	res = 0;
979 
980 done:
981 	read_unlock_irqrestore(&table->rwlock, flags);
982 	return res;
983 }
984 EXPORT_SYMBOL(rdma_query_gid);
985 
986 /**
987  * rdma_read_gid_hw_context - Read the HW GID context from GID attribute
988  * @attr:		Potinter to the GID attribute
989  *
990  * rdma_read_gid_hw_context() reads the drivers GID HW context corresponding
991  * to the SGID attr. Callers are required to already be holding the reference
992  * to an existing GID entry.
993  *
994  * Returns the HW GID context
995  *
996  */
997 void *rdma_read_gid_hw_context(const struct ib_gid_attr *attr)
998 {
999 	return container_of(attr, struct ib_gid_table_entry, attr)->context;
1000 }
1001 EXPORT_SYMBOL(rdma_read_gid_hw_context);
1002 
1003 /**
1004  * rdma_find_gid - Returns SGID attributes if the matching GID is found.
1005  * @device: The device to query.
1006  * @gid: The GID value to search for.
1007  * @gid_type: The GID type to search for.
1008  * @ndev: In RoCE, the net device of the device. NULL means ignore.
1009  *
1010  * rdma_find_gid() searches for the specified GID value in the software cache.
1011  *
1012  * Returns GID attributes if a valid GID is found or returns ERR_PTR for the
1013  * error. The caller must invoke rdma_put_gid_attr() to release the reference.
1014  *
1015  */
1016 const struct ib_gid_attr *rdma_find_gid(struct ib_device *device,
1017 					const union ib_gid *gid,
1018 					enum ib_gid_type gid_type,
1019 					struct net_device *ndev)
1020 {
1021 	unsigned long mask = GID_ATTR_FIND_MASK_GID |
1022 			     GID_ATTR_FIND_MASK_GID_TYPE;
1023 	struct ib_gid_attr gid_attr_val = {.ndev = ndev, .gid_type = gid_type};
1024 	u32 p;
1025 
1026 	if (ndev)
1027 		mask |= GID_ATTR_FIND_MASK_NETDEV;
1028 
1029 	rdma_for_each_port(device, p) {
1030 		struct ib_gid_table *table;
1031 		unsigned long flags;
1032 		int index;
1033 
1034 		table = device->port_data[p].cache.gid;
1035 		read_lock_irqsave(&table->rwlock, flags);
1036 		index = find_gid(table, gid, &gid_attr_val, false, mask, NULL);
1037 		if (index >= 0) {
1038 			const struct ib_gid_attr *attr;
1039 
1040 			get_gid_entry(table->data_vec[index]);
1041 			attr = &table->data_vec[index]->attr;
1042 			read_unlock_irqrestore(&table->rwlock, flags);
1043 			return attr;
1044 		}
1045 		read_unlock_irqrestore(&table->rwlock, flags);
1046 	}
1047 
1048 	return ERR_PTR(-ENOENT);
1049 }
1050 EXPORT_SYMBOL(rdma_find_gid);
1051 
1052 int ib_get_cached_pkey(struct ib_device *device,
1053 		       u32               port_num,
1054 		       int               index,
1055 		       u16              *pkey)
1056 {
1057 	struct ib_pkey_cache *cache;
1058 	unsigned long flags;
1059 	int ret = 0;
1060 
1061 	if (!rdma_is_port_valid(device, port_num))
1062 		return -EINVAL;
1063 
1064 	read_lock_irqsave(&device->cache_lock, flags);
1065 
1066 	cache = device->port_data[port_num].cache.pkey;
1067 
1068 	if (!cache || index < 0 || index >= cache->table_len)
1069 		ret = -EINVAL;
1070 	else
1071 		*pkey = cache->table[index];
1072 
1073 	read_unlock_irqrestore(&device->cache_lock, flags);
1074 
1075 	return ret;
1076 }
1077 EXPORT_SYMBOL(ib_get_cached_pkey);
1078 
1079 void ib_get_cached_subnet_prefix(struct ib_device *device, u32 port_num,
1080 				u64 *sn_pfx)
1081 {
1082 	unsigned long flags;
1083 
1084 	read_lock_irqsave(&device->cache_lock, flags);
1085 	*sn_pfx = device->port_data[port_num].cache.subnet_prefix;
1086 	read_unlock_irqrestore(&device->cache_lock, flags);
1087 }
1088 EXPORT_SYMBOL(ib_get_cached_subnet_prefix);
1089 
1090 int ib_find_cached_pkey(struct ib_device *device, u32 port_num,
1091 			u16 pkey, u16 *index)
1092 {
1093 	struct ib_pkey_cache *cache;
1094 	unsigned long flags;
1095 	int i;
1096 	int ret = -ENOENT;
1097 	int partial_ix = -1;
1098 
1099 	if (!rdma_is_port_valid(device, port_num))
1100 		return -EINVAL;
1101 
1102 	read_lock_irqsave(&device->cache_lock, flags);
1103 
1104 	cache = device->port_data[port_num].cache.pkey;
1105 	if (!cache) {
1106 		ret = -EINVAL;
1107 		goto err;
1108 	}
1109 
1110 	*index = -1;
1111 
1112 	for (i = 0; i < cache->table_len; ++i)
1113 		if ((cache->table[i] & 0x7fff) == (pkey & 0x7fff)) {
1114 			if (cache->table[i] & 0x8000) {
1115 				*index = i;
1116 				ret = 0;
1117 				break;
1118 			} else {
1119 				partial_ix = i;
1120 			}
1121 		}
1122 
1123 	if (ret && partial_ix >= 0) {
1124 		*index = partial_ix;
1125 		ret = 0;
1126 	}
1127 
1128 err:
1129 	read_unlock_irqrestore(&device->cache_lock, flags);
1130 
1131 	return ret;
1132 }
1133 EXPORT_SYMBOL(ib_find_cached_pkey);
1134 
1135 int ib_find_exact_cached_pkey(struct ib_device *device, u32 port_num,
1136 			      u16 pkey, u16 *index)
1137 {
1138 	struct ib_pkey_cache *cache;
1139 	unsigned long flags;
1140 	int i;
1141 	int ret = -ENOENT;
1142 
1143 	if (!rdma_is_port_valid(device, port_num))
1144 		return -EINVAL;
1145 
1146 	read_lock_irqsave(&device->cache_lock, flags);
1147 
1148 	cache = device->port_data[port_num].cache.pkey;
1149 	if (!cache) {
1150 		ret = -EINVAL;
1151 		goto err;
1152 	}
1153 
1154 	*index = -1;
1155 
1156 	for (i = 0; i < cache->table_len; ++i)
1157 		if (cache->table[i] == pkey) {
1158 			*index = i;
1159 			ret = 0;
1160 			break;
1161 		}
1162 
1163 err:
1164 	read_unlock_irqrestore(&device->cache_lock, flags);
1165 
1166 	return ret;
1167 }
1168 EXPORT_SYMBOL(ib_find_exact_cached_pkey);
1169 
1170 int ib_get_cached_lmc(struct ib_device *device, u32 port_num, u8 *lmc)
1171 {
1172 	unsigned long flags;
1173 	int ret = 0;
1174 
1175 	if (!rdma_is_port_valid(device, port_num))
1176 		return -EINVAL;
1177 
1178 	read_lock_irqsave(&device->cache_lock, flags);
1179 	*lmc = device->port_data[port_num].cache.lmc;
1180 	read_unlock_irqrestore(&device->cache_lock, flags);
1181 
1182 	return ret;
1183 }
1184 EXPORT_SYMBOL(ib_get_cached_lmc);
1185 
1186 int ib_get_cached_port_state(struct ib_device *device, u32 port_num,
1187 			     enum ib_port_state *port_state)
1188 {
1189 	unsigned long flags;
1190 	int ret = 0;
1191 
1192 	if (!rdma_is_port_valid(device, port_num))
1193 		return -EINVAL;
1194 
1195 	read_lock_irqsave(&device->cache_lock, flags);
1196 	*port_state = device->port_data[port_num].cache.port_state;
1197 	read_unlock_irqrestore(&device->cache_lock, flags);
1198 
1199 	return ret;
1200 }
1201 EXPORT_SYMBOL(ib_get_cached_port_state);
1202 
1203 /**
1204  * rdma_get_gid_attr - Returns GID attributes for a port of a device
1205  * at a requested gid_index, if a valid GID entry exists.
1206  * @device:		The device to query.
1207  * @port_num:		The port number on the device where the GID value
1208  *			is to be queried.
1209  * @index:		Index of the GID table entry whose attributes are to
1210  *                      be queried.
1211  *
1212  * rdma_get_gid_attr() acquires reference count of gid attributes from the
1213  * cached GID table. Caller must invoke rdma_put_gid_attr() to release
1214  * reference to gid attribute regardless of link layer.
1215  *
1216  * Returns pointer to valid gid attribute or ERR_PTR for the appropriate error
1217  * code.
1218  */
1219 const struct ib_gid_attr *
1220 rdma_get_gid_attr(struct ib_device *device, u32 port_num, int index)
1221 {
1222 	const struct ib_gid_attr *attr = ERR_PTR(-ENODATA);
1223 	struct ib_gid_table *table;
1224 	unsigned long flags;
1225 
1226 	if (!rdma_is_port_valid(device, port_num))
1227 		return ERR_PTR(-EINVAL);
1228 
1229 	table = rdma_gid_table(device, port_num);
1230 	if (index < 0 || index >= table->sz)
1231 		return ERR_PTR(-EINVAL);
1232 
1233 	read_lock_irqsave(&table->rwlock, flags);
1234 	if (!is_gid_entry_valid(table->data_vec[index]))
1235 		goto done;
1236 
1237 	get_gid_entry(table->data_vec[index]);
1238 	attr = &table->data_vec[index]->attr;
1239 done:
1240 	read_unlock_irqrestore(&table->rwlock, flags);
1241 	return attr;
1242 }
1243 EXPORT_SYMBOL(rdma_get_gid_attr);
1244 
1245 /**
1246  * rdma_query_gid_table - Reads GID table entries of all the ports of a device up to max_entries.
1247  * @device: The device to query.
1248  * @entries: Entries where GID entries are returned.
1249  * @max_entries: Maximum number of entries that can be returned.
1250  * Entries array must be allocated to hold max_entries number of entries.
1251  *
1252  * Returns number of entries on success or appropriate error code.
1253  */
1254 ssize_t rdma_query_gid_table(struct ib_device *device,
1255 			     struct ib_uverbs_gid_entry *entries,
1256 			     size_t max_entries)
1257 {
1258 	const struct ib_gid_attr *gid_attr;
1259 	ssize_t num_entries = 0, ret;
1260 	struct ib_gid_table *table;
1261 	u32 port_num, i;
1262 	struct net_device *ndev;
1263 	unsigned long flags;
1264 
1265 	rdma_for_each_port(device, port_num) {
1266 		table = rdma_gid_table(device, port_num);
1267 		read_lock_irqsave(&table->rwlock, flags);
1268 		for (i = 0; i < table->sz; i++) {
1269 			if (!is_gid_entry_valid(table->data_vec[i]))
1270 				continue;
1271 			if (num_entries >= max_entries) {
1272 				ret = -EINVAL;
1273 				goto err;
1274 			}
1275 
1276 			gid_attr = &table->data_vec[i]->attr;
1277 
1278 			memcpy(&entries->gid, &gid_attr->gid,
1279 			       sizeof(gid_attr->gid));
1280 			entries->gid_index = gid_attr->index;
1281 			entries->port_num = gid_attr->port_num;
1282 			entries->gid_type = gid_attr->gid_type;
1283 			ndev = rcu_dereference_protected(
1284 				gid_attr->ndev,
1285 				lockdep_is_held(&table->rwlock));
1286 			if (ndev)
1287 				entries->netdev_ifindex = ndev->ifindex;
1288 
1289 			num_entries++;
1290 			entries++;
1291 		}
1292 		read_unlock_irqrestore(&table->rwlock, flags);
1293 	}
1294 
1295 	return num_entries;
1296 err:
1297 	read_unlock_irqrestore(&table->rwlock, flags);
1298 	return ret;
1299 }
1300 EXPORT_SYMBOL(rdma_query_gid_table);
1301 
1302 /**
1303  * rdma_put_gid_attr - Release reference to the GID attribute
1304  * @attr:		Pointer to the GID attribute whose reference
1305  *			needs to be released.
1306  *
1307  * rdma_put_gid_attr() must be used to release reference whose
1308  * reference is acquired using rdma_get_gid_attr() or any APIs
1309  * which returns a pointer to the ib_gid_attr regardless of link layer
1310  * of IB or RoCE.
1311  *
1312  */
1313 void rdma_put_gid_attr(const struct ib_gid_attr *attr)
1314 {
1315 	struct ib_gid_table_entry *entry =
1316 		container_of(attr, struct ib_gid_table_entry, attr);
1317 
1318 	put_gid_entry(entry);
1319 }
1320 EXPORT_SYMBOL(rdma_put_gid_attr);
1321 
1322 /**
1323  * rdma_hold_gid_attr - Get reference to existing GID attribute
1324  *
1325  * @attr:		Pointer to the GID attribute whose reference
1326  *			needs to be taken.
1327  *
1328  * Increase the reference count to a GID attribute to keep it from being
1329  * freed. Callers are required to already be holding a reference to attribute.
1330  *
1331  */
1332 void rdma_hold_gid_attr(const struct ib_gid_attr *attr)
1333 {
1334 	struct ib_gid_table_entry *entry =
1335 		container_of(attr, struct ib_gid_table_entry, attr);
1336 
1337 	get_gid_entry(entry);
1338 }
1339 EXPORT_SYMBOL(rdma_hold_gid_attr);
1340 
1341 /**
1342  * rdma_read_gid_attr_ndev_rcu - Read GID attribute netdevice
1343  * which must be in UP state.
1344  *
1345  * @attr:Pointer to the GID attribute
1346  *
1347  * Returns pointer to netdevice if the netdevice was attached to GID and
1348  * netdevice is in UP state. Caller must hold RCU lock as this API
1349  * reads the netdev flags which can change while netdevice migrates to
1350  * different net namespace. Returns ERR_PTR with error code otherwise.
1351  *
1352  */
1353 struct net_device *rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr)
1354 {
1355 	struct ib_gid_table_entry *entry =
1356 			container_of(attr, struct ib_gid_table_entry, attr);
1357 	struct ib_device *device = entry->attr.device;
1358 	struct net_device *ndev = ERR_PTR(-EINVAL);
1359 	u32 port_num = entry->attr.port_num;
1360 	struct ib_gid_table *table;
1361 	unsigned long flags;
1362 	bool valid;
1363 
1364 	table = rdma_gid_table(device, port_num);
1365 
1366 	read_lock_irqsave(&table->rwlock, flags);
1367 	valid = is_gid_entry_valid(table->data_vec[attr->index]);
1368 	if (valid) {
1369 		ndev = rcu_dereference(attr->ndev);
1370 		if (!ndev)
1371 			ndev = ERR_PTR(-ENODEV);
1372 	}
1373 	read_unlock_irqrestore(&table->rwlock, flags);
1374 	return ndev;
1375 }
1376 EXPORT_SYMBOL(rdma_read_gid_attr_ndev_rcu);
1377 
1378 static int get_lower_dev_vlan(struct net_device *lower_dev,
1379 			      struct netdev_nested_priv *priv)
1380 {
1381 	u16 *vlan_id = (u16 *)priv->data;
1382 
1383 	if (is_vlan_dev(lower_dev))
1384 		*vlan_id = vlan_dev_vlan_id(lower_dev);
1385 
1386 	/* We are interested only in first level vlan device, so
1387 	 * always return 1 to stop iterating over next level devices.
1388 	 */
1389 	return 1;
1390 }
1391 
1392 /**
1393  * rdma_read_gid_l2_fields - Read the vlan ID and source MAC address
1394  *			     of a GID entry.
1395  *
1396  * @attr:	GID attribute pointer whose L2 fields to be read
1397  * @vlan_id:	Pointer to vlan id to fill up if the GID entry has
1398  *		vlan id. It is optional.
1399  * @smac:	Pointer to smac to fill up for a GID entry. It is optional.
1400  *
1401  * rdma_read_gid_l2_fields() returns 0 on success and returns vlan id
1402  * (if gid entry has vlan) and source MAC, or returns error.
1403  */
1404 int rdma_read_gid_l2_fields(const struct ib_gid_attr *attr,
1405 			    u16 *vlan_id, u8 *smac)
1406 {
1407 	struct netdev_nested_priv priv = {
1408 		.data = (void *)vlan_id,
1409 	};
1410 	struct net_device *ndev;
1411 
1412 	rcu_read_lock();
1413 	ndev = rcu_dereference(attr->ndev);
1414 	if (!ndev) {
1415 		rcu_read_unlock();
1416 		return -ENODEV;
1417 	}
1418 	if (smac)
1419 		ether_addr_copy(smac, ndev->dev_addr);
1420 	if (vlan_id) {
1421 		*vlan_id = 0xffff;
1422 		if (is_vlan_dev(ndev)) {
1423 			*vlan_id = vlan_dev_vlan_id(ndev);
1424 		} else {
1425 			/* If the netdev is upper device and if it's lower
1426 			 * device is vlan device, consider vlan id of the
1427 			 * the lower vlan device for this gid entry.
1428 			 */
1429 			netdev_walk_all_lower_dev_rcu(attr->ndev,
1430 					get_lower_dev_vlan, &priv);
1431 		}
1432 	}
1433 	rcu_read_unlock();
1434 	return 0;
1435 }
1436 EXPORT_SYMBOL(rdma_read_gid_l2_fields);
1437 
1438 static int config_non_roce_gid_cache(struct ib_device *device,
1439 				     u32 port, struct ib_port_attr *tprops)
1440 {
1441 	struct ib_gid_attr gid_attr = {};
1442 	struct ib_gid_table *table;
1443 	int ret = 0;
1444 	int i;
1445 
1446 	gid_attr.device = device;
1447 	gid_attr.port_num = port;
1448 	table = rdma_gid_table(device, port);
1449 
1450 	mutex_lock(&table->lock);
1451 	for (i = 0; i < tprops->gid_tbl_len; ++i) {
1452 		if (!device->ops.query_gid)
1453 			continue;
1454 		ret = device->ops.query_gid(device, port, i, &gid_attr.gid);
1455 		if (ret) {
1456 			dev_warn(&device->dev,
1457 				 "query_gid failed (%d) for index %d\n", ret,
1458 				 i);
1459 			goto err;
1460 		}
1461 		gid_attr.index = i;
1462 		tprops->subnet_prefix =
1463 			be64_to_cpu(gid_attr.gid.global.subnet_prefix);
1464 		add_modify_gid(table, &gid_attr);
1465 	}
1466 err:
1467 	mutex_unlock(&table->lock);
1468 	return ret;
1469 }
1470 
1471 static int
1472 ib_cache_update(struct ib_device *device, u32 port, bool update_gids,
1473 		bool update_pkeys, bool enforce_security)
1474 {
1475 	struct ib_port_attr       *tprops = NULL;
1476 	struct ib_pkey_cache      *pkey_cache = NULL;
1477 	struct ib_pkey_cache      *old_pkey_cache = NULL;
1478 	int                        i;
1479 	int                        ret;
1480 
1481 	if (!rdma_is_port_valid(device, port))
1482 		return -EINVAL;
1483 
1484 	tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
1485 	if (!tprops)
1486 		return -ENOMEM;
1487 
1488 	ret = ib_query_port(device, port, tprops);
1489 	if (ret) {
1490 		dev_warn(&device->dev, "ib_query_port failed (%d)\n", ret);
1491 		goto err;
1492 	}
1493 
1494 	if (!rdma_protocol_roce(device, port) && update_gids) {
1495 		ret = config_non_roce_gid_cache(device, port,
1496 						tprops);
1497 		if (ret)
1498 			goto err;
1499 	}
1500 
1501 	update_pkeys &= !!tprops->pkey_tbl_len;
1502 
1503 	if (update_pkeys) {
1504 		pkey_cache = kmalloc(struct_size(pkey_cache, table,
1505 						 tprops->pkey_tbl_len),
1506 				     GFP_KERNEL);
1507 		if (!pkey_cache) {
1508 			ret = -ENOMEM;
1509 			goto err;
1510 		}
1511 
1512 		pkey_cache->table_len = tprops->pkey_tbl_len;
1513 
1514 		for (i = 0; i < pkey_cache->table_len; ++i) {
1515 			ret = ib_query_pkey(device, port, i,
1516 					    pkey_cache->table + i);
1517 			if (ret) {
1518 				dev_warn(&device->dev,
1519 					 "ib_query_pkey failed (%d) for index %d\n",
1520 					 ret, i);
1521 				goto err;
1522 			}
1523 		}
1524 	}
1525 
1526 	write_lock_irq(&device->cache_lock);
1527 
1528 	if (update_pkeys) {
1529 		old_pkey_cache = device->port_data[port].cache.pkey;
1530 		device->port_data[port].cache.pkey = pkey_cache;
1531 	}
1532 	device->port_data[port].cache.lmc = tprops->lmc;
1533 	device->port_data[port].cache.port_state = tprops->state;
1534 
1535 	device->port_data[port].cache.subnet_prefix = tprops->subnet_prefix;
1536 	write_unlock_irq(&device->cache_lock);
1537 
1538 	if (enforce_security)
1539 		ib_security_cache_change(device,
1540 					 port,
1541 					 tprops->subnet_prefix);
1542 
1543 	kfree(old_pkey_cache);
1544 	kfree(tprops);
1545 	return 0;
1546 
1547 err:
1548 	kfree(pkey_cache);
1549 	kfree(tprops);
1550 	return ret;
1551 }
1552 
1553 static void ib_cache_event_task(struct work_struct *_work)
1554 {
1555 	struct ib_update_work *work =
1556 		container_of(_work, struct ib_update_work, work);
1557 	int ret;
1558 
1559 	/* Before distributing the cache update event, first sync
1560 	 * the cache.
1561 	 */
1562 	ret = ib_cache_update(work->event.device, work->event.element.port_num,
1563 			      work->event.event == IB_EVENT_GID_CHANGE,
1564 			      work->event.event == IB_EVENT_PKEY_CHANGE,
1565 			      work->enforce_security);
1566 
1567 	/* GID event is notified already for individual GID entries by
1568 	 * dispatch_gid_change_event(). Hence, notifiy for rest of the
1569 	 * events.
1570 	 */
1571 	if (!ret && work->event.event != IB_EVENT_GID_CHANGE)
1572 		ib_dispatch_event_clients(&work->event);
1573 
1574 	kfree(work);
1575 }
1576 
1577 static void ib_generic_event_task(struct work_struct *_work)
1578 {
1579 	struct ib_update_work *work =
1580 		container_of(_work, struct ib_update_work, work);
1581 
1582 	ib_dispatch_event_clients(&work->event);
1583 	kfree(work);
1584 }
1585 
1586 static bool is_cache_update_event(const struct ib_event *event)
1587 {
1588 	return (event->event == IB_EVENT_PORT_ERR    ||
1589 		event->event == IB_EVENT_PORT_ACTIVE ||
1590 		event->event == IB_EVENT_LID_CHANGE  ||
1591 		event->event == IB_EVENT_PKEY_CHANGE ||
1592 		event->event == IB_EVENT_CLIENT_REREGISTER ||
1593 		event->event == IB_EVENT_GID_CHANGE);
1594 }
1595 
1596 /**
1597  * ib_dispatch_event - Dispatch an asynchronous event
1598  * @event:Event to dispatch
1599  *
1600  * Low-level drivers must call ib_dispatch_event() to dispatch the
1601  * event to all registered event handlers when an asynchronous event
1602  * occurs.
1603  */
1604 void ib_dispatch_event(const struct ib_event *event)
1605 {
1606 	struct ib_update_work *work;
1607 
1608 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
1609 	if (!work)
1610 		return;
1611 
1612 	if (is_cache_update_event(event))
1613 		INIT_WORK(&work->work, ib_cache_event_task);
1614 	else
1615 		INIT_WORK(&work->work, ib_generic_event_task);
1616 
1617 	work->event = *event;
1618 	if (event->event == IB_EVENT_PKEY_CHANGE ||
1619 	    event->event == IB_EVENT_GID_CHANGE)
1620 		work->enforce_security = true;
1621 
1622 	queue_work(ib_wq, &work->work);
1623 }
1624 EXPORT_SYMBOL(ib_dispatch_event);
1625 
1626 int ib_cache_setup_one(struct ib_device *device)
1627 {
1628 	u32 p;
1629 	int err;
1630 
1631 	err = gid_table_setup_one(device);
1632 	if (err)
1633 		return err;
1634 
1635 	rdma_for_each_port (device, p) {
1636 		err = ib_cache_update(device, p, true, true, true);
1637 		if (err)
1638 			return err;
1639 	}
1640 
1641 	return 0;
1642 }
1643 
1644 void ib_cache_release_one(struct ib_device *device)
1645 {
1646 	u32 p;
1647 
1648 	/*
1649 	 * The release function frees all the cache elements.
1650 	 * This function should be called as part of freeing
1651 	 * all the device's resources when the cache could no
1652 	 * longer be accessed.
1653 	 */
1654 	rdma_for_each_port (device, p)
1655 		kfree(device->port_data[p].cache.pkey);
1656 
1657 	gid_table_release_one(device);
1658 }
1659 
1660 void ib_cache_cleanup_one(struct ib_device *device)
1661 {
1662 	/* The cleanup function waits for all in-progress workqueue
1663 	 * elements and cleans up the GID cache. This function should be
1664 	 * called after the device was removed from the devices list and
1665 	 * all clients were removed, so the cache exists but is
1666 	 * non-functional and shouldn't be updated anymore.
1667 	 */
1668 	flush_workqueue(ib_wq);
1669 	gid_table_cleanup_one(device);
1670 
1671 	/*
1672 	 * Flush the wq second time for any pending GID delete work.
1673 	 */
1674 	flush_workqueue(ib_wq);
1675 }
1676