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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
3
4#include <linux/module.h>
5#include <linux/slab.h>
6#include <linux/rhashtable.h>
7#include <linux/idr.h>
8#include <linux/list.h>
9#include <linux/sort.h>
10#include <linux/objagg.h>
11
12#define CREATE_TRACE_POINTS
13#include <trace/events/objagg.h>
14
15struct objagg_hints {
16 struct rhashtable node_ht;
17 struct rhashtable_params ht_params;
18 struct list_head node_list;
19 unsigned int node_count;
20 unsigned int root_count;
21 unsigned int refcount;
22 const struct objagg_ops *ops;
23};
24
25struct objagg_hints_node {
26 struct rhash_head ht_node; /* member of objagg_hints->node_ht */
27 struct list_head list; /* member of objagg_hints->node_list */
28 struct objagg_hints_node *parent;
29 unsigned int root_id;
30 struct objagg_obj_stats_info stats_info;
31 unsigned long obj[];
32};
33
34static struct objagg_hints_node *
35objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj)
36{
37 if (!objagg_hints)
38 return NULL;
39 return rhashtable_lookup_fast(&objagg_hints->node_ht, obj,
40 objagg_hints->ht_params);
41}
42
43struct objagg {
44 const struct objagg_ops *ops;
45 void *priv;
46 struct rhashtable obj_ht;
47 struct rhashtable_params ht_params;
48 struct list_head obj_list;
49 unsigned int obj_count;
50 struct ida root_ida;
51 struct objagg_hints *hints;
52};
53
54struct objagg_obj {
55 struct rhash_head ht_node; /* member of objagg->obj_ht */
56 struct list_head list; /* member of objagg->obj_list */
57 struct objagg_obj *parent; /* if the object is nested, this
58 * holds pointer to parent, otherwise NULL
59 */
60 union {
61 void *delta_priv; /* user delta private */
62 void *root_priv; /* user root private */
63 };
64 unsigned int root_id;
65 unsigned int refcount; /* counts number of users of this object
66 * including nested objects
67 */
68 struct objagg_obj_stats stats;
69 unsigned long obj[];
70};
71
72static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj)
73{
74 return ++objagg_obj->refcount;
75}
76
77static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj)
78{
79 return --objagg_obj->refcount;
80}
81
82static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj)
83{
84 objagg_obj->stats.user_count++;
85 objagg_obj->stats.delta_user_count++;
86 if (objagg_obj->parent)
87 objagg_obj->parent->stats.delta_user_count++;
88}
89
90static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj)
91{
92 objagg_obj->stats.user_count--;
93 objagg_obj->stats.delta_user_count--;
94 if (objagg_obj->parent)
95 objagg_obj->parent->stats.delta_user_count--;
96}
97
98static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj)
99{
100 /* Nesting is not supported, so we can use ->parent
101 * to figure out if the object is root.
102 */
103 return !objagg_obj->parent;
104}
105
106/**
107 * objagg_obj_root_priv - obtains root private for an object
108 * @objagg_obj: objagg object instance
109 *
110 * Note: all locking must be provided by the caller.
111 *
112 * Either the object is root itself when the private is returned
113 * directly, or the parent is root and its private is returned
114 * instead.
115 *
116 * Returns a user private root pointer.
117 */
118const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj)
119{
120 if (objagg_obj_is_root(objagg_obj))
121 return objagg_obj->root_priv;
122 WARN_ON(!objagg_obj_is_root(objagg_obj->parent));
123 return objagg_obj->parent->root_priv;
124}
125EXPORT_SYMBOL(objagg_obj_root_priv);
126
127/**
128 * objagg_obj_delta_priv - obtains delta private for an object
129 * @objagg_obj: objagg object instance
130 *
131 * Note: all locking must be provided by the caller.
132 *
133 * Returns user private delta pointer or NULL in case the passed
134 * object is root.
135 */
136const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj)
137{
138 if (objagg_obj_is_root(objagg_obj))
139 return NULL;
140 return objagg_obj->delta_priv;
141}
142EXPORT_SYMBOL(objagg_obj_delta_priv);
143
144/**
145 * objagg_obj_raw - obtains object user private pointer
146 * @objagg_obj: objagg object instance
147 *
148 * Note: all locking must be provided by the caller.
149 *
150 * Returns user private pointer as was passed to objagg_obj_get() by "obj" arg.
151 */
152const void *objagg_obj_raw(const struct objagg_obj *objagg_obj)
153{
154 return objagg_obj->obj;
155}
156EXPORT_SYMBOL(objagg_obj_raw);
157
158static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj)
159{
160 return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);
161}
162
163static int objagg_obj_parent_assign(struct objagg *objagg,
164 struct objagg_obj *objagg_obj,
165 struct objagg_obj *parent,
166 bool take_parent_ref)
167{
168 void *delta_priv;
169
170 delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj,
171 objagg_obj->obj);
172 if (IS_ERR(delta_priv))
173 return PTR_ERR(delta_priv);
174
175 /* User returned a delta private, that means that
176 * our object can be aggregated into the parent.
177 */
178 objagg_obj->parent = parent;
179 objagg_obj->delta_priv = delta_priv;
180 if (take_parent_ref)
181 objagg_obj_ref_inc(objagg_obj->parent);
182 trace_objagg_obj_parent_assign(objagg, objagg_obj,
183 parent,
184 parent->refcount);
185 return 0;
186}
187
188static int objagg_obj_parent_lookup_assign(struct objagg *objagg,
189 struct objagg_obj *objagg_obj)
190{
191 struct objagg_obj *objagg_obj_cur;
192 int err;
193
194 list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) {
195 /* Nesting is not supported. In case the object
196 * is not root, it cannot be assigned as parent.
197 */
198 if (!objagg_obj_is_root(objagg_obj_cur))
199 continue;
200 err = objagg_obj_parent_assign(objagg, objagg_obj,
201 objagg_obj_cur, true);
202 if (!err)
203 return 0;
204 }
205 return -ENOENT;
206}
207
208static void __objagg_obj_put(struct objagg *objagg,
209 struct objagg_obj *objagg_obj);
210
211static void objagg_obj_parent_unassign(struct objagg *objagg,
212 struct objagg_obj *objagg_obj)
213{
214 trace_objagg_obj_parent_unassign(objagg, objagg_obj,
215 objagg_obj->parent,
216 objagg_obj->parent->refcount);
217 objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);
218 __objagg_obj_put(objagg, objagg_obj->parent);
219}
220
221static int objagg_obj_root_id_alloc(struct objagg *objagg,
222 struct objagg_obj *objagg_obj,
223 struct objagg_hints_node *hnode)
224{
225 unsigned int min, max;
226 int root_id;
227
228 /* In case there are no hints available, the root id is invalid. */
229 if (!objagg->hints) {
230 objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID;
231 return 0;
232 }
233
234 if (hnode) {
235 min = hnode->root_id;
236 max = hnode->root_id;
237 } else {
238 /* For objects with no hint, start after the last
239 * hinted root_id.
240 */
241 min = objagg->hints->root_count;
242 max = ~0;
243 }
244
245 root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL);
246
247 if (root_id < 0)
248 return root_id;
249 objagg_obj->root_id = root_id;
250 return 0;
251}
252
253static void objagg_obj_root_id_free(struct objagg *objagg,
254 struct objagg_obj *objagg_obj)
255{
256 if (!objagg->hints)
257 return;
258 ida_free(&objagg->root_ida, objagg_obj->root_id);
259}
260
261static int objagg_obj_root_create(struct objagg *objagg,
262 struct objagg_obj *objagg_obj,
263 struct objagg_hints_node *hnode)
264{
265 int err;
266
267 err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode);
268 if (err)
269 return err;
270 objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,
271 objagg_obj->obj,
272 objagg_obj->root_id);
273 if (IS_ERR(objagg_obj->root_priv)) {
274 err = PTR_ERR(objagg_obj->root_priv);
275 goto err_root_create;
276 }
277 trace_objagg_obj_root_create(objagg, objagg_obj);
278 return 0;
279
280err_root_create:
281 objagg_obj_root_id_free(objagg, objagg_obj);
282 return err;
283}
284
285static void objagg_obj_root_destroy(struct objagg *objagg,
286 struct objagg_obj *objagg_obj)
287{
288 trace_objagg_obj_root_destroy(objagg, objagg_obj);
289 objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv);
290 objagg_obj_root_id_free(objagg, objagg_obj);
291}
292
293static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj);
294
295static int objagg_obj_init_with_hints(struct objagg *objagg,
296 struct objagg_obj *objagg_obj,
297 bool *hint_found)
298{
299 struct objagg_hints_node *hnode;
300 struct objagg_obj *parent;
301 int err;
302
303 hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj);
304 if (!hnode) {
305 *hint_found = false;
306 return 0;
307 }
308 *hint_found = true;
309
310 if (!hnode->parent)
311 return objagg_obj_root_create(objagg, objagg_obj, hnode);
312
313 parent = __objagg_obj_get(objagg, hnode->parent->obj);
314 if (IS_ERR(parent))
315 return PTR_ERR(parent);
316
317 err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false);
318 if (err) {
319 *hint_found = false;
320 err = 0;
321 goto err_parent_assign;
322 }
323
324 return 0;
325
326err_parent_assign:
327 objagg_obj_put(objagg, parent);
328 return err;
329}
330
331static int objagg_obj_init(struct objagg *objagg,
332 struct objagg_obj *objagg_obj)
333{
334 bool hint_found;
335 int err;
336
337 /* First, try to use hints if they are available and
338 * if they provide result.
339 */
340 err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found);
341 if (err)
342 return err;
343
344 if (hint_found)
345 return 0;
346
347 /* Try to find if the object can be aggregated under an existing one. */
348 err = objagg_obj_parent_lookup_assign(objagg, objagg_obj);
349 if (!err)
350 return 0;
351 /* If aggregation is not possible, make the object a root. */
352 return objagg_obj_root_create(objagg, objagg_obj, NULL);
353}
354
355static void objagg_obj_fini(struct objagg *objagg,
356 struct objagg_obj *objagg_obj)
357{
358 if (!objagg_obj_is_root(objagg_obj))
359 objagg_obj_parent_unassign(objagg, objagg_obj);
360 else
361 objagg_obj_root_destroy(objagg, objagg_obj);
362}
363
364static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj)
365{
366 struct objagg_obj *objagg_obj;
367 int err;
368
369 objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size,
370 GFP_KERNEL);
371 if (!objagg_obj)
372 return ERR_PTR(-ENOMEM);
373 objagg_obj_ref_inc(objagg_obj);
374 memcpy(objagg_obj->obj, obj, objagg->ops->obj_size);
375
376 err = objagg_obj_init(objagg, objagg_obj);
377 if (err)
378 goto err_obj_init;
379
380 err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node,
381 objagg->ht_params);
382 if (err)
383 goto err_ht_insert;
384 list_add(&objagg_obj->list, &objagg->obj_list);
385 objagg->obj_count++;
386 trace_objagg_obj_create(objagg, objagg_obj);
387
388 return objagg_obj;
389
390err_ht_insert:
391 objagg_obj_fini(objagg, objagg_obj);
392err_obj_init:
393 kfree(objagg_obj);
394 return ERR_PTR(err);
395}
396
397static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj)
398{
399 struct objagg_obj *objagg_obj;
400
401 /* First, try to find the object exactly as user passed it,
402 * perhaps it is already in use.
403 */
404 objagg_obj = objagg_obj_lookup(objagg, obj);
405 if (objagg_obj) {
406 objagg_obj_ref_inc(objagg_obj);
407 return objagg_obj;
408 }
409
410 return objagg_obj_create(objagg, obj);
411}
412
413/**
414 * objagg_obj_get - gets an object within objagg instance
415 * @objagg: objagg instance
416 * @obj: user-specific private object pointer
417 *
418 * Note: all locking must be provided by the caller.
419 *
420 * Size of the "obj" memory is specified in "objagg->ops".
421 *
422 * There are 3 main options this function wraps:
423 * 1) The object according to "obj" already exist. In that case
424 * the reference counter is incrementes and the object is returned.
425 * 2) The object does not exist, but it can be aggregated within
426 * another object. In that case, user ops->delta_create() is called
427 * to obtain delta data and a new object is created with returned
428 * user-delta private pointer.
429 * 3) The object does not exist and cannot be aggregated into
430 * any of the existing objects. In that case, user ops->root_create()
431 * is called to create the root and a new object is created with
432 * returned user-root private pointer.
433 *
434 * Returns a pointer to objagg object instance in case of success,
435 * otherwise it returns pointer error using ERR_PTR macro.
436 */
437struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj)
438{
439 struct objagg_obj *objagg_obj;
440
441 objagg_obj = __objagg_obj_get(objagg, obj);
442 if (IS_ERR(objagg_obj))
443 return objagg_obj;
444 objagg_obj_stats_inc(objagg_obj);
445 trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount);
446 return objagg_obj;
447}
448EXPORT_SYMBOL(objagg_obj_get);
449
450static void objagg_obj_destroy(struct objagg *objagg,
451 struct objagg_obj *objagg_obj)
452{
453 trace_objagg_obj_destroy(objagg, objagg_obj);
454 --objagg->obj_count;
455 list_del(&objagg_obj->list);
456 rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node,
457 objagg->ht_params);
458 objagg_obj_fini(objagg, objagg_obj);
459 kfree(objagg_obj);
460}
461
462static void __objagg_obj_put(struct objagg *objagg,
463 struct objagg_obj *objagg_obj)
464{
465 if (!objagg_obj_ref_dec(objagg_obj))
466 objagg_obj_destroy(objagg, objagg_obj);
467}
468
469/**
470 * objagg_obj_put - puts an object within objagg instance
471 * @objagg: objagg instance
472 * @objagg_obj: objagg object instance
473 *
474 * Note: all locking must be provided by the caller.
475 *
476 * Symmetric to objagg_obj_get().
477 */
478void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj)
479{
480 trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount);
481 objagg_obj_stats_dec(objagg_obj);
482 __objagg_obj_put(objagg, objagg_obj);
483}
484EXPORT_SYMBOL(objagg_obj_put);
485
486/**
487 * objagg_create - creates a new objagg instance
488 * @ops: user-specific callbacks
489 * @objagg_hints: hints, can be NULL
490 * @priv: pointer to a private data passed to the ops
491 *
492 * Note: all locking must be provided by the caller.
493 *
494 * The purpose of the library is to provide an infrastructure to
495 * aggregate user-specified objects. Library does not care about the type
496 * of the object. User fills-up ops which take care of the specific
497 * user object manipulation.
498 *
499 * As a very stupid example, consider integer numbers. For example
500 * number 8 as a root object. That can aggregate number 9 with delta 1,
501 * number 10 with delta 2, etc. This example is implemented as
502 * a part of a testing module in test_objagg.c file.
503 *
504 * Each objagg instance contains multiple trees. Each tree node is
505 * represented by "an object". In the current implementation there can be
506 * only roots and leafs nodes. Leaf nodes are called deltas.
507 * But in general, this can be easily extended for intermediate nodes.
508 * In that extension, a delta would be associated with all non-root
509 * nodes.
510 *
511 * Returns a pointer to newly created objagg instance in case of success,
512 * otherwise it returns pointer error using ERR_PTR macro.
513 */
514struct objagg *objagg_create(const struct objagg_ops *ops,
515 struct objagg_hints *objagg_hints, void *priv)
516{
517 struct objagg *objagg;
518 int err;
519
520 if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy ||
521 !ops->delta_check || !ops->delta_create ||
522 !ops->delta_destroy))
523 return ERR_PTR(-EINVAL);
524
525 objagg = kzalloc(sizeof(*objagg), GFP_KERNEL);
526 if (!objagg)
527 return ERR_PTR(-ENOMEM);
528 objagg->ops = ops;
529 if (objagg_hints) {
530 objagg->hints = objagg_hints;
531 objagg_hints->refcount++;
532 }
533 objagg->priv = priv;
534 INIT_LIST_HEAD(&objagg->obj_list);
535
536 objagg->ht_params.key_len = ops->obj_size;
537 objagg->ht_params.key_offset = offsetof(struct objagg_obj, obj);
538 objagg->ht_params.head_offset = offsetof(struct objagg_obj, ht_node);
539
540 err = rhashtable_init(&objagg->obj_ht, &objagg->ht_params);
541 if (err)
542 goto err_rhashtable_init;
543
544 ida_init(&objagg->root_ida);
545
546 trace_objagg_create(objagg);
547 return objagg;
548
549err_rhashtable_init:
550 kfree(objagg);
551 return ERR_PTR(err);
552}
553EXPORT_SYMBOL(objagg_create);
554
555/**
556 * objagg_destroy - destroys a new objagg instance
557 * @objagg: objagg instance
558 *
559 * Note: all locking must be provided by the caller.
560 */
561void objagg_destroy(struct objagg *objagg)
562{
563 trace_objagg_destroy(objagg);
564 ida_destroy(&objagg->root_ida);
565 WARN_ON(!list_empty(&objagg->obj_list));
566 rhashtable_destroy(&objagg->obj_ht);
567 if (objagg->hints)
568 objagg_hints_put(objagg->hints);
569 kfree(objagg);
570}
571EXPORT_SYMBOL(objagg_destroy);
572
573static int objagg_stats_info_sort_cmp_func(const void *a, const void *b)
574{
575 const struct objagg_obj_stats_info *stats_info1 = a;
576 const struct objagg_obj_stats_info *stats_info2 = b;
577
578 if (stats_info1->is_root != stats_info2->is_root)
579 return stats_info2->is_root - stats_info1->is_root;
580 if (stats_info1->stats.delta_user_count !=
581 stats_info2->stats.delta_user_count)
582 return stats_info2->stats.delta_user_count -
583 stats_info1->stats.delta_user_count;
584 return stats_info2->stats.user_count - stats_info1->stats.user_count;
585}
586
587/**
588 * objagg_stats_get - obtains stats of the objagg instance
589 * @objagg: objagg instance
590 *
591 * Note: all locking must be provided by the caller.
592 *
593 * The returned structure contains statistics of all object
594 * currently in use, ordered by following rules:
595 * 1) Root objects are always on lower indexes than the rest.
596 * 2) Objects with higher delta user count are always on lower
597 * indexes.
598 * 3) In case more objects have the same delta user count,
599 * the objects are ordered by user count.
600 *
601 * Returns a pointer to stats instance in case of success,
602 * otherwise it returns pointer error using ERR_PTR macro.
603 */
604const struct objagg_stats *objagg_stats_get(struct objagg *objagg)
605{
606 struct objagg_stats *objagg_stats;
607 struct objagg_obj *objagg_obj;
608 int i;
609
610 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
611 objagg->obj_count), GFP_KERNEL);
612 if (!objagg_stats)
613 return ERR_PTR(-ENOMEM);
614
615 i = 0;
616 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
617 memcpy(&objagg_stats->stats_info[i].stats, &objagg_obj->stats,
618 sizeof(objagg_stats->stats_info[0].stats));
619 objagg_stats->stats_info[i].objagg_obj = objagg_obj;
620 objagg_stats->stats_info[i].is_root =
621 objagg_obj_is_root(objagg_obj);
622 if (objagg_stats->stats_info[i].is_root)
623 objagg_stats->root_count++;
624 i++;
625 }
626 objagg_stats->stats_info_count = i;
627
628 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
629 sizeof(struct objagg_obj_stats_info),
630 objagg_stats_info_sort_cmp_func, NULL);
631
632 return objagg_stats;
633}
634EXPORT_SYMBOL(objagg_stats_get);
635
636/**
637 * objagg_stats_put - puts stats of the objagg instance
638 * @objagg_stats: objagg instance stats
639 *
640 * Note: all locking must be provided by the caller.
641 */
642void objagg_stats_put(const struct objagg_stats *objagg_stats)
643{
644 kfree(objagg_stats);
645}
646EXPORT_SYMBOL(objagg_stats_put);
647
648static struct objagg_hints_node *
649objagg_hints_node_create(struct objagg_hints *objagg_hints,
650 struct objagg_obj *objagg_obj, size_t obj_size,
651 struct objagg_hints_node *parent_hnode)
652{
653 unsigned int user_count = objagg_obj->stats.user_count;
654 struct objagg_hints_node *hnode;
655 int err;
656
657 hnode = kzalloc(sizeof(*hnode) + obj_size, GFP_KERNEL);
658 if (!hnode)
659 return ERR_PTR(-ENOMEM);
660 memcpy(hnode->obj, &objagg_obj->obj, obj_size);
661 hnode->stats_info.stats.user_count = user_count;
662 hnode->stats_info.stats.delta_user_count = user_count;
663 if (parent_hnode) {
664 parent_hnode->stats_info.stats.delta_user_count += user_count;
665 } else {
666 hnode->root_id = objagg_hints->root_count++;
667 hnode->stats_info.is_root = true;
668 }
669 hnode->stats_info.objagg_obj = objagg_obj;
670
671 err = rhashtable_insert_fast(&objagg_hints->node_ht, &hnode->ht_node,
672 objagg_hints->ht_params);
673 if (err)
674 goto err_ht_insert;
675
676 list_add(&hnode->list, &objagg_hints->node_list);
677 hnode->parent = parent_hnode;
678 objagg_hints->node_count++;
679
680 return hnode;
681
682err_ht_insert:
683 kfree(hnode);
684 return ERR_PTR(err);
685}
686
687static void objagg_hints_flush(struct objagg_hints *objagg_hints)
688{
689 struct objagg_hints_node *hnode, *tmp;
690
691 list_for_each_entry_safe(hnode, tmp, &objagg_hints->node_list, list) {
692 list_del(&hnode->list);
693 rhashtable_remove_fast(&objagg_hints->node_ht, &hnode->ht_node,
694 objagg_hints->ht_params);
695 kfree(hnode);
696 }
697}
698
699struct objagg_tmp_node {
700 struct objagg_obj *objagg_obj;
701 bool crossed_out;
702};
703
704struct objagg_tmp_graph {
705 struct objagg_tmp_node *nodes;
706 unsigned long nodes_count;
707 unsigned long *edges;
708};
709
710static int objagg_tmp_graph_edge_index(struct objagg_tmp_graph *graph,
711 int parent_index, int index)
712{
713 return index * graph->nodes_count + parent_index;
714}
715
716static void objagg_tmp_graph_edge_set(struct objagg_tmp_graph *graph,
717 int parent_index, int index)
718{
719 int edge_index = objagg_tmp_graph_edge_index(graph, index,
720 parent_index);
721
722 __set_bit(edge_index, graph->edges);
723}
724
725static bool objagg_tmp_graph_is_edge(struct objagg_tmp_graph *graph,
726 int parent_index, int index)
727{
728 int edge_index = objagg_tmp_graph_edge_index(graph, index,
729 parent_index);
730
731 return test_bit(edge_index, graph->edges);
732}
733
734static unsigned int objagg_tmp_graph_node_weight(struct objagg_tmp_graph *graph,
735 unsigned int index)
736{
737 struct objagg_tmp_node *node = &graph->nodes[index];
738 unsigned int weight = node->objagg_obj->stats.user_count;
739 int j;
740
741 /* Node weight is sum of node users and all other nodes users
742 * that this node can represent with delta.
743 */
744
745 for (j = 0; j < graph->nodes_count; j++) {
746 if (!objagg_tmp_graph_is_edge(graph, index, j))
747 continue;
748 node = &graph->nodes[j];
749 if (node->crossed_out)
750 continue;
751 weight += node->objagg_obj->stats.user_count;
752 }
753 return weight;
754}
755
756static int objagg_tmp_graph_node_max_weight(struct objagg_tmp_graph *graph)
757{
758 struct objagg_tmp_node *node;
759 unsigned int max_weight = 0;
760 unsigned int weight;
761 int max_index = -1;
762 int i;
763
764 for (i = 0; i < graph->nodes_count; i++) {
765 node = &graph->nodes[i];
766 if (node->crossed_out)
767 continue;
768 weight = objagg_tmp_graph_node_weight(graph, i);
769 if (weight >= max_weight) {
770 max_weight = weight;
771 max_index = i;
772 }
773 }
774 return max_index;
775}
776
777static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
778{
779 unsigned int nodes_count = objagg->obj_count;
780 struct objagg_tmp_graph *graph;
781 struct objagg_tmp_node *node;
782 struct objagg_tmp_node *pnode;
783 struct objagg_obj *objagg_obj;
784 size_t alloc_size;
785 int i, j;
786
787 graph = kzalloc(sizeof(*graph), GFP_KERNEL);
788 if (!graph)
789 return NULL;
790
791 graph->nodes = kcalloc(nodes_count, sizeof(*graph->nodes), GFP_KERNEL);
792 if (!graph->nodes)
793 goto err_nodes_alloc;
794 graph->nodes_count = nodes_count;
795
796 alloc_size = BITS_TO_LONGS(nodes_count * nodes_count) *
797 sizeof(unsigned long);
798 graph->edges = kzalloc(alloc_size, GFP_KERNEL);
799 if (!graph->edges)
800 goto err_edges_alloc;
801
802 i = 0;
803 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
804 node = &graph->nodes[i++];
805 node->objagg_obj = objagg_obj;
806 }
807
808 /* Assemble a temporary graph. Insert edge X->Y in case Y can be
809 * in delta of X.
810 */
811 for (i = 0; i < nodes_count; i++) {
812 for (j = 0; j < nodes_count; j++) {
813 if (i == j)
814 continue;
815 pnode = &graph->nodes[i];
816 node = &graph->nodes[j];
817 if (objagg->ops->delta_check(objagg->priv,
818 pnode->objagg_obj->obj,
819 node->objagg_obj->obj)) {
820 objagg_tmp_graph_edge_set(graph, i, j);
821
822 }
823 }
824 }
825 return graph;
826
827err_edges_alloc:
828 kfree(graph->nodes);
829err_nodes_alloc:
830 kfree(graph);
831 return NULL;
832}
833
834static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
835{
836 kfree(graph->edges);
837 kfree(graph->nodes);
838 kfree(graph);
839}
840
841static int
842objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints,
843 struct objagg *objagg)
844{
845 struct objagg_hints_node *hnode, *parent_hnode;
846 struct objagg_tmp_graph *graph;
847 struct objagg_tmp_node *node;
848 int index;
849 int j;
850 int err;
851
852 graph = objagg_tmp_graph_create(objagg);
853 if (!graph)
854 return -ENOMEM;
855
856 /* Find the nodes from the ones that can accommodate most users
857 * and cross them out of the graph. Save them to the hint list.
858 */
859 while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) {
860 node = &graph->nodes[index];
861 node->crossed_out = true;
862 hnode = objagg_hints_node_create(objagg_hints,
863 node->objagg_obj,
864 objagg->ops->obj_size,
865 NULL);
866 if (IS_ERR(hnode)) {
867 err = PTR_ERR(hnode);
868 goto out;
869 }
870 parent_hnode = hnode;
871 for (j = 0; j < graph->nodes_count; j++) {
872 if (!objagg_tmp_graph_is_edge(graph, index, j))
873 continue;
874 node = &graph->nodes[j];
875 if (node->crossed_out)
876 continue;
877 node->crossed_out = true;
878 hnode = objagg_hints_node_create(objagg_hints,
879 node->objagg_obj,
880 objagg->ops->obj_size,
881 parent_hnode);
882 if (IS_ERR(hnode)) {
883 err = PTR_ERR(hnode);
884 goto out;
885 }
886 }
887 }
888
889 err = 0;
890out:
891 objagg_tmp_graph_destroy(graph);
892 return err;
893}
894
895struct objagg_opt_algo {
896 int (*fillup_hints)(struct objagg_hints *objagg_hints,
897 struct objagg *objagg);
898};
899
900static const struct objagg_opt_algo objagg_opt_simple_greedy = {
901 .fillup_hints = objagg_opt_simple_greedy_fillup_hints,
902};
903
904
905static const struct objagg_opt_algo *objagg_opt_algos[] = {
906 [OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy,
907};
908
909static int objagg_hints_obj_cmp(struct rhashtable_compare_arg *arg,
910 const void *obj)
911{
912 struct rhashtable *ht = arg->ht;
913 struct objagg_hints *objagg_hints =
914 container_of(ht, struct objagg_hints, node_ht);
915 const struct objagg_ops *ops = objagg_hints->ops;
916 const char *ptr = obj;
917
918 ptr += ht->p.key_offset;
919 return ops->hints_obj_cmp ? ops->hints_obj_cmp(ptr, arg->key) :
920 memcmp(ptr, arg->key, ht->p.key_len);
921}
922
923/**
924 * objagg_hints_get - obtains hints instance
925 * @objagg: objagg instance
926 * @opt_algo_type: type of hints finding algorithm
927 *
928 * Note: all locking must be provided by the caller.
929 *
930 * According to the algo type, the existing objects of objagg instance
931 * are going to be went-through to assemble an optimal tree. We call this
932 * tree hints. These hints can be later on used for creation of
933 * a new objagg instance. There, the future object creations are going
934 * to be consulted with these hints in order to find out, where exactly
935 * the new object should be put as a root or delta.
936 *
937 * Returns a pointer to hints instance in case of success,
938 * otherwise it returns pointer error using ERR_PTR macro.
939 */
940struct objagg_hints *objagg_hints_get(struct objagg *objagg,
941 enum objagg_opt_algo_type opt_algo_type)
942{
943 const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type];
944 struct objagg_hints *objagg_hints;
945 int err;
946
947 objagg_hints = kzalloc(sizeof(*objagg_hints), GFP_KERNEL);
948 if (!objagg_hints)
949 return ERR_PTR(-ENOMEM);
950
951 objagg_hints->ops = objagg->ops;
952 objagg_hints->refcount = 1;
953
954 INIT_LIST_HEAD(&objagg_hints->node_list);
955
956 objagg_hints->ht_params.key_len = objagg->ops->obj_size;
957 objagg_hints->ht_params.key_offset =
958 offsetof(struct objagg_hints_node, obj);
959 objagg_hints->ht_params.head_offset =
960 offsetof(struct objagg_hints_node, ht_node);
961 objagg_hints->ht_params.obj_cmpfn = objagg_hints_obj_cmp;
962
963 err = rhashtable_init(&objagg_hints->node_ht, &objagg_hints->ht_params);
964 if (err)
965 goto err_rhashtable_init;
966
967 err = algo->fillup_hints(objagg_hints, objagg);
968 if (err)
969 goto err_fillup_hints;
970
971 if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) {
972 err = -EINVAL;
973 goto err_node_count_check;
974 }
975
976 return objagg_hints;
977
978err_node_count_check:
979err_fillup_hints:
980 objagg_hints_flush(objagg_hints);
981 rhashtable_destroy(&objagg_hints->node_ht);
982err_rhashtable_init:
983 kfree(objagg_hints);
984 return ERR_PTR(err);
985}
986EXPORT_SYMBOL(objagg_hints_get);
987
988/**
989 * objagg_hints_put - puts hints instance
990 * @objagg_hints: objagg hints instance
991 *
992 * Note: all locking must be provided by the caller.
993 */
994void objagg_hints_put(struct objagg_hints *objagg_hints)
995{
996 if (--objagg_hints->refcount)
997 return;
998 objagg_hints_flush(objagg_hints);
999 rhashtable_destroy(&objagg_hints->node_ht);
1000 kfree(objagg_hints);
1001}
1002EXPORT_SYMBOL(objagg_hints_put);
1003
1004/**
1005 * objagg_hints_stats_get - obtains stats of the hints instance
1006 * @objagg_hints: hints instance
1007 *
1008 * Note: all locking must be provided by the caller.
1009 *
1010 * The returned structure contains statistics of all objects
1011 * currently in use, ordered by following rules:
1012 * 1) Root objects are always on lower indexes than the rest.
1013 * 2) Objects with higher delta user count are always on lower
1014 * indexes.
1015 * 3) In case multiple objects have the same delta user count,
1016 * the objects are ordered by user count.
1017 *
1018 * Returns a pointer to stats instance in case of success,
1019 * otherwise it returns pointer error using ERR_PTR macro.
1020 */
1021const struct objagg_stats *
1022objagg_hints_stats_get(struct objagg_hints *objagg_hints)
1023{
1024 struct objagg_stats *objagg_stats;
1025 struct objagg_hints_node *hnode;
1026 int i;
1027
1028 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
1029 objagg_hints->node_count),
1030 GFP_KERNEL);
1031 if (!objagg_stats)
1032 return ERR_PTR(-ENOMEM);
1033
1034 i = 0;
1035 list_for_each_entry(hnode, &objagg_hints->node_list, list) {
1036 memcpy(&objagg_stats->stats_info[i], &hnode->stats_info,
1037 sizeof(objagg_stats->stats_info[0]));
1038 if (objagg_stats->stats_info[i].is_root)
1039 objagg_stats->root_count++;
1040 i++;
1041 }
1042 objagg_stats->stats_info_count = i;
1043
1044 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
1045 sizeof(struct objagg_obj_stats_info),
1046 objagg_stats_info_sort_cmp_func, NULL);
1047
1048 return objagg_stats;
1049}
1050EXPORT_SYMBOL(objagg_hints_stats_get);
1051
1052MODULE_LICENSE("Dual BSD/GPL");
1053MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
1054MODULE_DESCRIPTION("Object aggregation manager");
1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
3
4#include <linux/module.h>
5#include <linux/slab.h>
6#include <linux/rhashtable.h>
7#include <linux/idr.h>
8#include <linux/list.h>
9#include <linux/sort.h>
10#include <linux/objagg.h>
11
12#define CREATE_TRACE_POINTS
13#include <trace/events/objagg.h>
14
15struct objagg_hints {
16 struct rhashtable node_ht;
17 struct rhashtable_params ht_params;
18 struct list_head node_list;
19 unsigned int node_count;
20 unsigned int root_count;
21 unsigned int refcount;
22 const struct objagg_ops *ops;
23};
24
25struct objagg_hints_node {
26 struct rhash_head ht_node; /* member of objagg_hints->node_ht */
27 struct list_head list; /* member of objagg_hints->node_list */
28 struct objagg_hints_node *parent;
29 unsigned int root_id;
30 struct objagg_obj_stats_info stats_info;
31 unsigned long obj[];
32};
33
34static struct objagg_hints_node *
35objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj)
36{
37 if (!objagg_hints)
38 return NULL;
39 return rhashtable_lookup_fast(&objagg_hints->node_ht, obj,
40 objagg_hints->ht_params);
41}
42
43struct objagg {
44 const struct objagg_ops *ops;
45 void *priv;
46 struct rhashtable obj_ht;
47 struct rhashtable_params ht_params;
48 struct list_head obj_list;
49 unsigned int obj_count;
50 struct ida root_ida;
51 struct objagg_hints *hints;
52};
53
54struct objagg_obj {
55 struct rhash_head ht_node; /* member of objagg->obj_ht */
56 struct list_head list; /* member of objagg->obj_list */
57 struct objagg_obj *parent; /* if the object is nested, this
58 * holds pointer to parent, otherwise NULL
59 */
60 union {
61 void *delta_priv; /* user delta private */
62 void *root_priv; /* user root private */
63 };
64 unsigned int root_id;
65 unsigned int refcount; /* counts number of users of this object
66 * including nested objects
67 */
68 struct objagg_obj_stats stats;
69 unsigned long obj[];
70};
71
72static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj)
73{
74 return ++objagg_obj->refcount;
75}
76
77static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj)
78{
79 return --objagg_obj->refcount;
80}
81
82static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj)
83{
84 objagg_obj->stats.user_count++;
85 objagg_obj->stats.delta_user_count++;
86 if (objagg_obj->parent)
87 objagg_obj->parent->stats.delta_user_count++;
88}
89
90static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj)
91{
92 objagg_obj->stats.user_count--;
93 objagg_obj->stats.delta_user_count--;
94 if (objagg_obj->parent)
95 objagg_obj->parent->stats.delta_user_count--;
96}
97
98static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj)
99{
100 /* Nesting is not supported, so we can use ->parent
101 * to figure out if the object is root.
102 */
103 return !objagg_obj->parent;
104}
105
106/**
107 * objagg_obj_root_priv - obtains root private for an object
108 * @objagg_obj: objagg object instance
109 *
110 * Note: all locking must be provided by the caller.
111 *
112 * Either the object is root itself when the private is returned
113 * directly, or the parent is root and its private is returned
114 * instead.
115 *
116 * Returns a user private root pointer.
117 */
118const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj)
119{
120 if (objagg_obj_is_root(objagg_obj))
121 return objagg_obj->root_priv;
122 WARN_ON(!objagg_obj_is_root(objagg_obj->parent));
123 return objagg_obj->parent->root_priv;
124}
125EXPORT_SYMBOL(objagg_obj_root_priv);
126
127/**
128 * objagg_obj_delta_priv - obtains delta private for an object
129 * @objagg_obj: objagg object instance
130 *
131 * Note: all locking must be provided by the caller.
132 *
133 * Returns user private delta pointer or NULL in case the passed
134 * object is root.
135 */
136const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj)
137{
138 if (objagg_obj_is_root(objagg_obj))
139 return NULL;
140 return objagg_obj->delta_priv;
141}
142EXPORT_SYMBOL(objagg_obj_delta_priv);
143
144/**
145 * objagg_obj_raw - obtains object user private pointer
146 * @objagg_obj: objagg object instance
147 *
148 * Note: all locking must be provided by the caller.
149 *
150 * Returns user private pointer as was passed to objagg_obj_get() by "obj" arg.
151 */
152const void *objagg_obj_raw(const struct objagg_obj *objagg_obj)
153{
154 return objagg_obj->obj;
155}
156EXPORT_SYMBOL(objagg_obj_raw);
157
158static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj)
159{
160 return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);
161}
162
163static int objagg_obj_parent_assign(struct objagg *objagg,
164 struct objagg_obj *objagg_obj,
165 struct objagg_obj *parent,
166 bool take_parent_ref)
167{
168 void *delta_priv;
169
170 if (WARN_ON(!objagg_obj_is_root(parent)))
171 return -EINVAL;
172
173 delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj,
174 objagg_obj->obj);
175 if (IS_ERR(delta_priv))
176 return PTR_ERR(delta_priv);
177
178 /* User returned a delta private, that means that
179 * our object can be aggregated into the parent.
180 */
181 objagg_obj->parent = parent;
182 objagg_obj->delta_priv = delta_priv;
183 if (take_parent_ref)
184 objagg_obj_ref_inc(objagg_obj->parent);
185 trace_objagg_obj_parent_assign(objagg, objagg_obj,
186 parent,
187 parent->refcount);
188 return 0;
189}
190
191static int objagg_obj_parent_lookup_assign(struct objagg *objagg,
192 struct objagg_obj *objagg_obj)
193{
194 struct objagg_obj *objagg_obj_cur;
195 int err;
196
197 list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) {
198 /* Nesting is not supported. In case the object
199 * is not root, it cannot be assigned as parent.
200 */
201 if (!objagg_obj_is_root(objagg_obj_cur))
202 continue;
203 err = objagg_obj_parent_assign(objagg, objagg_obj,
204 objagg_obj_cur, true);
205 if (!err)
206 return 0;
207 }
208 return -ENOENT;
209}
210
211static void __objagg_obj_put(struct objagg *objagg,
212 struct objagg_obj *objagg_obj);
213
214static void objagg_obj_parent_unassign(struct objagg *objagg,
215 struct objagg_obj *objagg_obj)
216{
217 trace_objagg_obj_parent_unassign(objagg, objagg_obj,
218 objagg_obj->parent,
219 objagg_obj->parent->refcount);
220 objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);
221 __objagg_obj_put(objagg, objagg_obj->parent);
222}
223
224static int objagg_obj_root_id_alloc(struct objagg *objagg,
225 struct objagg_obj *objagg_obj,
226 struct objagg_hints_node *hnode)
227{
228 unsigned int min, max;
229 int root_id;
230
231 /* In case there are no hints available, the root id is invalid. */
232 if (!objagg->hints) {
233 objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID;
234 return 0;
235 }
236
237 if (hnode) {
238 min = hnode->root_id;
239 max = hnode->root_id;
240 } else {
241 /* For objects with no hint, start after the last
242 * hinted root_id.
243 */
244 min = objagg->hints->root_count;
245 max = ~0;
246 }
247
248 root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL);
249
250 if (root_id < 0)
251 return root_id;
252 objagg_obj->root_id = root_id;
253 return 0;
254}
255
256static void objagg_obj_root_id_free(struct objagg *objagg,
257 struct objagg_obj *objagg_obj)
258{
259 if (!objagg->hints)
260 return;
261 ida_free(&objagg->root_ida, objagg_obj->root_id);
262}
263
264static int objagg_obj_root_create(struct objagg *objagg,
265 struct objagg_obj *objagg_obj,
266 struct objagg_hints_node *hnode)
267{
268 int err;
269
270 err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode);
271 if (err)
272 return err;
273 objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,
274 objagg_obj->obj,
275 objagg_obj->root_id);
276 if (IS_ERR(objagg_obj->root_priv)) {
277 err = PTR_ERR(objagg_obj->root_priv);
278 goto err_root_create;
279 }
280 trace_objagg_obj_root_create(objagg, objagg_obj);
281 return 0;
282
283err_root_create:
284 objagg_obj_root_id_free(objagg, objagg_obj);
285 return err;
286}
287
288static void objagg_obj_root_destroy(struct objagg *objagg,
289 struct objagg_obj *objagg_obj)
290{
291 trace_objagg_obj_root_destroy(objagg, objagg_obj);
292 objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv);
293 objagg_obj_root_id_free(objagg, objagg_obj);
294}
295
296static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj);
297
298static int objagg_obj_init_with_hints(struct objagg *objagg,
299 struct objagg_obj *objagg_obj,
300 bool *hint_found)
301{
302 struct objagg_hints_node *hnode;
303 struct objagg_obj *parent;
304 int err;
305
306 hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj);
307 if (!hnode) {
308 *hint_found = false;
309 return 0;
310 }
311 *hint_found = true;
312
313 if (!hnode->parent)
314 return objagg_obj_root_create(objagg, objagg_obj, hnode);
315
316 parent = __objagg_obj_get(objagg, hnode->parent->obj);
317 if (IS_ERR(parent))
318 return PTR_ERR(parent);
319
320 err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false);
321 if (err) {
322 *hint_found = false;
323 err = 0;
324 goto err_parent_assign;
325 }
326
327 return 0;
328
329err_parent_assign:
330 objagg_obj_put(objagg, parent);
331 return err;
332}
333
334static int objagg_obj_init(struct objagg *objagg,
335 struct objagg_obj *objagg_obj)
336{
337 bool hint_found;
338 int err;
339
340 /* First, try to use hints if they are available and
341 * if they provide result.
342 */
343 err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found);
344 if (err)
345 return err;
346
347 if (hint_found)
348 return 0;
349
350 /* Try to find if the object can be aggregated under an existing one. */
351 err = objagg_obj_parent_lookup_assign(objagg, objagg_obj);
352 if (!err)
353 return 0;
354 /* If aggregation is not possible, make the object a root. */
355 return objagg_obj_root_create(objagg, objagg_obj, NULL);
356}
357
358static void objagg_obj_fini(struct objagg *objagg,
359 struct objagg_obj *objagg_obj)
360{
361 if (!objagg_obj_is_root(objagg_obj))
362 objagg_obj_parent_unassign(objagg, objagg_obj);
363 else
364 objagg_obj_root_destroy(objagg, objagg_obj);
365}
366
367static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj)
368{
369 struct objagg_obj *objagg_obj;
370 int err;
371
372 objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size,
373 GFP_KERNEL);
374 if (!objagg_obj)
375 return ERR_PTR(-ENOMEM);
376 objagg_obj_ref_inc(objagg_obj);
377 memcpy(objagg_obj->obj, obj, objagg->ops->obj_size);
378
379 err = objagg_obj_init(objagg, objagg_obj);
380 if (err)
381 goto err_obj_init;
382
383 err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node,
384 objagg->ht_params);
385 if (err)
386 goto err_ht_insert;
387 list_add(&objagg_obj->list, &objagg->obj_list);
388 objagg->obj_count++;
389 trace_objagg_obj_create(objagg, objagg_obj);
390
391 return objagg_obj;
392
393err_ht_insert:
394 objagg_obj_fini(objagg, objagg_obj);
395err_obj_init:
396 kfree(objagg_obj);
397 return ERR_PTR(err);
398}
399
400static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj)
401{
402 struct objagg_obj *objagg_obj;
403
404 /* First, try to find the object exactly as user passed it,
405 * perhaps it is already in use.
406 */
407 objagg_obj = objagg_obj_lookup(objagg, obj);
408 if (objagg_obj) {
409 objagg_obj_ref_inc(objagg_obj);
410 return objagg_obj;
411 }
412
413 return objagg_obj_create(objagg, obj);
414}
415
416/**
417 * objagg_obj_get - gets an object within objagg instance
418 * @objagg: objagg instance
419 * @obj: user-specific private object pointer
420 *
421 * Note: all locking must be provided by the caller.
422 *
423 * Size of the "obj" memory is specified in "objagg->ops".
424 *
425 * There are 3 main options this function wraps:
426 * 1) The object according to "obj" already exist. In that case
427 * the reference counter is incremented and the object is returned.
428 * 2) The object does not exist, but it can be aggregated within
429 * another object. In that case, user ops->delta_create() is called
430 * to obtain delta data and a new object is created with returned
431 * user-delta private pointer.
432 * 3) The object does not exist and cannot be aggregated into
433 * any of the existing objects. In that case, user ops->root_create()
434 * is called to create the root and a new object is created with
435 * returned user-root private pointer.
436 *
437 * Returns a pointer to objagg object instance in case of success,
438 * otherwise it returns pointer error using ERR_PTR macro.
439 */
440struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj)
441{
442 struct objagg_obj *objagg_obj;
443
444 objagg_obj = __objagg_obj_get(objagg, obj);
445 if (IS_ERR(objagg_obj))
446 return objagg_obj;
447 objagg_obj_stats_inc(objagg_obj);
448 trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount);
449 return objagg_obj;
450}
451EXPORT_SYMBOL(objagg_obj_get);
452
453static void objagg_obj_destroy(struct objagg *objagg,
454 struct objagg_obj *objagg_obj)
455{
456 trace_objagg_obj_destroy(objagg, objagg_obj);
457 --objagg->obj_count;
458 list_del(&objagg_obj->list);
459 rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node,
460 objagg->ht_params);
461 objagg_obj_fini(objagg, objagg_obj);
462 kfree(objagg_obj);
463}
464
465static void __objagg_obj_put(struct objagg *objagg,
466 struct objagg_obj *objagg_obj)
467{
468 if (!objagg_obj_ref_dec(objagg_obj))
469 objagg_obj_destroy(objagg, objagg_obj);
470}
471
472/**
473 * objagg_obj_put - puts an object within objagg instance
474 * @objagg: objagg instance
475 * @objagg_obj: objagg object instance
476 *
477 * Note: all locking must be provided by the caller.
478 *
479 * Symmetric to objagg_obj_get().
480 */
481void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj)
482{
483 trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount);
484 objagg_obj_stats_dec(objagg_obj);
485 __objagg_obj_put(objagg, objagg_obj);
486}
487EXPORT_SYMBOL(objagg_obj_put);
488
489/**
490 * objagg_create - creates a new objagg instance
491 * @ops: user-specific callbacks
492 * @objagg_hints: hints, can be NULL
493 * @priv: pointer to a private data passed to the ops
494 *
495 * Note: all locking must be provided by the caller.
496 *
497 * The purpose of the library is to provide an infrastructure to
498 * aggregate user-specified objects. Library does not care about the type
499 * of the object. User fills-up ops which take care of the specific
500 * user object manipulation.
501 *
502 * As a very stupid example, consider integer numbers. For example
503 * number 8 as a root object. That can aggregate number 9 with delta 1,
504 * number 10 with delta 2, etc. This example is implemented as
505 * a part of a testing module in test_objagg.c file.
506 *
507 * Each objagg instance contains multiple trees. Each tree node is
508 * represented by "an object". In the current implementation there can be
509 * only roots and leafs nodes. Leaf nodes are called deltas.
510 * But in general, this can be easily extended for intermediate nodes.
511 * In that extension, a delta would be associated with all non-root
512 * nodes.
513 *
514 * Returns a pointer to newly created objagg instance in case of success,
515 * otherwise it returns pointer error using ERR_PTR macro.
516 */
517struct objagg *objagg_create(const struct objagg_ops *ops,
518 struct objagg_hints *objagg_hints, void *priv)
519{
520 struct objagg *objagg;
521 int err;
522
523 if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy ||
524 !ops->delta_check || !ops->delta_create ||
525 !ops->delta_destroy))
526 return ERR_PTR(-EINVAL);
527
528 objagg = kzalloc(sizeof(*objagg), GFP_KERNEL);
529 if (!objagg)
530 return ERR_PTR(-ENOMEM);
531 objagg->ops = ops;
532 if (objagg_hints) {
533 objagg->hints = objagg_hints;
534 objagg_hints->refcount++;
535 }
536 objagg->priv = priv;
537 INIT_LIST_HEAD(&objagg->obj_list);
538
539 objagg->ht_params.key_len = ops->obj_size;
540 objagg->ht_params.key_offset = offsetof(struct objagg_obj, obj);
541 objagg->ht_params.head_offset = offsetof(struct objagg_obj, ht_node);
542
543 err = rhashtable_init(&objagg->obj_ht, &objagg->ht_params);
544 if (err)
545 goto err_rhashtable_init;
546
547 ida_init(&objagg->root_ida);
548
549 trace_objagg_create(objagg);
550 return objagg;
551
552err_rhashtable_init:
553 kfree(objagg);
554 return ERR_PTR(err);
555}
556EXPORT_SYMBOL(objagg_create);
557
558/**
559 * objagg_destroy - destroys a new objagg instance
560 * @objagg: objagg instance
561 *
562 * Note: all locking must be provided by the caller.
563 */
564void objagg_destroy(struct objagg *objagg)
565{
566 trace_objagg_destroy(objagg);
567 ida_destroy(&objagg->root_ida);
568 WARN_ON(!list_empty(&objagg->obj_list));
569 rhashtable_destroy(&objagg->obj_ht);
570 if (objagg->hints)
571 objagg_hints_put(objagg->hints);
572 kfree(objagg);
573}
574EXPORT_SYMBOL(objagg_destroy);
575
576static int objagg_stats_info_sort_cmp_func(const void *a, const void *b)
577{
578 const struct objagg_obj_stats_info *stats_info1 = a;
579 const struct objagg_obj_stats_info *stats_info2 = b;
580
581 if (stats_info1->is_root != stats_info2->is_root)
582 return stats_info2->is_root - stats_info1->is_root;
583 if (stats_info1->stats.delta_user_count !=
584 stats_info2->stats.delta_user_count)
585 return stats_info2->stats.delta_user_count -
586 stats_info1->stats.delta_user_count;
587 return stats_info2->stats.user_count - stats_info1->stats.user_count;
588}
589
590/**
591 * objagg_stats_get - obtains stats of the objagg instance
592 * @objagg: objagg instance
593 *
594 * Note: all locking must be provided by the caller.
595 *
596 * The returned structure contains statistics of all object
597 * currently in use, ordered by following rules:
598 * 1) Root objects are always on lower indexes than the rest.
599 * 2) Objects with higher delta user count are always on lower
600 * indexes.
601 * 3) In case more objects have the same delta user count,
602 * the objects are ordered by user count.
603 *
604 * Returns a pointer to stats instance in case of success,
605 * otherwise it returns pointer error using ERR_PTR macro.
606 */
607const struct objagg_stats *objagg_stats_get(struct objagg *objagg)
608{
609 struct objagg_stats *objagg_stats;
610 struct objagg_obj *objagg_obj;
611 int i;
612
613 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
614 objagg->obj_count), GFP_KERNEL);
615 if (!objagg_stats)
616 return ERR_PTR(-ENOMEM);
617
618 i = 0;
619 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
620 memcpy(&objagg_stats->stats_info[i].stats, &objagg_obj->stats,
621 sizeof(objagg_stats->stats_info[0].stats));
622 objagg_stats->stats_info[i].objagg_obj = objagg_obj;
623 objagg_stats->stats_info[i].is_root =
624 objagg_obj_is_root(objagg_obj);
625 if (objagg_stats->stats_info[i].is_root)
626 objagg_stats->root_count++;
627 i++;
628 }
629 objagg_stats->stats_info_count = i;
630
631 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
632 sizeof(struct objagg_obj_stats_info),
633 objagg_stats_info_sort_cmp_func, NULL);
634
635 return objagg_stats;
636}
637EXPORT_SYMBOL(objagg_stats_get);
638
639/**
640 * objagg_stats_put - puts stats of the objagg instance
641 * @objagg_stats: objagg instance stats
642 *
643 * Note: all locking must be provided by the caller.
644 */
645void objagg_stats_put(const struct objagg_stats *objagg_stats)
646{
647 kfree(objagg_stats);
648}
649EXPORT_SYMBOL(objagg_stats_put);
650
651static struct objagg_hints_node *
652objagg_hints_node_create(struct objagg_hints *objagg_hints,
653 struct objagg_obj *objagg_obj, size_t obj_size,
654 struct objagg_hints_node *parent_hnode)
655{
656 unsigned int user_count = objagg_obj->stats.user_count;
657 struct objagg_hints_node *hnode;
658 int err;
659
660 hnode = kzalloc(sizeof(*hnode) + obj_size, GFP_KERNEL);
661 if (!hnode)
662 return ERR_PTR(-ENOMEM);
663 memcpy(hnode->obj, &objagg_obj->obj, obj_size);
664 hnode->stats_info.stats.user_count = user_count;
665 hnode->stats_info.stats.delta_user_count = user_count;
666 if (parent_hnode) {
667 parent_hnode->stats_info.stats.delta_user_count += user_count;
668 } else {
669 hnode->root_id = objagg_hints->root_count++;
670 hnode->stats_info.is_root = true;
671 }
672 hnode->stats_info.objagg_obj = objagg_obj;
673
674 err = rhashtable_insert_fast(&objagg_hints->node_ht, &hnode->ht_node,
675 objagg_hints->ht_params);
676 if (err)
677 goto err_ht_insert;
678
679 list_add(&hnode->list, &objagg_hints->node_list);
680 hnode->parent = parent_hnode;
681 objagg_hints->node_count++;
682
683 return hnode;
684
685err_ht_insert:
686 kfree(hnode);
687 return ERR_PTR(err);
688}
689
690static void objagg_hints_flush(struct objagg_hints *objagg_hints)
691{
692 struct objagg_hints_node *hnode, *tmp;
693
694 list_for_each_entry_safe(hnode, tmp, &objagg_hints->node_list, list) {
695 list_del(&hnode->list);
696 rhashtable_remove_fast(&objagg_hints->node_ht, &hnode->ht_node,
697 objagg_hints->ht_params);
698 kfree(hnode);
699 }
700}
701
702struct objagg_tmp_node {
703 struct objagg_obj *objagg_obj;
704 bool crossed_out;
705};
706
707struct objagg_tmp_graph {
708 struct objagg_tmp_node *nodes;
709 unsigned long nodes_count;
710 unsigned long *edges;
711};
712
713static int objagg_tmp_graph_edge_index(struct objagg_tmp_graph *graph,
714 int parent_index, int index)
715{
716 return index * graph->nodes_count + parent_index;
717}
718
719static void objagg_tmp_graph_edge_set(struct objagg_tmp_graph *graph,
720 int parent_index, int index)
721{
722 int edge_index = objagg_tmp_graph_edge_index(graph, index,
723 parent_index);
724
725 __set_bit(edge_index, graph->edges);
726}
727
728static bool objagg_tmp_graph_is_edge(struct objagg_tmp_graph *graph,
729 int parent_index, int index)
730{
731 int edge_index = objagg_tmp_graph_edge_index(graph, index,
732 parent_index);
733
734 return test_bit(edge_index, graph->edges);
735}
736
737static unsigned int objagg_tmp_graph_node_weight(struct objagg_tmp_graph *graph,
738 unsigned int index)
739{
740 struct objagg_tmp_node *node = &graph->nodes[index];
741 unsigned int weight = node->objagg_obj->stats.user_count;
742 int j;
743
744 /* Node weight is sum of node users and all other nodes users
745 * that this node can represent with delta.
746 */
747
748 for (j = 0; j < graph->nodes_count; j++) {
749 if (!objagg_tmp_graph_is_edge(graph, index, j))
750 continue;
751 node = &graph->nodes[j];
752 if (node->crossed_out)
753 continue;
754 weight += node->objagg_obj->stats.user_count;
755 }
756 return weight;
757}
758
759static int objagg_tmp_graph_node_max_weight(struct objagg_tmp_graph *graph)
760{
761 struct objagg_tmp_node *node;
762 unsigned int max_weight = 0;
763 unsigned int weight;
764 int max_index = -1;
765 int i;
766
767 for (i = 0; i < graph->nodes_count; i++) {
768 node = &graph->nodes[i];
769 if (node->crossed_out)
770 continue;
771 weight = objagg_tmp_graph_node_weight(graph, i);
772 if (weight >= max_weight) {
773 max_weight = weight;
774 max_index = i;
775 }
776 }
777 return max_index;
778}
779
780static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
781{
782 unsigned int nodes_count = objagg->obj_count;
783 struct objagg_tmp_graph *graph;
784 struct objagg_tmp_node *node;
785 struct objagg_tmp_node *pnode;
786 struct objagg_obj *objagg_obj;
787 int i, j;
788
789 graph = kzalloc(sizeof(*graph), GFP_KERNEL);
790 if (!graph)
791 return NULL;
792
793 graph->nodes = kcalloc(nodes_count, sizeof(*graph->nodes), GFP_KERNEL);
794 if (!graph->nodes)
795 goto err_nodes_alloc;
796 graph->nodes_count = nodes_count;
797
798 graph->edges = bitmap_zalloc(nodes_count * nodes_count, GFP_KERNEL);
799 if (!graph->edges)
800 goto err_edges_alloc;
801
802 i = 0;
803 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
804 node = &graph->nodes[i++];
805 node->objagg_obj = objagg_obj;
806 }
807
808 /* Assemble a temporary graph. Insert edge X->Y in case Y can be
809 * in delta of X.
810 */
811 for (i = 0; i < nodes_count; i++) {
812 for (j = 0; j < nodes_count; j++) {
813 if (i == j)
814 continue;
815 pnode = &graph->nodes[i];
816 node = &graph->nodes[j];
817 if (objagg->ops->delta_check(objagg->priv,
818 pnode->objagg_obj->obj,
819 node->objagg_obj->obj)) {
820 objagg_tmp_graph_edge_set(graph, i, j);
821
822 }
823 }
824 }
825 return graph;
826
827err_edges_alloc:
828 kfree(graph->nodes);
829err_nodes_alloc:
830 kfree(graph);
831 return NULL;
832}
833
834static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
835{
836 bitmap_free(graph->edges);
837 kfree(graph->nodes);
838 kfree(graph);
839}
840
841static int
842objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints,
843 struct objagg *objagg)
844{
845 struct objagg_hints_node *hnode, *parent_hnode;
846 struct objagg_tmp_graph *graph;
847 struct objagg_tmp_node *node;
848 int index;
849 int j;
850 int err;
851
852 graph = objagg_tmp_graph_create(objagg);
853 if (!graph)
854 return -ENOMEM;
855
856 /* Find the nodes from the ones that can accommodate most users
857 * and cross them out of the graph. Save them to the hint list.
858 */
859 while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) {
860 node = &graph->nodes[index];
861 node->crossed_out = true;
862 hnode = objagg_hints_node_create(objagg_hints,
863 node->objagg_obj,
864 objagg->ops->obj_size,
865 NULL);
866 if (IS_ERR(hnode)) {
867 err = PTR_ERR(hnode);
868 goto out;
869 }
870 parent_hnode = hnode;
871 for (j = 0; j < graph->nodes_count; j++) {
872 if (!objagg_tmp_graph_is_edge(graph, index, j))
873 continue;
874 node = &graph->nodes[j];
875 if (node->crossed_out)
876 continue;
877 node->crossed_out = true;
878 hnode = objagg_hints_node_create(objagg_hints,
879 node->objagg_obj,
880 objagg->ops->obj_size,
881 parent_hnode);
882 if (IS_ERR(hnode)) {
883 err = PTR_ERR(hnode);
884 goto out;
885 }
886 }
887 }
888
889 err = 0;
890out:
891 objagg_tmp_graph_destroy(graph);
892 return err;
893}
894
895struct objagg_opt_algo {
896 int (*fillup_hints)(struct objagg_hints *objagg_hints,
897 struct objagg *objagg);
898};
899
900static const struct objagg_opt_algo objagg_opt_simple_greedy = {
901 .fillup_hints = objagg_opt_simple_greedy_fillup_hints,
902};
903
904
905static const struct objagg_opt_algo *objagg_opt_algos[] = {
906 [OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy,
907};
908
909/**
910 * objagg_hints_get - obtains hints instance
911 * @objagg: objagg instance
912 * @opt_algo_type: type of hints finding algorithm
913 *
914 * Note: all locking must be provided by the caller.
915 *
916 * According to the algo type, the existing objects of objagg instance
917 * are going to be went-through to assemble an optimal tree. We call this
918 * tree hints. These hints can be later on used for creation of
919 * a new objagg instance. There, the future object creations are going
920 * to be consulted with these hints in order to find out, where exactly
921 * the new object should be put as a root or delta.
922 *
923 * Returns a pointer to hints instance in case of success,
924 * otherwise it returns pointer error using ERR_PTR macro.
925 */
926struct objagg_hints *objagg_hints_get(struct objagg *objagg,
927 enum objagg_opt_algo_type opt_algo_type)
928{
929 const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type];
930 struct objagg_hints *objagg_hints;
931 int err;
932
933 objagg_hints = kzalloc(sizeof(*objagg_hints), GFP_KERNEL);
934 if (!objagg_hints)
935 return ERR_PTR(-ENOMEM);
936
937 objagg_hints->ops = objagg->ops;
938 objagg_hints->refcount = 1;
939
940 INIT_LIST_HEAD(&objagg_hints->node_list);
941
942 objagg_hints->ht_params.key_len = objagg->ops->obj_size;
943 objagg_hints->ht_params.key_offset =
944 offsetof(struct objagg_hints_node, obj);
945 objagg_hints->ht_params.head_offset =
946 offsetof(struct objagg_hints_node, ht_node);
947
948 err = rhashtable_init(&objagg_hints->node_ht, &objagg_hints->ht_params);
949 if (err)
950 goto err_rhashtable_init;
951
952 err = algo->fillup_hints(objagg_hints, objagg);
953 if (err)
954 goto err_fillup_hints;
955
956 if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) {
957 err = -EINVAL;
958 goto err_node_count_check;
959 }
960
961 return objagg_hints;
962
963err_node_count_check:
964err_fillup_hints:
965 objagg_hints_flush(objagg_hints);
966 rhashtable_destroy(&objagg_hints->node_ht);
967err_rhashtable_init:
968 kfree(objagg_hints);
969 return ERR_PTR(err);
970}
971EXPORT_SYMBOL(objagg_hints_get);
972
973/**
974 * objagg_hints_put - puts hints instance
975 * @objagg_hints: objagg hints instance
976 *
977 * Note: all locking must be provided by the caller.
978 */
979void objagg_hints_put(struct objagg_hints *objagg_hints)
980{
981 if (--objagg_hints->refcount)
982 return;
983 objagg_hints_flush(objagg_hints);
984 rhashtable_destroy(&objagg_hints->node_ht);
985 kfree(objagg_hints);
986}
987EXPORT_SYMBOL(objagg_hints_put);
988
989/**
990 * objagg_hints_stats_get - obtains stats of the hints instance
991 * @objagg_hints: hints instance
992 *
993 * Note: all locking must be provided by the caller.
994 *
995 * The returned structure contains statistics of all objects
996 * currently in use, ordered by following rules:
997 * 1) Root objects are always on lower indexes than the rest.
998 * 2) Objects with higher delta user count are always on lower
999 * indexes.
1000 * 3) In case multiple objects have the same delta user count,
1001 * the objects are ordered by user count.
1002 *
1003 * Returns a pointer to stats instance in case of success,
1004 * otherwise it returns pointer error using ERR_PTR macro.
1005 */
1006const struct objagg_stats *
1007objagg_hints_stats_get(struct objagg_hints *objagg_hints)
1008{
1009 struct objagg_stats *objagg_stats;
1010 struct objagg_hints_node *hnode;
1011 int i;
1012
1013 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
1014 objagg_hints->node_count),
1015 GFP_KERNEL);
1016 if (!objagg_stats)
1017 return ERR_PTR(-ENOMEM);
1018
1019 i = 0;
1020 list_for_each_entry(hnode, &objagg_hints->node_list, list) {
1021 memcpy(&objagg_stats->stats_info[i], &hnode->stats_info,
1022 sizeof(objagg_stats->stats_info[0]));
1023 if (objagg_stats->stats_info[i].is_root)
1024 objagg_stats->root_count++;
1025 i++;
1026 }
1027 objagg_stats->stats_info_count = i;
1028
1029 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
1030 sizeof(struct objagg_obj_stats_info),
1031 objagg_stats_info_sort_cmp_func, NULL);
1032
1033 return objagg_stats;
1034}
1035EXPORT_SYMBOL(objagg_hints_stats_get);
1036
1037MODULE_LICENSE("Dual BSD/GPL");
1038MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
1039MODULE_DESCRIPTION("Object aggregation manager");