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[0];
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[0];
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 size_t alloc_size;
609 int i;
610
611 alloc_size = sizeof(*objagg_stats) +
612 sizeof(objagg_stats->stats_info[0]) * objagg->obj_count;
613 objagg_stats = kzalloc(alloc_size, GFP_KERNEL);
614 if (!objagg_stats)
615 return ERR_PTR(-ENOMEM);
616
617 i = 0;
618 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
619 memcpy(&objagg_stats->stats_info[i].stats, &objagg_obj->stats,
620 sizeof(objagg_stats->stats_info[0].stats));
621 objagg_stats->stats_info[i].objagg_obj = objagg_obj;
622 objagg_stats->stats_info[i].is_root =
623 objagg_obj_is_root(objagg_obj);
624 if (objagg_stats->stats_info[i].is_root)
625 objagg_stats->root_count++;
626 i++;
627 }
628 objagg_stats->stats_info_count = i;
629
630 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
631 sizeof(struct objagg_obj_stats_info),
632 objagg_stats_info_sort_cmp_func, NULL);
633
634 return objagg_stats;
635}
636EXPORT_SYMBOL(objagg_stats_get);
637
638/**
639 * objagg_stats_put - puts stats of the objagg instance
640 * @objagg_stats: objagg instance stats
641 *
642 * Note: all locking must be provided by the caller.
643 */
644void objagg_stats_put(const struct objagg_stats *objagg_stats)
645{
646 kfree(objagg_stats);
647}
648EXPORT_SYMBOL(objagg_stats_put);
649
650static struct objagg_hints_node *
651objagg_hints_node_create(struct objagg_hints *objagg_hints,
652 struct objagg_obj *objagg_obj, size_t obj_size,
653 struct objagg_hints_node *parent_hnode)
654{
655 unsigned int user_count = objagg_obj->stats.user_count;
656 struct objagg_hints_node *hnode;
657 int err;
658
659 hnode = kzalloc(sizeof(*hnode) + obj_size, GFP_KERNEL);
660 if (!hnode)
661 return ERR_PTR(-ENOMEM);
662 memcpy(hnode->obj, &objagg_obj->obj, obj_size);
663 hnode->stats_info.stats.user_count = user_count;
664 hnode->stats_info.stats.delta_user_count = user_count;
665 if (parent_hnode) {
666 parent_hnode->stats_info.stats.delta_user_count += user_count;
667 } else {
668 hnode->root_id = objagg_hints->root_count++;
669 hnode->stats_info.is_root = true;
670 }
671 hnode->stats_info.objagg_obj = objagg_obj;
672
673 err = rhashtable_insert_fast(&objagg_hints->node_ht, &hnode->ht_node,
674 objagg_hints->ht_params);
675 if (err)
676 goto err_ht_insert;
677
678 list_add(&hnode->list, &objagg_hints->node_list);
679 hnode->parent = parent_hnode;
680 objagg_hints->node_count++;
681
682 return hnode;
683
684err_ht_insert:
685 kfree(hnode);
686 return ERR_PTR(err);
687}
688
689static void objagg_hints_flush(struct objagg_hints *objagg_hints)
690{
691 struct objagg_hints_node *hnode, *tmp;
692
693 list_for_each_entry_safe(hnode, tmp, &objagg_hints->node_list, list) {
694 list_del(&hnode->list);
695 rhashtable_remove_fast(&objagg_hints->node_ht, &hnode->ht_node,
696 objagg_hints->ht_params);
697 kfree(hnode);
698 }
699}
700
701struct objagg_tmp_node {
702 struct objagg_obj *objagg_obj;
703 bool crossed_out;
704};
705
706struct objagg_tmp_graph {
707 struct objagg_tmp_node *nodes;
708 unsigned long nodes_count;
709 unsigned long *edges;
710};
711
712static int objagg_tmp_graph_edge_index(struct objagg_tmp_graph *graph,
713 int parent_index, int index)
714{
715 return index * graph->nodes_count + parent_index;
716}
717
718static void objagg_tmp_graph_edge_set(struct objagg_tmp_graph *graph,
719 int parent_index, int index)
720{
721 int edge_index = objagg_tmp_graph_edge_index(graph, index,
722 parent_index);
723
724 __set_bit(edge_index, graph->edges);
725}
726
727static bool objagg_tmp_graph_is_edge(struct objagg_tmp_graph *graph,
728 int parent_index, int index)
729{
730 int edge_index = objagg_tmp_graph_edge_index(graph, index,
731 parent_index);
732
733 return test_bit(edge_index, graph->edges);
734}
735
736static unsigned int objagg_tmp_graph_node_weight(struct objagg_tmp_graph *graph,
737 unsigned int index)
738{
739 struct objagg_tmp_node *node = &graph->nodes[index];
740 unsigned int weight = node->objagg_obj->stats.user_count;
741 int j;
742
743 /* Node weight is sum of node users and all other nodes users
744 * that this node can represent with delta.
745 */
746
747 for (j = 0; j < graph->nodes_count; j++) {
748 if (!objagg_tmp_graph_is_edge(graph, index, j))
749 continue;
750 node = &graph->nodes[j];
751 if (node->crossed_out)
752 continue;
753 weight += node->objagg_obj->stats.user_count;
754 }
755 return weight;
756}
757
758static int objagg_tmp_graph_node_max_weight(struct objagg_tmp_graph *graph)
759{
760 struct objagg_tmp_node *node;
761 unsigned int max_weight = 0;
762 unsigned int weight;
763 int max_index = -1;
764 int i;
765
766 for (i = 0; i < graph->nodes_count; i++) {
767 node = &graph->nodes[i];
768 if (node->crossed_out)
769 continue;
770 weight = objagg_tmp_graph_node_weight(graph, i);
771 if (weight >= max_weight) {
772 max_weight = weight;
773 max_index = i;
774 }
775 }
776 return max_index;
777}
778
779static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
780{
781 unsigned int nodes_count = objagg->obj_count;
782 struct objagg_tmp_graph *graph;
783 struct objagg_tmp_node *node;
784 struct objagg_tmp_node *pnode;
785 struct objagg_obj *objagg_obj;
786 size_t alloc_size;
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 alloc_size = BITS_TO_LONGS(nodes_count * nodes_count) *
799 sizeof(unsigned long);
800 graph->edges = kzalloc(alloc_size, GFP_KERNEL);
801 if (!graph->edges)
802 goto err_edges_alloc;
803
804 i = 0;
805 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
806 node = &graph->nodes[i++];
807 node->objagg_obj = objagg_obj;
808 }
809
810 /* Assemble a temporary graph. Insert edge X->Y in case Y can be
811 * in delta of X.
812 */
813 for (i = 0; i < nodes_count; i++) {
814 for (j = 0; j < nodes_count; j++) {
815 if (i == j)
816 continue;
817 pnode = &graph->nodes[i];
818 node = &graph->nodes[j];
819 if (objagg->ops->delta_check(objagg->priv,
820 pnode->objagg_obj->obj,
821 node->objagg_obj->obj)) {
822 objagg_tmp_graph_edge_set(graph, i, j);
823
824 }
825 }
826 }
827 return graph;
828
829err_edges_alloc:
830 kfree(graph->nodes);
831err_nodes_alloc:
832 kfree(graph);
833 return NULL;
834}
835
836static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
837{
838 kfree(graph->edges);
839 kfree(graph->nodes);
840 kfree(graph);
841}
842
843static int
844objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints,
845 struct objagg *objagg)
846{
847 struct objagg_hints_node *hnode, *parent_hnode;
848 struct objagg_tmp_graph *graph;
849 struct objagg_tmp_node *node;
850 int index;
851 int j;
852 int err;
853
854 graph = objagg_tmp_graph_create(objagg);
855 if (!graph)
856 return -ENOMEM;
857
858 /* Find the nodes from the ones that can accommodate most users
859 * and cross them out of the graph. Save them to the hint list.
860 */
861 while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) {
862 node = &graph->nodes[index];
863 node->crossed_out = true;
864 hnode = objagg_hints_node_create(objagg_hints,
865 node->objagg_obj,
866 objagg->ops->obj_size,
867 NULL);
868 if (IS_ERR(hnode)) {
869 err = PTR_ERR(hnode);
870 goto out;
871 }
872 parent_hnode = hnode;
873 for (j = 0; j < graph->nodes_count; j++) {
874 if (!objagg_tmp_graph_is_edge(graph, index, j))
875 continue;
876 node = &graph->nodes[j];
877 if (node->crossed_out)
878 continue;
879 node->crossed_out = true;
880 hnode = objagg_hints_node_create(objagg_hints,
881 node->objagg_obj,
882 objagg->ops->obj_size,
883 parent_hnode);
884 if (IS_ERR(hnode)) {
885 err = PTR_ERR(hnode);
886 goto out;
887 }
888 }
889 }
890
891 err = 0;
892out:
893 objagg_tmp_graph_destroy(graph);
894 return err;
895}
896
897struct objagg_opt_algo {
898 int (*fillup_hints)(struct objagg_hints *objagg_hints,
899 struct objagg *objagg);
900};
901
902static const struct objagg_opt_algo objagg_opt_simple_greedy = {
903 .fillup_hints = objagg_opt_simple_greedy_fillup_hints,
904};
905
906
907static const struct objagg_opt_algo *objagg_opt_algos[] = {
908 [OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy,
909};
910
911static int objagg_hints_obj_cmp(struct rhashtable_compare_arg *arg,
912 const void *obj)
913{
914 struct rhashtable *ht = arg->ht;
915 struct objagg_hints *objagg_hints =
916 container_of(ht, struct objagg_hints, node_ht);
917 const struct objagg_ops *ops = objagg_hints->ops;
918 const char *ptr = obj;
919
920 ptr += ht->p.key_offset;
921 return ops->hints_obj_cmp ? ops->hints_obj_cmp(ptr, arg->key) :
922 memcmp(ptr, arg->key, ht->p.key_len);
923}
924
925/**
926 * objagg_hints_get - obtains hints instance
927 * @objagg: objagg instance
928 * @opt_algo_type: type of hints finding algorithm
929 *
930 * Note: all locking must be provided by the caller.
931 *
932 * According to the algo type, the existing objects of objagg instance
933 * are going to be went-through to assemble an optimal tree. We call this
934 * tree hints. These hints can be later on used for creation of
935 * a new objagg instance. There, the future object creations are going
936 * to be consulted with these hints in order to find out, where exactly
937 * the new object should be put as a root or delta.
938 *
939 * Returns a pointer to hints instance in case of success,
940 * otherwise it returns pointer error using ERR_PTR macro.
941 */
942struct objagg_hints *objagg_hints_get(struct objagg *objagg,
943 enum objagg_opt_algo_type opt_algo_type)
944{
945 const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type];
946 struct objagg_hints *objagg_hints;
947 int err;
948
949 objagg_hints = kzalloc(sizeof(*objagg_hints), GFP_KERNEL);
950 if (!objagg_hints)
951 return ERR_PTR(-ENOMEM);
952
953 objagg_hints->ops = objagg->ops;
954 objagg_hints->refcount = 1;
955
956 INIT_LIST_HEAD(&objagg_hints->node_list);
957
958 objagg_hints->ht_params.key_len = objagg->ops->obj_size;
959 objagg_hints->ht_params.key_offset =
960 offsetof(struct objagg_hints_node, obj);
961 objagg_hints->ht_params.head_offset =
962 offsetof(struct objagg_hints_node, ht_node);
963 objagg_hints->ht_params.obj_cmpfn = objagg_hints_obj_cmp;
964
965 err = rhashtable_init(&objagg_hints->node_ht, &objagg_hints->ht_params);
966 if (err)
967 goto err_rhashtable_init;
968
969 err = algo->fillup_hints(objagg_hints, objagg);
970 if (err)
971 goto err_fillup_hints;
972
973 if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) {
974 err = -EINVAL;
975 goto err_node_count_check;
976 }
977
978 return objagg_hints;
979
980err_node_count_check:
981err_fillup_hints:
982 objagg_hints_flush(objagg_hints);
983 rhashtable_destroy(&objagg_hints->node_ht);
984err_rhashtable_init:
985 kfree(objagg_hints);
986 return ERR_PTR(err);
987}
988EXPORT_SYMBOL(objagg_hints_get);
989
990/**
991 * objagg_hints_put - puts hints instance
992 * @objagg_hints: objagg hints instance
993 *
994 * Note: all locking must be provided by the caller.
995 */
996void objagg_hints_put(struct objagg_hints *objagg_hints)
997{
998 if (--objagg_hints->refcount)
999 return;
1000 objagg_hints_flush(objagg_hints);
1001 rhashtable_destroy(&objagg_hints->node_ht);
1002 kfree(objagg_hints);
1003}
1004EXPORT_SYMBOL(objagg_hints_put);
1005
1006/**
1007 * objagg_hints_stats_get - obtains stats of the hints instance
1008 * @objagg_hints: hints instance
1009 *
1010 * Note: all locking must be provided by the caller.
1011 *
1012 * The returned structure contains statistics of all objects
1013 * currently in use, ordered by following rules:
1014 * 1) Root objects are always on lower indexes than the rest.
1015 * 2) Objects with higher delta user count are always on lower
1016 * indexes.
1017 * 3) In case multiple objects have the same delta user count,
1018 * the objects are ordered by user count.
1019 *
1020 * Returns a pointer to stats instance in case of success,
1021 * otherwise it returns pointer error using ERR_PTR macro.
1022 */
1023const struct objagg_stats *
1024objagg_hints_stats_get(struct objagg_hints *objagg_hints)
1025{
1026 struct objagg_stats *objagg_stats;
1027 struct objagg_hints_node *hnode;
1028 int i;
1029
1030 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
1031 objagg_hints->node_count),
1032 GFP_KERNEL);
1033 if (!objagg_stats)
1034 return ERR_PTR(-ENOMEM);
1035
1036 i = 0;
1037 list_for_each_entry(hnode, &objagg_hints->node_list, list) {
1038 memcpy(&objagg_stats->stats_info[i], &hnode->stats_info,
1039 sizeof(objagg_stats->stats_info[0]));
1040 if (objagg_stats->stats_info[i].is_root)
1041 objagg_stats->root_count++;
1042 i++;
1043 }
1044 objagg_stats->stats_info_count = i;
1045
1046 sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
1047 sizeof(struct objagg_obj_stats_info),
1048 objagg_stats_info_sort_cmp_func, NULL);
1049
1050 return objagg_stats;
1051}
1052EXPORT_SYMBOL(objagg_hints_stats_get);
1053
1054MODULE_LICENSE("Dual BSD/GPL");
1055MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
1056MODULE_DESCRIPTION("Object aggregation manager");
1057