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(ht: &objagg_hints->node_ht, key: obj,
40 params: 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(ht: &objagg->obj_ht, key: obj, params: 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(ptr: delta_priv))
173 return PTR_ERR(ptr: 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: objagg_obj->parent);
182 trace_objagg_obj_parent_assign(objagg, obj: objagg_obj,
183 parent,
184 parent_refcount: 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: objagg_obj_cur))
199 continue;
200 err = objagg_obj_parent_assign(objagg, objagg_obj,
201 parent: objagg_obj_cur, take_parent_ref: 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, obj: objagg_obj,
215 parent: objagg_obj->parent,
216 parent_refcount: objagg_obj->parent->refcount);
217 objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);
218 __objagg_obj_put(objagg, objagg_obj: 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, id: 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(ptr: objagg_obj->root_priv)) {
274 err = PTR_ERR(ptr: objagg_obj->root_priv);
275 goto err_root_create;
276 }
277 trace_objagg_obj_root_create(objagg, obj: 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, obj: 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->hints, obj: 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, obj: hnode->parent->obj);
314 if (IS_ERR(ptr: parent))
315 return PTR_ERR(ptr: parent);
316
317 err = objagg_obj_parent_assign(objagg, objagg_obj, parent, take_parent_ref: 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, objagg_obj: 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: &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(size: sizeof(*objagg_obj) + objagg->ops->obj_size,
370 GFP_KERNEL);
371 if (!objagg_obj)
372 return ERR_PTR(error: -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(ht: &objagg->obj_ht, obj: &objagg_obj->ht_node,
381 params: objagg->ht_params);
382 if (err)
383 goto err_ht_insert;
384 list_add(new: &objagg_obj->list, head: &objagg->obj_list);
385 objagg->obj_count++;
386 trace_objagg_obj_create(objagg, obj: objagg_obj);
387
388 return objagg_obj;
389
390err_ht_insert:
391 objagg_obj_fini(objagg, objagg_obj);
392err_obj_init:
393 kfree(objp: objagg_obj);
394 return ERR_PTR(error: 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(ptr: objagg_obj))
443 return objagg_obj;
444 objagg_obj_stats_inc(objagg_obj);
445 trace_objagg_obj_get(objagg, obj: objagg_obj, refcount: 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, obj: objagg_obj);
454 --objagg->obj_count;
455 list_del(entry: &objagg_obj->list);
456 rhashtable_remove_fast(ht: &objagg->obj_ht, obj: &objagg_obj->ht_node,
457 params: objagg->ht_params);
458 objagg_obj_fini(objagg, objagg_obj);
459 kfree(objp: 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, obj: objagg_obj, refcount: 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(error: -EINVAL);
524
525 objagg = kzalloc(size: sizeof(*objagg), GFP_KERNEL);
526 if (!objagg)
527 return ERR_PTR(error: -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(list: &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(ht: &objagg->obj_ht, params: &objagg->ht_params);
541 if (err)
542 goto err_rhashtable_init;
543
544 ida_init(ida: &objagg->root_ida);
545
546 trace_objagg_create(objagg);
547 return objagg;
548
549err_rhashtable_init:
550 kfree(objp: objagg);
551 return ERR_PTR(error: 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(ida: &objagg->root_ida);
565 WARN_ON(!list_empty(&objagg->obj_list));
566 rhashtable_destroy(ht: &objagg->obj_ht);
567 if (objagg->hints)
568 objagg_hints_put(objagg_hints: objagg->hints);
569 kfree(objp: 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(error: -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(base: objagg_stats->stats_info, num: objagg_stats->stats_info_count,
629 size: sizeof(struct objagg_obj_stats_info),
630 cmp_func: 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(objp: 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(size: sizeof(*hnode) + obj_size, GFP_KERNEL);
658 if (!hnode)
659 return ERR_PTR(error: -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(ht: &objagg_hints->node_ht, obj: &hnode->ht_node,
672 params: objagg_hints->ht_params);
673 if (err)
674 goto err_ht_insert;
675
676 list_add(new: &hnode->list, head: &objagg_hints->node_list);
677 hnode->parent = parent_hnode;
678 objagg_hints->node_count++;
679
680 return hnode;
681
682err_ht_insert:
683 kfree(objp: hnode);
684 return ERR_PTR(error: 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(entry: &hnode->list);
693 rhashtable_remove_fast(ht: &objagg_hints->node_ht, obj: &hnode->ht_node,
694 params: objagg_hints->ht_params);
695 kfree(objp: 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, parent_index: index,
720 index: 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, parent_index: index,
729 index: 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, parent_index: index, 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, index: 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 int i, j;
785
786 graph = kzalloc(size: sizeof(*graph), GFP_KERNEL);
787 if (!graph)
788 return NULL;
789
790 graph->nodes = kcalloc(n: nodes_count, size: sizeof(*graph->nodes), GFP_KERNEL);
791 if (!graph->nodes)
792 goto err_nodes_alloc;
793 graph->nodes_count = nodes_count;
794
795 graph->edges = bitmap_zalloc(nbits: nodes_count * nodes_count, GFP_KERNEL);
796 if (!graph->edges)
797 goto err_edges_alloc;
798
799 i = 0;
800 list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
801 node = &graph->nodes[i++];
802 node->objagg_obj = objagg_obj;
803 }
804
805 /* Assemble a temporary graph. Insert edge X->Y in case Y can be
806 * in delta of X.
807 */
808 for (i = 0; i < nodes_count; i++) {
809 for (j = 0; j < nodes_count; j++) {
810 if (i == j)
811 continue;
812 pnode = &graph->nodes[i];
813 node = &graph->nodes[j];
814 if (objagg->ops->delta_check(objagg->priv,
815 pnode->objagg_obj->obj,
816 node->objagg_obj->obj)) {
817 objagg_tmp_graph_edge_set(graph, parent_index: i, index: j);
818
819 }
820 }
821 }
822 return graph;
823
824err_edges_alloc:
825 kfree(objp: graph->nodes);
826err_nodes_alloc:
827 kfree(objp: graph);
828 return NULL;
829}
830
831static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
832{
833 bitmap_free(bitmap: graph->edges);
834 kfree(objp: graph->nodes);
835 kfree(objp: graph);
836}
837
838static int
839objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints,
840 struct objagg *objagg)
841{
842 struct objagg_hints_node *hnode, *parent_hnode;
843 struct objagg_tmp_graph *graph;
844 struct objagg_tmp_node *node;
845 int index;
846 int j;
847 int err;
848
849 graph = objagg_tmp_graph_create(objagg);
850 if (!graph)
851 return -ENOMEM;
852
853 /* Find the nodes from the ones that can accommodate most users
854 * and cross them out of the graph. Save them to the hint list.
855 */
856 while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) {
857 node = &graph->nodes[index];
858 node->crossed_out = true;
859 hnode = objagg_hints_node_create(objagg_hints,
860 objagg_obj: node->objagg_obj,
861 obj_size: objagg->ops->obj_size,
862 NULL);
863 if (IS_ERR(ptr: hnode)) {
864 err = PTR_ERR(ptr: hnode);
865 goto out;
866 }
867 parent_hnode = hnode;
868 for (j = 0; j < graph->nodes_count; j++) {
869 if (!objagg_tmp_graph_is_edge(graph, parent_index: index, index: j))
870 continue;
871 node = &graph->nodes[j];
872 if (node->crossed_out)
873 continue;
874 node->crossed_out = true;
875 hnode = objagg_hints_node_create(objagg_hints,
876 objagg_obj: node->objagg_obj,
877 obj_size: objagg->ops->obj_size,
878 parent_hnode);
879 if (IS_ERR(ptr: hnode)) {
880 err = PTR_ERR(ptr: hnode);
881 goto out;
882 }
883 }
884 }
885
886 err = 0;
887out:
888 objagg_tmp_graph_destroy(graph);
889 return err;
890}
891
892struct objagg_opt_algo {
893 int (*fillup_hints)(struct objagg_hints *objagg_hints,
894 struct objagg *objagg);
895};
896
897static const struct objagg_opt_algo objagg_opt_simple_greedy = {
898 .fillup_hints = objagg_opt_simple_greedy_fillup_hints,
899};
900
901
902static const struct objagg_opt_algo *objagg_opt_algos[] = {
903 [OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy,
904};
905
906static int objagg_hints_obj_cmp(struct rhashtable_compare_arg *arg,
907 const void *obj)
908{
909 struct rhashtable *ht = arg->ht;
910 struct objagg_hints *objagg_hints =
911 container_of(ht, struct objagg_hints, node_ht);
912 const struct objagg_ops *ops = objagg_hints->ops;
913 const char *ptr = obj;
914
915 ptr += ht->p.key_offset;
916 return ops->hints_obj_cmp ? ops->hints_obj_cmp(ptr, arg->key) :
917 memcmp(p: ptr, q: arg->key, size: ht->p.key_len);
918}
919
920/**
921 * objagg_hints_get - obtains hints instance
922 * @objagg: objagg instance
923 * @opt_algo_type: type of hints finding algorithm
924 *
925 * Note: all locking must be provided by the caller.
926 *
927 * According to the algo type, the existing objects of objagg instance
928 * are going to be went-through to assemble an optimal tree. We call this
929 * tree hints. These hints can be later on used for creation of
930 * a new objagg instance. There, the future object creations are going
931 * to be consulted with these hints in order to find out, where exactly
932 * the new object should be put as a root or delta.
933 *
934 * Returns a pointer to hints instance in case of success,
935 * otherwise it returns pointer error using ERR_PTR macro.
936 */
937struct objagg_hints *objagg_hints_get(struct objagg *objagg,
938 enum objagg_opt_algo_type opt_algo_type)
939{
940 const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type];
941 struct objagg_hints *objagg_hints;
942 int err;
943
944 objagg_hints = kzalloc(size: sizeof(*objagg_hints), GFP_KERNEL);
945 if (!objagg_hints)
946 return ERR_PTR(error: -ENOMEM);
947
948 objagg_hints->ops = objagg->ops;
949 objagg_hints->refcount = 1;
950
951 INIT_LIST_HEAD(list: &objagg_hints->node_list);
952
953 objagg_hints->ht_params.key_len = objagg->ops->obj_size;
954 objagg_hints->ht_params.key_offset =
955 offsetof(struct objagg_hints_node, obj);
956 objagg_hints->ht_params.head_offset =
957 offsetof(struct objagg_hints_node, ht_node);
958 objagg_hints->ht_params.obj_cmpfn = objagg_hints_obj_cmp;
959
960 err = rhashtable_init(ht: &objagg_hints->node_ht, params: &objagg_hints->ht_params);
961 if (err)
962 goto err_rhashtable_init;
963
964 err = algo->fillup_hints(objagg_hints, objagg);
965 if (err)
966 goto err_fillup_hints;
967
968 if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) {
969 err = -EINVAL;
970 goto err_node_count_check;
971 }
972
973 return objagg_hints;
974
975err_node_count_check:
976err_fillup_hints:
977 objagg_hints_flush(objagg_hints);
978 rhashtable_destroy(ht: &objagg_hints->node_ht);
979err_rhashtable_init:
980 kfree(objp: objagg_hints);
981 return ERR_PTR(error: err);
982}
983EXPORT_SYMBOL(objagg_hints_get);
984
985/**
986 * objagg_hints_put - puts hints instance
987 * @objagg_hints: objagg hints instance
988 *
989 * Note: all locking must be provided by the caller.
990 */
991void objagg_hints_put(struct objagg_hints *objagg_hints)
992{
993 if (--objagg_hints->refcount)
994 return;
995 objagg_hints_flush(objagg_hints);
996 rhashtable_destroy(ht: &objagg_hints->node_ht);
997 kfree(objp: objagg_hints);
998}
999EXPORT_SYMBOL(objagg_hints_put);
1000
1001/**
1002 * objagg_hints_stats_get - obtains stats of the hints instance
1003 * @objagg_hints: hints instance
1004 *
1005 * Note: all locking must be provided by the caller.
1006 *
1007 * The returned structure contains statistics of all objects
1008 * currently in use, ordered by following rules:
1009 * 1) Root objects are always on lower indexes than the rest.
1010 * 2) Objects with higher delta user count are always on lower
1011 * indexes.
1012 * 3) In case multiple objects have the same delta user count,
1013 * the objects are ordered by user count.
1014 *
1015 * Returns a pointer to stats instance in case of success,
1016 * otherwise it returns pointer error using ERR_PTR macro.
1017 */
1018const struct objagg_stats *
1019objagg_hints_stats_get(struct objagg_hints *objagg_hints)
1020{
1021 struct objagg_stats *objagg_stats;
1022 struct objagg_hints_node *hnode;
1023 int i;
1024
1025 objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
1026 objagg_hints->node_count),
1027 GFP_KERNEL);
1028 if (!objagg_stats)
1029 return ERR_PTR(error: -ENOMEM);
1030
1031 i = 0;
1032 list_for_each_entry(hnode, &objagg_hints->node_list, list) {
1033 memcpy(&objagg_stats->stats_info[i], &hnode->stats_info,
1034 sizeof(objagg_stats->stats_info[0]));
1035 if (objagg_stats->stats_info[i].is_root)
1036 objagg_stats->root_count++;
1037 i++;
1038 }
1039 objagg_stats->stats_info_count = i;
1040
1041 sort(base: objagg_stats->stats_info, num: objagg_stats->stats_info_count,
1042 size: sizeof(struct objagg_obj_stats_info),
1043 cmp_func: objagg_stats_info_sort_cmp_func, NULL);
1044
1045 return objagg_stats;
1046}
1047EXPORT_SYMBOL(objagg_hints_stats_get);
1048
1049MODULE_LICENSE("Dual BSD/GPL");
1050MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
1051MODULE_DESCRIPTION("Object aggregation manager");
1052

source code of linux/lib/objagg.c