1
2
3
4
5
6
7
8
9
10
11
12#include <linux/rbtree_augmented.h>
13#include <linux/export.h>
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59static inline void rb_set_black(struct rb_node *rb)
60{
61 rb->__rb_parent_color |= RB_BLACK;
62}
63
64static inline struct rb_node *rb_red_parent(struct rb_node *red)
65{
66 return (struct rb_node *)red->__rb_parent_color;
67}
68
69
70
71
72
73
74static inline void
75__rb_rotate_set_parents(struct rb_node *old, struct rb_node *new,
76 struct rb_root *root, int color)
77{
78 struct rb_node *parent = rb_parent(old);
79 new->__rb_parent_color = old->__rb_parent_color;
80 rb_set_parent_color(old, new, color);
81 __rb_change_child(old, new, parent, root);
82}
83
84static __always_inline void
85__rb_insert(struct rb_node *node, struct rb_root *root,
86 bool newleft, struct rb_node **leftmost,
87 void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
88{
89 struct rb_node *parent = rb_red_parent(node), *gparent, *tmp;
90
91 if (newleft)
92 *leftmost = node;
93
94 while (true) {
95
96
97
98 if (unlikely(!parent)) {
99
100
101
102
103
104 rb_set_parent_color(node, NULL, RB_BLACK);
105 break;
106 }
107
108
109
110
111
112
113
114 if(rb_is_black(parent))
115 break;
116
117 gparent = rb_red_parent(parent);
118
119 tmp = gparent->rb_right;
120 if (parent != tmp) {
121 if (tmp && rb_is_red(tmp)) {
122
123
124
125
126
127
128
129
130
131
132
133
134
135 rb_set_parent_color(tmp, gparent, RB_BLACK);
136 rb_set_parent_color(parent, gparent, RB_BLACK);
137 node = gparent;
138 parent = rb_parent(node);
139 rb_set_parent_color(node, parent, RB_RED);
140 continue;
141 }
142
143 tmp = parent->rb_right;
144 if (node == tmp) {
145
146
147
148
149
150
151
152
153
154
155
156
157
158 tmp = node->rb_left;
159 WRITE_ONCE(parent->rb_right, tmp);
160 WRITE_ONCE(node->rb_left, parent);
161 if (tmp)
162 rb_set_parent_color(tmp, parent,
163 RB_BLACK);
164 rb_set_parent_color(parent, node, RB_RED);
165 augment_rotate(parent, node);
166 parent = node;
167 tmp = node->rb_right;
168 }
169
170
171
172
173
174
175
176
177
178
179
180 WRITE_ONCE(gparent->rb_left, tmp);
181 WRITE_ONCE(parent->rb_right, gparent);
182 if (tmp)
183 rb_set_parent_color(tmp, gparent, RB_BLACK);
184 __rb_rotate_set_parents(gparent, parent, root, RB_RED);
185 augment_rotate(gparent, parent);
186 break;
187 } else {
188 tmp = gparent->rb_left;
189 if (tmp && rb_is_red(tmp)) {
190
191 rb_set_parent_color(tmp, gparent, RB_BLACK);
192 rb_set_parent_color(parent, gparent, RB_BLACK);
193 node = gparent;
194 parent = rb_parent(node);
195 rb_set_parent_color(node, parent, RB_RED);
196 continue;
197 }
198
199 tmp = parent->rb_left;
200 if (node == tmp) {
201
202 tmp = node->rb_right;
203 WRITE_ONCE(parent->rb_left, tmp);
204 WRITE_ONCE(node->rb_right, parent);
205 if (tmp)
206 rb_set_parent_color(tmp, parent,
207 RB_BLACK);
208 rb_set_parent_color(parent, node, RB_RED);
209 augment_rotate(parent, node);
210 parent = node;
211 tmp = node->rb_left;
212 }
213
214
215 WRITE_ONCE(gparent->rb_right, tmp);
216 WRITE_ONCE(parent->rb_left, gparent);
217 if (tmp)
218 rb_set_parent_color(tmp, gparent, RB_BLACK);
219 __rb_rotate_set_parents(gparent, parent, root, RB_RED);
220 augment_rotate(gparent, parent);
221 break;
222 }
223 }
224}
225
226
227
228
229
230static __always_inline void
231____rb_erase_color(struct rb_node *parent, struct rb_root *root,
232 void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
233{
234 struct rb_node *node = NULL, *sibling, *tmp1, *tmp2;
235
236 while (true) {
237
238
239
240
241
242
243
244 sibling = parent->rb_right;
245 if (node != sibling) {
246 if (rb_is_red(sibling)) {
247
248
249
250
251
252
253
254
255
256 tmp1 = sibling->rb_left;
257 WRITE_ONCE(parent->rb_right, tmp1);
258 WRITE_ONCE(sibling->rb_left, parent);
259 rb_set_parent_color(tmp1, parent, RB_BLACK);
260 __rb_rotate_set_parents(parent, sibling, root,
261 RB_RED);
262 augment_rotate(parent, sibling);
263 sibling = tmp1;
264 }
265 tmp1 = sibling->rb_right;
266 if (!tmp1 || rb_is_black(tmp1)) {
267 tmp2 = sibling->rb_left;
268 if (!tmp2 || rb_is_black(tmp2)) {
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284 rb_set_parent_color(sibling, parent,
285 RB_RED);
286 if (rb_is_red(parent))
287 rb_set_black(parent);
288 else {
289 node = parent;
290 parent = rb_parent(node);
291 if (parent)
292 continue;
293 }
294 break;
295 }
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323 tmp1 = tmp2->rb_right;
324 WRITE_ONCE(sibling->rb_left, tmp1);
325 WRITE_ONCE(tmp2->rb_right, sibling);
326 WRITE_ONCE(parent->rb_right, tmp2);
327 if (tmp1)
328 rb_set_parent_color(tmp1, sibling,
329 RB_BLACK);
330 augment_rotate(sibling, tmp2);
331 tmp1 = sibling;
332 sibling = tmp2;
333 }
334
335
336
337
338
339
340
341
342
343
344
345
346 tmp2 = sibling->rb_left;
347 WRITE_ONCE(parent->rb_right, tmp2);
348 WRITE_ONCE(sibling->rb_left, parent);
349 rb_set_parent_color(tmp1, sibling, RB_BLACK);
350 if (tmp2)
351 rb_set_parent(tmp2, parent);
352 __rb_rotate_set_parents(parent, sibling, root,
353 RB_BLACK);
354 augment_rotate(parent, sibling);
355 break;
356 } else {
357 sibling = parent->rb_left;
358 if (rb_is_red(sibling)) {
359
360 tmp1 = sibling->rb_right;
361 WRITE_ONCE(parent->rb_left, tmp1);
362 WRITE_ONCE(sibling->rb_right, parent);
363 rb_set_parent_color(tmp1, parent, RB_BLACK);
364 __rb_rotate_set_parents(parent, sibling, root,
365 RB_RED);
366 augment_rotate(parent, sibling);
367 sibling = tmp1;
368 }
369 tmp1 = sibling->rb_left;
370 if (!tmp1 || rb_is_black(tmp1)) {
371 tmp2 = sibling->rb_right;
372 if (!tmp2 || rb_is_black(tmp2)) {
373
374 rb_set_parent_color(sibling, parent,
375 RB_RED);
376 if (rb_is_red(parent))
377 rb_set_black(parent);
378 else {
379 node = parent;
380 parent = rb_parent(node);
381 if (parent)
382 continue;
383 }
384 break;
385 }
386
387 tmp1 = tmp2->rb_left;
388 WRITE_ONCE(sibling->rb_right, tmp1);
389 WRITE_ONCE(tmp2->rb_left, sibling);
390 WRITE_ONCE(parent->rb_left, tmp2);
391 if (tmp1)
392 rb_set_parent_color(tmp1, sibling,
393 RB_BLACK);
394 augment_rotate(sibling, tmp2);
395 tmp1 = sibling;
396 sibling = tmp2;
397 }
398
399 tmp2 = sibling->rb_right;
400 WRITE_ONCE(parent->rb_left, tmp2);
401 WRITE_ONCE(sibling->rb_right, parent);
402 rb_set_parent_color(tmp1, sibling, RB_BLACK);
403 if (tmp2)
404 rb_set_parent(tmp2, parent);
405 __rb_rotate_set_parents(parent, sibling, root,
406 RB_BLACK);
407 augment_rotate(parent, sibling);
408 break;
409 }
410 }
411}
412
413
414void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
415 void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
416{
417 ____rb_erase_color(parent, root, augment_rotate);
418}
419
420
421
422
423
424
425
426
427static inline void dummy_propagate(struct rb_node *node, struct rb_node *stop) {}
428static inline void dummy_copy(struct rb_node *old, struct rb_node *new) {}
429static inline void dummy_rotate(struct rb_node *old, struct rb_node *new) {}
430
431static const struct rb_augment_callbacks dummy_callbacks = {
432 .propagate = dummy_propagate,
433 .copy = dummy_copy,
434 .rotate = dummy_rotate
435};
436
437void rb_insert_color(struct rb_node *node, struct rb_root *root)
438{
439 __rb_insert(node, root, false, NULL, dummy_rotate);
440}
441
442void rb_erase(struct rb_node *node, struct rb_root *root)
443{
444 struct rb_node *rebalance;
445 rebalance = __rb_erase_augmented(node, root,
446 NULL, &dummy_callbacks);
447 if (rebalance)
448 ____rb_erase_color(rebalance, root, dummy_rotate);
449}
450
451void rb_insert_color_cached(struct rb_node *node,
452 struct rb_root_cached *root, bool leftmost)
453{
454 __rb_insert(node, &root->rb_root, leftmost,
455 &root->rb_leftmost, dummy_rotate);
456}
457
458void rb_erase_cached(struct rb_node *node, struct rb_root_cached *root)
459{
460 struct rb_node *rebalance;
461 rebalance = __rb_erase_augmented(node, &root->rb_root,
462 &root->rb_leftmost, &dummy_callbacks);
463 if (rebalance)
464 ____rb_erase_color(rebalance, &root->rb_root, dummy_rotate);
465}
466
467
468
469
470
471
472
473
474void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
475 bool newleft, struct rb_node **leftmost,
476 void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
477{
478 __rb_insert(node, root, newleft, leftmost, augment_rotate);
479}
480
481
482
483
484struct rb_node *rb_first(const struct rb_root *root)
485{
486 struct rb_node *n;
487
488 n = root->rb_node;
489 if (!n)
490 return NULL;
491 while (n->rb_left)
492 n = n->rb_left;
493 return n;
494}
495
496struct rb_node *rb_last(const struct rb_root *root)
497{
498 struct rb_node *n;
499
500 n = root->rb_node;
501 if (!n)
502 return NULL;
503 while (n->rb_right)
504 n = n->rb_right;
505 return n;
506}
507
508struct rb_node *rb_next(const struct rb_node *node)
509{
510 struct rb_node *parent;
511
512 if (RB_EMPTY_NODE(node))
513 return NULL;
514
515
516
517
518
519 if (node->rb_right) {
520 node = node->rb_right;
521 while (node->rb_left)
522 node=node->rb_left;
523 return (struct rb_node *)node;
524 }
525
526
527
528
529
530
531
532
533 while ((parent = rb_parent(node)) && node == parent->rb_right)
534 node = parent;
535
536 return parent;
537}
538
539struct rb_node *rb_prev(const struct rb_node *node)
540{
541 struct rb_node *parent;
542
543 if (RB_EMPTY_NODE(node))
544 return NULL;
545
546
547
548
549
550 if (node->rb_left) {
551 node = node->rb_left;
552 while (node->rb_right)
553 node=node->rb_right;
554 return (struct rb_node *)node;
555 }
556
557
558
559
560
561 while ((parent = rb_parent(node)) && node == parent->rb_left)
562 node = parent;
563
564 return parent;
565}
566
567void rb_replace_node(struct rb_node *victim, struct rb_node *new,
568 struct rb_root *root)
569{
570 struct rb_node *parent = rb_parent(victim);
571
572
573 *new = *victim;
574
575
576 if (victim->rb_left)
577 rb_set_parent(victim->rb_left, new);
578 if (victim->rb_right)
579 rb_set_parent(victim->rb_right, new);
580 __rb_change_child(victim, new, parent, root);
581}
582
583void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
584 struct rb_root_cached *root)
585{
586 rb_replace_node(victim, new, &root->rb_root);
587
588 if (root->rb_leftmost == victim)
589 root->rb_leftmost = new;
590}
591
592static struct rb_node *rb_left_deepest_node(const struct rb_node *node)
593{
594 for (;;) {
595 if (node->rb_left)
596 node = node->rb_left;
597 else if (node->rb_right)
598 node = node->rb_right;
599 else
600 return (struct rb_node *)node;
601 }
602}
603
604struct rb_node *rb_next_postorder(const struct rb_node *node)
605{
606 const struct rb_node *parent;
607 if (!node)
608 return NULL;
609 parent = rb_parent(node);
610
611
612 if (parent && node == parent->rb_left && parent->rb_right) {
613
614
615 return rb_left_deepest_node(parent->rb_right);
616 } else
617
618
619 return (struct rb_node *)parent;
620}
621
622struct rb_node *rb_first_postorder(const struct rb_root *root)
623{
624 if (!root->rb_node)
625 return NULL;
626
627 return rb_left_deepest_node(root->rb_node);
628}
629