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25#include <linux/bitmap.h>
26#include <linux/bitops.h>
27#include <linux/bug.h>
28#include <linux/cpu.h>
29#include <linux/errno.h>
30#include <linux/export.h>
31#include <linux/idr.h>
32#include <linux/init.h>
33#include <linux/kernel.h>
34#include <linux/kmemleak.h>
35#include <linux/percpu.h>
36#include <linux/preempt.h>
37#include <linux/radix-tree.h>
38#include <linux/rcupdate.h>
39#include <linux/slab.h>
40#include <linux/string.h>
41
42
43
44static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly;
45
46
47
48
49static struct kmem_cache *radix_tree_node_cachep;
50
51
52
53
54
55
56
57
58
59
60
61
62#define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1)
63
64
65
66
67
68#define IDR_INDEX_BITS (8 * sizeof(int) - 1)
69#define IDR_MAX_PATH (DIV_ROUND_UP(IDR_INDEX_BITS, \
70 RADIX_TREE_MAP_SHIFT))
71#define IDR_PRELOAD_SIZE (IDR_MAX_PATH * 2 - 1)
72
73
74
75
76#define IDA_INDEX_BITS (8 * sizeof(int) - 1 - ilog2(IDA_BITMAP_BITS))
77#define IDA_MAX_PATH (DIV_ROUND_UP(IDA_INDEX_BITS, \
78 RADIX_TREE_MAP_SHIFT))
79#define IDA_PRELOAD_SIZE (IDA_MAX_PATH * 2 - 1)
80
81
82
83
84struct radix_tree_preload {
85 unsigned nr;
86
87 struct radix_tree_node *nodes;
88};
89static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
90
91static inline struct radix_tree_node *entry_to_node(void *ptr)
92{
93 return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
94}
95
96static inline void *node_to_entry(void *ptr)
97{
98 return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE);
99}
100
101#define RADIX_TREE_RETRY node_to_entry(NULL)
102
103#ifdef CONFIG_RADIX_TREE_MULTIORDER
104
105static inline
106bool is_sibling_entry(const struct radix_tree_node *parent, void *node)
107{
108 void __rcu **ptr = node;
109 return (parent->slots <= ptr) &&
110 (ptr < parent->slots + RADIX_TREE_MAP_SIZE);
111}
112#else
113static inline
114bool is_sibling_entry(const struct radix_tree_node *parent, void *node)
115{
116 return false;
117}
118#endif
119
120static inline unsigned long
121get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot)
122{
123 return slot - parent->slots;
124}
125
126static unsigned int radix_tree_descend(const struct radix_tree_node *parent,
127 struct radix_tree_node **nodep, unsigned long index)
128{
129 unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK;
130 void __rcu **entry = rcu_dereference_raw(parent->slots[offset]);
131
132#ifdef CONFIG_RADIX_TREE_MULTIORDER
133 if (radix_tree_is_internal_node(entry)) {
134 if (is_sibling_entry(parent, entry)) {
135 void __rcu **sibentry;
136 sibentry = (void __rcu **) entry_to_node(entry);
137 offset = get_slot_offset(parent, sibentry);
138 entry = rcu_dereference_raw(*sibentry);
139 }
140 }
141#endif
142
143 *nodep = (void *)entry;
144 return offset;
145}
146
147static inline gfp_t root_gfp_mask(const struct radix_tree_root *root)
148{
149 return root->gfp_mask & (__GFP_BITS_MASK & ~GFP_ZONEMASK);
150}
151
152static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
153 int offset)
154{
155 __set_bit(offset, node->tags[tag]);
156}
157
158static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
159 int offset)
160{
161 __clear_bit(offset, node->tags[tag]);
162}
163
164static inline int tag_get(const struct radix_tree_node *node, unsigned int tag,
165 int offset)
166{
167 return test_bit(offset, node->tags[tag]);
168}
169
170static inline void root_tag_set(struct radix_tree_root *root, unsigned tag)
171{
172 root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT));
173}
174
175static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag)
176{
177 root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT));
178}
179
180static inline void root_tag_clear_all(struct radix_tree_root *root)
181{
182 root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1;
183}
184
185static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag)
186{
187 return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT));
188}
189
190static inline unsigned root_tags_get(const struct radix_tree_root *root)
191{
192 return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT;
193}
194
195static inline bool is_idr(const struct radix_tree_root *root)
196{
197 return !!(root->gfp_mask & ROOT_IS_IDR);
198}
199
200
201
202
203
204static inline int any_tag_set(const struct radix_tree_node *node,
205 unsigned int tag)
206{
207 unsigned idx;
208 for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
209 if (node->tags[tag][idx])
210 return 1;
211 }
212 return 0;
213}
214
215static inline void all_tag_set(struct radix_tree_node *node, unsigned int tag)
216{
217 bitmap_fill(node->tags[tag], RADIX_TREE_MAP_SIZE);
218}
219
220
221
222
223
224
225
226
227
228
229
230
231static __always_inline unsigned long
232radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag,
233 unsigned long offset)
234{
235 const unsigned long *addr = node->tags[tag];
236
237 if (offset < RADIX_TREE_MAP_SIZE) {
238 unsigned long tmp;
239
240 addr += offset / BITS_PER_LONG;
241 tmp = *addr >> (offset % BITS_PER_LONG);
242 if (tmp)
243 return __ffs(tmp) + offset;
244 offset = (offset + BITS_PER_LONG) & ~(BITS_PER_LONG - 1);
245 while (offset < RADIX_TREE_MAP_SIZE) {
246 tmp = *++addr;
247 if (tmp)
248 return __ffs(tmp) + offset;
249 offset += BITS_PER_LONG;
250 }
251 }
252 return RADIX_TREE_MAP_SIZE;
253}
254
255static unsigned int iter_offset(const struct radix_tree_iter *iter)
256{
257 return (iter->index >> iter_shift(iter)) & RADIX_TREE_MAP_MASK;
258}
259
260
261
262
263static inline unsigned long shift_maxindex(unsigned int shift)
264{
265 return (RADIX_TREE_MAP_SIZE << shift) - 1;
266}
267
268static inline unsigned long node_maxindex(const struct radix_tree_node *node)
269{
270 return shift_maxindex(node->shift);
271}
272
273static unsigned long next_index(unsigned long index,
274 const struct radix_tree_node *node,
275 unsigned long offset)
276{
277 return (index & ~node_maxindex(node)) + (offset << node->shift);
278}
279
280#ifndef __KERNEL__
281static void dump_node(struct radix_tree_node *node, unsigned long index)
282{
283 unsigned long i;
284
285 pr_debug("radix node: %p offset %d indices %lu-%lu parent %p tags %lx %lx %lx shift %d count %d exceptional %d\n",
286 node, node->offset, index, index | node_maxindex(node),
287 node->parent,
288 node->tags[0][0], node->tags[1][0], node->tags[2][0],
289 node->shift, node->count, node->exceptional);
290
291 for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
292 unsigned long first = index | (i << node->shift);
293 unsigned long last = first | ((1UL << node->shift) - 1);
294 void *entry = node->slots[i];
295 if (!entry)
296 continue;
297 if (entry == RADIX_TREE_RETRY) {
298 pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n",
299 i, first, last, node);
300 } else if (!radix_tree_is_internal_node(entry)) {
301 pr_debug("radix entry %p offset %ld indices %lu-%lu parent %p\n",
302 entry, i, first, last, node);
303 } else if (is_sibling_entry(node, entry)) {
304 pr_debug("radix sblng %p offset %ld indices %lu-%lu parent %p val %p\n",
305 entry, i, first, last, node,
306 *(void **)entry_to_node(entry));
307 } else {
308 dump_node(entry_to_node(entry), first);
309 }
310 }
311}
312
313
314static void radix_tree_dump(struct radix_tree_root *root)
315{
316 pr_debug("radix root: %p rnode %p tags %x\n",
317 root, root->rnode,
318 root->gfp_mask >> ROOT_TAG_SHIFT);
319 if (!radix_tree_is_internal_node(root->rnode))
320 return;
321 dump_node(entry_to_node(root->rnode), 0);
322}
323
324static void dump_ida_node(void *entry, unsigned long index)
325{
326 unsigned long i;
327
328 if (!entry)
329 return;
330
331 if (radix_tree_is_internal_node(entry)) {
332 struct radix_tree_node *node = entry_to_node(entry);
333
334 pr_debug("ida node: %p offset %d indices %lu-%lu parent %p free %lx shift %d count %d\n",
335 node, node->offset, index * IDA_BITMAP_BITS,
336 ((index | node_maxindex(node)) + 1) *
337 IDA_BITMAP_BITS - 1,
338 node->parent, node->tags[0][0], node->shift,
339 node->count);
340 for (i = 0; i < RADIX_TREE_MAP_SIZE; i++)
341 dump_ida_node(node->slots[i],
342 index | (i << node->shift));
343 } else if (radix_tree_exceptional_entry(entry)) {
344 pr_debug("ida excp: %p offset %d indices %lu-%lu data %lx\n",
345 entry, (int)(index & RADIX_TREE_MAP_MASK),
346 index * IDA_BITMAP_BITS,
347 index * IDA_BITMAP_BITS + BITS_PER_LONG -
348 RADIX_TREE_EXCEPTIONAL_SHIFT,
349 (unsigned long)entry >>
350 RADIX_TREE_EXCEPTIONAL_SHIFT);
351 } else {
352 struct ida_bitmap *bitmap = entry;
353
354 pr_debug("ida btmp: %p offset %d indices %lu-%lu data", bitmap,
355 (int)(index & RADIX_TREE_MAP_MASK),
356 index * IDA_BITMAP_BITS,
357 (index + 1) * IDA_BITMAP_BITS - 1);
358 for (i = 0; i < IDA_BITMAP_LONGS; i++)
359 pr_cont(" %lx", bitmap->bitmap[i]);
360 pr_cont("\n");
361 }
362}
363
364static void ida_dump(struct ida *ida)
365{
366 struct radix_tree_root *root = &ida->ida_rt;
367 pr_debug("ida: %p node %p free %d\n", ida, root->rnode,
368 root->gfp_mask >> ROOT_TAG_SHIFT);
369 dump_ida_node(root->rnode, 0);
370}
371#endif
372
373
374
375
376
377static struct radix_tree_node *
378radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent,
379 struct radix_tree_root *root,
380 unsigned int shift, unsigned int offset,
381 unsigned int count, unsigned int exceptional)
382{
383 struct radix_tree_node *ret = NULL;
384
385
386
387
388
389
390 if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) {
391 struct radix_tree_preload *rtp;
392
393
394
395
396
397
398 ret = kmem_cache_alloc(radix_tree_node_cachep,
399 gfp_mask | __GFP_NOWARN);
400 if (ret)
401 goto out;
402
403
404
405
406
407
408 rtp = this_cpu_ptr(&radix_tree_preloads);
409 if (rtp->nr) {
410 ret = rtp->nodes;
411 rtp->nodes = ret->parent;
412 rtp->nr--;
413 }
414
415
416
417
418 kmemleak_update_trace(ret);
419 goto out;
420 }
421 ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
422out:
423 BUG_ON(radix_tree_is_internal_node(ret));
424 if (ret) {
425 ret->shift = shift;
426 ret->offset = offset;
427 ret->count = count;
428 ret->exceptional = exceptional;
429 ret->parent = parent;
430 ret->root = root;
431 }
432 return ret;
433}
434
435static void radix_tree_node_rcu_free(struct rcu_head *head)
436{
437 struct radix_tree_node *node =
438 container_of(head, struct radix_tree_node, rcu_head);
439
440
441
442
443
444
445 memset(node->slots, 0, sizeof(node->slots));
446 memset(node->tags, 0, sizeof(node->tags));
447 INIT_LIST_HEAD(&node->private_list);
448
449 kmem_cache_free(radix_tree_node_cachep, node);
450}
451
452static inline void
453radix_tree_node_free(struct radix_tree_node *node)
454{
455 call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
456}
457
458
459
460
461
462
463
464
465
466
467static __must_check int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
468{
469 struct radix_tree_preload *rtp;
470 struct radix_tree_node *node;
471 int ret = -ENOMEM;
472
473
474
475
476
477 gfp_mask &= ~__GFP_ACCOUNT;
478
479 preempt_disable();
480 rtp = this_cpu_ptr(&radix_tree_preloads);
481 while (rtp->nr < nr) {
482 preempt_enable();
483 node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
484 if (node == NULL)
485 goto out;
486 preempt_disable();
487 rtp = this_cpu_ptr(&radix_tree_preloads);
488 if (rtp->nr < nr) {
489 node->parent = rtp->nodes;
490 rtp->nodes = node;
491 rtp->nr++;
492 } else {
493 kmem_cache_free(radix_tree_node_cachep, node);
494 }
495 }
496 ret = 0;
497out:
498 return ret;
499}
500
501
502
503
504
505
506
507
508
509
510int radix_tree_preload(gfp_t gfp_mask)
511{
512
513 WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
514 return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE);
515}
516EXPORT_SYMBOL(radix_tree_preload);
517
518
519
520
521
522
523int radix_tree_maybe_preload(gfp_t gfp_mask)
524{
525 if (gfpflags_allow_blocking(gfp_mask))
526 return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE);
527
528 preempt_disable();
529 return 0;
530}
531EXPORT_SYMBOL(radix_tree_maybe_preload);
532
533#ifdef CONFIG_RADIX_TREE_MULTIORDER
534
535
536
537
538int radix_tree_split_preload(unsigned int old_order, unsigned int new_order,
539 gfp_t gfp_mask)
540{
541 unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT);
542 unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) -
543 (new_order / RADIX_TREE_MAP_SHIFT);
544 unsigned nr = 0;
545
546 WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
547 BUG_ON(new_order >= old_order);
548
549 while (layers--)
550 nr = nr * RADIX_TREE_MAP_SIZE + 1;
551 return __radix_tree_preload(gfp_mask, top * nr);
552}
553#endif
554
555
556
557
558
559int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order)
560{
561 unsigned long nr_subtrees;
562 int nr_nodes, subtree_height;
563
564
565 if (!gfpflags_allow_blocking(gfp_mask)) {
566 preempt_disable();
567 return 0;
568 }
569
570
571
572
573
574 nr_subtrees = 1 << order;
575 for (subtree_height = 0; nr_subtrees > RADIX_TREE_MAP_SIZE;
576 subtree_height++)
577 nr_subtrees >>= RADIX_TREE_MAP_SHIFT;
578
579
580
581
582
583
584
585
586 nr_nodes = RADIX_TREE_MAX_PATH;
587
588
589 nr_nodes += RADIX_TREE_MAX_PATH - subtree_height;
590
591
592 nr_nodes--;
593
594
595 nr_nodes += nr_subtrees * height_to_maxnodes[subtree_height];
596
597 return __radix_tree_preload(gfp_mask, nr_nodes);
598}
599
600static unsigned radix_tree_load_root(const struct radix_tree_root *root,
601 struct radix_tree_node **nodep, unsigned long *maxindex)
602{
603 struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
604
605 *nodep = node;
606
607 if (likely(radix_tree_is_internal_node(node))) {
608 node = entry_to_node(node);
609 *maxindex = node_maxindex(node);
610 return node->shift + RADIX_TREE_MAP_SHIFT;
611 }
612
613 *maxindex = 0;
614 return 0;
615}
616
617
618
619
620static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp,
621 unsigned long index, unsigned int shift)
622{
623 void *entry;
624 unsigned int maxshift;
625 int tag;
626
627
628 maxshift = shift;
629 while (index > shift_maxindex(maxshift))
630 maxshift += RADIX_TREE_MAP_SHIFT;
631
632 entry = rcu_dereference_raw(root->rnode);
633 if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE)))
634 goto out;
635
636 do {
637 struct radix_tree_node *node = radix_tree_node_alloc(gfp, NULL,
638 root, shift, 0, 1, 0);
639 if (!node)
640 return -ENOMEM;
641
642 if (is_idr(root)) {
643 all_tag_set(node, IDR_FREE);
644 if (!root_tag_get(root, IDR_FREE)) {
645 tag_clear(node, IDR_FREE, 0);
646 root_tag_set(root, IDR_FREE);
647 }
648 } else {
649
650 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
651 if (root_tag_get(root, tag))
652 tag_set(node, tag, 0);
653 }
654 }
655
656 BUG_ON(shift > BITS_PER_LONG);
657 if (radix_tree_is_internal_node(entry)) {
658 entry_to_node(entry)->parent = node;
659 } else if (radix_tree_exceptional_entry(entry)) {
660
661 node->exceptional = 1;
662 }
663
664
665
666
667 node->slots[0] = (void __rcu *)entry;
668 entry = node_to_entry(node);
669 rcu_assign_pointer(root->rnode, entry);
670 shift += RADIX_TREE_MAP_SHIFT;
671 } while (shift <= maxshift);
672out:
673 return maxshift + RADIX_TREE_MAP_SHIFT;
674}
675
676
677
678
679
680static inline bool radix_tree_shrink(struct radix_tree_root *root,
681 radix_tree_update_node_t update_node)
682{
683 bool shrunk = false;
684
685 for (;;) {
686 struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
687 struct radix_tree_node *child;
688
689 if (!radix_tree_is_internal_node(node))
690 break;
691 node = entry_to_node(node);
692
693
694
695
696
697
698 if (node->count != 1)
699 break;
700 child = rcu_dereference_raw(node->slots[0]);
701 if (!child)
702 break;
703 if (!radix_tree_is_internal_node(child) && node->shift)
704 break;
705
706 if (radix_tree_is_internal_node(child))
707 entry_to_node(child)->parent = NULL;
708
709
710
711
712
713
714
715
716 root->rnode = (void __rcu *)child;
717 if (is_idr(root) && !tag_get(node, IDR_FREE, 0))
718 root_tag_clear(root, IDR_FREE);
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738 node->count = 0;
739 if (!radix_tree_is_internal_node(child)) {
740 node->slots[0] = (void __rcu *)RADIX_TREE_RETRY;
741 if (update_node)
742 update_node(node);
743 }
744
745 WARN_ON_ONCE(!list_empty(&node->private_list));
746 radix_tree_node_free(node);
747 shrunk = true;
748 }
749
750 return shrunk;
751}
752
753static bool delete_node(struct radix_tree_root *root,
754 struct radix_tree_node *node,
755 radix_tree_update_node_t update_node)
756{
757 bool deleted = false;
758
759 do {
760 struct radix_tree_node *parent;
761
762 if (node->count) {
763 if (node_to_entry(node) ==
764 rcu_dereference_raw(root->rnode))
765 deleted |= radix_tree_shrink(root,
766 update_node);
767 return deleted;
768 }
769
770 parent = node->parent;
771 if (parent) {
772 parent->slots[node->offset] = NULL;
773 parent->count--;
774 } else {
775
776
777
778
779 if (!is_idr(root))
780 root_tag_clear_all(root);
781 root->rnode = NULL;
782 }
783
784 WARN_ON_ONCE(!list_empty(&node->private_list));
785 radix_tree_node_free(node);
786 deleted = true;
787
788 node = parent;
789 } while (node);
790
791 return deleted;
792}
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
812 unsigned order, struct radix_tree_node **nodep,
813 void __rcu ***slotp)
814{
815 struct radix_tree_node *node = NULL, *child;
816 void __rcu **slot = (void __rcu **)&root->rnode;
817 unsigned long maxindex;
818 unsigned int shift, offset = 0;
819 unsigned long max = index | ((1UL << order) - 1);
820 gfp_t gfp = root_gfp_mask(root);
821
822 shift = radix_tree_load_root(root, &child, &maxindex);
823
824
825 if (order > 0 && max == ((1UL << order) - 1))
826 max++;
827 if (max > maxindex) {
828 int error = radix_tree_extend(root, gfp, max, shift);
829 if (error < 0)
830 return error;
831 shift = error;
832 child = rcu_dereference_raw(root->rnode);
833 }
834
835 while (shift > order) {
836 shift -= RADIX_TREE_MAP_SHIFT;
837 if (child == NULL) {
838
839 child = radix_tree_node_alloc(gfp, node, root, shift,
840 offset, 0, 0);
841 if (!child)
842 return -ENOMEM;
843 rcu_assign_pointer(*slot, node_to_entry(child));
844 if (node)
845 node->count++;
846 } else if (!radix_tree_is_internal_node(child))
847 break;
848
849
850 node = entry_to_node(child);
851 offset = radix_tree_descend(node, &child, index);
852 slot = &node->slots[offset];
853 }
854
855 if (nodep)
856 *nodep = node;
857 if (slotp)
858 *slotp = slot;
859 return 0;
860}
861
862
863
864
865
866
867
868
869
870
871static void radix_tree_free_nodes(struct radix_tree_node *node)
872{
873 unsigned offset = 0;
874 struct radix_tree_node *child = entry_to_node(node);
875
876 for (;;) {
877 void *entry = rcu_dereference_raw(child->slots[offset]);
878 if (radix_tree_is_internal_node(entry) &&
879 !is_sibling_entry(child, entry)) {
880 child = entry_to_node(entry);
881 offset = 0;
882 continue;
883 }
884 offset++;
885 while (offset == RADIX_TREE_MAP_SIZE) {
886 struct radix_tree_node *old = child;
887 offset = child->offset + 1;
888 child = child->parent;
889 WARN_ON_ONCE(!list_empty(&old->private_list));
890 radix_tree_node_free(old);
891 if (old == entry_to_node(node))
892 return;
893 }
894 }
895}
896
897#ifdef CONFIG_RADIX_TREE_MULTIORDER
898static inline int insert_entries(struct radix_tree_node *node,
899 void __rcu **slot, void *item, unsigned order, bool replace)
900{
901 struct radix_tree_node *child;
902 unsigned i, n, tag, offset, tags = 0;
903
904 if (node) {
905 if (order > node->shift)
906 n = 1 << (order - node->shift);
907 else
908 n = 1;
909 offset = get_slot_offset(node, slot);
910 } else {
911 n = 1;
912 offset = 0;
913 }
914
915 if (n > 1) {
916 offset = offset & ~(n - 1);
917 slot = &node->slots[offset];
918 }
919 child = node_to_entry(slot);
920
921 for (i = 0; i < n; i++) {
922 if (slot[i]) {
923 if (replace) {
924 node->count--;
925 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
926 if (tag_get(node, tag, offset + i))
927 tags |= 1 << tag;
928 } else
929 return -EEXIST;
930 }
931 }
932
933 for (i = 0; i < n; i++) {
934 struct radix_tree_node *old = rcu_dereference_raw(slot[i]);
935 if (i) {
936 rcu_assign_pointer(slot[i], child);
937 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
938 if (tags & (1 << tag))
939 tag_clear(node, tag, offset + i);
940 } else {
941 rcu_assign_pointer(slot[i], item);
942 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
943 if (tags & (1 << tag))
944 tag_set(node, tag, offset);
945 }
946 if (radix_tree_is_internal_node(old) &&
947 !is_sibling_entry(node, old) &&
948 (old != RADIX_TREE_RETRY))
949 radix_tree_free_nodes(old);
950 if (radix_tree_exceptional_entry(old))
951 node->exceptional--;
952 }
953 if (node) {
954 node->count += n;
955 if (radix_tree_exceptional_entry(item))
956 node->exceptional += n;
957 }
958 return n;
959}
960#else
961static inline int insert_entries(struct radix_tree_node *node,
962 void __rcu **slot, void *item, unsigned order, bool replace)
963{
964 if (*slot)
965 return -EEXIST;
966 rcu_assign_pointer(*slot, item);
967 if (node) {
968 node->count++;
969 if (radix_tree_exceptional_entry(item))
970 node->exceptional++;
971 }
972 return 1;
973}
974#endif
975
976
977
978
979
980
981
982
983
984
985int __radix_tree_insert(struct radix_tree_root *root, unsigned long index,
986 unsigned order, void *item)
987{
988 struct radix_tree_node *node;
989 void __rcu **slot;
990 int error;
991
992 BUG_ON(radix_tree_is_internal_node(item));
993
994 error = __radix_tree_create(root, index, order, &node, &slot);
995 if (error)
996 return error;
997
998 error = insert_entries(node, slot, item, order, false);
999 if (error < 0)
1000 return error;
1001
1002 if (node) {
1003 unsigned offset = get_slot_offset(node, slot);
1004 BUG_ON(tag_get(node, 0, offset));
1005 BUG_ON(tag_get(node, 1, offset));
1006 BUG_ON(tag_get(node, 2, offset));
1007 } else {
1008 BUG_ON(root_tags_get(root));
1009 }
1010
1011 return 0;
1012}
1013EXPORT_SYMBOL(__radix_tree_insert);
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029void *__radix_tree_lookup(const struct radix_tree_root *root,
1030 unsigned long index, struct radix_tree_node **nodep,
1031 void __rcu ***slotp)
1032{
1033 struct radix_tree_node *node, *parent;
1034 unsigned long maxindex;
1035 void __rcu **slot;
1036
1037 restart:
1038 parent = NULL;
1039 slot = (void __rcu **)&root->rnode;
1040 radix_tree_load_root(root, &node, &maxindex);
1041 if (index > maxindex)
1042 return NULL;
1043
1044 while (radix_tree_is_internal_node(node)) {
1045 unsigned offset;
1046
1047 if (node == RADIX_TREE_RETRY)
1048 goto restart;
1049 parent = entry_to_node(node);
1050 offset = radix_tree_descend(parent, &node, index);
1051 slot = parent->slots + offset;
1052 }
1053
1054 if (nodep)
1055 *nodep = parent;
1056 if (slotp)
1057 *slotp = slot;
1058 return node;
1059}
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *root,
1075 unsigned long index)
1076{
1077 void __rcu **slot;
1078
1079 if (!__radix_tree_lookup(root, index, NULL, &slot))
1080 return NULL;
1081 return slot;
1082}
1083EXPORT_SYMBOL(radix_tree_lookup_slot);
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index)
1098{
1099 return __radix_tree_lookup(root, index, NULL, NULL);
1100}
1101EXPORT_SYMBOL(radix_tree_lookup);
1102
1103static inline void replace_sibling_entries(struct radix_tree_node *node,
1104 void __rcu **slot, int count, int exceptional)
1105{
1106#ifdef CONFIG_RADIX_TREE_MULTIORDER
1107 void *ptr = node_to_entry(slot);
1108 unsigned offset = get_slot_offset(node, slot) + 1;
1109
1110 while (offset < RADIX_TREE_MAP_SIZE) {
1111 if (rcu_dereference_raw(node->slots[offset]) != ptr)
1112 break;
1113 if (count < 0) {
1114 node->slots[offset] = NULL;
1115 node->count--;
1116 }
1117 node->exceptional += exceptional;
1118 offset++;
1119 }
1120#endif
1121}
1122
1123static void replace_slot(void __rcu **slot, void *item,
1124 struct radix_tree_node *node, int count, int exceptional)
1125{
1126 if (WARN_ON_ONCE(radix_tree_is_internal_node(item)))
1127 return;
1128
1129 if (node && (count || exceptional)) {
1130 node->count += count;
1131 node->exceptional += exceptional;
1132 replace_sibling_entries(node, slot, count, exceptional);
1133 }
1134
1135 rcu_assign_pointer(*slot, item);
1136}
1137
1138static bool node_tag_get(const struct radix_tree_root *root,
1139 const struct radix_tree_node *node,
1140 unsigned int tag, unsigned int offset)
1141{
1142 if (node)
1143 return tag_get(node, tag, offset);
1144 return root_tag_get(root, tag);
1145}
1146
1147
1148
1149
1150
1151
1152
1153
1154static int calculate_count(struct radix_tree_root *root,
1155 struct radix_tree_node *node, void __rcu **slot,
1156 void *item, void *old)
1157{
1158 if (is_idr(root)) {
1159 unsigned offset = get_slot_offset(node, slot);
1160 bool free = node_tag_get(root, node, IDR_FREE, offset);
1161 if (!free)
1162 return 0;
1163 if (!old)
1164 return 1;
1165 }
1166 return !!item - !!old;
1167}
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180void __radix_tree_replace(struct radix_tree_root *root,
1181 struct radix_tree_node *node,
1182 void __rcu **slot, void *item,
1183 radix_tree_update_node_t update_node)
1184{
1185 void *old = rcu_dereference_raw(*slot);
1186 int exceptional = !!radix_tree_exceptional_entry(item) -
1187 !!radix_tree_exceptional_entry(old);
1188 int count = calculate_count(root, node, slot, item, old);
1189
1190
1191
1192
1193
1194
1195 WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) &&
1196 (count || exceptional));
1197 replace_slot(slot, item, node, count, exceptional);
1198
1199 if (!node)
1200 return;
1201
1202 if (update_node)
1203 update_node(node);
1204
1205 delete_node(root, node, update_node);
1206}
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224void radix_tree_replace_slot(struct radix_tree_root *root,
1225 void __rcu **slot, void *item)
1226{
1227 __radix_tree_replace(root, NULL, slot, item, NULL);
1228}
1229EXPORT_SYMBOL(radix_tree_replace_slot);
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240void radix_tree_iter_replace(struct radix_tree_root *root,
1241 const struct radix_tree_iter *iter,
1242 void __rcu **slot, void *item)
1243{
1244 __radix_tree_replace(root, iter->node, slot, item, NULL);
1245}
1246
1247#ifdef CONFIG_RADIX_TREE_MULTIORDER
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262int radix_tree_join(struct radix_tree_root *root, unsigned long index,
1263 unsigned order, void *item)
1264{
1265 struct radix_tree_node *node;
1266 void __rcu **slot;
1267 int error;
1268
1269 BUG_ON(radix_tree_is_internal_node(item));
1270
1271 error = __radix_tree_create(root, index, order, &node, &slot);
1272 if (!error)
1273 error = insert_entries(node, slot, item, order, true);
1274 if (error > 0)
1275 error = 0;
1276
1277 return error;
1278}
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297int radix_tree_split(struct radix_tree_root *root, unsigned long index,
1298 unsigned order)
1299{
1300 struct radix_tree_node *parent, *node, *child;
1301 void __rcu **slot;
1302 unsigned int offset, end;
1303 unsigned n, tag, tags = 0;
1304 gfp_t gfp = root_gfp_mask(root);
1305
1306 if (!__radix_tree_lookup(root, index, &parent, &slot))
1307 return -ENOENT;
1308 if (!parent)
1309 return -ENOENT;
1310
1311 offset = get_slot_offset(parent, slot);
1312
1313 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1314 if (tag_get(parent, tag, offset))
1315 tags |= 1 << tag;
1316
1317 for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) {
1318 if (!is_sibling_entry(parent,
1319 rcu_dereference_raw(parent->slots[end])))
1320 break;
1321 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1322 if (tags & (1 << tag))
1323 tag_set(parent, tag, end);
1324
1325 rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY);
1326 }
1327 rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY);
1328 parent->exceptional -= (end - offset);
1329
1330 if (order == parent->shift)
1331 return 0;
1332 if (order > parent->shift) {
1333 while (offset < end)
1334 offset += insert_entries(parent, &parent->slots[offset],
1335 RADIX_TREE_RETRY, order, true);
1336 return 0;
1337 }
1338
1339 node = parent;
1340
1341 for (;;) {
1342 if (node->shift > order) {
1343 child = radix_tree_node_alloc(gfp, node, root,
1344 node->shift - RADIX_TREE_MAP_SHIFT,
1345 offset, 0, 0);
1346 if (!child)
1347 goto nomem;
1348 if (node != parent) {
1349 node->count++;
1350 rcu_assign_pointer(node->slots[offset],
1351 node_to_entry(child));
1352 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1353 if (tags & (1 << tag))
1354 tag_set(node, tag, offset);
1355 }
1356
1357 node = child;
1358 offset = 0;
1359 continue;
1360 }
1361
1362 n = insert_entries(node, &node->slots[offset],
1363 RADIX_TREE_RETRY, order, false);
1364 BUG_ON(n > RADIX_TREE_MAP_SIZE);
1365
1366 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1367 if (tags & (1 << tag))
1368 tag_set(node, tag, offset);
1369 offset += n;
1370
1371 while (offset == RADIX_TREE_MAP_SIZE) {
1372 if (node == parent)
1373 break;
1374 offset = node->offset;
1375 child = node;
1376 node = node->parent;
1377 rcu_assign_pointer(node->slots[offset],
1378 node_to_entry(child));
1379 offset++;
1380 }
1381 if ((node == parent) && (offset == end))
1382 return 0;
1383 }
1384
1385 nomem:
1386
1387
1388 WARN_ON(1);
1389 return -ENOMEM;
1390}
1391#endif
1392
1393static void node_tag_set(struct radix_tree_root *root,
1394 struct radix_tree_node *node,
1395 unsigned int tag, unsigned int offset)
1396{
1397 while (node) {
1398 if (tag_get(node, tag, offset))
1399 return;
1400 tag_set(node, tag, offset);
1401 offset = node->offset;
1402 node = node->parent;
1403 }
1404
1405 if (!root_tag_get(root, tag))
1406 root_tag_set(root, tag);
1407}
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422void *radix_tree_tag_set(struct radix_tree_root *root,
1423 unsigned long index, unsigned int tag)
1424{
1425 struct radix_tree_node *node, *parent;
1426 unsigned long maxindex;
1427
1428 radix_tree_load_root(root, &node, &maxindex);
1429 BUG_ON(index > maxindex);
1430
1431 while (radix_tree_is_internal_node(node)) {
1432 unsigned offset;
1433
1434 parent = entry_to_node(node);
1435 offset = radix_tree_descend(parent, &node, index);
1436 BUG_ON(!node);
1437
1438 if (!tag_get(parent, tag, offset))
1439 tag_set(parent, tag, offset);
1440 }
1441
1442
1443 if (!root_tag_get(root, tag))
1444 root_tag_set(root, tag);
1445
1446 return node;
1447}
1448EXPORT_SYMBOL(radix_tree_tag_set);
1449
1450
1451
1452
1453
1454
1455
1456void radix_tree_iter_tag_set(struct radix_tree_root *root,
1457 const struct radix_tree_iter *iter, unsigned int tag)
1458{
1459 node_tag_set(root, iter->node, tag, iter_offset(iter));
1460}
1461
1462static void node_tag_clear(struct radix_tree_root *root,
1463 struct radix_tree_node *node,
1464 unsigned int tag, unsigned int offset)
1465{
1466 while (node) {
1467 if (!tag_get(node, tag, offset))
1468 return;
1469 tag_clear(node, tag, offset);
1470 if (any_tag_set(node, tag))
1471 return;
1472
1473 offset = node->offset;
1474 node = node->parent;
1475 }
1476
1477
1478 if (root_tag_get(root, tag))
1479 root_tag_clear(root, tag);
1480}
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496void *radix_tree_tag_clear(struct radix_tree_root *root,
1497 unsigned long index, unsigned int tag)
1498{
1499 struct radix_tree_node *node, *parent;
1500 unsigned long maxindex;
1501 int uninitialized_var(offset);
1502
1503 radix_tree_load_root(root, &node, &maxindex);
1504 if (index > maxindex)
1505 return NULL;
1506
1507 parent = NULL;
1508
1509 while (radix_tree_is_internal_node(node)) {
1510 parent = entry_to_node(node);
1511 offset = radix_tree_descend(parent, &node, index);
1512 }
1513
1514 if (node)
1515 node_tag_clear(root, parent, tag, offset);
1516
1517 return node;
1518}
1519EXPORT_SYMBOL(radix_tree_tag_clear);
1520
1521
1522
1523
1524
1525
1526
1527void radix_tree_iter_tag_clear(struct radix_tree_root *root,
1528 const struct radix_tree_iter *iter, unsigned int tag)
1529{
1530 node_tag_clear(root, iter->node, tag, iter_offset(iter));
1531}
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548int radix_tree_tag_get(const struct radix_tree_root *root,
1549 unsigned long index, unsigned int tag)
1550{
1551 struct radix_tree_node *node, *parent;
1552 unsigned long maxindex;
1553
1554 if (!root_tag_get(root, tag))
1555 return 0;
1556
1557 radix_tree_load_root(root, &node, &maxindex);
1558 if (index > maxindex)
1559 return 0;
1560
1561 while (radix_tree_is_internal_node(node)) {
1562 unsigned offset;
1563
1564 parent = entry_to_node(node);
1565 offset = radix_tree_descend(parent, &node, index);
1566
1567 if (!tag_get(parent, tag, offset))
1568 return 0;
1569 if (node == RADIX_TREE_RETRY)
1570 break;
1571 }
1572
1573 return 1;
1574}
1575EXPORT_SYMBOL(radix_tree_tag_get);
1576
1577static inline void __set_iter_shift(struct radix_tree_iter *iter,
1578 unsigned int shift)
1579{
1580#ifdef CONFIG_RADIX_TREE_MULTIORDER
1581 iter->shift = shift;
1582#endif
1583}
1584
1585
1586static void set_iter_tags(struct radix_tree_iter *iter,
1587 struct radix_tree_node *node, unsigned offset,
1588 unsigned tag)
1589{
1590 unsigned tag_long = offset / BITS_PER_LONG;
1591 unsigned tag_bit = offset % BITS_PER_LONG;
1592
1593 if (!node) {
1594 iter->tags = 1;
1595 return;
1596 }
1597
1598 iter->tags = node->tags[tag][tag_long] >> tag_bit;
1599
1600
1601 if (tag_long < RADIX_TREE_TAG_LONGS - 1) {
1602
1603 if (tag_bit)
1604 iter->tags |= node->tags[tag][tag_long + 1] <<
1605 (BITS_PER_LONG - tag_bit);
1606
1607 iter->next_index = __radix_tree_iter_add(iter, BITS_PER_LONG);
1608 }
1609}
1610
1611#ifdef CONFIG_RADIX_TREE_MULTIORDER
1612static void __rcu **skip_siblings(struct radix_tree_node **nodep,
1613 void __rcu **slot, struct radix_tree_iter *iter)
1614{
1615 while (iter->index < iter->next_index) {
1616 *nodep = rcu_dereference_raw(*slot);
1617 if (*nodep && !is_sibling_entry(iter->node, *nodep))
1618 return slot;
1619 slot++;
1620 iter->index = __radix_tree_iter_add(iter, 1);
1621 iter->tags >>= 1;
1622 }
1623
1624 *nodep = NULL;
1625 return NULL;
1626}
1627
1628void __rcu **__radix_tree_next_slot(void __rcu **slot,
1629 struct radix_tree_iter *iter, unsigned flags)
1630{
1631 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
1632 struct radix_tree_node *node;
1633
1634 slot = skip_siblings(&node, slot, iter);
1635
1636 while (radix_tree_is_internal_node(node)) {
1637 unsigned offset;
1638 unsigned long next_index;
1639
1640 if (node == RADIX_TREE_RETRY)
1641 return slot;
1642 node = entry_to_node(node);
1643 iter->node = node;
1644 iter->shift = node->shift;
1645
1646 if (flags & RADIX_TREE_ITER_TAGGED) {
1647 offset = radix_tree_find_next_bit(node, tag, 0);
1648 if (offset == RADIX_TREE_MAP_SIZE)
1649 return NULL;
1650 slot = &node->slots[offset];
1651 iter->index = __radix_tree_iter_add(iter, offset);
1652 set_iter_tags(iter, node, offset, tag);
1653 node = rcu_dereference_raw(*slot);
1654 } else {
1655 offset = 0;
1656 slot = &node->slots[0];
1657 for (;;) {
1658 node = rcu_dereference_raw(*slot);
1659 if (node)
1660 break;
1661 slot++;
1662 offset++;
1663 if (offset == RADIX_TREE_MAP_SIZE)
1664 return NULL;
1665 }
1666 iter->index = __radix_tree_iter_add(iter, offset);
1667 }
1668 if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0))
1669 goto none;
1670 next_index = (iter->index | shift_maxindex(iter->shift)) + 1;
1671 if (next_index < iter->next_index)
1672 iter->next_index = next_index;
1673 }
1674
1675 return slot;
1676 none:
1677 iter->next_index = 0;
1678 return NULL;
1679}
1680EXPORT_SYMBOL(__radix_tree_next_slot);
1681#else
1682static void __rcu **skip_siblings(struct radix_tree_node **nodep,
1683 void __rcu **slot, struct radix_tree_iter *iter)
1684{
1685 return slot;
1686}
1687#endif
1688
1689void __rcu **radix_tree_iter_resume(void __rcu **slot,
1690 struct radix_tree_iter *iter)
1691{
1692 struct radix_tree_node *node;
1693
1694 slot++;
1695 iter->index = __radix_tree_iter_add(iter, 1);
1696 skip_siblings(&node, slot, iter);
1697 iter->next_index = iter->index;
1698 iter->tags = 0;
1699 return NULL;
1700}
1701EXPORT_SYMBOL(radix_tree_iter_resume);
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root,
1712 struct radix_tree_iter *iter, unsigned flags)
1713{
1714 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
1715 struct radix_tree_node *node, *child;
1716 unsigned long index, offset, maxindex;
1717
1718 if ((flags & RADIX_TREE_ITER_TAGGED) && !root_tag_get(root, tag))
1719 return NULL;
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730 index = iter->next_index;
1731 if (!index && iter->index)
1732 return NULL;
1733
1734 restart:
1735 radix_tree_load_root(root, &child, &maxindex);
1736 if (index > maxindex)
1737 return NULL;
1738 if (!child)
1739 return NULL;
1740
1741 if (!radix_tree_is_internal_node(child)) {
1742
1743 iter->index = index;
1744 iter->next_index = maxindex + 1;
1745 iter->tags = 1;
1746 iter->node = NULL;
1747 __set_iter_shift(iter, 0);
1748 return (void __rcu **)&root->rnode;
1749 }
1750
1751 do {
1752 node = entry_to_node(child);
1753 offset = radix_tree_descend(node, &child, index);
1754
1755 if ((flags & RADIX_TREE_ITER_TAGGED) ?
1756 !tag_get(node, tag, offset) : !child) {
1757
1758 if (flags & RADIX_TREE_ITER_CONTIG)
1759 return NULL;
1760
1761 if (flags & RADIX_TREE_ITER_TAGGED)
1762 offset = radix_tree_find_next_bit(node, tag,
1763 offset + 1);
1764 else
1765 while (++offset < RADIX_TREE_MAP_SIZE) {
1766 void *slot = rcu_dereference_raw(
1767 node->slots[offset]);
1768 if (is_sibling_entry(node, slot))
1769 continue;
1770 if (slot)
1771 break;
1772 }
1773 index &= ~node_maxindex(node);
1774 index += offset << node->shift;
1775
1776 if (!index)
1777 return NULL;
1778 if (offset == RADIX_TREE_MAP_SIZE)
1779 goto restart;
1780 child = rcu_dereference_raw(node->slots[offset]);
1781 }
1782
1783 if (!child)
1784 goto restart;
1785 if (child == RADIX_TREE_RETRY)
1786 break;
1787 } while (radix_tree_is_internal_node(child));
1788
1789
1790 iter->index = (index &~ node_maxindex(node)) | (offset << node->shift);
1791 iter->next_index = (index | node_maxindex(node)) + 1;
1792 iter->node = node;
1793 __set_iter_shift(iter, node->shift);
1794
1795 if (flags & RADIX_TREE_ITER_TAGGED)
1796 set_iter_tags(iter, node, offset, tag);
1797
1798 return node->slots + offset;
1799}
1800EXPORT_SYMBOL(radix_tree_next_chunk);
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822unsigned int
1823radix_tree_gang_lookup(const struct radix_tree_root *root, void **results,
1824 unsigned long first_index, unsigned int max_items)
1825{
1826 struct radix_tree_iter iter;
1827 void __rcu **slot;
1828 unsigned int ret = 0;
1829
1830 if (unlikely(!max_items))
1831 return 0;
1832
1833 radix_tree_for_each_slot(slot, root, &iter, first_index) {
1834 results[ret] = rcu_dereference_raw(*slot);
1835 if (!results[ret])
1836 continue;
1837 if (radix_tree_is_internal_node(results[ret])) {
1838 slot = radix_tree_iter_retry(&iter);
1839 continue;
1840 }
1841 if (++ret == max_items)
1842 break;
1843 }
1844
1845 return ret;
1846}
1847EXPORT_SYMBOL(radix_tree_gang_lookup);
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867unsigned int
1868radix_tree_gang_lookup_slot(const struct radix_tree_root *root,
1869 void __rcu ***results, unsigned long *indices,
1870 unsigned long first_index, unsigned int max_items)
1871{
1872 struct radix_tree_iter iter;
1873 void __rcu **slot;
1874 unsigned int ret = 0;
1875
1876 if (unlikely(!max_items))
1877 return 0;
1878
1879 radix_tree_for_each_slot(slot, root, &iter, first_index) {
1880 results[ret] = slot;
1881 if (indices)
1882 indices[ret] = iter.index;
1883 if (++ret == max_items)
1884 break;
1885 }
1886
1887 return ret;
1888}
1889EXPORT_SYMBOL(radix_tree_gang_lookup_slot);
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904unsigned int
1905radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results,
1906 unsigned long first_index, unsigned int max_items,
1907 unsigned int tag)
1908{
1909 struct radix_tree_iter iter;
1910 void __rcu **slot;
1911 unsigned int ret = 0;
1912
1913 if (unlikely(!max_items))
1914 return 0;
1915
1916 radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
1917 results[ret] = rcu_dereference_raw(*slot);
1918 if (!results[ret])
1919 continue;
1920 if (radix_tree_is_internal_node(results[ret])) {
1921 slot = radix_tree_iter_retry(&iter);
1922 continue;
1923 }
1924 if (++ret == max_items)
1925 break;
1926 }
1927
1928 return ret;
1929}
1930EXPORT_SYMBOL(radix_tree_gang_lookup_tag);
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945unsigned int
1946radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root,
1947 void __rcu ***results, unsigned long first_index,
1948 unsigned int max_items, unsigned int tag)
1949{
1950 struct radix_tree_iter iter;
1951 void __rcu **slot;
1952 unsigned int ret = 0;
1953
1954 if (unlikely(!max_items))
1955 return 0;
1956
1957 radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
1958 results[ret] = slot;
1959 if (++ret == max_items)
1960 break;
1961 }
1962
1963 return ret;
1964}
1965EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977void __radix_tree_delete_node(struct radix_tree_root *root,
1978 struct radix_tree_node *node,
1979 radix_tree_update_node_t update_node)
1980{
1981 delete_node(root, node, update_node);
1982}
1983
1984static bool __radix_tree_delete(struct radix_tree_root *root,
1985 struct radix_tree_node *node, void __rcu **slot)
1986{
1987 void *old = rcu_dereference_raw(*slot);
1988 int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0;
1989 unsigned offset = get_slot_offset(node, slot);
1990 int tag;
1991
1992 if (is_idr(root))
1993 node_tag_set(root, node, IDR_FREE, offset);
1994 else
1995 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1996 node_tag_clear(root, node, tag, offset);
1997
1998 replace_slot(slot, NULL, node, -1, exceptional);
1999 return node && delete_node(root, node, NULL);
2000}
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014void radix_tree_iter_delete(struct radix_tree_root *root,
2015 struct radix_tree_iter *iter, void __rcu **slot)
2016{
2017 if (__radix_tree_delete(root, iter->node, slot))
2018 iter->index = iter->next_index;
2019}
2020EXPORT_SYMBOL(radix_tree_iter_delete);
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033void *radix_tree_delete_item(struct radix_tree_root *root,
2034 unsigned long index, void *item)
2035{
2036 struct radix_tree_node *node = NULL;
2037 void __rcu **slot = NULL;
2038 void *entry;
2039
2040 entry = __radix_tree_lookup(root, index, &node, &slot);
2041 if (!slot)
2042 return NULL;
2043 if (!entry && (!is_idr(root) || node_tag_get(root, node, IDR_FREE,
2044 get_slot_offset(node, slot))))
2045 return NULL;
2046
2047 if (item && entry != item)
2048 return NULL;
2049
2050 __radix_tree_delete(root, node, slot);
2051
2052 return entry;
2053}
2054EXPORT_SYMBOL(radix_tree_delete_item);
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
2066{
2067 return radix_tree_delete_item(root, index, NULL);
2068}
2069EXPORT_SYMBOL(radix_tree_delete);
2070
2071void radix_tree_clear_tags(struct radix_tree_root *root,
2072 struct radix_tree_node *node,
2073 void __rcu **slot)
2074{
2075 if (node) {
2076 unsigned int tag, offset = get_slot_offset(node, slot);
2077 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
2078 node_tag_clear(root, node, tag, offset);
2079 } else {
2080 root_tag_clear_all(root);
2081 }
2082}
2083
2084
2085
2086
2087
2088
2089int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag)
2090{
2091 return root_tag_get(root, tag);
2092}
2093EXPORT_SYMBOL(radix_tree_tagged);
2094
2095
2096
2097
2098
2099
2100
2101
2102void idr_preload(gfp_t gfp_mask)
2103{
2104 if (__radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE))
2105 preempt_disable();
2106}
2107EXPORT_SYMBOL(idr_preload);
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117int ida_pre_get(struct ida *ida, gfp_t gfp)
2118{
2119
2120
2121
2122
2123
2124 if (!__radix_tree_preload(gfp, IDA_PRELOAD_SIZE))
2125 preempt_enable();
2126
2127 if (!this_cpu_read(ida_bitmap)) {
2128 struct ida_bitmap *bitmap = kzalloc(sizeof(*bitmap), gfp);
2129 if (!bitmap)
2130 return 0;
2131 if (this_cpu_cmpxchg(ida_bitmap, NULL, bitmap))
2132 kfree(bitmap);
2133 }
2134
2135 return 1;
2136}
2137EXPORT_SYMBOL(ida_pre_get);
2138
2139void __rcu **idr_get_free(struct radix_tree_root *root,
2140 struct radix_tree_iter *iter, gfp_t gfp,
2141 unsigned long max)
2142{
2143 struct radix_tree_node *node = NULL, *child;
2144 void __rcu **slot = (void __rcu **)&root->rnode;
2145 unsigned long maxindex, start = iter->next_index;
2146 unsigned int shift, offset = 0;
2147
2148 grow:
2149 shift = radix_tree_load_root(root, &child, &maxindex);
2150 if (!radix_tree_tagged(root, IDR_FREE))
2151 start = max(start, maxindex + 1);
2152 if (start > max)
2153 return ERR_PTR(-ENOSPC);
2154
2155 if (start > maxindex) {
2156 int error = radix_tree_extend(root, gfp, start, shift);
2157 if (error < 0)
2158 return ERR_PTR(error);
2159 shift = error;
2160 child = rcu_dereference_raw(root->rnode);
2161 }
2162
2163 while (shift) {
2164 shift -= RADIX_TREE_MAP_SHIFT;
2165 if (child == NULL) {
2166
2167 child = radix_tree_node_alloc(gfp, node, root, shift,
2168 offset, 0, 0);
2169 if (!child)
2170 return ERR_PTR(-ENOMEM);
2171 all_tag_set(child, IDR_FREE);
2172 rcu_assign_pointer(*slot, node_to_entry(child));
2173 if (node)
2174 node->count++;
2175 } else if (!radix_tree_is_internal_node(child))
2176 break;
2177
2178 node = entry_to_node(child);
2179 offset = radix_tree_descend(node, &child, start);
2180 if (!tag_get(node, IDR_FREE, offset)) {
2181 offset = radix_tree_find_next_bit(node, IDR_FREE,
2182 offset + 1);
2183 start = next_index(start, node, offset);
2184 if (start > max)
2185 return ERR_PTR(-ENOSPC);
2186 while (offset == RADIX_TREE_MAP_SIZE) {
2187 offset = node->offset + 1;
2188 node = node->parent;
2189 if (!node)
2190 goto grow;
2191 shift = node->shift;
2192 }
2193 child = rcu_dereference_raw(node->slots[offset]);
2194 }
2195 slot = &node->slots[offset];
2196 }
2197
2198 iter->index = start;
2199 if (node)
2200 iter->next_index = 1 + min(max, (start | node_maxindex(node)));
2201 else
2202 iter->next_index = 1;
2203 iter->node = node;
2204 __set_iter_shift(iter, shift);
2205 set_iter_tags(iter, node, offset, IDR_FREE);
2206
2207 return slot;
2208}
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221void idr_destroy(struct idr *idr)
2222{
2223 struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode);
2224 if (radix_tree_is_internal_node(node))
2225 radix_tree_free_nodes(node);
2226 idr->idr_rt.rnode = NULL;
2227 root_tag_set(&idr->idr_rt, IDR_FREE);
2228}
2229EXPORT_SYMBOL(idr_destroy);
2230
2231static void
2232radix_tree_node_ctor(void *arg)
2233{
2234 struct radix_tree_node *node = arg;
2235
2236 memset(node, 0, sizeof(*node));
2237 INIT_LIST_HEAD(&node->private_list);
2238}
2239
2240static __init unsigned long __maxindex(unsigned int height)
2241{
2242 unsigned int width = height * RADIX_TREE_MAP_SHIFT;
2243 int shift = RADIX_TREE_INDEX_BITS - width;
2244
2245 if (shift < 0)
2246 return ~0UL;
2247 if (shift >= BITS_PER_LONG)
2248 return 0UL;
2249 return ~0UL >> shift;
2250}
2251
2252static __init void radix_tree_init_maxnodes(void)
2253{
2254 unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1];
2255 unsigned int i, j;
2256
2257 for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++)
2258 height_to_maxindex[i] = __maxindex(i);
2259 for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) {
2260 for (j = i; j > 0; j--)
2261 height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1;
2262 }
2263}
2264
2265static int radix_tree_cpu_dead(unsigned int cpu)
2266{
2267 struct radix_tree_preload *rtp;
2268 struct radix_tree_node *node;
2269
2270
2271 rtp = &per_cpu(radix_tree_preloads, cpu);
2272 while (rtp->nr) {
2273 node = rtp->nodes;
2274 rtp->nodes = node->parent;
2275 kmem_cache_free(radix_tree_node_cachep, node);
2276 rtp->nr--;
2277 }
2278 kfree(per_cpu(ida_bitmap, cpu));
2279 per_cpu(ida_bitmap, cpu) = NULL;
2280 return 0;
2281}
2282
2283void __init radix_tree_init(void)
2284{
2285 int ret;
2286
2287 BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32);
2288 BUILD_BUG_ON(ROOT_IS_IDR & ~GFP_ZONEMASK);
2289 radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
2290 sizeof(struct radix_tree_node), 0,
2291 SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
2292 radix_tree_node_ctor);
2293 radix_tree_init_maxnodes();
2294 ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead",
2295 NULL, radix_tree_cpu_dead);
2296 WARN_ON(ret < 0);
2297}
2298