1 // SPDX-License-Identifier: GPL-2.0+
3 * Maple Tree implementation
4 * Copyright (c) 2018-2022 Oracle Corporation
5 * Authors: Liam R. Howlett <Liam.Howlett@oracle.com>
6 * Matthew Wilcox <willy@infradead.org>
10 * DOC: Interesting implementation details of the Maple Tree
12 * Each node type has a number of slots for entries and a number of slots for
13 * pivots. In the case of dense nodes, the pivots are implied by the position
14 * and are simply the slot index + the minimum of the node.
16 * In regular B-Tree terms, pivots are called keys. The term pivot is used to
17 * indicate that the tree is specifying ranges, Pivots may appear in the
18 * subtree with an entry attached to the value where as keys are unique to a
19 * specific position of a B-tree. Pivot values are inclusive of the slot with
23 * The following illustrates the layout of a range64 nodes slots and pivots.
26 * Slots -> | 0 | 1 | 2 | ... | 12 | 13 | 14 | 15 |
28 * │ │ │ │ │ │ │ │ └─ Implied maximum
29 * │ │ │ │ │ │ │ └─ Pivot 14
30 * │ │ │ │ │ │ └─ Pivot 13
31 * │ │ │ │ │ └─ Pivot 12
39 * Internal (non-leaf) nodes contain pointers to other nodes.
40 * Leaf nodes contain entries.
42 * The location of interest is often referred to as an offset. All offsets have
43 * a slot, but the last offset has an implied pivot from the node above (or
44 * UINT_MAX for the root node.
46 * Ranges complicate certain write activities. When modifying any of
47 * the B-tree variants, it is known that one entry will either be added or
48 * deleted. When modifying the Maple Tree, one store operation may overwrite
49 * the entire data set, or one half of the tree, or the middle half of the tree.
54 #include <linux/maple_tree.h>
55 #include <linux/xarray.h>
56 #include <linux/types.h>
57 #include <linux/export.h>
58 #include <linux/slab.h>
59 #include <linux/limits.h>
60 #include <asm/barrier.h>
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/maple_tree.h>
65 #define MA_ROOT_PARENT 1
69 * * MA_STATE_BULK - Bulk insert mode
70 * * MA_STATE_REBALANCE - Indicate a rebalance during bulk insert
71 * * MA_STATE_PREALLOC - Preallocated nodes, WARN_ON allocation
73 #define MA_STATE_BULK 1
74 #define MA_STATE_REBALANCE 2
75 #define MA_STATE_PREALLOC 4
77 #define ma_parent_ptr(x) ((struct maple_pnode *)(x))
78 #define ma_mnode_ptr(x) ((struct maple_node *)(x))
79 #define ma_enode_ptr(x) ((struct maple_enode *)(x))
80 static struct kmem_cache *maple_node_cache;
82 #ifdef CONFIG_DEBUG_MAPLE_TREE
83 static const unsigned long mt_max[] = {
84 [maple_dense] = MAPLE_NODE_SLOTS,
85 [maple_leaf_64] = ULONG_MAX,
86 [maple_range_64] = ULONG_MAX,
87 [maple_arange_64] = ULONG_MAX,
89 #define mt_node_max(x) mt_max[mte_node_type(x)]
92 static const unsigned char mt_slots[] = {
93 [maple_dense] = MAPLE_NODE_SLOTS,
94 [maple_leaf_64] = MAPLE_RANGE64_SLOTS,
95 [maple_range_64] = MAPLE_RANGE64_SLOTS,
96 [maple_arange_64] = MAPLE_ARANGE64_SLOTS,
98 #define mt_slot_count(x) mt_slots[mte_node_type(x)]
100 static const unsigned char mt_pivots[] = {
102 [maple_leaf_64] = MAPLE_RANGE64_SLOTS - 1,
103 [maple_range_64] = MAPLE_RANGE64_SLOTS - 1,
104 [maple_arange_64] = MAPLE_ARANGE64_SLOTS - 1,
106 #define mt_pivot_count(x) mt_pivots[mte_node_type(x)]
108 static const unsigned char mt_min_slots[] = {
109 [maple_dense] = MAPLE_NODE_SLOTS / 2,
110 [maple_leaf_64] = (MAPLE_RANGE64_SLOTS / 2) - 2,
111 [maple_range_64] = (MAPLE_RANGE64_SLOTS / 2) - 2,
112 [maple_arange_64] = (MAPLE_ARANGE64_SLOTS / 2) - 1,
114 #define mt_min_slot_count(x) mt_min_slots[mte_node_type(x)]
116 #define MAPLE_BIG_NODE_SLOTS (MAPLE_RANGE64_SLOTS * 2 + 2)
117 #define MAPLE_BIG_NODE_GAPS (MAPLE_ARANGE64_SLOTS * 2 + 1)
119 struct maple_big_node {
120 struct maple_pnode *parent;
121 unsigned long pivot[MAPLE_BIG_NODE_SLOTS - 1];
123 struct maple_enode *slot[MAPLE_BIG_NODE_SLOTS];
125 unsigned long padding[MAPLE_BIG_NODE_GAPS];
126 unsigned long gap[MAPLE_BIG_NODE_GAPS];
130 enum maple_type type;
134 * The maple_subtree_state is used to build a tree to replace a segment of an
135 * existing tree in a more atomic way. Any walkers of the older tree will hit a
136 * dead node and restart on updates.
138 struct maple_subtree_state {
139 struct ma_state *orig_l; /* Original left side of subtree */
140 struct ma_state *orig_r; /* Original right side of subtree */
141 struct ma_state *l; /* New left side of subtree */
142 struct ma_state *m; /* New middle of subtree (rare) */
143 struct ma_state *r; /* New right side of subtree */
144 struct ma_topiary *free; /* nodes to be freed */
145 struct ma_topiary *destroy; /* Nodes to be destroyed (walked and freed) */
146 struct maple_big_node *bn;
149 #ifdef CONFIG_KASAN_STACK
150 /* Prevent mas_wr_bnode() from exceeding the stack frame limit */
151 #define noinline_for_kasan noinline_for_stack
153 #define noinline_for_kasan inline
157 static inline struct maple_node *mt_alloc_one(gfp_t gfp)
159 return kmem_cache_alloc(maple_node_cache, gfp);
162 static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes)
164 return kmem_cache_alloc_bulk(maple_node_cache, gfp, size, nodes);
167 static inline void mt_free_bulk(size_t size, void __rcu **nodes)
169 kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes);
172 static void mt_free_rcu(struct rcu_head *head)
174 struct maple_node *node = container_of(head, struct maple_node, rcu);
176 kmem_cache_free(maple_node_cache, node);
180 * ma_free_rcu() - Use rcu callback to free a maple node
181 * @node: The node to free
183 * The maple tree uses the parent pointer to indicate this node is no longer in
184 * use and will be freed.
186 static void ma_free_rcu(struct maple_node *node)
188 WARN_ON(node->parent != ma_parent_ptr(node));
189 call_rcu(&node->rcu, mt_free_rcu);
192 static void mas_set_height(struct ma_state *mas)
194 unsigned int new_flags = mas->tree->ma_flags;
196 new_flags &= ~MT_FLAGS_HEIGHT_MASK;
197 BUG_ON(mas->depth > MAPLE_HEIGHT_MAX);
198 new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET;
199 mas->tree->ma_flags = new_flags;
202 static unsigned int mas_mt_height(struct ma_state *mas)
204 return mt_height(mas->tree);
207 static inline enum maple_type mte_node_type(const struct maple_enode *entry)
209 return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) &
210 MAPLE_NODE_TYPE_MASK;
213 static inline bool ma_is_dense(const enum maple_type type)
215 return type < maple_leaf_64;
218 static inline bool ma_is_leaf(const enum maple_type type)
220 return type < maple_range_64;
223 static inline bool mte_is_leaf(const struct maple_enode *entry)
225 return ma_is_leaf(mte_node_type(entry));
229 * We also reserve values with the bottom two bits set to '10' which are
232 static inline bool mt_is_reserved(const void *entry)
234 return ((unsigned long)entry < MAPLE_RESERVED_RANGE) &&
235 xa_is_internal(entry);
238 static inline void mas_set_err(struct ma_state *mas, long err)
240 mas->node = MA_ERROR(err);
243 static inline bool mas_is_ptr(struct ma_state *mas)
245 return mas->node == MAS_ROOT;
248 static inline bool mas_is_start(struct ma_state *mas)
250 return mas->node == MAS_START;
253 bool mas_is_err(struct ma_state *mas)
255 return xa_is_err(mas->node);
258 static inline bool mas_searchable(struct ma_state *mas)
260 if (mas_is_none(mas))
269 static inline struct maple_node *mte_to_node(const struct maple_enode *entry)
271 return (struct maple_node *)((unsigned long)entry & ~MAPLE_NODE_MASK);
275 * mte_to_mat() - Convert a maple encoded node to a maple topiary node.
276 * @entry: The maple encoded node
278 * Return: a maple topiary pointer
280 static inline struct maple_topiary *mte_to_mat(const struct maple_enode *entry)
282 return (struct maple_topiary *)
283 ((unsigned long)entry & ~MAPLE_NODE_MASK);
287 * mas_mn() - Get the maple state node.
288 * @mas: The maple state
290 * Return: the maple node (not encoded - bare pointer).
292 static inline struct maple_node *mas_mn(const struct ma_state *mas)
294 return mte_to_node(mas->node);
298 * mte_set_node_dead() - Set a maple encoded node as dead.
299 * @mn: The maple encoded node.
301 static inline void mte_set_node_dead(struct maple_enode *mn)
303 mte_to_node(mn)->parent = ma_parent_ptr(mte_to_node(mn));
304 smp_wmb(); /* Needed for RCU */
307 /* Bit 1 indicates the root is a node */
308 #define MAPLE_ROOT_NODE 0x02
309 /* maple_type stored bit 3-6 */
310 #define MAPLE_ENODE_TYPE_SHIFT 0x03
311 /* Bit 2 means a NULL somewhere below */
312 #define MAPLE_ENODE_NULL 0x04
314 static inline struct maple_enode *mt_mk_node(const struct maple_node *node,
315 enum maple_type type)
317 return (void *)((unsigned long)node |
318 (type << MAPLE_ENODE_TYPE_SHIFT) | MAPLE_ENODE_NULL);
321 static inline void *mte_mk_root(const struct maple_enode *node)
323 return (void *)((unsigned long)node | MAPLE_ROOT_NODE);
326 static inline void *mte_safe_root(const struct maple_enode *node)
328 return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
331 static inline void *mte_set_full(const struct maple_enode *node)
333 return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
336 static inline void *mte_clear_full(const struct maple_enode *node)
338 return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
341 static inline bool mte_has_null(const struct maple_enode *node)
343 return (unsigned long)node & MAPLE_ENODE_NULL;
346 static inline bool ma_is_root(struct maple_node *node)
348 return ((unsigned long)node->parent & MA_ROOT_PARENT);
351 static inline bool mte_is_root(const struct maple_enode *node)
353 return ma_is_root(mte_to_node(node));
356 static inline bool mas_is_root_limits(const struct ma_state *mas)
358 return !mas->min && mas->max == ULONG_MAX;
361 static inline bool mt_is_alloc(struct maple_tree *mt)
363 return (mt->ma_flags & MT_FLAGS_ALLOC_RANGE);
368 * Excluding root, the parent pointer is 256B aligned like all other tree nodes.
369 * When storing a 32 or 64 bit values, the offset can fit into 5 bits. The 16
370 * bit values need an extra bit to store the offset. This extra bit comes from
371 * a reuse of the last bit in the node type. This is possible by using bit 1 to
372 * indicate if bit 2 is part of the type or the slot.
376 * 0x?00 = 16 bit nodes
377 * 0x010 = 32 bit nodes
378 * 0x110 = 64 bit nodes
380 * Slot size and alignment
382 * 0b?00 : 16 bit values, type in 0-1, slot in 2-7
383 * 0b010 : 32 bit values, type in 0-2, slot in 3-7
384 * 0b110 : 64 bit values, type in 0-2, slot in 3-7
387 #define MAPLE_PARENT_ROOT 0x01
389 #define MAPLE_PARENT_SLOT_SHIFT 0x03
390 #define MAPLE_PARENT_SLOT_MASK 0xF8
392 #define MAPLE_PARENT_16B_SLOT_SHIFT 0x02
393 #define MAPLE_PARENT_16B_SLOT_MASK 0xFC
395 #define MAPLE_PARENT_RANGE64 0x06
396 #define MAPLE_PARENT_RANGE32 0x04
397 #define MAPLE_PARENT_NOT_RANGE16 0x02
400 * mte_parent_shift() - Get the parent shift for the slot storage.
401 * @parent: The parent pointer cast as an unsigned long
402 * Return: The shift into that pointer to the star to of the slot
404 static inline unsigned long mte_parent_shift(unsigned long parent)
406 /* Note bit 1 == 0 means 16B */
407 if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
408 return MAPLE_PARENT_SLOT_SHIFT;
410 return MAPLE_PARENT_16B_SLOT_SHIFT;
414 * mte_parent_slot_mask() - Get the slot mask for the parent.
415 * @parent: The parent pointer cast as an unsigned long.
416 * Return: The slot mask for that parent.
418 static inline unsigned long mte_parent_slot_mask(unsigned long parent)
420 /* Note bit 1 == 0 means 16B */
421 if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
422 return MAPLE_PARENT_SLOT_MASK;
424 return MAPLE_PARENT_16B_SLOT_MASK;
428 * mas_parent_enum() - Return the maple_type of the parent from the stored
430 * @mas: The maple state
431 * @node: The maple_enode to extract the parent's enum
432 * Return: The node->parent maple_type
435 enum maple_type mte_parent_enum(struct maple_enode *p_enode,
436 struct maple_tree *mt)
438 unsigned long p_type;
440 p_type = (unsigned long)p_enode;
441 if (p_type & MAPLE_PARENT_ROOT)
442 return 0; /* Validated in the caller. */
444 p_type &= MAPLE_NODE_MASK;
445 p_type = p_type & ~(MAPLE_PARENT_ROOT | mte_parent_slot_mask(p_type));
448 case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
450 return maple_arange_64;
451 return maple_range_64;
458 enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode)
460 return mte_parent_enum(ma_enode_ptr(mte_to_node(enode)->parent), mas->tree);
464 * mte_set_parent() - Set the parent node and encode the slot
465 * @enode: The encoded maple node.
466 * @parent: The encoded maple node that is the parent of @enode.
467 * @slot: The slot that @enode resides in @parent.
469 * Slot number is encoded in the enode->parent bit 3-6 or 2-6, depending on the
473 void mte_set_parent(struct maple_enode *enode, const struct maple_enode *parent,
476 unsigned long val = (unsigned long)parent;
479 enum maple_type p_type = mte_node_type(parent);
481 BUG_ON(p_type == maple_dense);
482 BUG_ON(p_type == maple_leaf_64);
486 case maple_arange_64:
487 shift = MAPLE_PARENT_SLOT_SHIFT;
488 type = MAPLE_PARENT_RANGE64;
497 val &= ~MAPLE_NODE_MASK; /* Clear all node metadata in parent */
498 val |= (slot << shift) | type;
499 mte_to_node(enode)->parent = ma_parent_ptr(val);
503 * mte_parent_slot() - get the parent slot of @enode.
504 * @enode: The encoded maple node.
506 * Return: The slot in the parent node where @enode resides.
508 static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
510 unsigned long val = (unsigned long)mte_to_node(enode)->parent;
512 if (val & MA_ROOT_PARENT)
516 * Okay to use MAPLE_PARENT_16B_SLOT_MASK as the last bit will be lost
517 * by shift if the parent shift is MAPLE_PARENT_SLOT_SHIFT
519 return (val & MAPLE_PARENT_16B_SLOT_MASK) >> mte_parent_shift(val);
523 * mte_parent() - Get the parent of @node.
524 * @node: The encoded maple node.
526 * Return: The parent maple node.
528 static inline struct maple_node *mte_parent(const struct maple_enode *enode)
530 return (void *)((unsigned long)
531 (mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK);
535 * ma_dead_node() - check if the @enode is dead.
536 * @enode: The encoded maple node
538 * Return: true if dead, false otherwise.
540 static inline bool ma_dead_node(const struct maple_node *node)
542 struct maple_node *parent;
544 /* Do not reorder reads from the node prior to the parent check */
546 parent = (void *)((unsigned long) node->parent & ~MAPLE_NODE_MASK);
547 return (parent == node);
551 * mte_dead_node() - check if the @enode is dead.
552 * @enode: The encoded maple node
554 * Return: true if dead, false otherwise.
556 static inline bool mte_dead_node(const struct maple_enode *enode)
558 struct maple_node *parent, *node;
560 node = mte_to_node(enode);
561 /* Do not reorder reads from the node prior to the parent check */
563 parent = mte_parent(enode);
564 return (parent == node);
568 * mas_allocated() - Get the number of nodes allocated in a maple state.
569 * @mas: The maple state
571 * The ma_state alloc member is overloaded to hold a pointer to the first
572 * allocated node or to the number of requested nodes to allocate. If bit 0 is
573 * set, then the alloc contains the number of requested nodes. If there is an
574 * allocated node, then the total allocated nodes is in that node.
576 * Return: The total number of nodes allocated
578 static inline unsigned long mas_allocated(const struct ma_state *mas)
580 if (!mas->alloc || ((unsigned long)mas->alloc & 0x1))
583 return mas->alloc->total;
587 * mas_set_alloc_req() - Set the requested number of allocations.
588 * @mas: the maple state
589 * @count: the number of allocations.
591 * The requested number of allocations is either in the first allocated node,
592 * located in @mas->alloc->request_count, or directly in @mas->alloc if there is
593 * no allocated node. Set the request either in the node or do the necessary
594 * encoding to store in @mas->alloc directly.
596 static inline void mas_set_alloc_req(struct ma_state *mas, unsigned long count)
598 if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) {
602 mas->alloc = (struct maple_alloc *)(((count) << 1U) | 1U);
606 mas->alloc->request_count = count;
610 * mas_alloc_req() - get the requested number of allocations.
611 * @mas: The maple state
613 * The alloc count is either stored directly in @mas, or in
614 * @mas->alloc->request_count if there is at least one node allocated. Decode
615 * the request count if it's stored directly in @mas->alloc.
617 * Return: The allocation request count.
619 static inline unsigned int mas_alloc_req(const struct ma_state *mas)
621 if ((unsigned long)mas->alloc & 0x1)
622 return (unsigned long)(mas->alloc) >> 1;
624 return mas->alloc->request_count;
629 * ma_pivots() - Get a pointer to the maple node pivots.
630 * @node - the maple node
631 * @type - the node type
633 * In the event of a dead node, this array may be %NULL
635 * Return: A pointer to the maple node pivots
637 static inline unsigned long *ma_pivots(struct maple_node *node,
638 enum maple_type type)
641 case maple_arange_64:
642 return node->ma64.pivot;
645 return node->mr64.pivot;
653 * ma_gaps() - Get a pointer to the maple node gaps.
654 * @node - the maple node
655 * @type - the node type
657 * Return: A pointer to the maple node gaps
659 static inline unsigned long *ma_gaps(struct maple_node *node,
660 enum maple_type type)
663 case maple_arange_64:
664 return node->ma64.gap;
674 * mte_pivot() - Get the pivot at @piv of the maple encoded node.
675 * @mn: The maple encoded node.
678 * Return: the pivot at @piv of @mn.
680 static inline unsigned long mte_pivot(const struct maple_enode *mn,
683 struct maple_node *node = mte_to_node(mn);
684 enum maple_type type = mte_node_type(mn);
686 if (piv >= mt_pivots[type]) {
691 case maple_arange_64:
692 return node->ma64.pivot[piv];
695 return node->mr64.pivot[piv];
703 * mas_safe_pivot() - get the pivot at @piv or mas->max.
704 * @mas: The maple state
705 * @pivots: The pointer to the maple node pivots
706 * @piv: The pivot to fetch
707 * @type: The maple node type
709 * Return: The pivot at @piv within the limit of the @pivots array, @mas->max
712 static inline unsigned long
713 mas_safe_pivot(const struct ma_state *mas, unsigned long *pivots,
714 unsigned char piv, enum maple_type type)
716 if (piv >= mt_pivots[type])
723 * mas_safe_min() - Return the minimum for a given offset.
724 * @mas: The maple state
725 * @pivots: The pointer to the maple node pivots
726 * @offset: The offset into the pivot array
728 * Return: The minimum range value that is contained in @offset.
730 static inline unsigned long
731 mas_safe_min(struct ma_state *mas, unsigned long *pivots, unsigned char offset)
734 return pivots[offset - 1] + 1;
740 * mas_logical_pivot() - Get the logical pivot of a given offset.
741 * @mas: The maple state
742 * @pivots: The pointer to the maple node pivots
743 * @offset: The offset into the pivot array
744 * @type: The maple node type
746 * When there is no value at a pivot (beyond the end of the data), then the
747 * pivot is actually @mas->max.
749 * Return: the logical pivot of a given @offset.
751 static inline unsigned long
752 mas_logical_pivot(struct ma_state *mas, unsigned long *pivots,
753 unsigned char offset, enum maple_type type)
755 unsigned long lpiv = mas_safe_pivot(mas, pivots, offset, type);
767 * mte_set_pivot() - Set a pivot to a value in an encoded maple node.
768 * @mn: The encoded maple node
769 * @piv: The pivot offset
770 * @val: The value of the pivot
772 static inline void mte_set_pivot(struct maple_enode *mn, unsigned char piv,
775 struct maple_node *node = mte_to_node(mn);
776 enum maple_type type = mte_node_type(mn);
778 BUG_ON(piv >= mt_pivots[type]);
783 node->mr64.pivot[piv] = val;
785 case maple_arange_64:
786 node->ma64.pivot[piv] = val;
795 * ma_slots() - Get a pointer to the maple node slots.
796 * @mn: The maple node
797 * @mt: The maple node type
799 * Return: A pointer to the maple node slots
801 static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt)
805 case maple_arange_64:
806 return mn->ma64.slot;
809 return mn->mr64.slot;
815 static inline bool mt_locked(const struct maple_tree *mt)
817 return mt_external_lock(mt) ? mt_lock_is_held(mt) :
818 lockdep_is_held(&mt->ma_lock);
821 static inline void *mt_slot(const struct maple_tree *mt,
822 void __rcu **slots, unsigned char offset)
824 return rcu_dereference_check(slots[offset], mt_locked(mt));
827 static inline void *mt_slot_locked(struct maple_tree *mt, void __rcu **slots,
828 unsigned char offset)
830 return rcu_dereference_protected(slots[offset], mt_locked(mt));
833 * mas_slot_locked() - Get the slot value when holding the maple tree lock.
834 * @mas: The maple state
835 * @slots: The pointer to the slots
836 * @offset: The offset into the slots array to fetch
838 * Return: The entry stored in @slots at the @offset.
840 static inline void *mas_slot_locked(struct ma_state *mas, void __rcu **slots,
841 unsigned char offset)
843 return mt_slot_locked(mas->tree, slots, offset);
847 * mas_slot() - Get the slot value when not holding the maple tree lock.
848 * @mas: The maple state
849 * @slots: The pointer to the slots
850 * @offset: The offset into the slots array to fetch
852 * Return: The entry stored in @slots at the @offset
854 static inline void *mas_slot(struct ma_state *mas, void __rcu **slots,
855 unsigned char offset)
857 return mt_slot(mas->tree, slots, offset);
861 * mas_root() - Get the maple tree root.
862 * @mas: The maple state.
864 * Return: The pointer to the root of the tree
866 static inline void *mas_root(struct ma_state *mas)
868 return rcu_dereference_check(mas->tree->ma_root, mt_locked(mas->tree));
871 static inline void *mt_root_locked(struct maple_tree *mt)
873 return rcu_dereference_protected(mt->ma_root, mt_locked(mt));
877 * mas_root_locked() - Get the maple tree root when holding the maple tree lock.
878 * @mas: The maple state.
880 * Return: The pointer to the root of the tree
882 static inline void *mas_root_locked(struct ma_state *mas)
884 return mt_root_locked(mas->tree);
887 static inline struct maple_metadata *ma_meta(struct maple_node *mn,
891 case maple_arange_64:
892 return &mn->ma64.meta;
894 return &mn->mr64.meta;
899 * ma_set_meta() - Set the metadata information of a node.
900 * @mn: The maple node
901 * @mt: The maple node type
902 * @offset: The offset of the highest sub-gap in this node.
903 * @end: The end of the data in this node.
905 static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt,
906 unsigned char offset, unsigned char end)
908 struct maple_metadata *meta = ma_meta(mn, mt);
915 * mt_clear_meta() - clear the metadata information of a node, if it exists
916 * @mt: The maple tree
917 * @mn: The maple node
918 * @type: The maple node type
919 * @offset: The offset of the highest sub-gap in this node.
920 * @end: The end of the data in this node.
922 static inline void mt_clear_meta(struct maple_tree *mt, struct maple_node *mn,
923 enum maple_type type)
925 struct maple_metadata *meta;
926 unsigned long *pivots;
932 pivots = mn->mr64.pivot;
933 if (unlikely(pivots[MAPLE_RANGE64_SLOTS - 2])) {
934 slots = mn->mr64.slot;
935 next = mt_slot_locked(mt, slots,
936 MAPLE_RANGE64_SLOTS - 1);
937 if (unlikely((mte_to_node(next) &&
938 mte_node_type(next))))
939 return; /* no metadata, could be node */
942 case maple_arange_64:
943 meta = ma_meta(mn, type);
954 * ma_meta_end() - Get the data end of a node from the metadata
955 * @mn: The maple node
956 * @mt: The maple node type
958 static inline unsigned char ma_meta_end(struct maple_node *mn,
961 struct maple_metadata *meta = ma_meta(mn, mt);
967 * ma_meta_gap() - Get the largest gap location of a node from the metadata
968 * @mn: The maple node
969 * @mt: The maple node type
971 static inline unsigned char ma_meta_gap(struct maple_node *mn,
974 BUG_ON(mt != maple_arange_64);
976 return mn->ma64.meta.gap;
980 * ma_set_meta_gap() - Set the largest gap location in a nodes metadata
981 * @mn: The maple node
982 * @mn: The maple node type
983 * @offset: The location of the largest gap.
985 static inline void ma_set_meta_gap(struct maple_node *mn, enum maple_type mt,
986 unsigned char offset)
989 struct maple_metadata *meta = ma_meta(mn, mt);
995 * mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes.
996 * @mat - the ma_topiary, a linked list of dead nodes.
997 * @dead_enode - the node to be marked as dead and added to the tail of the list
999 * Add the @dead_enode to the linked list in @mat.
1001 static inline void mat_add(struct ma_topiary *mat,
1002 struct maple_enode *dead_enode)
1004 mte_set_node_dead(dead_enode);
1005 mte_to_mat(dead_enode)->next = NULL;
1007 mat->tail = mat->head = dead_enode;
1011 mte_to_mat(mat->tail)->next = dead_enode;
1012 mat->tail = dead_enode;
1015 static void mte_destroy_walk(struct maple_enode *, struct maple_tree *);
1016 static inline void mas_free(struct ma_state *mas, struct maple_enode *used);
1019 * mas_mat_free() - Free all nodes in a dead list.
1020 * @mas - the maple state
1021 * @mat - the ma_topiary linked list of dead nodes to free.
1023 * Free walk a dead list.
1025 static void mas_mat_free(struct ma_state *mas, struct ma_topiary *mat)
1027 struct maple_enode *next;
1030 next = mte_to_mat(mat->head)->next;
1031 mas_free(mas, mat->head);
1037 * mas_mat_destroy() - Free all nodes and subtrees in a dead list.
1038 * @mas - the maple state
1039 * @mat - the ma_topiary linked list of dead nodes to free.
1041 * Destroy walk a dead list.
1043 static void mas_mat_destroy(struct ma_state *mas, struct ma_topiary *mat)
1045 struct maple_enode *next;
1048 next = mte_to_mat(mat->head)->next;
1049 mte_destroy_walk(mat->head, mat->mtree);
1054 * mas_descend() - Descend into the slot stored in the ma_state.
1055 * @mas - the maple state.
1057 * Note: Not RCU safe, only use in write side or debug code.
1059 static inline void mas_descend(struct ma_state *mas)
1061 enum maple_type type;
1062 unsigned long *pivots;
1063 struct maple_node *node;
1067 type = mte_node_type(mas->node);
1068 pivots = ma_pivots(node, type);
1069 slots = ma_slots(node, type);
1072 mas->min = pivots[mas->offset - 1] + 1;
1073 mas->max = mas_safe_pivot(mas, pivots, mas->offset, type);
1074 mas->node = mas_slot(mas, slots, mas->offset);
1078 * mte_set_gap() - Set a maple node gap.
1079 * @mn: The encoded maple node
1080 * @gap: The offset of the gap to set
1081 * @val: The gap value
1083 static inline void mte_set_gap(const struct maple_enode *mn,
1084 unsigned char gap, unsigned long val)
1086 switch (mte_node_type(mn)) {
1089 case maple_arange_64:
1090 mte_to_node(mn)->ma64.gap[gap] = val;
1096 * mas_ascend() - Walk up a level of the tree.
1097 * @mas: The maple state
1099 * Sets the @mas->max and @mas->min to the correct values when walking up. This
1100 * may cause several levels of walking up to find the correct min and max.
1101 * May find a dead node which will cause a premature return.
1102 * Return: 1 on dead node, 0 otherwise
1104 static int mas_ascend(struct ma_state *mas)
1106 struct maple_enode *p_enode; /* parent enode. */
1107 struct maple_enode *a_enode; /* ancestor enode. */
1108 struct maple_node *a_node; /* ancestor node. */
1109 struct maple_node *p_node; /* parent node. */
1110 unsigned char a_slot;
1111 enum maple_type a_type;
1112 unsigned long min, max;
1113 unsigned long *pivots;
1114 unsigned char offset;
1115 bool set_max = false, set_min = false;
1117 a_node = mas_mn(mas);
1118 if (ma_is_root(a_node)) {
1123 p_node = mte_parent(mas->node);
1124 if (unlikely(a_node == p_node))
1126 a_type = mas_parent_enum(mas, mas->node);
1127 offset = mte_parent_slot(mas->node);
1128 a_enode = mt_mk_node(p_node, a_type);
1130 /* Check to make sure all parent information is still accurate */
1131 if (p_node != mte_parent(mas->node))
1134 mas->node = a_enode;
1135 mas->offset = offset;
1137 if (mte_is_root(a_enode)) {
1138 mas->max = ULONG_MAX;
1147 a_type = mas_parent_enum(mas, p_enode);
1148 a_node = mte_parent(p_enode);
1149 a_slot = mte_parent_slot(p_enode);
1150 a_enode = mt_mk_node(a_node, a_type);
1151 pivots = ma_pivots(a_node, a_type);
1153 if (unlikely(ma_dead_node(a_node)))
1156 if (!set_min && a_slot) {
1158 min = pivots[a_slot - 1] + 1;
1161 if (!set_max && a_slot < mt_pivots[a_type]) {
1163 max = pivots[a_slot];
1166 if (unlikely(ma_dead_node(a_node)))
1169 if (unlikely(ma_is_root(a_node)))
1172 } while (!set_min || !set_max);
1180 * mas_pop_node() - Get a previously allocated maple node from the maple state.
1181 * @mas: The maple state
1183 * Return: A pointer to a maple node.
1185 static inline struct maple_node *mas_pop_node(struct ma_state *mas)
1187 struct maple_alloc *ret, *node = mas->alloc;
1188 unsigned long total = mas_allocated(mas);
1189 unsigned int req = mas_alloc_req(mas);
1191 /* nothing or a request pending. */
1192 if (WARN_ON(!total))
1196 /* single allocation in this ma_state */
1202 if (node->node_count == 1) {
1203 /* Single allocation in this node. */
1204 mas->alloc = node->slot[0];
1205 mas->alloc->total = node->total - 1;
1210 ret = node->slot[--node->node_count];
1211 node->slot[node->node_count] = NULL;
1217 mas_set_alloc_req(mas, req);
1220 memset(ret, 0, sizeof(*ret));
1221 return (struct maple_node *)ret;
1225 * mas_push_node() - Push a node back on the maple state allocation.
1226 * @mas: The maple state
1227 * @used: The used maple node
1229 * Stores the maple node back into @mas->alloc for reuse. Updates allocated and
1230 * requested node count as necessary.
1232 static inline void mas_push_node(struct ma_state *mas, struct maple_node *used)
1234 struct maple_alloc *reuse = (struct maple_alloc *)used;
1235 struct maple_alloc *head = mas->alloc;
1236 unsigned long count;
1237 unsigned int requested = mas_alloc_req(mas);
1239 count = mas_allocated(mas);
1241 reuse->request_count = 0;
1242 reuse->node_count = 0;
1243 if (count && (head->node_count < MAPLE_ALLOC_SLOTS)) {
1244 head->slot[head->node_count++] = reuse;
1250 if ((head) && !((unsigned long)head & 0x1)) {
1251 reuse->slot[0] = head;
1252 reuse->node_count = 1;
1253 reuse->total += head->total;
1259 mas_set_alloc_req(mas, requested - 1);
1263 * mas_alloc_nodes() - Allocate nodes into a maple state
1264 * @mas: The maple state
1265 * @gfp: The GFP Flags
1267 static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
1269 struct maple_alloc *node;
1270 unsigned long allocated = mas_allocated(mas);
1271 unsigned int requested = mas_alloc_req(mas);
1273 void **slots = NULL;
1274 unsigned int max_req = 0;
1279 mas_set_alloc_req(mas, 0);
1280 if (mas->mas_flags & MA_STATE_PREALLOC) {
1283 WARN_ON(!allocated);
1286 if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS) {
1287 node = (struct maple_alloc *)mt_alloc_one(gfp);
1292 node->slot[0] = mas->alloc;
1293 node->node_count = 1;
1295 node->node_count = 0;
1299 node->total = ++allocated;
1304 node->request_count = 0;
1306 max_req = MAPLE_ALLOC_SLOTS - node->node_count;
1307 slots = (void **)&node->slot[node->node_count];
1308 max_req = min(requested, max_req);
1309 count = mt_alloc_bulk(gfp, max_req, slots);
1313 if (node->node_count == 0) {
1314 node->slot[0]->node_count = 0;
1315 node->slot[0]->request_count = 0;
1318 node->node_count += count;
1320 node = node->slot[0];
1323 mas->alloc->total = allocated;
1327 /* Clean up potential freed allocations on bulk failure */
1328 memset(slots, 0, max_req * sizeof(unsigned long));
1330 mas_set_alloc_req(mas, requested);
1331 if (mas->alloc && !(((unsigned long)mas->alloc & 0x1)))
1332 mas->alloc->total = allocated;
1333 mas_set_err(mas, -ENOMEM);
1337 * mas_free() - Free an encoded maple node
1338 * @mas: The maple state
1339 * @used: The encoded maple node to free.
1341 * Uses rcu free if necessary, pushes @used back on the maple state allocations
1344 static inline void mas_free(struct ma_state *mas, struct maple_enode *used)
1346 struct maple_node *tmp = mte_to_node(used);
1348 if (mt_in_rcu(mas->tree))
1351 mas_push_node(mas, tmp);
1355 * mas_node_count() - Check if enough nodes are allocated and request more if
1356 * there is not enough nodes.
1357 * @mas: The maple state
1358 * @count: The number of nodes needed
1359 * @gfp: the gfp flags
1361 static void mas_node_count_gfp(struct ma_state *mas, int count, gfp_t gfp)
1363 unsigned long allocated = mas_allocated(mas);
1365 if (allocated < count) {
1366 mas_set_alloc_req(mas, count - allocated);
1367 mas_alloc_nodes(mas, gfp);
1372 * mas_node_count() - Check if enough nodes are allocated and request more if
1373 * there is not enough nodes.
1374 * @mas: The maple state
1375 * @count: The number of nodes needed
1377 * Note: Uses GFP_NOWAIT | __GFP_NOWARN for gfp flags.
1379 static void mas_node_count(struct ma_state *mas, int count)
1381 return mas_node_count_gfp(mas, count, GFP_NOWAIT | __GFP_NOWARN);
1385 * mas_start() - Sets up maple state for operations.
1386 * @mas: The maple state.
1388 * If mas->node == MAS_START, then set the min, max and depth to
1392 * - If mas->node is an error or not MAS_START, return NULL.
1393 * - If it's an empty tree: NULL & mas->node == MAS_NONE
1394 * - If it's a single entry: The entry & mas->node == MAS_ROOT
1395 * - If it's a tree: NULL & mas->node == safe root node.
1397 static inline struct maple_enode *mas_start(struct ma_state *mas)
1399 if (likely(mas_is_start(mas))) {
1400 struct maple_enode *root;
1403 mas->max = ULONG_MAX;
1407 root = mas_root(mas);
1408 /* Tree with nodes */
1409 if (likely(xa_is_node(root))) {
1411 mas->node = mte_safe_root(root);
1413 if (mte_dead_node(mas->node))
1420 if (unlikely(!root)) {
1421 mas->node = MAS_NONE;
1422 mas->offset = MAPLE_NODE_SLOTS;
1426 /* Single entry tree */
1427 mas->node = MAS_ROOT;
1428 mas->offset = MAPLE_NODE_SLOTS;
1430 /* Single entry tree. */
1441 * ma_data_end() - Find the end of the data in a node.
1442 * @node: The maple node
1443 * @type: The maple node type
1444 * @pivots: The array of pivots in the node
1445 * @max: The maximum value in the node
1447 * Uses metadata to find the end of the data when possible.
1448 * Return: The zero indexed last slot with data (may be null).
1450 static inline unsigned char ma_data_end(struct maple_node *node,
1451 enum maple_type type,
1452 unsigned long *pivots,
1455 unsigned char offset;
1460 if (type == maple_arange_64)
1461 return ma_meta_end(node, type);
1463 offset = mt_pivots[type] - 1;
1464 if (likely(!pivots[offset]))
1465 return ma_meta_end(node, type);
1467 if (likely(pivots[offset] == max))
1470 return mt_pivots[type];
1474 * mas_data_end() - Find the end of the data (slot).
1475 * @mas: the maple state
1477 * This method is optimized to check the metadata of a node if the node type
1478 * supports data end metadata.
1480 * Return: The zero indexed last slot with data (may be null).
1482 static inline unsigned char mas_data_end(struct ma_state *mas)
1484 enum maple_type type;
1485 struct maple_node *node;
1486 unsigned char offset;
1487 unsigned long *pivots;
1489 type = mte_node_type(mas->node);
1491 if (type == maple_arange_64)
1492 return ma_meta_end(node, type);
1494 pivots = ma_pivots(node, type);
1495 if (unlikely(ma_dead_node(node)))
1498 offset = mt_pivots[type] - 1;
1499 if (likely(!pivots[offset]))
1500 return ma_meta_end(node, type);
1502 if (likely(pivots[offset] == mas->max))
1505 return mt_pivots[type];
1509 * mas_leaf_max_gap() - Returns the largest gap in a leaf node
1510 * @mas - the maple state
1512 * Return: The maximum gap in the leaf.
1514 static unsigned long mas_leaf_max_gap(struct ma_state *mas)
1517 unsigned long pstart, gap, max_gap;
1518 struct maple_node *mn;
1519 unsigned long *pivots;
1522 unsigned char max_piv;
1524 mt = mte_node_type(mas->node);
1526 slots = ma_slots(mn, mt);
1528 if (unlikely(ma_is_dense(mt))) {
1530 for (i = 0; i < mt_slots[mt]; i++) {
1545 * Check the first implied pivot optimizes the loop below and slot 1 may
1546 * be skipped if there is a gap in slot 0.
1548 pivots = ma_pivots(mn, mt);
1549 if (likely(!slots[0])) {
1550 max_gap = pivots[0] - mas->min + 1;
1556 /* reduce max_piv as the special case is checked before the loop */
1557 max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1;
1559 * Check end implied pivot which can only be a gap on the right most
1562 if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) {
1563 gap = ULONG_MAX - pivots[max_piv];
1568 for (; i <= max_piv; i++) {
1569 /* data == no gap. */
1570 if (likely(slots[i]))
1573 pstart = pivots[i - 1];
1574 gap = pivots[i] - pstart;
1578 /* There cannot be two gaps in a row. */
1585 * ma_max_gap() - Get the maximum gap in a maple node (non-leaf)
1586 * @node: The maple node
1587 * @gaps: The pointer to the gaps
1588 * @mt: The maple node type
1589 * @*off: Pointer to store the offset location of the gap.
1591 * Uses the metadata data end to scan backwards across set gaps.
1593 * Return: The maximum gap value
1595 static inline unsigned long
1596 ma_max_gap(struct maple_node *node, unsigned long *gaps, enum maple_type mt,
1599 unsigned char offset, i;
1600 unsigned long max_gap = 0;
1602 i = offset = ma_meta_end(node, mt);
1604 if (gaps[i] > max_gap) {
1615 * mas_max_gap() - find the largest gap in a non-leaf node and set the slot.
1616 * @mas: The maple state.
1618 * If the metadata gap is set to MAPLE_ARANGE64_META_MAX, there is no gap.
1620 * Return: The gap value.
1622 static inline unsigned long mas_max_gap(struct ma_state *mas)
1624 unsigned long *gaps;
1625 unsigned char offset;
1627 struct maple_node *node;
1629 mt = mte_node_type(mas->node);
1631 return mas_leaf_max_gap(mas);
1634 offset = ma_meta_gap(node, mt);
1635 if (offset == MAPLE_ARANGE64_META_MAX)
1638 gaps = ma_gaps(node, mt);
1639 return gaps[offset];
1643 * mas_parent_gap() - Set the parent gap and any gaps above, as needed
1644 * @mas: The maple state
1645 * @offset: The gap offset in the parent to set
1646 * @new: The new gap value.
1648 * Set the parent gap then continue to set the gap upwards, using the metadata
1649 * of the parent to see if it is necessary to check the node above.
1651 static inline void mas_parent_gap(struct ma_state *mas, unsigned char offset,
1654 unsigned long meta_gap = 0;
1655 struct maple_node *pnode;
1656 struct maple_enode *penode;
1657 unsigned long *pgaps;
1658 unsigned char meta_offset;
1659 enum maple_type pmt;
1661 pnode = mte_parent(mas->node);
1662 pmt = mas_parent_enum(mas, mas->node);
1663 penode = mt_mk_node(pnode, pmt);
1664 pgaps = ma_gaps(pnode, pmt);
1667 meta_offset = ma_meta_gap(pnode, pmt);
1668 if (meta_offset == MAPLE_ARANGE64_META_MAX)
1671 meta_gap = pgaps[meta_offset];
1673 pgaps[offset] = new;
1675 if (meta_gap == new)
1678 if (offset != meta_offset) {
1682 ma_set_meta_gap(pnode, pmt, offset);
1683 } else if (new < meta_gap) {
1685 new = ma_max_gap(pnode, pgaps, pmt, &meta_offset);
1686 ma_set_meta_gap(pnode, pmt, meta_offset);
1689 if (ma_is_root(pnode))
1692 /* Go to the parent node. */
1693 pnode = mte_parent(penode);
1694 pmt = mas_parent_enum(mas, penode);
1695 pgaps = ma_gaps(pnode, pmt);
1696 offset = mte_parent_slot(penode);
1697 penode = mt_mk_node(pnode, pmt);
1702 * mas_update_gap() - Update a nodes gaps and propagate up if necessary.
1703 * @mas - the maple state.
1705 static inline void mas_update_gap(struct ma_state *mas)
1707 unsigned char pslot;
1708 unsigned long p_gap;
1709 unsigned long max_gap;
1711 if (!mt_is_alloc(mas->tree))
1714 if (mte_is_root(mas->node))
1717 max_gap = mas_max_gap(mas);
1719 pslot = mte_parent_slot(mas->node);
1720 p_gap = ma_gaps(mte_parent(mas->node),
1721 mas_parent_enum(mas, mas->node))[pslot];
1723 if (p_gap != max_gap)
1724 mas_parent_gap(mas, pslot, max_gap);
1728 * mas_adopt_children() - Set the parent pointer of all nodes in @parent to
1729 * @parent with the slot encoded.
1730 * @mas - the maple state (for the tree)
1731 * @parent - the maple encoded node containing the children.
1733 static inline void mas_adopt_children(struct ma_state *mas,
1734 struct maple_enode *parent)
1736 enum maple_type type = mte_node_type(parent);
1737 struct maple_node *node = mas_mn(mas);
1738 void __rcu **slots = ma_slots(node, type);
1739 unsigned long *pivots = ma_pivots(node, type);
1740 struct maple_enode *child;
1741 unsigned char offset;
1743 offset = ma_data_end(node, type, pivots, mas->max);
1745 child = mas_slot_locked(mas, slots, offset);
1746 mte_set_parent(child, parent, offset);
1751 * mas_replace() - Replace a maple node in the tree with mas->node. Uses the
1752 * parent encoding to locate the maple node in the tree.
1753 * @mas - the ma_state to use for operations.
1754 * @advanced - boolean to adopt the child nodes and free the old node (false) or
1755 * leave the node (true) and handle the adoption and free elsewhere.
1757 static inline void mas_replace(struct ma_state *mas, bool advanced)
1758 __must_hold(mas->tree->lock)
1760 struct maple_node *mn = mas_mn(mas);
1761 struct maple_enode *old_enode;
1762 unsigned char offset = 0;
1763 void __rcu **slots = NULL;
1765 if (ma_is_root(mn)) {
1766 old_enode = mas_root_locked(mas);
1768 offset = mte_parent_slot(mas->node);
1769 slots = ma_slots(mte_parent(mas->node),
1770 mas_parent_enum(mas, mas->node));
1771 old_enode = mas_slot_locked(mas, slots, offset);
1774 if (!advanced && !mte_is_leaf(mas->node))
1775 mas_adopt_children(mas, mas->node);
1777 if (mte_is_root(mas->node)) {
1778 mn->parent = ma_parent_ptr(
1779 ((unsigned long)mas->tree | MA_ROOT_PARENT));
1780 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
1781 mas_set_height(mas);
1783 rcu_assign_pointer(slots[offset], mas->node);
1787 mte_set_node_dead(old_enode);
1788 mas_free(mas, old_enode);
1793 * mas_new_child() - Find the new child of a node.
1794 * @mas: the maple state
1795 * @child: the maple state to store the child.
1797 static inline bool mas_new_child(struct ma_state *mas, struct ma_state *child)
1798 __must_hold(mas->tree->lock)
1801 unsigned char offset;
1803 unsigned long *pivots;
1804 struct maple_enode *entry;
1805 struct maple_node *node;
1808 mt = mte_node_type(mas->node);
1810 slots = ma_slots(node, mt);
1811 pivots = ma_pivots(node, mt);
1812 end = ma_data_end(node, mt, pivots, mas->max);
1813 for (offset = mas->offset; offset <= end; offset++) {
1814 entry = mas_slot_locked(mas, slots, offset);
1815 if (mte_parent(entry) == node) {
1817 mas->offset = offset + 1;
1818 child->offset = offset;
1828 * mab_shift_right() - Shift the data in mab right. Note, does not clean out the
1829 * old data or set b_node->b_end.
1830 * @b_node: the maple_big_node
1831 * @shift: the shift count
1833 static inline void mab_shift_right(struct maple_big_node *b_node,
1834 unsigned char shift)
1836 unsigned long size = b_node->b_end * sizeof(unsigned long);
1838 memmove(b_node->pivot + shift, b_node->pivot, size);
1839 memmove(b_node->slot + shift, b_node->slot, size);
1840 if (b_node->type == maple_arange_64)
1841 memmove(b_node->gap + shift, b_node->gap, size);
1845 * mab_middle_node() - Check if a middle node is needed (unlikely)
1846 * @b_node: the maple_big_node that contains the data.
1847 * @size: the amount of data in the b_node
1848 * @split: the potential split location
1849 * @slot_count: the size that can be stored in a single node being considered.
1851 * Return: true if a middle node is required.
1853 static inline bool mab_middle_node(struct maple_big_node *b_node, int split,
1854 unsigned char slot_count)
1856 unsigned char size = b_node->b_end;
1858 if (size >= 2 * slot_count)
1861 if (!b_node->slot[split] && (size >= 2 * slot_count - 1))
1868 * mab_no_null_split() - ensure the split doesn't fall on a NULL
1869 * @b_node: the maple_big_node with the data
1870 * @split: the suggested split location
1871 * @slot_count: the number of slots in the node being considered.
1873 * Return: the split location.
1875 static inline int mab_no_null_split(struct maple_big_node *b_node,
1876 unsigned char split, unsigned char slot_count)
1878 if (!b_node->slot[split]) {
1880 * If the split is less than the max slot && the right side will
1881 * still be sufficient, then increment the split on NULL.
1883 if ((split < slot_count - 1) &&
1884 (b_node->b_end - split) > (mt_min_slots[b_node->type]))
1893 * mab_calc_split() - Calculate the split location and if there needs to be two
1895 * @bn: The maple_big_node with the data
1896 * @mid_split: The second split, if required. 0 otherwise.
1898 * Return: The first split location. The middle split is set in @mid_split.
1900 static inline int mab_calc_split(struct ma_state *mas,
1901 struct maple_big_node *bn, unsigned char *mid_split, unsigned long min)
1903 unsigned char b_end = bn->b_end;
1904 int split = b_end / 2; /* Assume equal split. */
1905 unsigned char slot_min, slot_count = mt_slots[bn->type];
1908 * To support gap tracking, all NULL entries are kept together and a node cannot
1909 * end on a NULL entry, with the exception of the left-most leaf. The
1910 * limitation means that the split of a node must be checked for this condition
1911 * and be able to put more data in one direction or the other.
1913 if (unlikely((mas->mas_flags & MA_STATE_BULK))) {
1915 split = b_end - mt_min_slots[bn->type];
1917 if (!ma_is_leaf(bn->type))
1920 mas->mas_flags |= MA_STATE_REBALANCE;
1921 if (!bn->slot[split])
1927 * Although extremely rare, it is possible to enter what is known as the 3-way
1928 * split scenario. The 3-way split comes about by means of a store of a range
1929 * that overwrites the end and beginning of two full nodes. The result is a set
1930 * of entries that cannot be stored in 2 nodes. Sometimes, these two nodes can
1931 * also be located in different parent nodes which are also full. This can
1932 * carry upwards all the way to the root in the worst case.
1934 if (unlikely(mab_middle_node(bn, split, slot_count))) {
1936 *mid_split = split * 2;
1938 slot_min = mt_min_slots[bn->type];
1942 * Avoid having a range less than the slot count unless it
1943 * causes one node to be deficient.
1944 * NOTE: mt_min_slots is 1 based, b_end and split are zero.
1946 while (((bn->pivot[split] - min) < slot_count - 1) &&
1947 (split < slot_count - 1) && (b_end - split > slot_min))
1951 /* Avoid ending a node on a NULL entry */
1952 split = mab_no_null_split(bn, split, slot_count);
1954 if (unlikely(*mid_split))
1955 *mid_split = mab_no_null_split(bn, *mid_split, slot_count);
1961 * mas_mab_cp() - Copy data from a maple state inclusively to a maple_big_node
1962 * and set @b_node->b_end to the next free slot.
1963 * @mas: The maple state
1964 * @mas_start: The starting slot to copy
1965 * @mas_end: The end slot to copy (inclusively)
1966 * @b_node: The maple_big_node to place the data
1967 * @mab_start: The starting location in maple_big_node to store the data.
1969 static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
1970 unsigned char mas_end, struct maple_big_node *b_node,
1971 unsigned char mab_start)
1974 struct maple_node *node;
1976 unsigned long *pivots, *gaps;
1977 int i = mas_start, j = mab_start;
1978 unsigned char piv_end;
1981 mt = mte_node_type(mas->node);
1982 pivots = ma_pivots(node, mt);
1984 b_node->pivot[j] = pivots[i++];
1985 if (unlikely(i > mas_end))
1990 piv_end = min(mas_end, mt_pivots[mt]);
1991 for (; i < piv_end; i++, j++) {
1992 b_node->pivot[j] = pivots[i];
1993 if (unlikely(!b_node->pivot[j]))
1996 if (unlikely(mas->max == b_node->pivot[j]))
2000 if (likely(i <= mas_end))
2001 b_node->pivot[j] = mas_safe_pivot(mas, pivots, i, mt);
2004 b_node->b_end = ++j;
2006 slots = ma_slots(node, mt);
2007 memcpy(b_node->slot + mab_start, slots + mas_start, sizeof(void *) * j);
2008 if (!ma_is_leaf(mt) && mt_is_alloc(mas->tree)) {
2009 gaps = ma_gaps(node, mt);
2010 memcpy(b_node->gap + mab_start, gaps + mas_start,
2011 sizeof(unsigned long) * j);
2016 * mas_leaf_set_meta() - Set the metadata of a leaf if possible.
2017 * @mas: The maple state
2018 * @node: The maple node
2019 * @pivots: pointer to the maple node pivots
2020 * @mt: The maple type
2021 * @end: The assumed end
2023 * Note, end may be incremented within this function but not modified at the
2024 * source. This is fine since the metadata is the last thing to be stored in a
2025 * node during a write.
2027 static inline void mas_leaf_set_meta(struct ma_state *mas,
2028 struct maple_node *node, unsigned long *pivots,
2029 enum maple_type mt, unsigned char end)
2031 /* There is no room for metadata already */
2032 if (mt_pivots[mt] <= end)
2035 if (pivots[end] && pivots[end] < mas->max)
2038 if (end < mt_slots[mt] - 1)
2039 ma_set_meta(node, mt, 0, end);
2043 * mab_mas_cp() - Copy data from maple_big_node to a maple encoded node.
2044 * @b_node: the maple_big_node that has the data
2045 * @mab_start: the start location in @b_node.
2046 * @mab_end: The end location in @b_node (inclusively)
2047 * @mas: The maple state with the maple encoded node.
2049 static inline void mab_mas_cp(struct maple_big_node *b_node,
2050 unsigned char mab_start, unsigned char mab_end,
2051 struct ma_state *mas, bool new_max)
2054 enum maple_type mt = mte_node_type(mas->node);
2055 struct maple_node *node = mte_to_node(mas->node);
2056 void __rcu **slots = ma_slots(node, mt);
2057 unsigned long *pivots = ma_pivots(node, mt);
2058 unsigned long *gaps = NULL;
2061 if (mab_end - mab_start > mt_pivots[mt])
2064 if (!pivots[mt_pivots[mt] - 1])
2065 slots[mt_pivots[mt]] = NULL;
2069 pivots[j++] = b_node->pivot[i++];
2070 } while (i <= mab_end && likely(b_node->pivot[i]));
2072 memcpy(slots, b_node->slot + mab_start,
2073 sizeof(void *) * (i - mab_start));
2076 mas->max = b_node->pivot[i - 1];
2079 if (likely(!ma_is_leaf(mt) && mt_is_alloc(mas->tree))) {
2080 unsigned long max_gap = 0;
2081 unsigned char offset = 15;
2083 gaps = ma_gaps(node, mt);
2085 gaps[--j] = b_node->gap[--i];
2086 if (gaps[j] > max_gap) {
2092 ma_set_meta(node, mt, offset, end);
2094 mas_leaf_set_meta(mas, node, pivots, mt, end);
2099 * mas_descend_adopt() - Descend through a sub-tree and adopt children.
2100 * @mas: the maple state with the maple encoded node of the sub-tree.
2102 * Descend through a sub-tree and adopt children who do not have the correct
2103 * parents set. Follow the parents which have the correct parents as they are
2104 * the new entries which need to be followed to find other incorrectly set
2107 static inline void mas_descend_adopt(struct ma_state *mas)
2109 struct ma_state list[3], next[3];
2113 * At each level there may be up to 3 correct parent pointers which indicates
2114 * the new nodes which need to be walked to find any new nodes at a lower level.
2117 for (i = 0; i < 3; i++) {
2124 while (!mte_is_leaf(list[0].node)) {
2126 for (i = 0; i < 3; i++) {
2127 if (mas_is_none(&list[i]))
2130 if (i && list[i-1].node == list[i].node)
2133 while ((n < 3) && (mas_new_child(&list[i], &next[n])))
2136 mas_adopt_children(&list[i], list[i].node);
2140 next[n++].node = MAS_NONE;
2142 /* descend by setting the list to the children */
2143 for (i = 0; i < 3; i++)
2149 * mas_bulk_rebalance() - Rebalance the end of a tree after a bulk insert.
2150 * @mas: The maple state
2151 * @end: The maple node end
2152 * @mt: The maple node type
2154 static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end,
2157 if (!(mas->mas_flags & MA_STATE_BULK))
2160 if (mte_is_root(mas->node))
2163 if (end > mt_min_slots[mt]) {
2164 mas->mas_flags &= ~MA_STATE_REBALANCE;
2170 * mas_store_b_node() - Store an @entry into the b_node while also copying the
2171 * data from a maple encoded node.
2172 * @wr_mas: the maple write state
2173 * @b_node: the maple_big_node to fill with data
2174 * @offset_end: the offset to end copying
2176 * Return: The actual end of the data stored in @b_node
2178 static noinline_for_kasan void mas_store_b_node(struct ma_wr_state *wr_mas,
2179 struct maple_big_node *b_node, unsigned char offset_end)
2182 unsigned char b_end;
2183 /* Possible underflow of piv will wrap back to 0 before use. */
2185 struct ma_state *mas = wr_mas->mas;
2187 b_node->type = wr_mas->type;
2191 /* Copy start data up to insert. */
2192 mas_mab_cp(mas, 0, slot - 1, b_node, 0);
2193 b_end = b_node->b_end;
2194 piv = b_node->pivot[b_end - 1];
2198 if (piv + 1 < mas->index) {
2199 /* Handle range starting after old range */
2200 b_node->slot[b_end] = wr_mas->content;
2201 if (!wr_mas->content)
2202 b_node->gap[b_end] = mas->index - 1 - piv;
2203 b_node->pivot[b_end++] = mas->index - 1;
2206 /* Store the new entry. */
2207 mas->offset = b_end;
2208 b_node->slot[b_end] = wr_mas->entry;
2209 b_node->pivot[b_end] = mas->last;
2212 if (mas->last >= mas->max)
2215 /* Handle new range ending before old range ends */
2216 piv = mas_logical_pivot(mas, wr_mas->pivots, offset_end, wr_mas->type);
2217 if (piv > mas->last) {
2218 if (piv == ULONG_MAX)
2219 mas_bulk_rebalance(mas, b_node->b_end, wr_mas->type);
2221 if (offset_end != slot)
2222 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
2225 b_node->slot[++b_end] = wr_mas->content;
2226 if (!wr_mas->content)
2227 b_node->gap[b_end] = piv - mas->last + 1;
2228 b_node->pivot[b_end] = piv;
2231 slot = offset_end + 1;
2232 if (slot > wr_mas->node_end)
2235 /* Copy end data to the end of the node. */
2236 mas_mab_cp(mas, slot, wr_mas->node_end + 1, b_node, ++b_end);
2241 b_node->b_end = b_end;
2245 * mas_prev_sibling() - Find the previous node with the same parent.
2246 * @mas: the maple state
2248 * Return: True if there is a previous sibling, false otherwise.
2250 static inline bool mas_prev_sibling(struct ma_state *mas)
2252 unsigned int p_slot = mte_parent_slot(mas->node);
2254 if (mte_is_root(mas->node))
2261 mas->offset = p_slot - 1;
2267 * mas_next_sibling() - Find the next node with the same parent.
2268 * @mas: the maple state
2270 * Return: true if there is a next sibling, false otherwise.
2272 static inline bool mas_next_sibling(struct ma_state *mas)
2274 MA_STATE(parent, mas->tree, mas->index, mas->last);
2276 if (mte_is_root(mas->node))
2280 mas_ascend(&parent);
2281 parent.offset = mte_parent_slot(mas->node) + 1;
2282 if (parent.offset > mas_data_end(&parent))
2291 * mte_node_or_node() - Return the encoded node or MAS_NONE.
2292 * @enode: The encoded maple node.
2294 * Shorthand to avoid setting %NULLs in the tree or maple_subtree_state.
2296 * Return: @enode or MAS_NONE
2298 static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode)
2303 return ma_enode_ptr(MAS_NONE);
2307 * mas_wr_node_walk() - Find the correct offset for the index in the @mas.
2308 * @wr_mas: The maple write state
2310 * Uses mas_slot_locked() and does not need to worry about dead nodes.
2312 static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas)
2314 struct ma_state *mas = wr_mas->mas;
2315 unsigned char count;
2316 unsigned char offset;
2317 unsigned long index, min, max;
2319 if (unlikely(ma_is_dense(wr_mas->type))) {
2320 wr_mas->r_max = wr_mas->r_min = mas->index;
2321 mas->offset = mas->index = mas->min;
2325 wr_mas->node = mas_mn(wr_mas->mas);
2326 wr_mas->pivots = ma_pivots(wr_mas->node, wr_mas->type);
2327 count = wr_mas->node_end = ma_data_end(wr_mas->node, wr_mas->type,
2328 wr_mas->pivots, mas->max);
2329 offset = mas->offset;
2330 min = mas_safe_min(mas, wr_mas->pivots, offset);
2331 if (unlikely(offset == count))
2334 max = wr_mas->pivots[offset];
2336 if (unlikely(index <= max))
2339 if (unlikely(!max && offset))
2343 while (++offset < count) {
2344 max = wr_mas->pivots[offset];
2347 else if (unlikely(!max))
2356 wr_mas->r_max = max;
2357 wr_mas->r_min = min;
2358 wr_mas->offset_end = mas->offset = offset;
2362 * mas_topiary_range() - Add a range of slots to the topiary.
2363 * @mas: The maple state
2364 * @destroy: The topiary to add the slots (usually destroy)
2365 * @start: The starting slot inclusively
2366 * @end: The end slot inclusively
2368 static inline void mas_topiary_range(struct ma_state *mas,
2369 struct ma_topiary *destroy, unsigned char start, unsigned char end)
2372 unsigned char offset;
2374 MT_BUG_ON(mas->tree, mte_is_leaf(mas->node));
2375 slots = ma_slots(mas_mn(mas), mte_node_type(mas->node));
2376 for (offset = start; offset <= end; offset++) {
2377 struct maple_enode *enode = mas_slot_locked(mas, slots, offset);
2379 if (mte_dead_node(enode))
2382 mat_add(destroy, enode);
2387 * mast_topiary() - Add the portions of the tree to the removal list; either to
2388 * be freed or discarded (destroy walk).
2389 * @mast: The maple_subtree_state.
2391 static inline void mast_topiary(struct maple_subtree_state *mast)
2393 MA_WR_STATE(wr_mas, mast->orig_l, NULL);
2394 unsigned char r_start, r_end;
2395 unsigned char l_start, l_end;
2396 void __rcu **l_slots, **r_slots;
2398 wr_mas.type = mte_node_type(mast->orig_l->node);
2399 mast->orig_l->index = mast->orig_l->last;
2400 mas_wr_node_walk(&wr_mas);
2401 l_start = mast->orig_l->offset + 1;
2402 l_end = mas_data_end(mast->orig_l);
2404 r_end = mast->orig_r->offset;
2409 l_slots = ma_slots(mas_mn(mast->orig_l),
2410 mte_node_type(mast->orig_l->node));
2412 r_slots = ma_slots(mas_mn(mast->orig_r),
2413 mte_node_type(mast->orig_r->node));
2415 if ((l_start < l_end) &&
2416 mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_start))) {
2420 if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_end))) {
2425 if ((l_start > r_end) && (mast->orig_l->node == mast->orig_r->node))
2428 /* At the node where left and right sides meet, add the parts between */
2429 if (mast->orig_l->node == mast->orig_r->node) {
2430 return mas_topiary_range(mast->orig_l, mast->destroy,
2434 /* mast->orig_r is different and consumed. */
2435 if (mte_is_leaf(mast->orig_r->node))
2438 if (mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_end)))
2442 if (l_start <= l_end)
2443 mas_topiary_range(mast->orig_l, mast->destroy, l_start, l_end);
2445 if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_start)))
2448 if (r_start <= r_end)
2449 mas_topiary_range(mast->orig_r, mast->destroy, 0, r_end);
2453 * mast_rebalance_next() - Rebalance against the next node
2454 * @mast: The maple subtree state
2455 * @old_r: The encoded maple node to the right (next node).
2457 static inline void mast_rebalance_next(struct maple_subtree_state *mast)
2459 unsigned char b_end = mast->bn->b_end;
2461 mas_mab_cp(mast->orig_r, 0, mt_slot_count(mast->orig_r->node),
2463 mast->orig_r->last = mast->orig_r->max;
2467 * mast_rebalance_prev() - Rebalance against the previous node
2468 * @mast: The maple subtree state
2469 * @old_l: The encoded maple node to the left (previous node)
2471 static inline void mast_rebalance_prev(struct maple_subtree_state *mast)
2473 unsigned char end = mas_data_end(mast->orig_l) + 1;
2474 unsigned char b_end = mast->bn->b_end;
2476 mab_shift_right(mast->bn, end);
2477 mas_mab_cp(mast->orig_l, 0, end - 1, mast->bn, 0);
2478 mast->l->min = mast->orig_l->min;
2479 mast->orig_l->index = mast->orig_l->min;
2480 mast->bn->b_end = end + b_end;
2481 mast->l->offset += end;
2485 * mast_spanning_rebalance() - Rebalance nodes with nearest neighbour favouring
2486 * the node to the right. Checking the nodes to the right then the left at each
2487 * level upwards until root is reached. Free and destroy as needed.
2488 * Data is copied into the @mast->bn.
2489 * @mast: The maple_subtree_state.
2492 bool mast_spanning_rebalance(struct maple_subtree_state *mast)
2494 struct ma_state r_tmp = *mast->orig_r;
2495 struct ma_state l_tmp = *mast->orig_l;
2496 struct maple_enode *ancestor = NULL;
2497 unsigned char start, end;
2498 unsigned char depth = 0;
2500 r_tmp = *mast->orig_r;
2501 l_tmp = *mast->orig_l;
2503 mas_ascend(mast->orig_r);
2504 mas_ascend(mast->orig_l);
2507 (mast->orig_r->node == mast->orig_l->node)) {
2508 ancestor = mast->orig_r->node;
2509 end = mast->orig_r->offset - 1;
2510 start = mast->orig_l->offset + 1;
2513 if (mast->orig_r->offset < mas_data_end(mast->orig_r)) {
2515 ancestor = mast->orig_r->node;
2519 mast->orig_r->offset++;
2521 mas_descend(mast->orig_r);
2522 mast->orig_r->offset = 0;
2526 mast_rebalance_next(mast);
2528 unsigned char l_off = 0;
2529 struct maple_enode *child = r_tmp.node;
2532 if (ancestor == r_tmp.node)
2538 if (l_off < r_tmp.offset)
2539 mas_topiary_range(&r_tmp, mast->destroy,
2540 l_off, r_tmp.offset);
2542 if (l_tmp.node != child)
2543 mat_add(mast->free, child);
2545 } while (r_tmp.node != ancestor);
2547 *mast->orig_l = l_tmp;
2550 } else if (mast->orig_l->offset != 0) {
2552 ancestor = mast->orig_l->node;
2553 end = mas_data_end(mast->orig_l);
2556 mast->orig_l->offset--;
2558 mas_descend(mast->orig_l);
2559 mast->orig_l->offset =
2560 mas_data_end(mast->orig_l);
2564 mast_rebalance_prev(mast);
2566 unsigned char r_off;
2567 struct maple_enode *child = l_tmp.node;
2570 if (ancestor == l_tmp.node)
2573 r_off = mas_data_end(&l_tmp);
2575 if (l_tmp.offset < r_off)
2578 if (l_tmp.offset < r_off)
2579 mas_topiary_range(&l_tmp, mast->destroy,
2580 l_tmp.offset, r_off);
2582 if (r_tmp.node != child)
2583 mat_add(mast->free, child);
2585 } while (l_tmp.node != ancestor);
2587 *mast->orig_r = r_tmp;
2590 } while (!mte_is_root(mast->orig_r->node));
2592 *mast->orig_r = r_tmp;
2593 *mast->orig_l = l_tmp;
2598 * mast_ascend_free() - Add current original maple state nodes to the free list
2600 * @mast: the maple subtree state.
2602 * Ascend the original left and right sides and add the previous nodes to the
2603 * free list. Set the slots to point to the correct location in the new nodes.
2606 mast_ascend_free(struct maple_subtree_state *mast)
2608 MA_WR_STATE(wr_mas, mast->orig_r, NULL);
2609 struct maple_enode *left = mast->orig_l->node;
2610 struct maple_enode *right = mast->orig_r->node;
2612 mas_ascend(mast->orig_l);
2613 mas_ascend(mast->orig_r);
2614 mat_add(mast->free, left);
2617 mat_add(mast->free, right);
2619 mast->orig_r->offset = 0;
2620 mast->orig_r->index = mast->r->max;
2621 /* last should be larger than or equal to index */
2622 if (mast->orig_r->last < mast->orig_r->index)
2623 mast->orig_r->last = mast->orig_r->index;
2625 * The node may not contain the value so set slot to ensure all
2626 * of the nodes contents are freed or destroyed.
2628 wr_mas.type = mte_node_type(mast->orig_r->node);
2629 mas_wr_node_walk(&wr_mas);
2630 /* Set up the left side of things */
2631 mast->orig_l->offset = 0;
2632 mast->orig_l->index = mast->l->min;
2633 wr_mas.mas = mast->orig_l;
2634 wr_mas.type = mte_node_type(mast->orig_l->node);
2635 mas_wr_node_walk(&wr_mas);
2637 mast->bn->type = wr_mas.type;
2641 * mas_new_ma_node() - Create and return a new maple node. Helper function.
2642 * @mas: the maple state with the allocations.
2643 * @b_node: the maple_big_node with the type encoding.
2645 * Use the node type from the maple_big_node to allocate a new node from the
2646 * ma_state. This function exists mainly for code readability.
2648 * Return: A new maple encoded node
2650 static inline struct maple_enode
2651 *mas_new_ma_node(struct ma_state *mas, struct maple_big_node *b_node)
2653 return mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), b_node->type);
2657 * mas_mab_to_node() - Set up right and middle nodes
2659 * @mas: the maple state that contains the allocations.
2660 * @b_node: the node which contains the data.
2661 * @left: The pointer which will have the left node
2662 * @right: The pointer which may have the right node
2663 * @middle: the pointer which may have the middle node (rare)
2664 * @mid_split: the split location for the middle node
2666 * Return: the split of left.
2668 static inline unsigned char mas_mab_to_node(struct ma_state *mas,
2669 struct maple_big_node *b_node, struct maple_enode **left,
2670 struct maple_enode **right, struct maple_enode **middle,
2671 unsigned char *mid_split, unsigned long min)
2673 unsigned char split = 0;
2674 unsigned char slot_count = mt_slots[b_node->type];
2676 *left = mas_new_ma_node(mas, b_node);
2681 if (b_node->b_end < slot_count) {
2682 split = b_node->b_end;
2684 split = mab_calc_split(mas, b_node, mid_split, min);
2685 *right = mas_new_ma_node(mas, b_node);
2689 *middle = mas_new_ma_node(mas, b_node);
2696 * mab_set_b_end() - Add entry to b_node at b_node->b_end and increment the end
2698 * @b_node - the big node to add the entry
2699 * @mas - the maple state to get the pivot (mas->max)
2700 * @entry - the entry to add, if NULL nothing happens.
2702 static inline void mab_set_b_end(struct maple_big_node *b_node,
2703 struct ma_state *mas,
2709 b_node->slot[b_node->b_end] = entry;
2710 if (mt_is_alloc(mas->tree))
2711 b_node->gap[b_node->b_end] = mas_max_gap(mas);
2712 b_node->pivot[b_node->b_end++] = mas->max;
2716 * mas_set_split_parent() - combine_then_separate helper function. Sets the parent
2717 * of @mas->node to either @left or @right, depending on @slot and @split
2719 * @mas - the maple state with the node that needs a parent
2720 * @left - possible parent 1
2721 * @right - possible parent 2
2722 * @slot - the slot the mas->node was placed
2723 * @split - the split location between @left and @right
2725 static inline void mas_set_split_parent(struct ma_state *mas,
2726 struct maple_enode *left,
2727 struct maple_enode *right,
2728 unsigned char *slot, unsigned char split)
2730 if (mas_is_none(mas))
2733 if ((*slot) <= split)
2734 mte_set_parent(mas->node, left, *slot);
2736 mte_set_parent(mas->node, right, (*slot) - split - 1);
2742 * mte_mid_split_check() - Check if the next node passes the mid-split
2743 * @**l: Pointer to left encoded maple node.
2744 * @**m: Pointer to middle encoded maple node.
2745 * @**r: Pointer to right encoded maple node.
2747 * @*split: The split location.
2748 * @mid_split: The middle split.
2750 static inline void mte_mid_split_check(struct maple_enode **l,
2751 struct maple_enode **r,
2752 struct maple_enode *right,
2754 unsigned char *split,
2755 unsigned char mid_split)
2760 if (slot < mid_split)
2769 * mast_set_split_parents() - Helper function to set three nodes parents. Slot
2770 * is taken from @mast->l.
2771 * @mast - the maple subtree state
2772 * @left - the left node
2773 * @right - the right node
2774 * @split - the split location.
2776 static inline void mast_set_split_parents(struct maple_subtree_state *mast,
2777 struct maple_enode *left,
2778 struct maple_enode *middle,
2779 struct maple_enode *right,
2780 unsigned char split,
2781 unsigned char mid_split)
2784 struct maple_enode *l = left;
2785 struct maple_enode *r = right;
2787 if (mas_is_none(mast->l))
2793 slot = mast->l->offset;
2795 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2796 mas_set_split_parent(mast->l, l, r, &slot, split);
2798 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2799 mas_set_split_parent(mast->m, l, r, &slot, split);
2801 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2802 mas_set_split_parent(mast->r, l, r, &slot, split);
2806 * mas_wmb_replace() - Write memory barrier and replace
2807 * @mas: The maple state
2808 * @free: the maple topiary list of nodes to free
2809 * @destroy: The maple topiary list of nodes to destroy (walk and free)
2811 * Updates gap as necessary.
2813 static inline void mas_wmb_replace(struct ma_state *mas,
2814 struct ma_topiary *free,
2815 struct ma_topiary *destroy)
2817 /* All nodes must see old data as dead prior to replacing that data */
2818 smp_wmb(); /* Needed for RCU */
2820 /* Insert the new data in the tree */
2821 mas_replace(mas, true);
2823 if (!mte_is_leaf(mas->node))
2824 mas_descend_adopt(mas);
2826 mas_mat_free(mas, free);
2829 mas_mat_destroy(mas, destroy);
2831 if (mte_is_leaf(mas->node))
2834 mas_update_gap(mas);
2838 * mast_new_root() - Set a new tree root during subtree creation
2839 * @mast: The maple subtree state
2840 * @mas: The maple state
2842 static inline void mast_new_root(struct maple_subtree_state *mast,
2843 struct ma_state *mas)
2845 mas_mn(mast->l)->parent =
2846 ma_parent_ptr(((unsigned long)mas->tree | MA_ROOT_PARENT));
2847 if (!mte_dead_node(mast->orig_l->node) &&
2848 !mte_is_root(mast->orig_l->node)) {
2850 mast_ascend_free(mast);
2852 } while (!mte_is_root(mast->orig_l->node));
2854 if ((mast->orig_l->node != mas->node) &&
2855 (mast->l->depth > mas_mt_height(mas))) {
2856 mat_add(mast->free, mas->node);
2861 * mast_cp_to_nodes() - Copy data out to nodes.
2862 * @mast: The maple subtree state
2863 * @left: The left encoded maple node
2864 * @middle: The middle encoded maple node
2865 * @right: The right encoded maple node
2866 * @split: The location to split between left and (middle ? middle : right)
2867 * @mid_split: The location to split between middle and right.
2869 static inline void mast_cp_to_nodes(struct maple_subtree_state *mast,
2870 struct maple_enode *left, struct maple_enode *middle,
2871 struct maple_enode *right, unsigned char split, unsigned char mid_split)
2873 bool new_lmax = true;
2875 mast->l->node = mte_node_or_none(left);
2876 mast->m->node = mte_node_or_none(middle);
2877 mast->r->node = mte_node_or_none(right);
2879 mast->l->min = mast->orig_l->min;
2880 if (split == mast->bn->b_end) {
2881 mast->l->max = mast->orig_r->max;
2885 mab_mas_cp(mast->bn, 0, split, mast->l, new_lmax);
2888 mab_mas_cp(mast->bn, 1 + split, mid_split, mast->m, true);
2889 mast->m->min = mast->bn->pivot[split] + 1;
2893 mast->r->max = mast->orig_r->max;
2895 mab_mas_cp(mast->bn, 1 + split, mast->bn->b_end, mast->r, false);
2896 mast->r->min = mast->bn->pivot[split] + 1;
2901 * mast_combine_cp_left - Copy in the original left side of the tree into the
2902 * combined data set in the maple subtree state big node.
2903 * @mast: The maple subtree state
2905 static inline void mast_combine_cp_left(struct maple_subtree_state *mast)
2907 unsigned char l_slot = mast->orig_l->offset;
2912 mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
2916 * mast_combine_cp_right: Copy in the original right side of the tree into the
2917 * combined data set in the maple subtree state big node.
2918 * @mast: The maple subtree state
2920 static inline void mast_combine_cp_right(struct maple_subtree_state *mast)
2922 if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max)
2925 mas_mab_cp(mast->orig_r, mast->orig_r->offset + 1,
2926 mt_slot_count(mast->orig_r->node), mast->bn,
2928 mast->orig_r->last = mast->orig_r->max;
2932 * mast_sufficient: Check if the maple subtree state has enough data in the big
2933 * node to create at least one sufficient node
2934 * @mast: the maple subtree state
2936 static inline bool mast_sufficient(struct maple_subtree_state *mast)
2938 if (mast->bn->b_end > mt_min_slot_count(mast->orig_l->node))
2945 * mast_overflow: Check if there is too much data in the subtree state for a
2947 * @mast: The maple subtree state
2949 static inline bool mast_overflow(struct maple_subtree_state *mast)
2951 if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node))
2957 static inline void *mtree_range_walk(struct ma_state *mas)
2959 unsigned long *pivots;
2960 unsigned char offset;
2961 struct maple_node *node;
2962 struct maple_enode *next, *last;
2963 enum maple_type type;
2966 unsigned long max, min;
2967 unsigned long prev_max, prev_min;
2975 node = mte_to_node(next);
2976 type = mte_node_type(next);
2977 pivots = ma_pivots(node, type);
2978 end = ma_data_end(node, type, pivots, max);
2979 if (unlikely(ma_dead_node(node)))
2982 if (pivots[offset] >= mas->index) {
2985 max = pivots[offset];
2991 } while ((offset < end) && (pivots[offset] < mas->index));
2994 min = pivots[offset - 1] + 1;
2996 if (likely(offset < end && pivots[offset]))
2997 max = pivots[offset];
3000 slots = ma_slots(node, type);
3001 next = mt_slot(mas->tree, slots, offset);
3002 if (unlikely(ma_dead_node(node)))
3004 } while (!ma_is_leaf(type));
3006 mas->offset = offset;
3009 mas->min = prev_min;
3010 mas->max = prev_max;
3012 return (void *)next;
3020 * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
3021 * @mas: The starting maple state
3022 * @mast: The maple_subtree_state, keeps track of 4 maple states.
3023 * @count: The estimated count of iterations needed.
3025 * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
3026 * is hit. First @b_node is split into two entries which are inserted into the
3027 * next iteration of the loop. @b_node is returned populated with the final
3028 * iteration. @mas is used to obtain allocations. orig_l_mas keeps track of the
3029 * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
3030 * to account of what has been copied into the new sub-tree. The update of
3031 * orig_l_mas->last is used in mas_consume to find the slots that will need to
3032 * be either freed or destroyed. orig_l_mas->depth keeps track of the height of
3033 * the new sub-tree in case the sub-tree becomes the full tree.
3035 * Return: the number of elements in b_node during the last loop.
3037 static int mas_spanning_rebalance(struct ma_state *mas,
3038 struct maple_subtree_state *mast, unsigned char count)
3040 unsigned char split, mid_split;
3041 unsigned char slot = 0;
3042 struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
3044 MA_STATE(l_mas, mas->tree, mas->index, mas->index);
3045 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
3046 MA_STATE(m_mas, mas->tree, mas->index, mas->index);
3047 MA_TOPIARY(free, mas->tree);
3048 MA_TOPIARY(destroy, mas->tree);
3051 * The tree needs to be rebalanced and leaves need to be kept at the same level.
3052 * Rebalancing is done by use of the ``struct maple_topiary``.
3058 mast->destroy = &destroy;
3059 l_mas.node = r_mas.node = m_mas.node = MAS_NONE;
3061 /* Check if this is not root and has sufficient data. */
3062 if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) &&
3063 unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
3064 mast_spanning_rebalance(mast);
3066 mast->orig_l->depth = 0;
3069 * Each level of the tree is examined and balanced, pushing data to the left or
3070 * right, or rebalancing against left or right nodes is employed to avoid
3071 * rippling up the tree to limit the amount of churn. Once a new sub-section of
3072 * the tree is created, there may be a mix of new and old nodes. The old nodes
3073 * will have the incorrect parent pointers and currently be in two trees: the
3074 * original tree and the partially new tree. To remedy the parent pointers in
3075 * the old tree, the new data is swapped into the active tree and a walk down
3076 * the tree is performed and the parent pointers are updated.
3077 * See mas_descend_adopt() for more information..
3081 mast->bn->type = mte_node_type(mast->orig_l->node);
3082 split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
3083 &mid_split, mast->orig_l->min);
3084 mast_set_split_parents(mast, left, middle, right, split,
3086 mast_cp_to_nodes(mast, left, middle, right, split, mid_split);
3089 * Copy data from next level in the tree to mast->bn from next
3092 memset(mast->bn, 0, sizeof(struct maple_big_node));
3093 mast->bn->type = mte_node_type(left);
3094 mast->orig_l->depth++;
3096 /* Root already stored in l->node. */
3097 if (mas_is_root_limits(mast->l))
3100 mast_ascend_free(mast);
3101 mast_combine_cp_left(mast);
3102 l_mas.offset = mast->bn->b_end;
3103 mab_set_b_end(mast->bn, &l_mas, left);
3104 mab_set_b_end(mast->bn, &m_mas, middle);
3105 mab_set_b_end(mast->bn, &r_mas, right);
3107 /* Copy anything necessary out of the right node. */
3108 mast_combine_cp_right(mast);
3110 mast->orig_l->last = mast->orig_l->max;
3112 if (mast_sufficient(mast))
3115 if (mast_overflow(mast))
3118 /* May be a new root stored in mast->bn */
3119 if (mas_is_root_limits(mast->orig_l))
3122 mast_spanning_rebalance(mast);
3124 /* rebalancing from other nodes may require another loop. */
3129 l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
3130 mte_node_type(mast->orig_l->node));
3131 mast->orig_l->depth++;
3132 mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
3133 mte_set_parent(left, l_mas.node, slot);
3135 mte_set_parent(middle, l_mas.node, ++slot);
3138 mte_set_parent(right, l_mas.node, ++slot);
3140 if (mas_is_root_limits(mast->l)) {
3142 mast_new_root(mast, mas);
3144 mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent;
3147 if (!mte_dead_node(mast->orig_l->node))
3148 mat_add(&free, mast->orig_l->node);
3150 mas->depth = mast->orig_l->depth;
3151 *mast->orig_l = l_mas;
3152 mte_set_node_dead(mas->node);
3154 /* Set up mas for insertion. */
3155 mast->orig_l->depth = mas->depth;
3156 mast->orig_l->alloc = mas->alloc;
3157 *mas = *mast->orig_l;
3158 mas_wmb_replace(mas, &free, &destroy);
3159 mtree_range_walk(mas);
3160 return mast->bn->b_end;
3164 * mas_rebalance() - Rebalance a given node.
3165 * @mas: The maple state
3166 * @b_node: The big maple node.
3168 * Rebalance two nodes into a single node or two new nodes that are sufficient.
3169 * Continue upwards until tree is sufficient.
3171 * Return: the number of elements in b_node during the last loop.
3173 static inline int mas_rebalance(struct ma_state *mas,
3174 struct maple_big_node *b_node)
3176 char empty_count = mas_mt_height(mas);
3177 struct maple_subtree_state mast;
3178 unsigned char shift, b_end = ++b_node->b_end;
3180 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3181 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
3183 trace_ma_op(__func__, mas);
3186 * Rebalancing occurs if a node is insufficient. Data is rebalanced
3187 * against the node to the right if it exists, otherwise the node to the
3188 * left of this node is rebalanced against this node. If rebalancing
3189 * causes just one node to be produced instead of two, then the parent
3190 * is also examined and rebalanced if it is insufficient. Every level
3191 * tries to combine the data in the same way. If one node contains the
3192 * entire range of the tree, then that node is used as a new root node.
3194 mas_node_count(mas, 1 + empty_count * 3);
3195 if (mas_is_err(mas))
3198 mast.orig_l = &l_mas;
3199 mast.orig_r = &r_mas;
3201 mast.bn->type = mte_node_type(mas->node);
3203 l_mas = r_mas = *mas;
3205 if (mas_next_sibling(&r_mas)) {
3206 mas_mab_cp(&r_mas, 0, mt_slot_count(r_mas.node), b_node, b_end);
3207 r_mas.last = r_mas.index = r_mas.max;
3209 mas_prev_sibling(&l_mas);
3210 shift = mas_data_end(&l_mas) + 1;
3211 mab_shift_right(b_node, shift);
3212 mas->offset += shift;
3213 mas_mab_cp(&l_mas, 0, shift - 1, b_node, 0);
3214 b_node->b_end = shift + b_end;
3215 l_mas.index = l_mas.last = l_mas.min;
3218 return mas_spanning_rebalance(mas, &mast, empty_count);
3222 * mas_destroy_rebalance() - Rebalance left-most node while destroying the maple
3224 * @mas: The maple state
3225 * @end: The end of the left-most node.
3227 * During a mass-insert event (such as forking), it may be necessary to
3228 * rebalance the left-most node when it is not sufficient.
3230 static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end)
3232 enum maple_type mt = mte_node_type(mas->node);
3233 struct maple_node reuse, *newnode, *parent, *new_left, *left, *node;
3234 struct maple_enode *eparent;
3235 unsigned char offset, tmp, split = mt_slots[mt] / 2;
3236 void __rcu **l_slots, **slots;
3237 unsigned long *l_pivs, *pivs, gap;
3238 bool in_rcu = mt_in_rcu(mas->tree);
3240 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3243 mas_prev_sibling(&l_mas);
3247 /* Allocate for both left and right as well as parent. */
3248 mas_node_count(mas, 3);
3249 if (mas_is_err(mas))
3252 newnode = mas_pop_node(mas);
3258 newnode->parent = node->parent;
3259 slots = ma_slots(newnode, mt);
3260 pivs = ma_pivots(newnode, mt);
3261 left = mas_mn(&l_mas);
3262 l_slots = ma_slots(left, mt);
3263 l_pivs = ma_pivots(left, mt);
3264 if (!l_slots[split])
3266 tmp = mas_data_end(&l_mas) - split;
3268 memcpy(slots, l_slots + split + 1, sizeof(void *) * tmp);
3269 memcpy(pivs, l_pivs + split + 1, sizeof(unsigned long) * tmp);
3270 pivs[tmp] = l_mas.max;
3271 memcpy(slots + tmp, ma_slots(node, mt), sizeof(void *) * end);
3272 memcpy(pivs + tmp, ma_pivots(node, mt), sizeof(unsigned long) * end);
3274 l_mas.max = l_pivs[split];
3275 mas->min = l_mas.max + 1;
3276 eparent = mt_mk_node(mte_parent(l_mas.node),
3277 mas_parent_enum(&l_mas, l_mas.node));
3280 unsigned char max_p = mt_pivots[mt];
3281 unsigned char max_s = mt_slots[mt];
3284 memset(pivs + tmp, 0,
3285 sizeof(unsigned long *) * (max_p - tmp));
3287 if (tmp < mt_slots[mt])
3288 memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp));
3290 memcpy(node, newnode, sizeof(struct maple_node));
3291 ma_set_meta(node, mt, 0, tmp - 1);
3292 mte_set_pivot(eparent, mte_parent_slot(l_mas.node),
3295 /* Remove data from l_pivs. */
3297 memset(l_pivs + tmp, 0, sizeof(unsigned long) * (max_p - tmp));
3298 memset(l_slots + tmp, 0, sizeof(void *) * (max_s - tmp));
3299 ma_set_meta(left, mt, 0, split);
3304 /* RCU requires replacing both l_mas, mas, and parent. */
3305 mas->node = mt_mk_node(newnode, mt);
3306 ma_set_meta(newnode, mt, 0, tmp);
3308 new_left = mas_pop_node(mas);
3309 new_left->parent = left->parent;
3310 mt = mte_node_type(l_mas.node);
3311 slots = ma_slots(new_left, mt);
3312 pivs = ma_pivots(new_left, mt);
3313 memcpy(slots, l_slots, sizeof(void *) * split);
3314 memcpy(pivs, l_pivs, sizeof(unsigned long) * split);
3315 ma_set_meta(new_left, mt, 0, split);
3316 l_mas.node = mt_mk_node(new_left, mt);
3318 /* replace parent. */
3319 offset = mte_parent_slot(mas->node);
3320 mt = mas_parent_enum(&l_mas, l_mas.node);
3321 parent = mas_pop_node(mas);
3322 slots = ma_slots(parent, mt);
3323 pivs = ma_pivots(parent, mt);
3324 memcpy(parent, mte_to_node(eparent), sizeof(struct maple_node));
3325 rcu_assign_pointer(slots[offset], mas->node);
3326 rcu_assign_pointer(slots[offset - 1], l_mas.node);
3327 pivs[offset - 1] = l_mas.max;
3328 eparent = mt_mk_node(parent, mt);
3330 gap = mas_leaf_max_gap(mas);
3331 mte_set_gap(eparent, mte_parent_slot(mas->node), gap);
3332 gap = mas_leaf_max_gap(&l_mas);
3333 mte_set_gap(eparent, mte_parent_slot(l_mas.node), gap);
3337 mas_replace(mas, false);
3339 mas_update_gap(mas);
3343 * mas_split_final_node() - Split the final node in a subtree operation.
3344 * @mast: the maple subtree state
3345 * @mas: The maple state
3346 * @height: The height of the tree in case it's a new root.
3348 static inline bool mas_split_final_node(struct maple_subtree_state *mast,
3349 struct ma_state *mas, int height)
3351 struct maple_enode *ancestor;
3353 if (mte_is_root(mas->node)) {
3354 if (mt_is_alloc(mas->tree))
3355 mast->bn->type = maple_arange_64;
3357 mast->bn->type = maple_range_64;
3358 mas->depth = height;
3361 * Only a single node is used here, could be root.
3362 * The Big_node data should just fit in a single node.
3364 ancestor = mas_new_ma_node(mas, mast->bn);
3365 mte_set_parent(mast->l->node, ancestor, mast->l->offset);
3366 mte_set_parent(mast->r->node, ancestor, mast->r->offset);
3367 mte_to_node(ancestor)->parent = mas_mn(mas)->parent;
3369 mast->l->node = ancestor;
3370 mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true);
3371 mas->offset = mast->bn->b_end - 1;
3376 * mast_fill_bnode() - Copy data into the big node in the subtree state
3377 * @mast: The maple subtree state
3378 * @mas: the maple state
3379 * @skip: The number of entries to skip for new nodes insertion.
3381 static inline void mast_fill_bnode(struct maple_subtree_state *mast,
3382 struct ma_state *mas,
3386 struct maple_enode *old = mas->node;
3387 unsigned char split;
3389 memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap));
3390 memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot));
3391 memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot));
3392 mast->bn->b_end = 0;
3394 if (mte_is_root(mas->node)) {
3398 mat_add(mast->free, old);
3399 mas->offset = mte_parent_slot(mas->node);
3402 if (cp && mast->l->offset)
3403 mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0);
3405 split = mast->bn->b_end;
3406 mab_set_b_end(mast->bn, mast->l, mast->l->node);
3407 mast->r->offset = mast->bn->b_end;
3408 mab_set_b_end(mast->bn, mast->r, mast->r->node);
3409 if (mast->bn->pivot[mast->bn->b_end - 1] == mas->max)
3413 mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1,
3414 mast->bn, mast->bn->b_end);
3417 mast->bn->type = mte_node_type(mas->node);
3421 * mast_split_data() - Split the data in the subtree state big node into regular
3423 * @mast: The maple subtree state
3424 * @mas: The maple state
3425 * @split: The location to split the big node
3427 static inline void mast_split_data(struct maple_subtree_state *mast,
3428 struct ma_state *mas, unsigned char split)
3430 unsigned char p_slot;
3432 mab_mas_cp(mast->bn, 0, split, mast->l, true);
3433 mte_set_pivot(mast->r->node, 0, mast->r->max);
3434 mab_mas_cp(mast->bn, split + 1, mast->bn->b_end, mast->r, false);
3435 mast->l->offset = mte_parent_slot(mas->node);
3436 mast->l->max = mast->bn->pivot[split];
3437 mast->r->min = mast->l->max + 1;
3438 if (mte_is_leaf(mas->node))
3441 p_slot = mast->orig_l->offset;
3442 mas_set_split_parent(mast->orig_l, mast->l->node, mast->r->node,
3444 mas_set_split_parent(mast->orig_r, mast->l->node, mast->r->node,
3449 * mas_push_data() - Instead of splitting a node, it is beneficial to push the
3450 * data to the right or left node if there is room.
3451 * @mas: The maple state
3452 * @height: The current height of the maple state
3453 * @mast: The maple subtree state
3454 * @left: Push left or not.
3456 * Keeping the height of the tree low means faster lookups.
3458 * Return: True if pushed, false otherwise.
3460 static inline bool mas_push_data(struct ma_state *mas, int height,
3461 struct maple_subtree_state *mast, bool left)
3463 unsigned char slot_total = mast->bn->b_end;
3464 unsigned char end, space, split;
3466 MA_STATE(tmp_mas, mas->tree, mas->index, mas->last);
3468 tmp_mas.depth = mast->l->depth;
3470 if (left && !mas_prev_sibling(&tmp_mas))
3472 else if (!left && !mas_next_sibling(&tmp_mas))
3475 end = mas_data_end(&tmp_mas);
3477 space = 2 * mt_slot_count(mas->node) - 2;
3478 /* -2 instead of -1 to ensure there isn't a triple split */
3479 if (ma_is_leaf(mast->bn->type))
3482 if (mas->max == ULONG_MAX)
3485 if (slot_total >= space)
3488 /* Get the data; Fill mast->bn */
3491 mab_shift_right(mast->bn, end + 1);
3492 mas_mab_cp(&tmp_mas, 0, end, mast->bn, 0);
3493 mast->bn->b_end = slot_total + 1;
3495 mas_mab_cp(&tmp_mas, 0, end, mast->bn, mast->bn->b_end);
3498 /* Configure mast for splitting of mast->bn */
3499 split = mt_slots[mast->bn->type] - 2;
3501 /* Switch mas to prev node */
3502 mat_add(mast->free, mas->node);
3504 /* Start using mast->l for the left side. */
3505 tmp_mas.node = mast->l->node;
3508 mat_add(mast->free, tmp_mas.node);
3509 tmp_mas.node = mast->r->node;
3511 split = slot_total - split;
3513 split = mab_no_null_split(mast->bn, split, mt_slots[mast->bn->type]);
3514 /* Update parent slot for split calculation. */
3516 mast->orig_l->offset += end + 1;
3518 mast_split_data(mast, mas, split);
3519 mast_fill_bnode(mast, mas, 2);
3520 mas_split_final_node(mast, mas, height + 1);
3525 * mas_split() - Split data that is too big for one node into two.
3526 * @mas: The maple state
3527 * @b_node: The maple big node
3528 * Return: 1 on success, 0 on failure.
3530 static int mas_split(struct ma_state *mas, struct maple_big_node *b_node)
3532 struct maple_subtree_state mast;
3534 unsigned char mid_split, split = 0;
3537 * Splitting is handled differently from any other B-tree; the Maple
3538 * Tree splits upwards. Splitting up means that the split operation
3539 * occurs when the walk of the tree hits the leaves and not on the way
3540 * down. The reason for splitting up is that it is impossible to know
3541 * how much space will be needed until the leaf is (or leaves are)
3542 * reached. Since overwriting data is allowed and a range could
3543 * overwrite more than one range or result in changing one entry into 3
3544 * entries, it is impossible to know if a split is required until the
3547 * Splitting is a balancing act between keeping allocations to a minimum
3548 * and avoiding a 'jitter' event where a tree is expanded to make room
3549 * for an entry followed by a contraction when the entry is removed. To
3550 * accomplish the balance, there are empty slots remaining in both left
3551 * and right nodes after a split.
3553 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3554 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
3555 MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last);
3556 MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);
3557 MA_TOPIARY(mat, mas->tree);
3559 trace_ma_op(__func__, mas);
3560 mas->depth = mas_mt_height(mas);
3561 /* Allocation failures will happen early. */
3562 mas_node_count(mas, 1 + mas->depth * 2);
3563 if (mas_is_err(mas))
3568 mast.orig_l = &prev_l_mas;
3569 mast.orig_r = &prev_r_mas;
3573 while (height++ <= mas->depth) {
3574 if (mt_slots[b_node->type] > b_node->b_end) {
3575 mas_split_final_node(&mast, mas, height);
3579 l_mas = r_mas = *mas;
3580 l_mas.node = mas_new_ma_node(mas, b_node);
3581 r_mas.node = mas_new_ma_node(mas, b_node);
3583 * Another way that 'jitter' is avoided is to terminate a split up early if the
3584 * left or right node has space to spare. This is referred to as "pushing left"
3585 * or "pushing right" and is similar to the B* tree, except the nodes left or
3586 * right can rarely be reused due to RCU, but the ripple upwards is halted which
3587 * is a significant savings.
3589 /* Try to push left. */
3590 if (mas_push_data(mas, height, &mast, true))
3593 /* Try to push right. */
3594 if (mas_push_data(mas, height, &mast, false))
3597 split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min);
3598 mast_split_data(&mast, mas, split);
3600 * Usually correct, mab_mas_cp in the above call overwrites
3603 mast.r->max = mas->max;
3604 mast_fill_bnode(&mast, mas, 1);
3605 prev_l_mas = *mast.l;
3606 prev_r_mas = *mast.r;
3609 /* Set the original node as dead */
3610 mat_add(mast.free, mas->node);
3611 mas->node = l_mas.node;
3612 mas_wmb_replace(mas, mast.free, NULL);
3613 mtree_range_walk(mas);
3618 * mas_reuse_node() - Reuse the node to store the data.
3619 * @wr_mas: The maple write state
3620 * @bn: The maple big node
3621 * @end: The end of the data.
3623 * Will always return false in RCU mode.
3625 * Return: True if node was reused, false otherwise.
3627 static inline bool mas_reuse_node(struct ma_wr_state *wr_mas,
3628 struct maple_big_node *bn, unsigned char end)
3630 /* Need to be rcu safe. */
3631 if (mt_in_rcu(wr_mas->mas->tree))
3634 if (end > bn->b_end) {
3635 int clear = mt_slots[wr_mas->type] - bn->b_end;
3637 memset(wr_mas->slots + bn->b_end, 0, sizeof(void *) * clear--);
3638 memset(wr_mas->pivots + bn->b_end, 0, sizeof(void *) * clear);
3640 mab_mas_cp(bn, 0, bn->b_end, wr_mas->mas, false);
3645 * mas_commit_b_node() - Commit the big node into the tree.
3646 * @wr_mas: The maple write state
3647 * @b_node: The maple big node
3648 * @end: The end of the data.
3650 static noinline_for_kasan int mas_commit_b_node(struct ma_wr_state *wr_mas,
3651 struct maple_big_node *b_node, unsigned char end)
3653 struct maple_node *node;
3654 unsigned char b_end = b_node->b_end;
3655 enum maple_type b_type = b_node->type;
3657 if ((b_end < mt_min_slots[b_type]) &&
3658 (!mte_is_root(wr_mas->mas->node)) &&
3659 (mas_mt_height(wr_mas->mas) > 1))
3660 return mas_rebalance(wr_mas->mas, b_node);
3662 if (b_end >= mt_slots[b_type])
3663 return mas_split(wr_mas->mas, b_node);
3665 if (mas_reuse_node(wr_mas, b_node, end))
3668 mas_node_count(wr_mas->mas, 1);
3669 if (mas_is_err(wr_mas->mas))
3672 node = mas_pop_node(wr_mas->mas);
3673 node->parent = mas_mn(wr_mas->mas)->parent;
3674 wr_mas->mas->node = mt_mk_node(node, b_type);
3675 mab_mas_cp(b_node, 0, b_end, wr_mas->mas, false);
3676 mas_replace(wr_mas->mas, false);
3678 mas_update_gap(wr_mas->mas);
3683 * mas_root_expand() - Expand a root to a node
3684 * @mas: The maple state
3685 * @entry: The entry to store into the tree
3687 static inline int mas_root_expand(struct ma_state *mas, void *entry)
3689 void *contents = mas_root_locked(mas);
3690 enum maple_type type = maple_leaf_64;
3691 struct maple_node *node;
3693 unsigned long *pivots;
3696 mas_node_count(mas, 1);
3697 if (unlikely(mas_is_err(mas)))
3700 node = mas_pop_node(mas);
3701 pivots = ma_pivots(node, type);
3702 slots = ma_slots(node, type);
3703 node->parent = ma_parent_ptr(
3704 ((unsigned long)mas->tree | MA_ROOT_PARENT));
3705 mas->node = mt_mk_node(node, type);
3709 rcu_assign_pointer(slots[slot], contents);
3710 if (likely(mas->index > 1))
3713 pivots[slot++] = mas->index - 1;
3716 rcu_assign_pointer(slots[slot], entry);
3718 pivots[slot] = mas->last;
3719 if (mas->last != ULONG_MAX)
3722 mas_set_height(mas);
3723 ma_set_meta(node, maple_leaf_64, 0, slot);
3724 /* swap the new root into the tree */
3725 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
3729 static inline void mas_store_root(struct ma_state *mas, void *entry)
3731 if (likely((mas->last != 0) || (mas->index != 0)))
3732 mas_root_expand(mas, entry);
3733 else if (((unsigned long) (entry) & 3) == 2)
3734 mas_root_expand(mas, entry);
3736 rcu_assign_pointer(mas->tree->ma_root, entry);
3737 mas->node = MAS_START;
3742 * mas_is_span_wr() - Check if the write needs to be treated as a write that
3744 * @mas: The maple state
3745 * @piv: The pivot value being written
3746 * @type: The maple node type
3747 * @entry: The data to write
3749 * Spanning writes are writes that start in one node and end in another OR if
3750 * the write of a %NULL will cause the node to end with a %NULL.
3752 * Return: True if this is a spanning write, false otherwise.
3754 static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
3757 unsigned long last = wr_mas->mas->last;
3758 unsigned long piv = wr_mas->r_max;
3759 enum maple_type type = wr_mas->type;
3760 void *entry = wr_mas->entry;
3762 /* Contained in this pivot */
3766 max = wr_mas->mas->max;
3767 if (unlikely(ma_is_leaf(type))) {
3768 /* Fits in the node, but may span slots. */
3772 /* Writes to the end of the node but not null. */
3773 if ((last == max) && entry)
3777 * Writing ULONG_MAX is not a spanning write regardless of the
3778 * value being written as long as the range fits in the node.
3780 if ((last == ULONG_MAX) && (last == max))
3782 } else if (piv == last) {
3786 /* Detect spanning store wr walk */
3787 if (last == ULONG_MAX)
3791 trace_ma_write(__func__, wr_mas->mas, piv, entry);
3796 static inline void mas_wr_walk_descend(struct ma_wr_state *wr_mas)
3798 wr_mas->type = mte_node_type(wr_mas->mas->node);
3799 mas_wr_node_walk(wr_mas);
3800 wr_mas->slots = ma_slots(wr_mas->node, wr_mas->type);
3803 static inline void mas_wr_walk_traverse(struct ma_wr_state *wr_mas)
3805 wr_mas->mas->max = wr_mas->r_max;
3806 wr_mas->mas->min = wr_mas->r_min;
3807 wr_mas->mas->node = wr_mas->content;
3808 wr_mas->mas->offset = 0;
3809 wr_mas->mas->depth++;
3812 * mas_wr_walk() - Walk the tree for a write.
3813 * @wr_mas: The maple write state
3815 * Uses mas_slot_locked() and does not need to worry about dead nodes.
3817 * Return: True if it's contained in a node, false on spanning write.
3819 static bool mas_wr_walk(struct ma_wr_state *wr_mas)
3821 struct ma_state *mas = wr_mas->mas;
3824 mas_wr_walk_descend(wr_mas);
3825 if (unlikely(mas_is_span_wr(wr_mas)))
3828 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
3830 if (ma_is_leaf(wr_mas->type))
3833 mas_wr_walk_traverse(wr_mas);
3839 static bool mas_wr_walk_index(struct ma_wr_state *wr_mas)
3841 struct ma_state *mas = wr_mas->mas;
3844 mas_wr_walk_descend(wr_mas);
3845 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
3847 if (ma_is_leaf(wr_mas->type))
3849 mas_wr_walk_traverse(wr_mas);
3855 * mas_extend_spanning_null() - Extend a store of a %NULL to include surrounding %NULLs.
3856 * @l_wr_mas: The left maple write state
3857 * @r_wr_mas: The right maple write state
3859 static inline void mas_extend_spanning_null(struct ma_wr_state *l_wr_mas,
3860 struct ma_wr_state *r_wr_mas)
3862 struct ma_state *r_mas = r_wr_mas->mas;
3863 struct ma_state *l_mas = l_wr_mas->mas;
3864 unsigned char l_slot;
3866 l_slot = l_mas->offset;
3867 if (!l_wr_mas->content)
3868 l_mas->index = l_wr_mas->r_min;
3870 if ((l_mas->index == l_wr_mas->r_min) &&
3872 !mas_slot_locked(l_mas, l_wr_mas->slots, l_slot - 1))) {
3874 l_mas->index = l_wr_mas->pivots[l_slot - 2] + 1;
3876 l_mas->index = l_mas->min;
3878 l_mas->offset = l_slot - 1;
3881 if (!r_wr_mas->content) {
3882 if (r_mas->last < r_wr_mas->r_max)
3883 r_mas->last = r_wr_mas->r_max;
3885 } else if ((r_mas->last == r_wr_mas->r_max) &&
3886 (r_mas->last < r_mas->max) &&
3887 !mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) {
3888 r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots,
3889 r_wr_mas->type, r_mas->offset + 1);
3894 static inline void *mas_state_walk(struct ma_state *mas)
3898 entry = mas_start(mas);
3899 if (mas_is_none(mas))
3902 if (mas_is_ptr(mas))
3905 return mtree_range_walk(mas);
3909 * mtree_lookup_walk() - Internal quick lookup that does not keep maple state up
3912 * @mas: The maple state.
3914 * Note: Leaves mas in undesirable state.
3915 * Return: The entry for @mas->index or %NULL on dead node.
3917 static inline void *mtree_lookup_walk(struct ma_state *mas)
3919 unsigned long *pivots;
3920 unsigned char offset;
3921 struct maple_node *node;
3922 struct maple_enode *next;
3923 enum maple_type type;
3932 node = mte_to_node(next);
3933 type = mte_node_type(next);
3934 pivots = ma_pivots(node, type);
3935 end = ma_data_end(node, type, pivots, max);
3936 if (unlikely(ma_dead_node(node)))
3939 if (pivots[offset] >= mas->index) {
3940 max = pivots[offset];
3943 } while (++offset < end);
3945 slots = ma_slots(node, type);
3946 next = mt_slot(mas->tree, slots, offset);
3947 if (unlikely(ma_dead_node(node)))
3949 } while (!ma_is_leaf(type));
3951 return (void *)next;
3959 * mas_new_root() - Create a new root node that only contains the entry passed
3961 * @mas: The maple state
3962 * @entry: The entry to store.
3964 * Only valid when the index == 0 and the last == ULONG_MAX
3966 * Return 0 on error, 1 on success.
3968 static inline int mas_new_root(struct ma_state *mas, void *entry)
3970 struct maple_enode *root = mas_root_locked(mas);
3971 enum maple_type type = maple_leaf_64;
3972 struct maple_node *node;
3974 unsigned long *pivots;
3976 if (!entry && !mas->index && mas->last == ULONG_MAX) {
3978 mas_set_height(mas);
3979 rcu_assign_pointer(mas->tree->ma_root, entry);
3980 mas->node = MAS_START;
3984 mas_node_count(mas, 1);
3985 if (mas_is_err(mas))
3988 node = mas_pop_node(mas);
3989 pivots = ma_pivots(node, type);
3990 slots = ma_slots(node, type);
3991 node->parent = ma_parent_ptr(
3992 ((unsigned long)mas->tree | MA_ROOT_PARENT));
3993 mas->node = mt_mk_node(node, type);
3994 rcu_assign_pointer(slots[0], entry);
3995 pivots[0] = mas->last;
3997 mas_set_height(mas);
3998 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
4001 if (xa_is_node(root))
4002 mte_destroy_walk(root, mas->tree);
4007 * mas_wr_spanning_store() - Create a subtree with the store operation completed
4008 * and new nodes where necessary, then place the sub-tree in the actual tree.
4009 * Note that mas is expected to point to the node which caused the store to
4011 * @wr_mas: The maple write state
4013 * Return: 0 on error, positive on success.
4015 static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
4017 struct maple_subtree_state mast;
4018 struct maple_big_node b_node;
4019 struct ma_state *mas;
4020 unsigned char height;
4022 /* Left and Right side of spanning store */
4023 MA_STATE(l_mas, NULL, 0, 0);
4024 MA_STATE(r_mas, NULL, 0, 0);
4026 MA_WR_STATE(r_wr_mas, &r_mas, wr_mas->entry);
4027 MA_WR_STATE(l_wr_mas, &l_mas, wr_mas->entry);
4030 * A store operation that spans multiple nodes is called a spanning
4031 * store and is handled early in the store call stack by the function
4032 * mas_is_span_wr(). When a spanning store is identified, the maple
4033 * state is duplicated. The first maple state walks the left tree path
4034 * to ``index``, the duplicate walks the right tree path to ``last``.
4035 * The data in the two nodes are combined into a single node, two nodes,
4036 * or possibly three nodes (see the 3-way split above). A ``NULL``
4037 * written to the last entry of a node is considered a spanning store as
4038 * a rebalance is required for the operation to complete and an overflow
4039 * of data may happen.
4042 trace_ma_op(__func__, mas);
4044 if (unlikely(!mas->index && mas->last == ULONG_MAX))
4045 return mas_new_root(mas, wr_mas->entry);
4047 * Node rebalancing may occur due to this store, so there may be three new
4048 * entries per level plus a new root.
4050 height = mas_mt_height(mas);
4051 mas_node_count(mas, 1 + height * 3);
4052 if (mas_is_err(mas))
4056 * Set up right side. Need to get to the next offset after the spanning
4057 * store to ensure it's not NULL and to combine both the next node and
4058 * the node with the start together.
4061 /* Avoid overflow, walk to next slot in the tree. */
4065 r_mas.index = r_mas.last;
4066 mas_wr_walk_index(&r_wr_mas);
4067 r_mas.last = r_mas.index = mas->last;
4069 /* Set up left side. */
4071 mas_wr_walk_index(&l_wr_mas);
4073 if (!wr_mas->entry) {
4074 mas_extend_spanning_null(&l_wr_mas, &r_wr_mas);
4075 mas->offset = l_mas.offset;
4076 mas->index = l_mas.index;
4077 mas->last = l_mas.last = r_mas.last;
4080 /* expanding NULLs may make this cover the entire range */
4081 if (!l_mas.index && r_mas.last == ULONG_MAX) {
4082 mas_set_range(mas, 0, ULONG_MAX);
4083 return mas_new_root(mas, wr_mas->entry);
4086 memset(&b_node, 0, sizeof(struct maple_big_node));
4087 /* Copy l_mas and store the value in b_node. */
4088 mas_store_b_node(&l_wr_mas, &b_node, l_wr_mas.node_end);
4089 /* Copy r_mas into b_node. */
4090 if (r_mas.offset <= r_wr_mas.node_end)
4091 mas_mab_cp(&r_mas, r_mas.offset, r_wr_mas.node_end,
4092 &b_node, b_node.b_end + 1);
4096 /* Stop spanning searches by searching for just index. */
4097 l_mas.index = l_mas.last = mas->index;
4100 mast.orig_l = &l_mas;
4101 mast.orig_r = &r_mas;
4102 /* Combine l_mas and r_mas and split them up evenly again. */
4103 return mas_spanning_rebalance(mas, &mast, height + 1);
4107 * mas_wr_node_store() - Attempt to store the value in a node
4108 * @wr_mas: The maple write state
4110 * Attempts to reuse the node, but may allocate.
4112 * Return: True if stored, false otherwise
4114 static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas)
4116 struct ma_state *mas = wr_mas->mas;
4117 void __rcu **dst_slots;
4118 unsigned long *dst_pivots;
4119 unsigned char dst_offset;
4120 unsigned char new_end = wr_mas->node_end;
4121 unsigned char offset;
4122 unsigned char node_slots = mt_slots[wr_mas->type];
4123 struct maple_node reuse, *newnode;
4124 unsigned char copy_size, max_piv = mt_pivots[wr_mas->type];
4125 bool in_rcu = mt_in_rcu(mas->tree);
4127 offset = mas->offset;
4128 if (mas->last == wr_mas->r_max) {
4129 /* runs right to the end of the node */
4130 if (mas->last == mas->max)
4132 /* don't copy this offset */
4133 wr_mas->offset_end++;
4134 } else if (mas->last < wr_mas->r_max) {
4135 /* new range ends in this range */
4136 if (unlikely(wr_mas->r_max == ULONG_MAX))
4137 mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);
4141 if (wr_mas->end_piv == mas->last)
4142 wr_mas->offset_end++;
4144 new_end -= wr_mas->offset_end - offset - 1;
4147 /* new range starts within a range */
4148 if (wr_mas->r_min < mas->index)
4151 /* Not enough room */
4152 if (new_end >= node_slots)
4155 /* Not enough data. */
4156 if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) &&
4157 !(mas->mas_flags & MA_STATE_BULK))
4162 mas_node_count(mas, 1);
4163 if (mas_is_err(mas))
4166 newnode = mas_pop_node(mas);
4168 memset(&reuse, 0, sizeof(struct maple_node));
4172 newnode->parent = mas_mn(mas)->parent;
4173 dst_pivots = ma_pivots(newnode, wr_mas->type);
4174 dst_slots = ma_slots(newnode, wr_mas->type);
4175 /* Copy from start to insert point */
4176 memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * (offset + 1));
4177 memcpy(dst_slots, wr_mas->slots, sizeof(void *) * (offset + 1));
4178 dst_offset = offset;
4180 /* Handle insert of new range starting after old range */
4181 if (wr_mas->r_min < mas->index) {
4183 rcu_assign_pointer(dst_slots[dst_offset], wr_mas->content);
4184 dst_pivots[dst_offset++] = mas->index - 1;
4187 /* Store the new entry and range end. */
4188 if (dst_offset < max_piv)
4189 dst_pivots[dst_offset] = mas->last;
4190 mas->offset = dst_offset;
4191 rcu_assign_pointer(dst_slots[dst_offset], wr_mas->entry);
4194 * this range wrote to the end of the node or it overwrote the rest of
4197 if (wr_mas->offset_end > wr_mas->node_end || mas->last >= mas->max) {
4198 new_end = dst_offset;
4203 /* Copy to the end of node if necessary. */
4204 copy_size = wr_mas->node_end - wr_mas->offset_end + 1;
4205 memcpy(dst_slots + dst_offset, wr_mas->slots + wr_mas->offset_end,
4206 sizeof(void *) * copy_size);
4207 if (dst_offset < max_piv) {
4208 if (copy_size > max_piv - dst_offset)
4209 copy_size = max_piv - dst_offset;
4211 memcpy(dst_pivots + dst_offset,
4212 wr_mas->pivots + wr_mas->offset_end,
4213 sizeof(unsigned long) * copy_size);
4216 if ((wr_mas->node_end == node_slots - 1) && (new_end < node_slots - 1))
4217 dst_pivots[new_end] = mas->max;
4220 mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end);
4222 mte_set_node_dead(mas->node);
4223 mas->node = mt_mk_node(newnode, wr_mas->type);
4224 mas_replace(mas, false);
4226 memcpy(wr_mas->node, newnode, sizeof(struct maple_node));
4228 trace_ma_write(__func__, mas, 0, wr_mas->entry);
4229 mas_update_gap(mas);
4234 * mas_wr_slot_store: Attempt to store a value in a slot.
4235 * @wr_mas: the maple write state
4237 * Return: True if stored, false otherwise
4239 static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas)
4241 struct ma_state *mas = wr_mas->mas;
4242 unsigned long lmax; /* Logical max. */
4243 unsigned char offset = mas->offset;
4245 if ((wr_mas->r_max > mas->last) && ((wr_mas->r_min != mas->index) ||
4246 (offset != wr_mas->node_end)))
4249 if (offset == wr_mas->node_end - 1)
4252 lmax = wr_mas->pivots[offset + 1];
4254 /* going to overwrite too many slots. */
4255 if (lmax < mas->last)
4258 if (wr_mas->r_min == mas->index) {
4259 /* overwriting two or more ranges with one. */
4260 if (lmax == mas->last)
4263 /* Overwriting all of offset and a portion of offset + 1. */
4264 rcu_assign_pointer(wr_mas->slots[offset], wr_mas->entry);
4265 wr_mas->pivots[offset] = mas->last;
4269 /* Doesn't end on the next range end. */
4270 if (lmax != mas->last)
4273 /* Overwriting a portion of offset and all of offset + 1 */
4274 if ((offset + 1 < mt_pivots[wr_mas->type]) &&
4275 (wr_mas->entry || wr_mas->pivots[offset + 1]))
4276 wr_mas->pivots[offset + 1] = mas->last;
4278 rcu_assign_pointer(wr_mas->slots[offset + 1], wr_mas->entry);
4279 wr_mas->pivots[offset] = mas->index - 1;
4280 mas->offset++; /* Keep mas accurate. */
4283 trace_ma_write(__func__, mas, 0, wr_mas->entry);
4284 mas_update_gap(mas);
4288 static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
4290 while ((wr_mas->mas->last > wr_mas->end_piv) &&
4291 (wr_mas->offset_end < wr_mas->node_end))
4292 wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end];
4294 if (wr_mas->mas->last > wr_mas->end_piv)
4295 wr_mas->end_piv = wr_mas->mas->max;
4298 static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas)
4300 struct ma_state *mas = wr_mas->mas;
4302 if (mas->last < wr_mas->end_piv && !wr_mas->slots[wr_mas->offset_end])
4303 mas->last = wr_mas->end_piv;
4305 /* Check next slot(s) if we are overwriting the end */
4306 if ((mas->last == wr_mas->end_piv) &&
4307 (wr_mas->node_end != wr_mas->offset_end) &&
4308 !wr_mas->slots[wr_mas->offset_end + 1]) {
4309 wr_mas->offset_end++;
4310 if (wr_mas->offset_end == wr_mas->node_end)
4311 mas->last = mas->max;
4313 mas->last = wr_mas->pivots[wr_mas->offset_end];
4314 wr_mas->end_piv = mas->last;
4317 if (!wr_mas->content) {
4318 /* If this one is null, the next and prev are not */
4319 mas->index = wr_mas->r_min;
4321 /* Check prev slot if we are overwriting the start */
4322 if (mas->index == wr_mas->r_min && mas->offset &&
4323 !wr_mas->slots[mas->offset - 1]) {
4325 wr_mas->r_min = mas->index =
4326 mas_safe_min(mas, wr_mas->pivots, mas->offset);
4327 wr_mas->r_max = wr_mas->pivots[mas->offset];
4332 static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
4334 unsigned char end = wr_mas->node_end;
4335 unsigned char new_end = end + 1;
4336 struct ma_state *mas = wr_mas->mas;
4337 unsigned char node_pivots = mt_pivots[wr_mas->type];
4339 if ((mas->index != wr_mas->r_min) && (mas->last == wr_mas->r_max)) {
4340 if (new_end < node_pivots)
4341 wr_mas->pivots[new_end] = wr_mas->pivots[end];
4343 if (new_end < node_pivots)
4344 ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
4346 rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry);
4347 mas->offset = new_end;
4348 wr_mas->pivots[end] = mas->index - 1;
4353 if ((mas->index == wr_mas->r_min) && (mas->last < wr_mas->r_max)) {
4354 if (new_end < node_pivots)
4355 wr_mas->pivots[new_end] = wr_mas->pivots[end];
4357 rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content);
4358 if (new_end < node_pivots)
4359 ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
4361 wr_mas->pivots[end] = mas->last;
4362 rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry);
4370 * mas_wr_bnode() - Slow path for a modification.
4371 * @wr_mas: The write maple state
4373 * This is where split, rebalance end up.
4375 static void mas_wr_bnode(struct ma_wr_state *wr_mas)
4377 struct maple_big_node b_node;
4379 trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
4380 memset(&b_node, 0, sizeof(struct maple_big_node));
4381 mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
4382 mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
4385 static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
4387 unsigned char node_slots;
4388 unsigned char node_size;
4389 struct ma_state *mas = wr_mas->mas;
4391 /* Direct replacement */
4392 if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
4393 rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
4394 if (!!wr_mas->entry ^ !!wr_mas->content)
4395 mas_update_gap(mas);
4399 /* Attempt to append */
4400 node_slots = mt_slots[wr_mas->type];
4401 node_size = wr_mas->node_end - wr_mas->offset_end + mas->offset + 2;
4402 if (mas->max == ULONG_MAX)
4405 /* slot and node store will not fit, go to the slow path */
4406 if (unlikely(node_size >= node_slots))
4409 if (wr_mas->entry && (wr_mas->node_end < node_slots - 1) &&
4410 (mas->offset == wr_mas->node_end) && mas_wr_append(wr_mas)) {
4411 if (!wr_mas->content || !wr_mas->entry)
4412 mas_update_gap(mas);
4416 if ((wr_mas->offset_end - mas->offset <= 1) && mas_wr_slot_store(wr_mas))
4418 else if (mas_wr_node_store(wr_mas))
4421 if (mas_is_err(mas))
4425 mas_wr_bnode(wr_mas);
4429 * mas_wr_store_entry() - Internal call to store a value
4430 * @mas: The maple state
4431 * @entry: The entry to store.
4433 * Return: The contents that was stored at the index.
4435 static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas)
4437 struct ma_state *mas = wr_mas->mas;
4439 wr_mas->content = mas_start(mas);
4440 if (mas_is_none(mas) || mas_is_ptr(mas)) {
4441 mas_store_root(mas, wr_mas->entry);
4442 return wr_mas->content;
4445 if (unlikely(!mas_wr_walk(wr_mas))) {
4446 mas_wr_spanning_store(wr_mas);
4447 return wr_mas->content;
4450 /* At this point, we are at the leaf node that needs to be altered. */
4451 wr_mas->end_piv = wr_mas->r_max;
4452 mas_wr_end_piv(wr_mas);
4455 mas_wr_extend_null(wr_mas);
4457 /* New root for a single pointer */
4458 if (unlikely(!mas->index && mas->last == ULONG_MAX)) {
4459 mas_new_root(mas, wr_mas->entry);
4460 return wr_mas->content;
4463 mas_wr_modify(wr_mas);
4464 return wr_mas->content;
4468 * mas_insert() - Internal call to insert a value
4469 * @mas: The maple state
4470 * @entry: The entry to store
4472 * Return: %NULL or the contents that already exists at the requested index
4473 * otherwise. The maple state needs to be checked for error conditions.
4475 static inline void *mas_insert(struct ma_state *mas, void *entry)
4477 MA_WR_STATE(wr_mas, mas, entry);
4480 * Inserting a new range inserts either 0, 1, or 2 pivots within the
4481 * tree. If the insert fits exactly into an existing gap with a value
4482 * of NULL, then the slot only needs to be written with the new value.
4483 * If the range being inserted is adjacent to another range, then only a
4484 * single pivot needs to be inserted (as well as writing the entry). If
4485 * the new range is within a gap but does not touch any other ranges,
4486 * then two pivots need to be inserted: the start - 1, and the end. As
4487 * usual, the entry must be written. Most operations require a new node
4488 * to be allocated and replace an existing node to ensure RCU safety,
4489 * when in RCU mode. The exception to requiring a newly allocated node
4490 * is when inserting at the end of a node (appending). When done
4491 * carefully, appending can reuse the node in place.
4493 wr_mas.content = mas_start(mas);
4497 if (mas_is_none(mas) || mas_is_ptr(mas)) {
4498 mas_store_root(mas, entry);
4502 /* spanning writes always overwrite something */
4503 if (!mas_wr_walk(&wr_mas))
4506 /* At this point, we are at the leaf node that needs to be altered. */
4507 wr_mas.offset_end = mas->offset;
4508 wr_mas.end_piv = wr_mas.r_max;
4510 if (wr_mas.content || (mas->last > wr_mas.r_max))
4516 mas_wr_modify(&wr_mas);
4517 return wr_mas.content;
4520 mas_set_err(mas, -EEXIST);
4521 return wr_mas.content;
4526 * mas_prev_node() - Find the prev non-null entry at the same level in the
4527 * tree. The prev value will be mas->node[mas->offset] or MAS_NONE.
4528 * @mas: The maple state
4529 * @min: The lower limit to search
4531 * The prev node value will be mas->node[mas->offset] or MAS_NONE.
4532 * Return: 1 if the node is dead, 0 otherwise.
4534 static inline int mas_prev_node(struct ma_state *mas, unsigned long min)
4539 struct maple_node *node;
4540 struct maple_enode *enode;
4541 unsigned long *pivots;
4543 if (mas_is_none(mas))
4549 if (ma_is_root(node))
4553 if (unlikely(mas_ascend(mas)))
4555 offset = mas->offset;
4560 mt = mte_node_type(mas->node);
4562 slots = ma_slots(node, mt);
4563 pivots = ma_pivots(node, mt);
4564 if (unlikely(ma_dead_node(node)))
4567 mas->max = pivots[offset];
4569 mas->min = pivots[offset - 1] + 1;
4570 if (unlikely(ma_dead_node(node)))
4578 enode = mas_slot(mas, slots, offset);
4579 if (unlikely(ma_dead_node(node)))
4583 mt = mte_node_type(mas->node);
4585 slots = ma_slots(node, mt);
4586 pivots = ma_pivots(node, mt);
4587 offset = ma_data_end(node, mt, pivots, mas->max);
4588 if (unlikely(ma_dead_node(node)))
4592 mas->min = pivots[offset - 1] + 1;
4594 if (offset < mt_pivots[mt])
4595 mas->max = pivots[offset];
4601 mas->node = mas_slot(mas, slots, offset);
4602 if (unlikely(ma_dead_node(node)))
4605 mas->offset = mas_data_end(mas);
4606 if (unlikely(mte_dead_node(mas->node)))
4612 mas->offset = offset;
4614 mas->min = pivots[offset - 1] + 1;
4616 if (unlikely(ma_dead_node(node)))
4619 mas->node = MAS_NONE;
4624 * mas_next_node() - Get the next node at the same level in the tree.
4625 * @mas: The maple state
4626 * @max: The maximum pivot value to check.
4628 * The next value will be mas->node[mas->offset] or MAS_NONE.
4629 * Return: 1 on dead node, 0 otherwise.
4631 static inline int mas_next_node(struct ma_state *mas, struct maple_node *node,
4634 unsigned long min, pivot;
4635 unsigned long *pivots;
4636 struct maple_enode *enode;
4638 unsigned char offset;
4639 unsigned char node_end;
4643 if (mas->max >= max)
4648 if (ma_is_root(node))
4655 if (unlikely(mas_ascend(mas)))
4658 offset = mas->offset;
4661 mt = mte_node_type(mas->node);
4662 pivots = ma_pivots(node, mt);
4663 node_end = ma_data_end(node, mt, pivots, mas->max);
4664 if (unlikely(ma_dead_node(node)))
4667 } while (unlikely(offset == node_end));
4669 slots = ma_slots(node, mt);
4670 pivot = mas_safe_pivot(mas, pivots, ++offset, mt);
4671 while (unlikely(level > 1)) {
4672 /* Descend, if necessary */
4673 enode = mas_slot(mas, slots, offset);
4674 if (unlikely(ma_dead_node(node)))
4680 mt = mte_node_type(mas->node);
4681 slots = ma_slots(node, mt);
4682 pivots = ma_pivots(node, mt);
4683 if (unlikely(ma_dead_node(node)))
4690 enode = mas_slot(mas, slots, offset);
4691 if (unlikely(ma_dead_node(node)))
4700 if (unlikely(ma_dead_node(node)))
4703 mas->node = MAS_NONE;
4708 * mas_next_nentry() - Get the next node entry
4709 * @mas: The maple state
4710 * @max: The maximum value to check
4711 * @*range_start: Pointer to store the start of the range.
4713 * Sets @mas->offset to the offset of the next node entry, @mas->last to the
4714 * pivot of the entry.
4716 * Return: The next entry, %NULL otherwise
4718 static inline void *mas_next_nentry(struct ma_state *mas,
4719 struct maple_node *node, unsigned long max, enum maple_type type)
4721 unsigned char count;
4722 unsigned long pivot;
4723 unsigned long *pivots;
4727 if (mas->last == mas->max) {
4728 mas->index = mas->max;
4732 slots = ma_slots(node, type);
4733 pivots = ma_pivots(node, type);
4734 count = ma_data_end(node, type, pivots, mas->max);
4735 if (unlikely(ma_dead_node(node)))
4738 mas->index = mas_safe_min(mas, pivots, mas->offset);
4739 if (unlikely(ma_dead_node(node)))
4742 if (mas->index > max)
4745 if (mas->offset > count)
4748 while (mas->offset < count) {
4749 pivot = pivots[mas->offset];
4750 entry = mas_slot(mas, slots, mas->offset);
4751 if (ma_dead_node(node))
4760 mas->index = pivot + 1;
4764 if (mas->index > mas->max) {
4765 mas->index = mas->last;
4769 pivot = mas_safe_pivot(mas, pivots, mas->offset, type);
4770 entry = mas_slot(mas, slots, mas->offset);
4771 if (ma_dead_node(node))
4785 static inline void mas_rewalk(struct ma_state *mas, unsigned long index)
4788 mas_set(mas, index);
4789 mas_state_walk(mas);
4790 if (mas_is_start(mas))
4795 * mas_next_entry() - Internal function to get the next entry.
4796 * @mas: The maple state
4797 * @limit: The maximum range start.
4799 * Set the @mas->node to the next entry and the range_start to
4800 * the beginning value for the entry. Does not check beyond @limit.
4801 * Sets @mas->index and @mas->last to the limit if it is hit.
4802 * Restarts on dead nodes.
4804 * Return: the next entry or %NULL.
4806 static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit)
4809 struct maple_enode *prev_node;
4810 struct maple_node *node;
4811 unsigned char offset;
4815 if (mas->index > limit) {
4816 mas->index = mas->last = limit;
4822 offset = mas->offset;
4823 prev_node = mas->node;
4825 mt = mte_node_type(mas->node);
4827 if (unlikely(mas->offset >= mt_slots[mt])) {
4828 mas->offset = mt_slots[mt] - 1;
4832 while (!mas_is_none(mas)) {
4833 entry = mas_next_nentry(mas, node, limit, mt);
4834 if (unlikely(ma_dead_node(node))) {
4835 mas_rewalk(mas, last);
4842 if (unlikely((mas->index > limit)))
4846 prev_node = mas->node;
4847 offset = mas->offset;
4848 if (unlikely(mas_next_node(mas, node, limit))) {
4849 mas_rewalk(mas, last);
4854 mt = mte_node_type(mas->node);
4857 mas->index = mas->last = limit;
4858 mas->offset = offset;
4859 mas->node = prev_node;
4864 * mas_prev_nentry() - Get the previous node entry.
4865 * @mas: The maple state.
4866 * @limit: The lower limit to check for a value.
4868 * Return: the entry, %NULL otherwise.
4870 static inline void *mas_prev_nentry(struct ma_state *mas, unsigned long limit,
4871 unsigned long index)
4873 unsigned long pivot, min;
4874 unsigned char offset;
4875 struct maple_node *mn;
4877 unsigned long *pivots;
4886 mt = mte_node_type(mas->node);
4887 offset = mas->offset - 1;
4888 if (offset >= mt_slots[mt])
4889 offset = mt_slots[mt] - 1;
4891 slots = ma_slots(mn, mt);
4892 pivots = ma_pivots(mn, mt);
4893 if (unlikely(ma_dead_node(mn))) {
4894 mas_rewalk(mas, index);
4898 if (offset == mt_pivots[mt])
4901 pivot = pivots[offset];
4903 if (unlikely(ma_dead_node(mn))) {
4904 mas_rewalk(mas, index);
4908 while (offset && ((!mas_slot(mas, slots, offset) && pivot >= limit) ||
4910 pivot = pivots[--offset];
4912 min = mas_safe_min(mas, pivots, offset);
4913 entry = mas_slot(mas, slots, offset);
4914 if (unlikely(ma_dead_node(mn))) {
4915 mas_rewalk(mas, index);
4919 if (likely(entry)) {
4920 mas->offset = offset;
4927 static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min)
4931 if (mas->index < min) {
4932 mas->index = mas->last = min;
4933 mas->node = MAS_NONE;
4937 while (likely(!mas_is_none(mas))) {
4938 entry = mas_prev_nentry(mas, min, mas->index);
4939 if (unlikely(mas->last < min))
4945 if (unlikely(mas_prev_node(mas, min))) {
4946 mas_rewalk(mas, mas->index);
4955 mas->index = mas->last = min;
4960 * mas_rev_awalk() - Internal function. Reverse allocation walk. Find the
4961 * highest gap address of a given size in a given node and descend.
4962 * @mas: The maple state
4963 * @size: The needed size.
4965 * Return: True if found in a leaf, false otherwise.
4968 static bool mas_rev_awalk(struct ma_state *mas, unsigned long size,
4969 unsigned long *gap_min, unsigned long *gap_max)
4971 enum maple_type type = mte_node_type(mas->node);
4972 struct maple_node *node = mas_mn(mas);
4973 unsigned long *pivots, *gaps;
4975 unsigned long gap = 0;
4976 unsigned long max, min;
4977 unsigned char offset;
4979 if (unlikely(mas_is_err(mas)))
4982 if (ma_is_dense(type)) {
4984 mas->offset = (unsigned char)(mas->index - mas->min);
4988 pivots = ma_pivots(node, type);
4989 slots = ma_slots(node, type);
4990 gaps = ma_gaps(node, type);
4991 offset = mas->offset;
4992 min = mas_safe_min(mas, pivots, offset);
4993 /* Skip out of bounds. */
4994 while (mas->last < min)
4995 min = mas_safe_min(mas, pivots, --offset);
4997 max = mas_safe_pivot(mas, pivots, offset, type);
4998 while (mas->index <= max) {
5002 else if (!mas_slot(mas, slots, offset))
5003 gap = max - min + 1;
5006 if ((size <= gap) && (size <= mas->last - min + 1))
5010 /* Skip the next slot, it cannot be a gap. */
5015 max = pivots[offset];
5016 min = mas_safe_min(mas, pivots, offset);
5026 min = mas_safe_min(mas, pivots, offset);
5029 if (unlikely((mas->index > max) || (size - 1 > max - mas->index)))
5032 if (unlikely(ma_is_leaf(type))) {
5033 mas->offset = offset;
5035 *gap_max = min + gap - 1;
5039 /* descend, only happens under lock. */
5040 mas->node = mas_slot(mas, slots, offset);
5043 mas->offset = mas_data_end(mas);
5047 if (!mte_is_root(mas->node))
5051 mas_set_err(mas, -EBUSY);
5055 static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
5057 enum maple_type type = mte_node_type(mas->node);
5058 unsigned long pivot, min, gap = 0;
5059 unsigned char offset, data_end;
5060 unsigned long *gaps, *pivots;
5062 struct maple_node *node;
5065 if (ma_is_dense(type)) {
5066 mas->offset = (unsigned char)(mas->index - mas->min);
5071 pivots = ma_pivots(node, type);
5072 slots = ma_slots(node, type);
5073 gaps = ma_gaps(node, type);
5074 offset = mas->offset;
5075 min = mas_safe_min(mas, pivots, offset);
5076 data_end = ma_data_end(node, type, pivots, mas->max);
5077 for (; offset <= data_end; offset++) {
5078 pivot = mas_logical_pivot(mas, pivots, offset, type);
5080 /* Not within lower bounds */
5081 if (mas->index > pivot)
5086 else if (!mas_slot(mas, slots, offset))
5087 gap = min(pivot, mas->last) - max(mas->index, min) + 1;
5092 if (ma_is_leaf(type)) {
5096 if (mas->index <= pivot) {
5097 mas->node = mas_slot(mas, slots, offset);
5106 if (mas->last <= pivot) {
5107 mas_set_err(mas, -EBUSY);
5112 if (mte_is_root(mas->node))
5115 mas->offset = offset;
5120 * mas_walk() - Search for @mas->index in the tree.
5121 * @mas: The maple state.
5123 * mas->index and mas->last will be set to the range if there is a value. If
5124 * mas->node is MAS_NONE, reset to MAS_START.
5126 * Return: the entry at the location or %NULL.
5128 void *mas_walk(struct ma_state *mas)
5133 entry = mas_state_walk(mas);
5134 if (mas_is_start(mas))
5137 if (mas_is_ptr(mas)) {
5142 mas->last = ULONG_MAX;
5147 if (mas_is_none(mas)) {
5149 mas->last = ULONG_MAX;
5154 EXPORT_SYMBOL_GPL(mas_walk);
5156 static inline bool mas_rewind_node(struct ma_state *mas)
5161 if (mte_is_root(mas->node)) {
5171 mas->offset = --slot;
5176 * mas_skip_node() - Internal function. Skip over a node.
5177 * @mas: The maple state.
5179 * Return: true if there is another node, false otherwise.
5181 static inline bool mas_skip_node(struct ma_state *mas)
5183 if (mas_is_err(mas))
5187 if (mte_is_root(mas->node)) {
5188 if (mas->offset >= mas_data_end(mas)) {
5189 mas_set_err(mas, -EBUSY);
5195 } while (mas->offset >= mas_data_end(mas));
5202 * mas_awalk() - Allocation walk. Search from low address to high, for a gap of
5204 * @mas: The maple state
5205 * @size: The size of the gap required
5207 * Search between @mas->index and @mas->last for a gap of @size.
5209 static inline void mas_awalk(struct ma_state *mas, unsigned long size)
5211 struct maple_enode *last = NULL;
5214 * There are 4 options:
5215 * go to child (descend)
5216 * go back to parent (ascend)
5217 * no gap found. (return, slot == MAPLE_NODE_SLOTS)
5218 * found the gap. (return, slot != MAPLE_NODE_SLOTS)
5220 while (!mas_is_err(mas) && !mas_anode_descend(mas, size)) {
5221 if (last == mas->node)
5229 * mas_fill_gap() - Fill a located gap with @entry.
5230 * @mas: The maple state
5231 * @entry: The value to store
5232 * @slot: The offset into the node to store the @entry
5233 * @size: The size of the entry
5234 * @index: The start location
5236 static inline void mas_fill_gap(struct ma_state *mas, void *entry,
5237 unsigned char slot, unsigned long size, unsigned long *index)
5239 MA_WR_STATE(wr_mas, mas, entry);
5240 unsigned char pslot = mte_parent_slot(mas->node);
5241 struct maple_enode *mn = mas->node;
5242 unsigned long *pivots;
5243 enum maple_type ptype;
5245 * mas->index is the start address for the search
5246 * which may no longer be needed.
5247 * mas->last is the end address for the search
5250 *index = mas->index;
5251 mas->last = mas->index + size - 1;
5254 * It is possible that using mas->max and mas->min to correctly
5255 * calculate the index and last will cause an issue in the gap
5256 * calculation, so fix the ma_state here
5259 ptype = mte_node_type(mas->node);
5260 pivots = ma_pivots(mas_mn(mas), ptype);
5261 mas->max = mas_safe_pivot(mas, pivots, pslot, ptype);
5262 mas->min = mas_safe_min(mas, pivots, pslot);
5265 mas_wr_store_entry(&wr_mas);
5269 * mas_sparse_area() - Internal function. Return upper or lower limit when
5270 * searching for a gap in an empty tree.
5271 * @mas: The maple state
5272 * @min: the minimum range
5273 * @max: The maximum range
5274 * @size: The size of the gap
5275 * @fwd: Searching forward or back
5277 static inline void mas_sparse_area(struct ma_state *mas, unsigned long min,
5278 unsigned long max, unsigned long size, bool fwd)
5280 unsigned long start = 0;
5282 if (!unlikely(mas_is_none(mas)))
5291 mas->last = start + size - 1;
5299 * mas_empty_area() - Get the lowest address within the range that is
5300 * sufficient for the size requested.
5301 * @mas: The maple state
5302 * @min: The lowest value of the range
5303 * @max: The highest value of the range
5304 * @size: The size needed
5306 int mas_empty_area(struct ma_state *mas, unsigned long min,
5307 unsigned long max, unsigned long size)
5309 unsigned char offset;
5310 unsigned long *pivots;
5316 if (mas_is_start(mas))
5318 else if (mas->offset >= 2)
5320 else if (!mas_skip_node(mas))
5324 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5325 mas_sparse_area(mas, min, max, size, true);
5329 /* The start of the window can only be within these values */
5332 mas_awalk(mas, size);
5334 if (unlikely(mas_is_err(mas)))
5335 return xa_err(mas->node);
5337 offset = mas->offset;
5338 if (unlikely(offset == MAPLE_NODE_SLOTS))
5341 mt = mte_node_type(mas->node);
5342 pivots = ma_pivots(mas_mn(mas), mt);
5344 mas->min = pivots[offset - 1] + 1;
5346 if (offset < mt_pivots[mt])
5347 mas->max = pivots[offset];
5349 if (mas->index < mas->min)
5350 mas->index = mas->min;
5352 mas->last = mas->index + size - 1;
5355 EXPORT_SYMBOL_GPL(mas_empty_area);
5358 * mas_empty_area_rev() - Get the highest address within the range that is
5359 * sufficient for the size requested.
5360 * @mas: The maple state
5361 * @min: The lowest value of the range
5362 * @max: The highest value of the range
5363 * @size: The size needed
5365 int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
5366 unsigned long max, unsigned long size)
5368 struct maple_enode *last = mas->node;
5373 if (mas_is_start(mas)) {
5375 mas->offset = mas_data_end(mas);
5376 } else if (mas->offset >= 2) {
5378 } else if (!mas_rewind_node(mas)) {
5383 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5384 mas_sparse_area(mas, min, max, size, false);
5388 /* The start of the window can only be within these values. */
5392 while (!mas_rev_awalk(mas, size, &min, &max)) {
5393 if (last == mas->node) {
5394 if (!mas_rewind_node(mas))
5401 if (mas_is_err(mas))
5402 return xa_err(mas->node);
5404 if (unlikely(mas->offset == MAPLE_NODE_SLOTS))
5407 /* Trim the upper limit to the max. */
5408 if (max <= mas->last)
5411 mas->index = mas->last - size + 1;
5414 EXPORT_SYMBOL_GPL(mas_empty_area_rev);
5416 static inline int mas_alloc(struct ma_state *mas, void *entry,
5417 unsigned long size, unsigned long *index)
5422 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5423 mas_root_expand(mas, entry);
5424 if (mas_is_err(mas))
5425 return xa_err(mas->node);
5428 return mte_pivot(mas->node, 0);
5429 return mte_pivot(mas->node, 1);
5432 /* Must be walking a tree. */
5433 mas_awalk(mas, size);
5434 if (mas_is_err(mas))
5435 return xa_err(mas->node);
5437 if (mas->offset == MAPLE_NODE_SLOTS)
5441 * At this point, mas->node points to the right node and we have an
5442 * offset that has a sufficient gap.
5446 min = mte_pivot(mas->node, mas->offset - 1) + 1;
5448 if (mas->index < min)
5451 mas_fill_gap(mas, entry, mas->offset, size, index);
5458 static inline int mas_rev_alloc(struct ma_state *mas, unsigned long min,
5459 unsigned long max, void *entry,
5460 unsigned long size, unsigned long *index)
5464 ret = mas_empty_area_rev(mas, min, max, size);
5468 if (mas_is_err(mas))
5469 return xa_err(mas->node);
5471 if (mas->offset == MAPLE_NODE_SLOTS)
5474 mas_fill_gap(mas, entry, mas->offset, size, index);
5482 * mte_dead_leaves() - Mark all leaves of a node as dead.
5483 * @mas: The maple state
5484 * @slots: Pointer to the slot array
5485 * @type: The maple node type
5487 * Must hold the write lock.
5489 * Return: The number of leaves marked as dead.
5492 unsigned char mte_dead_leaves(struct maple_enode *enode, struct maple_tree *mt,
5495 struct maple_node *node;
5496 enum maple_type type;
5500 for (offset = 0; offset < mt_slot_count(enode); offset++) {
5501 entry = mt_slot(mt, slots, offset);
5502 type = mte_node_type(entry);
5503 node = mte_to_node(entry);
5504 /* Use both node and type to catch LE & BE metadata */
5508 mte_set_node_dead(entry);
5510 rcu_assign_pointer(slots[offset], node);
5517 * mte_dead_walk() - Walk down a dead tree to just before the leaves
5518 * @enode: The maple encoded node
5519 * @offset: The starting offset
5521 * Note: This can only be used from the RCU callback context.
5523 static void __rcu **mte_dead_walk(struct maple_enode **enode, unsigned char offset)
5525 struct maple_node *node, *next;
5526 void __rcu **slots = NULL;
5528 next = mte_to_node(*enode);
5530 *enode = ma_enode_ptr(next);
5531 node = mte_to_node(*enode);
5532 slots = ma_slots(node, node->type);
5533 next = rcu_dereference_protected(slots[offset],
5534 lock_is_held(&rcu_callback_map));
5536 } while (!ma_is_leaf(next->type));
5542 * mt_free_walk() - Walk & free a tree in the RCU callback context
5543 * @head: The RCU head that's within the node.
5545 * Note: This can only be used from the RCU callback context.
5547 static void mt_free_walk(struct rcu_head *head)
5550 struct maple_node *node, *start;
5551 struct maple_enode *enode;
5552 unsigned char offset;
5553 enum maple_type type;
5555 node = container_of(head, struct maple_node, rcu);
5557 if (ma_is_leaf(node->type))
5561 enode = mt_mk_node(node, node->type);
5562 slots = mte_dead_walk(&enode, 0);
5563 node = mte_to_node(enode);
5565 mt_free_bulk(node->slot_len, slots);
5566 offset = node->parent_slot + 1;
5567 enode = node->piv_parent;
5568 if (mte_to_node(enode) == node)
5571 type = mte_node_type(enode);
5572 slots = ma_slots(mte_to_node(enode), type);
5573 if ((offset < mt_slots[type]) &&
5574 rcu_dereference_protected(slots[offset],
5575 lock_is_held(&rcu_callback_map)))
5576 slots = mte_dead_walk(&enode, offset);
5577 node = mte_to_node(enode);
5578 } while ((node != start) || (node->slot_len < offset));
5580 slots = ma_slots(node, node->type);
5581 mt_free_bulk(node->slot_len, slots);
5584 mt_free_rcu(&node->rcu);
5587 static inline void __rcu **mte_destroy_descend(struct maple_enode **enode,
5588 struct maple_tree *mt, struct maple_enode *prev, unsigned char offset)
5590 struct maple_node *node;
5591 struct maple_enode *next = *enode;
5592 void __rcu **slots = NULL;
5593 enum maple_type type;
5594 unsigned char next_offset = 0;
5598 node = mte_to_node(*enode);
5599 type = mte_node_type(*enode);
5600 slots = ma_slots(node, type);
5601 next = mt_slot_locked(mt, slots, next_offset);
5602 if ((mte_dead_node(next)))
5603 next = mt_slot_locked(mt, slots, ++next_offset);
5605 mte_set_node_dead(*enode);
5607 node->piv_parent = prev;
5608 node->parent_slot = offset;
5609 offset = next_offset;
5612 } while (!mte_is_leaf(next));
5617 static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt,
5621 struct maple_node *node = mte_to_node(enode);
5622 struct maple_enode *start;
5624 if (mte_is_leaf(enode)) {
5625 node->type = mte_node_type(enode);
5630 slots = mte_destroy_descend(&enode, mt, start, 0);
5631 node = mte_to_node(enode); // Updated in the above call.
5633 enum maple_type type;
5634 unsigned char offset;
5635 struct maple_enode *parent, *tmp;
5637 node->slot_len = mte_dead_leaves(enode, mt, slots);
5639 mt_free_bulk(node->slot_len, slots);
5640 offset = node->parent_slot + 1;
5641 enode = node->piv_parent;
5642 if (mte_to_node(enode) == node)
5645 type = mte_node_type(enode);
5646 slots = ma_slots(mte_to_node(enode), type);
5647 if (offset >= mt_slots[type])
5650 tmp = mt_slot_locked(mt, slots, offset);
5651 if (mte_node_type(tmp) && mte_to_node(tmp)) {
5654 slots = mte_destroy_descend(&enode, mt, parent, offset);
5657 node = mte_to_node(enode);
5658 } while (start != enode);
5660 node = mte_to_node(enode);
5661 node->slot_len = mte_dead_leaves(enode, mt, slots);
5663 mt_free_bulk(node->slot_len, slots);
5667 mt_free_rcu(&node->rcu);
5669 mt_clear_meta(mt, node, node->type);
5673 * mte_destroy_walk() - Free a tree or sub-tree.
5674 * @enode: the encoded maple node (maple_enode) to start
5675 * @mt: the tree to free - needed for node types.
5677 * Must hold the write lock.
5679 static inline void mte_destroy_walk(struct maple_enode *enode,
5680 struct maple_tree *mt)
5682 struct maple_node *node = mte_to_node(enode);
5684 if (mt_in_rcu(mt)) {
5685 mt_destroy_walk(enode, mt, false);
5686 call_rcu(&node->rcu, mt_free_walk);
5688 mt_destroy_walk(enode, mt, true);
5692 static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
5694 if (unlikely(mas_is_paused(wr_mas->mas)))
5695 mas_reset(wr_mas->mas);
5697 if (!mas_is_start(wr_mas->mas)) {
5698 if (mas_is_none(wr_mas->mas)) {
5699 mas_reset(wr_mas->mas);
5701 wr_mas->r_max = wr_mas->mas->max;
5702 wr_mas->type = mte_node_type(wr_mas->mas->node);
5703 if (mas_is_span_wr(wr_mas))
5704 mas_reset(wr_mas->mas);
5712 * mas_store() - Store an @entry.
5713 * @mas: The maple state.
5714 * @entry: The entry to store.
5716 * The @mas->index and @mas->last is used to set the range for the @entry.
5717 * Note: The @mas should have pre-allocated entries to ensure there is memory to
5718 * store the entry. Please see mas_expected_entries()/mas_destroy() for more details.
5720 * Return: the first entry between mas->index and mas->last or %NULL.
5722 void *mas_store(struct ma_state *mas, void *entry)
5724 MA_WR_STATE(wr_mas, mas, entry);
5726 trace_ma_write(__func__, mas, 0, entry);
5727 #ifdef CONFIG_DEBUG_MAPLE_TREE
5728 if (mas->index > mas->last)
5729 pr_err("Error %lu > %lu %p\n", mas->index, mas->last, entry);
5730 MT_BUG_ON(mas->tree, mas->index > mas->last);
5731 if (mas->index > mas->last) {
5732 mas_set_err(mas, -EINVAL);
5739 * Storing is the same operation as insert with the added caveat that it
5740 * can overwrite entries. Although this seems simple enough, one may
5741 * want to examine what happens if a single store operation was to
5742 * overwrite multiple entries within a self-balancing B-Tree.
5744 mas_wr_store_setup(&wr_mas);
5745 mas_wr_store_entry(&wr_mas);
5746 return wr_mas.content;
5748 EXPORT_SYMBOL_GPL(mas_store);
5751 * mas_store_gfp() - Store a value into the tree.
5752 * @mas: The maple state
5753 * @entry: The entry to store
5754 * @gfp: The GFP_FLAGS to use for allocations if necessary.
5756 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
5759 int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp)
5761 MA_WR_STATE(wr_mas, mas, entry);
5763 mas_wr_store_setup(&wr_mas);
5764 trace_ma_write(__func__, mas, 0, entry);
5766 mas_wr_store_entry(&wr_mas);
5767 if (unlikely(mas_nomem(mas, gfp)))
5770 if (unlikely(mas_is_err(mas)))
5771 return xa_err(mas->node);
5775 EXPORT_SYMBOL_GPL(mas_store_gfp);
5778 * mas_store_prealloc() - Store a value into the tree using memory
5779 * preallocated in the maple state.
5780 * @mas: The maple state
5781 * @entry: The entry to store.
5783 void mas_store_prealloc(struct ma_state *mas, void *entry)
5785 MA_WR_STATE(wr_mas, mas, entry);
5787 mas_wr_store_setup(&wr_mas);
5788 trace_ma_write(__func__, mas, 0, entry);
5789 mas_wr_store_entry(&wr_mas);
5790 BUG_ON(mas_is_err(mas));
5793 EXPORT_SYMBOL_GPL(mas_store_prealloc);
5796 * mas_preallocate() - Preallocate enough nodes for a store operation
5797 * @mas: The maple state
5798 * @gfp: The GFP_FLAGS to use for allocations.
5800 * Return: 0 on success, -ENOMEM if memory could not be allocated.
5802 int mas_preallocate(struct ma_state *mas, gfp_t gfp)
5806 mas_node_count_gfp(mas, 1 + mas_mt_height(mas) * 3, gfp);
5807 mas->mas_flags |= MA_STATE_PREALLOC;
5808 if (likely(!mas_is_err(mas)))
5811 mas_set_alloc_req(mas, 0);
5812 ret = xa_err(mas->node);
5820 * mas_destroy() - destroy a maple state.
5821 * @mas: The maple state
5823 * Upon completion, check the left-most node and rebalance against the node to
5824 * the right if necessary. Frees any allocated nodes associated with this maple
5827 void mas_destroy(struct ma_state *mas)
5829 struct maple_alloc *node;
5830 unsigned long total;
5833 * When using mas_for_each() to insert an expected number of elements,
5834 * it is possible that the number inserted is less than the expected
5835 * number. To fix an invalid final node, a check is performed here to
5836 * rebalance the previous node with the final node.
5838 if (mas->mas_flags & MA_STATE_REBALANCE) {
5841 if (mas_is_start(mas))
5844 mtree_range_walk(mas);
5845 end = mas_data_end(mas) + 1;
5846 if (end < mt_min_slot_count(mas->node) - 1)
5847 mas_destroy_rebalance(mas, end);
5849 mas->mas_flags &= ~MA_STATE_REBALANCE;
5851 mas->mas_flags &= ~(MA_STATE_BULK|MA_STATE_PREALLOC);
5853 total = mas_allocated(mas);
5856 mas->alloc = node->slot[0];
5857 if (node->node_count > 1) {
5858 size_t count = node->node_count - 1;
5860 mt_free_bulk(count, (void __rcu **)&node->slot[1]);
5863 kmem_cache_free(maple_node_cache, node);
5869 EXPORT_SYMBOL_GPL(mas_destroy);
5872 * mas_expected_entries() - Set the expected number of entries that will be inserted.
5873 * @mas: The maple state
5874 * @nr_entries: The number of expected entries.
5876 * This will attempt to pre-allocate enough nodes to store the expected number
5877 * of entries. The allocations will occur using the bulk allocator interface
5878 * for speed. Please call mas_destroy() on the @mas after inserting the entries
5879 * to ensure any unused nodes are freed.
5881 * Return: 0 on success, -ENOMEM if memory could not be allocated.
5883 int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
5885 int nonleaf_cap = MAPLE_ARANGE64_SLOTS - 2;
5886 struct maple_enode *enode = mas->node;
5891 * Sometimes it is necessary to duplicate a tree to a new tree, such as
5892 * forking a process and duplicating the VMAs from one tree to a new
5893 * tree. When such a situation arises, it is known that the new tree is
5894 * not going to be used until the entire tree is populated. For
5895 * performance reasons, it is best to use a bulk load with RCU disabled.
5896 * This allows for optimistic splitting that favours the left and reuse
5897 * of nodes during the operation.
5900 /* Optimize splitting for bulk insert in-order */
5901 mas->mas_flags |= MA_STATE_BULK;
5904 * Avoid overflow, assume a gap between each entry and a trailing null.
5905 * If this is wrong, it just means allocation can happen during
5906 * insertion of entries.
5908 nr_nodes = max(nr_entries, nr_entries * 2 + 1);
5909 if (!mt_is_alloc(mas->tree))
5910 nonleaf_cap = MAPLE_RANGE64_SLOTS - 2;
5912 /* Leaves; reduce slots to keep space for expansion */
5913 nr_nodes = DIV_ROUND_UP(nr_nodes, MAPLE_RANGE64_SLOTS - 2);
5914 /* Internal nodes */
5915 nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
5916 /* Add working room for split (2 nodes) + new parents */
5917 mas_node_count(mas, nr_nodes + 3);
5919 /* Detect if allocations run out */
5920 mas->mas_flags |= MA_STATE_PREALLOC;
5922 if (!mas_is_err(mas))
5925 ret = xa_err(mas->node);
5931 EXPORT_SYMBOL_GPL(mas_expected_entries);
5934 * mas_next() - Get the next entry.
5935 * @mas: The maple state
5936 * @max: The maximum index to check.
5938 * Returns the next entry after @mas->index.
5939 * Must hold rcu_read_lock or the write lock.
5940 * Can return the zero entry.
5942 * Return: The next entry or %NULL
5944 void *mas_next(struct ma_state *mas, unsigned long max)
5946 if (mas_is_none(mas) || mas_is_paused(mas))
5947 mas->node = MAS_START;
5949 if (mas_is_start(mas))
5950 mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
5952 if (mas_is_ptr(mas)) {
5955 mas->last = ULONG_MAX;
5960 if (mas->last == ULONG_MAX)
5963 /* Retries on dead nodes handled by mas_next_entry */
5964 return mas_next_entry(mas, max);
5966 EXPORT_SYMBOL_GPL(mas_next);
5969 * mt_next() - get the next value in the maple tree
5970 * @mt: The maple tree
5971 * @index: The start index
5972 * @max: The maximum index to check
5974 * Return: The entry at @index or higher, or %NULL if nothing is found.
5976 void *mt_next(struct maple_tree *mt, unsigned long index, unsigned long max)
5979 MA_STATE(mas, mt, index, index);
5982 entry = mas_next(&mas, max);
5986 EXPORT_SYMBOL_GPL(mt_next);
5989 * mas_prev() - Get the previous entry
5990 * @mas: The maple state
5991 * @min: The minimum value to check.
5993 * Must hold rcu_read_lock or the write lock.
5994 * Will reset mas to MAS_START if the node is MAS_NONE. Will stop on not
5997 * Return: the previous value or %NULL.
5999 void *mas_prev(struct ma_state *mas, unsigned long min)
6002 /* Nothing comes before 0 */
6004 mas->node = MAS_NONE;
6008 if (unlikely(mas_is_ptr(mas)))
6011 if (mas_is_none(mas) || mas_is_paused(mas))
6012 mas->node = MAS_START;
6014 if (mas_is_start(mas)) {
6020 if (mas_is_ptr(mas)) {
6026 mas->index = mas->last = 0;
6027 return mas_root_locked(mas);
6029 return mas_prev_entry(mas, min);
6031 EXPORT_SYMBOL_GPL(mas_prev);
6034 * mt_prev() - get the previous value in the maple tree
6035 * @mt: The maple tree
6036 * @index: The start index
6037 * @min: The minimum index to check
6039 * Return: The entry at @index or lower, or %NULL if nothing is found.
6041 void *mt_prev(struct maple_tree *mt, unsigned long index, unsigned long min)
6044 MA_STATE(mas, mt, index, index);
6047 entry = mas_prev(&mas, min);
6051 EXPORT_SYMBOL_GPL(mt_prev);
6054 * mas_pause() - Pause a mas_find/mas_for_each to drop the lock.
6055 * @mas: The maple state to pause
6057 * Some users need to pause a walk and drop the lock they're holding in
6058 * order to yield to a higher priority thread or carry out an operation
6059 * on an entry. Those users should call this function before they drop
6060 * the lock. It resets the @mas to be suitable for the next iteration
6061 * of the loop after the user has reacquired the lock. If most entries
6062 * found during a walk require you to call mas_pause(), the mt_for_each()
6063 * iterator may be more appropriate.
6066 void mas_pause(struct ma_state *mas)
6068 mas->node = MAS_PAUSE;
6070 EXPORT_SYMBOL_GPL(mas_pause);
6073 * mas_find() - On the first call, find the entry at or after mas->index up to
6074 * %max. Otherwise, find the entry after mas->index.
6075 * @mas: The maple state
6076 * @max: The maximum value to check.
6078 * Must hold rcu_read_lock or the write lock.
6079 * If an entry exists, last and index are updated accordingly.
6080 * May set @mas->node to MAS_NONE.
6082 * Return: The entry or %NULL.
6084 void *mas_find(struct ma_state *mas, unsigned long max)
6086 if (unlikely(mas_is_paused(mas))) {
6087 if (unlikely(mas->last == ULONG_MAX)) {
6088 mas->node = MAS_NONE;
6091 mas->node = MAS_START;
6092 mas->index = ++mas->last;
6095 if (unlikely(mas_is_none(mas)))
6096 mas->node = MAS_START;
6098 if (unlikely(mas_is_start(mas))) {
6099 /* First run or continue */
6102 if (mas->index > max)
6105 entry = mas_walk(mas);
6110 if (unlikely(!mas_searchable(mas)))
6113 /* Retries on dead nodes handled by mas_next_entry */
6114 return mas_next_entry(mas, max);
6116 EXPORT_SYMBOL_GPL(mas_find);
6119 * mas_find_rev: On the first call, find the first non-null entry at or below
6120 * mas->index down to %min. Otherwise find the first non-null entry below
6121 * mas->index down to %min.
6122 * @mas: The maple state
6123 * @min: The minimum value to check.
6125 * Must hold rcu_read_lock or the write lock.
6126 * If an entry exists, last and index are updated accordingly.
6127 * May set @mas->node to MAS_NONE.
6129 * Return: The entry or %NULL.
6131 void *mas_find_rev(struct ma_state *mas, unsigned long min)
6133 if (unlikely(mas_is_paused(mas))) {
6134 if (unlikely(mas->last == ULONG_MAX)) {
6135 mas->node = MAS_NONE;
6138 mas->node = MAS_START;
6139 mas->last = --mas->index;
6142 if (unlikely(mas_is_start(mas))) {
6143 /* First run or continue */
6146 if (mas->index < min)
6149 entry = mas_walk(mas);
6154 if (unlikely(!mas_searchable(mas)))
6157 if (mas->index < min)
6160 /* Retries on dead nodes handled by mas_prev_entry */
6161 return mas_prev_entry(mas, min);
6163 EXPORT_SYMBOL_GPL(mas_find_rev);
6166 * mas_erase() - Find the range in which index resides and erase the entire
6168 * @mas: The maple state
6170 * Must hold the write lock.
6171 * Searches for @mas->index, sets @mas->index and @mas->last to the range and
6172 * erases that range.
6174 * Return: the entry that was erased or %NULL, @mas->index and @mas->last are updated.
6176 void *mas_erase(struct ma_state *mas)
6179 MA_WR_STATE(wr_mas, mas, NULL);
6181 if (mas_is_none(mas) || mas_is_paused(mas))
6182 mas->node = MAS_START;
6184 /* Retry unnecessary when holding the write lock. */
6185 entry = mas_state_walk(mas);
6190 /* Must reset to ensure spanning writes of last slot are detected */
6192 mas_wr_store_setup(&wr_mas);
6193 mas_wr_store_entry(&wr_mas);
6194 if (mas_nomem(mas, GFP_KERNEL))
6199 EXPORT_SYMBOL_GPL(mas_erase);
6202 * mas_nomem() - Check if there was an error allocating and do the allocation
6203 * if necessary If there are allocations, then free them.
6204 * @mas: The maple state
6205 * @gfp: The GFP_FLAGS to use for allocations
6206 * Return: true on allocation, false otherwise.
6208 bool mas_nomem(struct ma_state *mas, gfp_t gfp)
6209 __must_hold(mas->tree->lock)
6211 if (likely(mas->node != MA_ERROR(-ENOMEM))) {
6216 if (gfpflags_allow_blocking(gfp) && !mt_external_lock(mas->tree)) {
6217 mtree_unlock(mas->tree);
6218 mas_alloc_nodes(mas, gfp);
6219 mtree_lock(mas->tree);
6221 mas_alloc_nodes(mas, gfp);
6224 if (!mas_allocated(mas))
6227 mas->node = MAS_START;
6231 void __init maple_tree_init(void)
6233 maple_node_cache = kmem_cache_create("maple_node",
6234 sizeof(struct maple_node), sizeof(struct maple_node),
6239 * mtree_load() - Load a value stored in a maple tree
6240 * @mt: The maple tree
6241 * @index: The index to load
6243 * Return: the entry or %NULL
6245 void *mtree_load(struct maple_tree *mt, unsigned long index)
6247 MA_STATE(mas, mt, index, index);
6250 trace_ma_read(__func__, &mas);
6253 entry = mas_start(&mas);
6254 if (unlikely(mas_is_none(&mas)))
6257 if (unlikely(mas_is_ptr(&mas))) {
6264 entry = mtree_lookup_walk(&mas);
6265 if (!entry && unlikely(mas_is_start(&mas)))
6269 if (xa_is_zero(entry))
6274 EXPORT_SYMBOL(mtree_load);
6277 * mtree_store_range() - Store an entry at a given range.
6278 * @mt: The maple tree
6279 * @index: The start of the range
6280 * @last: The end of the range
6281 * @entry: The entry to store
6282 * @gfp: The GFP_FLAGS to use for allocations
6284 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
6287 int mtree_store_range(struct maple_tree *mt, unsigned long index,
6288 unsigned long last, void *entry, gfp_t gfp)
6290 MA_STATE(mas, mt, index, last);
6291 MA_WR_STATE(wr_mas, &mas, entry);
6293 trace_ma_write(__func__, &mas, 0, entry);
6294 if (WARN_ON_ONCE(xa_is_advanced(entry)))
6302 mas_wr_store_entry(&wr_mas);
6303 if (mas_nomem(&mas, gfp))
6307 if (mas_is_err(&mas))
6308 return xa_err(mas.node);
6312 EXPORT_SYMBOL(mtree_store_range);
6315 * mtree_store() - Store an entry at a given index.
6316 * @mt: The maple tree
6317 * @index: The index to store the value
6318 * @entry: The entry to store
6319 * @gfp: The GFP_FLAGS to use for allocations
6321 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
6324 int mtree_store(struct maple_tree *mt, unsigned long index, void *entry,
6327 return mtree_store_range(mt, index, index, entry, gfp);
6329 EXPORT_SYMBOL(mtree_store);
6332 * mtree_insert_range() - Insert an entry at a give range if there is no value.
6333 * @mt: The maple tree
6334 * @first: The start of the range
6335 * @last: The end of the range
6336 * @entry: The entry to store
6337 * @gfp: The GFP_FLAGS to use for allocations.
6339 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
6340 * request, -ENOMEM if memory could not be allocated.
6342 int mtree_insert_range(struct maple_tree *mt, unsigned long first,
6343 unsigned long last, void *entry, gfp_t gfp)
6345 MA_STATE(ms, mt, first, last);
6347 if (WARN_ON_ONCE(xa_is_advanced(entry)))
6355 mas_insert(&ms, entry);
6356 if (mas_nomem(&ms, gfp))
6360 if (mas_is_err(&ms))
6361 return xa_err(ms.node);
6365 EXPORT_SYMBOL(mtree_insert_range);
6368 * mtree_insert() - Insert an entry at a give index if there is no value.
6369 * @mt: The maple tree
6370 * @index : The index to store the value
6371 * @entry: The entry to store
6372 * @gfp: The FGP_FLAGS to use for allocations.
6374 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
6375 * request, -ENOMEM if memory could not be allocated.
6377 int mtree_insert(struct maple_tree *mt, unsigned long index, void *entry,
6380 return mtree_insert_range(mt, index, index, entry, gfp);
6382 EXPORT_SYMBOL(mtree_insert);
6384 int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
6385 void *entry, unsigned long size, unsigned long min,
6386 unsigned long max, gfp_t gfp)
6390 MA_STATE(mas, mt, min, max - size);
6391 if (!mt_is_alloc(mt))
6394 if (WARN_ON_ONCE(mt_is_reserved(entry)))
6410 mas.last = max - size;
6411 ret = mas_alloc(&mas, entry, size, startp);
6412 if (mas_nomem(&mas, gfp))
6418 EXPORT_SYMBOL(mtree_alloc_range);
6420 int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
6421 void *entry, unsigned long size, unsigned long min,
6422 unsigned long max, gfp_t gfp)
6426 MA_STATE(mas, mt, min, max - size);
6427 if (!mt_is_alloc(mt))
6430 if (WARN_ON_ONCE(mt_is_reserved(entry)))
6444 ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
6445 if (mas_nomem(&mas, gfp))
6451 EXPORT_SYMBOL(mtree_alloc_rrange);
6454 * mtree_erase() - Find an index and erase the entire range.
6455 * @mt: The maple tree
6456 * @index: The index to erase
6458 * Erasing is the same as a walk to an entry then a store of a NULL to that
6459 * ENTIRE range. In fact, it is implemented as such using the advanced API.
6461 * Return: The entry stored at the @index or %NULL
6463 void *mtree_erase(struct maple_tree *mt, unsigned long index)
6467 MA_STATE(mas, mt, index, index);
6468 trace_ma_op(__func__, &mas);
6471 entry = mas_erase(&mas);
6476 EXPORT_SYMBOL(mtree_erase);
6479 * __mt_destroy() - Walk and free all nodes of a locked maple tree.
6480 * @mt: The maple tree
6482 * Note: Does not handle locking.
6484 void __mt_destroy(struct maple_tree *mt)
6486 void *root = mt_root_locked(mt);
6488 rcu_assign_pointer(mt->ma_root, NULL);
6489 if (xa_is_node(root))
6490 mte_destroy_walk(root, mt);
6494 EXPORT_SYMBOL_GPL(__mt_destroy);
6497 * mtree_destroy() - Destroy a maple tree
6498 * @mt: The maple tree
6500 * Frees all resources used by the tree. Handles locking.
6502 void mtree_destroy(struct maple_tree *mt)
6508 EXPORT_SYMBOL(mtree_destroy);
6511 * mt_find() - Search from the start up until an entry is found.
6512 * @mt: The maple tree
6513 * @index: Pointer which contains the start location of the search
6514 * @max: The maximum value to check
6516 * Handles locking. @index will be incremented to one beyond the range.
6518 * Return: The entry at or after the @index or %NULL
6520 void *mt_find(struct maple_tree *mt, unsigned long *index, unsigned long max)
6522 MA_STATE(mas, mt, *index, *index);
6524 #ifdef CONFIG_DEBUG_MAPLE_TREE
6525 unsigned long copy = *index;
6528 trace_ma_read(__func__, &mas);
6535 entry = mas_state_walk(&mas);
6536 if (mas_is_start(&mas))
6539 if (unlikely(xa_is_zero(entry)))
6545 while (mas_searchable(&mas) && (mas.index < max)) {
6546 entry = mas_next_entry(&mas, max);
6547 if (likely(entry && !xa_is_zero(entry)))
6551 if (unlikely(xa_is_zero(entry)))
6555 if (likely(entry)) {
6556 *index = mas.last + 1;
6557 #ifdef CONFIG_DEBUG_MAPLE_TREE
6558 if ((*index) && (*index) <= copy)
6559 pr_err("index not increased! %lx <= %lx\n",
6561 MT_BUG_ON(mt, (*index) && ((*index) <= copy));
6567 EXPORT_SYMBOL(mt_find);
6570 * mt_find_after() - Search from the start up until an entry is found.
6571 * @mt: The maple tree
6572 * @index: Pointer which contains the start location of the search
6573 * @max: The maximum value to check
6575 * Handles locking, detects wrapping on index == 0
6577 * Return: The entry at or after the @index or %NULL
6579 void *mt_find_after(struct maple_tree *mt, unsigned long *index,
6585 return mt_find(mt, index, max);
6587 EXPORT_SYMBOL(mt_find_after);
6589 #ifdef CONFIG_DEBUG_MAPLE_TREE
6590 atomic_t maple_tree_tests_run;
6591 EXPORT_SYMBOL_GPL(maple_tree_tests_run);
6592 atomic_t maple_tree_tests_passed;
6593 EXPORT_SYMBOL_GPL(maple_tree_tests_passed);
6596 extern void kmem_cache_set_non_kernel(struct kmem_cache *, unsigned int);
6597 void mt_set_non_kernel(unsigned int val)
6599 kmem_cache_set_non_kernel(maple_node_cache, val);
6602 extern unsigned long kmem_cache_get_alloc(struct kmem_cache *);
6603 unsigned long mt_get_alloc_size(void)
6605 return kmem_cache_get_alloc(maple_node_cache);
6608 extern void kmem_cache_zero_nr_tallocated(struct kmem_cache *);
6609 void mt_zero_nr_tallocated(void)
6611 kmem_cache_zero_nr_tallocated(maple_node_cache);
6614 extern unsigned int kmem_cache_nr_tallocated(struct kmem_cache *);
6615 unsigned int mt_nr_tallocated(void)
6617 return kmem_cache_nr_tallocated(maple_node_cache);
6620 extern unsigned int kmem_cache_nr_allocated(struct kmem_cache *);
6621 unsigned int mt_nr_allocated(void)
6623 return kmem_cache_nr_allocated(maple_node_cache);
6627 * mas_dead_node() - Check if the maple state is pointing to a dead node.
6628 * @mas: The maple state
6629 * @index: The index to restore in @mas.
6631 * Used in test code.
6632 * Return: 1 if @mas has been reset to MAS_START, 0 otherwise.
6634 static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
6636 if (unlikely(!mas_searchable(mas) || mas_is_start(mas)))
6639 if (likely(!mte_dead_node(mas->node)))
6642 mas_rewalk(mas, index);
6646 void mt_cache_shrink(void)
6651 * mt_cache_shrink() - For testing, don't use this.
6653 * Certain testcases can trigger an OOM when combined with other memory
6654 * debugging configuration options. This function is used to reduce the
6655 * possibility of an out of memory even due to kmem_cache objects remaining
6656 * around for longer than usual.
6658 void mt_cache_shrink(void)
6660 kmem_cache_shrink(maple_node_cache);
6663 EXPORT_SYMBOL_GPL(mt_cache_shrink);
6665 #endif /* not defined __KERNEL__ */
6667 * mas_get_slot() - Get the entry in the maple state node stored at @offset.
6668 * @mas: The maple state
6669 * @offset: The offset into the slot array to fetch.
6671 * Return: The entry stored at @offset.
6673 static inline struct maple_enode *mas_get_slot(struct ma_state *mas,
6674 unsigned char offset)
6676 return mas_slot(mas, ma_slots(mas_mn(mas), mte_node_type(mas->node)),
6682 * mas_first_entry() - Go the first leaf and find the first entry.
6683 * @mas: the maple state.
6684 * @limit: the maximum index to check.
6685 * @*r_start: Pointer to set to the range start.
6687 * Sets mas->offset to the offset of the entry, r_start to the range minimum.
6689 * Return: The first entry or MAS_NONE.
6691 static inline void *mas_first_entry(struct ma_state *mas, struct maple_node *mn,
6692 unsigned long limit, enum maple_type mt)
6696 unsigned long *pivots;
6700 mas->index = mas->min;
6701 if (mas->index > limit)
6706 while (likely(!ma_is_leaf(mt))) {
6707 MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
6708 slots = ma_slots(mn, mt);
6709 entry = mas_slot(mas, slots, 0);
6710 pivots = ma_pivots(mn, mt);
6711 if (unlikely(ma_dead_node(mn)))
6716 mt = mte_node_type(mas->node);
6718 MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
6721 slots = ma_slots(mn, mt);
6722 entry = mas_slot(mas, slots, 0);
6723 if (unlikely(ma_dead_node(mn)))
6726 /* Slot 0 or 1 must be set */
6727 if (mas->index > limit)
6734 entry = mas_slot(mas, slots, 1);
6735 pivots = ma_pivots(mn, mt);
6736 if (unlikely(ma_dead_node(mn)))
6739 mas->index = pivots[0] + 1;
6740 if (mas->index > limit)
6747 if (likely(!ma_dead_node(mn)))
6748 mas->node = MAS_NONE;
6752 /* Depth first search, post-order */
6753 static void mas_dfs_postorder(struct ma_state *mas, unsigned long max)
6756 struct maple_enode *p = MAS_NONE, *mn = mas->node;
6757 unsigned long p_min, p_max;
6759 mas_next_node(mas, mas_mn(mas), max);
6760 if (!mas_is_none(mas))
6763 if (mte_is_root(mn))
6768 while (mas->node != MAS_NONE) {
6772 mas_prev_node(mas, 0);
6783 /* Tree validations */
6784 static void mt_dump_node(const struct maple_tree *mt, void *entry,
6785 unsigned long min, unsigned long max, unsigned int depth);
6786 static void mt_dump_range(unsigned long min, unsigned long max,
6789 static const char spaces[] = " ";
6792 pr_info("%.*s%lu: ", depth * 2, spaces, min);
6794 pr_info("%.*s%lu-%lu: ", depth * 2, spaces, min, max);
6797 static void mt_dump_entry(void *entry, unsigned long min, unsigned long max,
6800 mt_dump_range(min, max, depth);
6802 if (xa_is_value(entry))
6803 pr_cont("value %ld (0x%lx) [%p]\n", xa_to_value(entry),
6804 xa_to_value(entry), entry);
6805 else if (xa_is_zero(entry))
6806 pr_cont("zero (%ld)\n", xa_to_internal(entry));
6807 else if (mt_is_reserved(entry))
6808 pr_cont("UNKNOWN ENTRY (%p)\n", entry);
6810 pr_cont("%p\n", entry);
6813 static void mt_dump_range64(const struct maple_tree *mt, void *entry,
6814 unsigned long min, unsigned long max, unsigned int depth)
6816 struct maple_range_64 *node = &mte_to_node(entry)->mr64;
6817 bool leaf = mte_is_leaf(entry);
6818 unsigned long first = min;
6821 pr_cont(" contents: ");
6822 for (i = 0; i < MAPLE_RANGE64_SLOTS - 1; i++)
6823 pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
6824 pr_cont("%p\n", node->slot[i]);
6825 for (i = 0; i < MAPLE_RANGE64_SLOTS; i++) {
6826 unsigned long last = max;
6828 if (i < (MAPLE_RANGE64_SLOTS - 1))
6829 last = node->pivot[i];
6830 else if (!node->slot[i] && max != mt_node_max(entry))
6832 if (last == 0 && i > 0)
6835 mt_dump_entry(mt_slot(mt, node->slot, i),
6836 first, last, depth + 1);
6837 else if (node->slot[i])
6838 mt_dump_node(mt, mt_slot(mt, node->slot, i),
6839 first, last, depth + 1);
6844 pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
6845 node, last, max, i);
6852 static void mt_dump_arange64(const struct maple_tree *mt, void *entry,
6853 unsigned long min, unsigned long max, unsigned int depth)
6855 struct maple_arange_64 *node = &mte_to_node(entry)->ma64;
6856 bool leaf = mte_is_leaf(entry);
6857 unsigned long first = min;
6860 pr_cont(" contents: ");
6861 for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++)
6862 pr_cont("%lu ", node->gap[i]);
6863 pr_cont("| %02X %02X| ", node->meta.end, node->meta.gap);
6864 for (i = 0; i < MAPLE_ARANGE64_SLOTS - 1; i++)
6865 pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
6866 pr_cont("%p\n", node->slot[i]);
6867 for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) {
6868 unsigned long last = max;
6870 if (i < (MAPLE_ARANGE64_SLOTS - 1))
6871 last = node->pivot[i];
6872 else if (!node->slot[i])
6874 if (last == 0 && i > 0)
6877 mt_dump_entry(mt_slot(mt, node->slot, i),
6878 first, last, depth + 1);
6879 else if (node->slot[i])
6880 mt_dump_node(mt, mt_slot(mt, node->slot, i),
6881 first, last, depth + 1);
6886 pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
6887 node, last, max, i);
6894 static void mt_dump_node(const struct maple_tree *mt, void *entry,
6895 unsigned long min, unsigned long max, unsigned int depth)
6897 struct maple_node *node = mte_to_node(entry);
6898 unsigned int type = mte_node_type(entry);
6901 mt_dump_range(min, max, depth);
6903 pr_cont("node %p depth %d type %d parent %p", node, depth, type,
6904 node ? node->parent : NULL);
6908 for (i = 0; i < MAPLE_NODE_SLOTS; i++) {
6910 pr_cont("OUT OF RANGE: ");
6911 mt_dump_entry(mt_slot(mt, node->slot, i),
6912 min + i, min + i, depth);
6916 case maple_range_64:
6917 mt_dump_range64(mt, entry, min, max, depth);
6919 case maple_arange_64:
6920 mt_dump_arange64(mt, entry, min, max, depth);
6924 pr_cont(" UNKNOWN TYPE\n");
6928 void mt_dump(const struct maple_tree *mt)
6930 void *entry = rcu_dereference_check(mt->ma_root, mt_locked(mt));
6932 pr_info("maple_tree(%p) flags %X, height %u root %p\n",
6933 mt, mt->ma_flags, mt_height(mt), entry);
6934 if (!xa_is_node(entry))
6935 mt_dump_entry(entry, 0, 0, 0);
6937 mt_dump_node(mt, entry, 0, mt_node_max(entry), 0);
6939 EXPORT_SYMBOL_GPL(mt_dump);
6942 * Calculate the maximum gap in a node and check if that's what is reported in
6943 * the parent (unless root).
6945 static void mas_validate_gaps(struct ma_state *mas)
6947 struct maple_enode *mte = mas->node;
6948 struct maple_node *p_mn;
6949 unsigned long gap = 0, max_gap = 0;
6950 unsigned long p_end, p_start = mas->min;
6951 unsigned char p_slot;
6952 unsigned long *gaps = NULL;
6953 unsigned long *pivots = ma_pivots(mte_to_node(mte), mte_node_type(mte));
6956 if (ma_is_dense(mte_node_type(mte))) {
6957 for (i = 0; i < mt_slot_count(mte); i++) {
6958 if (mas_get_slot(mas, i)) {
6969 gaps = ma_gaps(mte_to_node(mte), mte_node_type(mte));
6970 for (i = 0; i < mt_slot_count(mte); i++) {
6971 p_end = mas_logical_pivot(mas, pivots, i, mte_node_type(mte));
6974 if (mas_get_slot(mas, i)) {
6979 gap += p_end - p_start + 1;
6981 void *entry = mas_get_slot(mas, i);
6985 if (gap != p_end - p_start + 1) {
6986 pr_err("%p[%u] -> %p %lu != %lu - %lu + 1\n",
6988 mas_get_slot(mas, i), gap,
6992 MT_BUG_ON(mas->tree,
6993 gap != p_end - p_start + 1);
6996 if (gap > p_end - p_start + 1) {
6997 pr_err("%p[%u] %lu >= %lu - %lu + 1 (%lu)\n",
6998 mas_mn(mas), i, gap, p_end, p_start,
6999 p_end - p_start + 1);
7000 MT_BUG_ON(mas->tree,
7001 gap > p_end - p_start + 1);
7009 p_start = p_end + 1;
7010 if (p_end >= mas->max)
7015 if (mte_is_root(mte))
7018 p_slot = mte_parent_slot(mas->node);
7019 p_mn = mte_parent(mte);
7020 MT_BUG_ON(mas->tree, max_gap > mas->max);
7021 if (ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap) {
7022 pr_err("gap %p[%u] != %lu\n", p_mn, p_slot, max_gap);
7026 MT_BUG_ON(mas->tree,
7027 ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap);
7030 static void mas_validate_parent_slot(struct ma_state *mas)
7032 struct maple_node *parent;
7033 struct maple_enode *node;
7034 enum maple_type p_type = mas_parent_enum(mas, mas->node);
7035 unsigned char p_slot = mte_parent_slot(mas->node);
7039 if (mte_is_root(mas->node))
7042 parent = mte_parent(mas->node);
7043 slots = ma_slots(parent, p_type);
7044 MT_BUG_ON(mas->tree, mas_mn(mas) == parent);
7046 /* Check prev/next parent slot for duplicate node entry */
7048 for (i = 0; i < mt_slots[p_type]; i++) {
7049 node = mas_slot(mas, slots, i);
7051 if (node != mas->node)
7052 pr_err("parent %p[%u] does not have %p\n",
7053 parent, i, mas_mn(mas));
7054 MT_BUG_ON(mas->tree, node != mas->node);
7055 } else if (node == mas->node) {
7056 pr_err("Invalid child %p at parent %p[%u] p_slot %u\n",
7057 mas_mn(mas), parent, i, p_slot);
7058 MT_BUG_ON(mas->tree, node == mas->node);
7063 static void mas_validate_child_slot(struct ma_state *mas)
7065 enum maple_type type = mte_node_type(mas->node);
7066 void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
7067 unsigned long *pivots = ma_pivots(mte_to_node(mas->node), type);
7068 struct maple_enode *child;
7071 if (mte_is_leaf(mas->node))
7074 for (i = 0; i < mt_slots[type]; i++) {
7075 child = mas_slot(mas, slots, i);
7076 if (!pivots[i] || pivots[i] == mas->max)
7082 if (mte_parent_slot(child) != i) {
7083 pr_err("Slot error at %p[%u]: child %p has pslot %u\n",
7084 mas_mn(mas), i, mte_to_node(child),
7085 mte_parent_slot(child));
7086 MT_BUG_ON(mas->tree, 1);
7089 if (mte_parent(child) != mte_to_node(mas->node)) {
7090 pr_err("child %p has parent %p not %p\n",
7091 mte_to_node(child), mte_parent(child),
7092 mte_to_node(mas->node));
7093 MT_BUG_ON(mas->tree, 1);
7099 * Validate all pivots are within mas->min and mas->max.
7101 static void mas_validate_limits(struct ma_state *mas)
7104 unsigned long prev_piv = 0;
7105 enum maple_type type = mte_node_type(mas->node);
7106 void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
7107 unsigned long *pivots = ma_pivots(mas_mn(mas), type);
7109 /* all limits are fine here. */
7110 if (mte_is_root(mas->node))
7113 for (i = 0; i < mt_slots[type]; i++) {
7116 piv = mas_safe_pivot(mas, pivots, i, type);
7118 if (!piv && (i != 0))
7121 if (!mte_is_leaf(mas->node)) {
7122 void *entry = mas_slot(mas, slots, i);
7125 pr_err("%p[%u] cannot be null\n",
7128 MT_BUG_ON(mas->tree, !entry);
7131 if (prev_piv > piv) {
7132 pr_err("%p[%u] piv %lu < prev_piv %lu\n",
7133 mas_mn(mas), i, piv, prev_piv);
7134 MT_BUG_ON(mas->tree, piv < prev_piv);
7137 if (piv < mas->min) {
7138 pr_err("%p[%u] %lu < %lu\n", mas_mn(mas), i,
7140 MT_BUG_ON(mas->tree, piv < mas->min);
7142 if (piv > mas->max) {
7143 pr_err("%p[%u] %lu > %lu\n", mas_mn(mas), i,
7145 MT_BUG_ON(mas->tree, piv > mas->max);
7148 if (piv == mas->max)
7151 for (i += 1; i < mt_slots[type]; i++) {
7152 void *entry = mas_slot(mas, slots, i);
7154 if (entry && (i != mt_slots[type] - 1)) {
7155 pr_err("%p[%u] should not have entry %p\n", mas_mn(mas),
7157 MT_BUG_ON(mas->tree, entry != NULL);
7160 if (i < mt_pivots[type]) {
7161 unsigned long piv = pivots[i];
7166 pr_err("%p[%u] should not have piv %lu\n",
7167 mas_mn(mas), i, piv);
7168 MT_BUG_ON(mas->tree, i < mt_pivots[type] - 1);
7173 static void mt_validate_nulls(struct maple_tree *mt)
7175 void *entry, *last = (void *)1;
7176 unsigned char offset = 0;
7178 MA_STATE(mas, mt, 0, 0);
7181 if (mas_is_none(&mas) || (mas.node == MAS_ROOT))
7184 while (!mte_is_leaf(mas.node))
7187 slots = ma_slots(mte_to_node(mas.node), mte_node_type(mas.node));
7189 entry = mas_slot(&mas, slots, offset);
7190 if (!last && !entry) {
7191 pr_err("Sequential nulls end at %p[%u]\n",
7192 mas_mn(&mas), offset);
7194 MT_BUG_ON(mt, !last && !entry);
7196 if (offset == mas_data_end(&mas)) {
7197 mas_next_node(&mas, mas_mn(&mas), ULONG_MAX);
7198 if (mas_is_none(&mas))
7201 slots = ma_slots(mte_to_node(mas.node),
7202 mte_node_type(mas.node));
7207 } while (!mas_is_none(&mas));
7211 * validate a maple tree by checking:
7212 * 1. The limits (pivots are within mas->min to mas->max)
7213 * 2. The gap is correctly set in the parents
7215 void mt_validate(struct maple_tree *mt)
7219 MA_STATE(mas, mt, 0, 0);
7222 if (!mas_searchable(&mas))
7225 mas_first_entry(&mas, mas_mn(&mas), ULONG_MAX, mte_node_type(mas.node));
7226 while (!mas_is_none(&mas)) {
7227 MT_BUG_ON(mas.tree, mte_dead_node(mas.node));
7228 if (!mte_is_root(mas.node)) {
7229 end = mas_data_end(&mas);
7230 if ((end < mt_min_slot_count(mas.node)) &&
7231 (mas.max != ULONG_MAX)) {
7232 pr_err("Invalid size %u of %p\n", end,
7234 MT_BUG_ON(mas.tree, 1);
7238 mas_validate_parent_slot(&mas);
7239 mas_validate_child_slot(&mas);
7240 mas_validate_limits(&mas);
7241 if (mt_is_alloc(mt))
7242 mas_validate_gaps(&mas);
7243 mas_dfs_postorder(&mas, ULONG_MAX);
7245 mt_validate_nulls(mt);
7250 EXPORT_SYMBOL_GPL(mt_validate);
7252 #endif /* CONFIG_DEBUG_MAPLE_TREE */