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;
150 static inline struct maple_node *mt_alloc_one(gfp_t gfp)
152 return kmem_cache_alloc(maple_node_cache, gfp | __GFP_ZERO);
155 static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes)
157 return kmem_cache_alloc_bulk(maple_node_cache, gfp | __GFP_ZERO, size,
161 static inline void mt_free_bulk(size_t size, void __rcu **nodes)
163 kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes);
166 static void mt_free_rcu(struct rcu_head *head)
168 struct maple_node *node = container_of(head, struct maple_node, rcu);
170 kmem_cache_free(maple_node_cache, node);
174 * ma_free_rcu() - Use rcu callback to free a maple node
175 * @node: The node to free
177 * The maple tree uses the parent pointer to indicate this node is no longer in
178 * use and will be freed.
180 static void ma_free_rcu(struct maple_node *node)
182 node->parent = ma_parent_ptr(node);
183 call_rcu(&node->rcu, mt_free_rcu);
186 static unsigned int mt_height(const struct maple_tree *mt)
188 return (mt->ma_flags & MT_FLAGS_HEIGHT_MASK) >> MT_FLAGS_HEIGHT_OFFSET;
191 static void mas_set_height(struct ma_state *mas)
193 unsigned int new_flags = mas->tree->ma_flags;
195 new_flags &= ~MT_FLAGS_HEIGHT_MASK;
196 BUG_ON(mas->depth > MAPLE_HEIGHT_MAX);
197 new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET;
198 mas->tree->ma_flags = new_flags;
201 static unsigned int mas_mt_height(struct ma_state *mas)
203 return mt_height(mas->tree);
206 static inline enum maple_type mte_node_type(const struct maple_enode *entry)
208 return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) &
209 MAPLE_NODE_TYPE_MASK;
212 static inline bool ma_is_dense(const enum maple_type type)
214 return type < maple_leaf_64;
217 static inline bool ma_is_leaf(const enum maple_type type)
219 return type < maple_range_64;
222 static inline bool mte_is_leaf(const struct maple_enode *entry)
224 return ma_is_leaf(mte_node_type(entry));
228 * We also reserve values with the bottom two bits set to '10' which are
231 static inline bool mt_is_reserved(const void *entry)
233 return ((unsigned long)entry < MAPLE_RESERVED_RANGE) &&
234 xa_is_internal(entry);
237 static inline void mas_set_err(struct ma_state *mas, long err)
239 mas->node = MA_ERROR(err);
242 static inline bool mas_is_ptr(struct ma_state *mas)
244 return mas->node == MAS_ROOT;
247 static inline bool mas_is_start(struct ma_state *mas)
249 return mas->node == MAS_START;
252 bool mas_is_err(struct ma_state *mas)
254 return xa_is_err(mas->node);
257 static inline bool mas_searchable(struct ma_state *mas)
259 if (mas_is_none(mas))
268 static inline struct maple_node *mte_to_node(const struct maple_enode *entry)
270 return (struct maple_node *)((unsigned long)entry & ~MAPLE_NODE_MASK);
274 * mte_to_mat() - Convert a maple encoded node to a maple topiary node.
275 * @entry: The maple encoded node
277 * Return: a maple topiary pointer
279 static inline struct maple_topiary *mte_to_mat(const struct maple_enode *entry)
281 return (struct maple_topiary *)
282 ((unsigned long)entry & ~MAPLE_NODE_MASK);
286 * mas_mn() - Get the maple state node.
287 * @mas: The maple state
289 * Return: the maple node (not encoded - bare pointer).
291 static inline struct maple_node *mas_mn(const struct ma_state *mas)
293 return mte_to_node(mas->node);
297 * mte_set_node_dead() - Set a maple encoded node as dead.
298 * @mn: The maple encoded node.
300 static inline void mte_set_node_dead(struct maple_enode *mn)
302 mte_to_node(mn)->parent = ma_parent_ptr(mte_to_node(mn));
303 smp_wmb(); /* Needed for RCU */
306 /* Bit 1 indicates the root is a node */
307 #define MAPLE_ROOT_NODE 0x02
308 /* maple_type stored bit 3-6 */
309 #define MAPLE_ENODE_TYPE_SHIFT 0x03
310 /* Bit 2 means a NULL somewhere below */
311 #define MAPLE_ENODE_NULL 0x04
313 static inline struct maple_enode *mt_mk_node(const struct maple_node *node,
314 enum maple_type type)
316 return (void *)((unsigned long)node |
317 (type << MAPLE_ENODE_TYPE_SHIFT) | MAPLE_ENODE_NULL);
320 static inline void *mte_mk_root(const struct maple_enode *node)
322 return (void *)((unsigned long)node | MAPLE_ROOT_NODE);
325 static inline void *mte_safe_root(const struct maple_enode *node)
327 return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
330 static inline void mte_set_full(const struct maple_enode *node)
332 node = (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
335 static inline void mte_clear_full(const struct maple_enode *node)
337 node = (void *)((unsigned long)node | MAPLE_ENODE_NULL);
340 static inline bool ma_is_root(struct maple_node *node)
342 return ((unsigned long)node->parent & MA_ROOT_PARENT);
345 static inline bool mte_is_root(const struct maple_enode *node)
347 return ma_is_root(mte_to_node(node));
350 static inline bool mas_is_root_limits(const struct ma_state *mas)
352 return !mas->min && mas->max == ULONG_MAX;
355 static inline bool mt_is_alloc(struct maple_tree *mt)
357 return (mt->ma_flags & MT_FLAGS_ALLOC_RANGE);
362 * Excluding root, the parent pointer is 256B aligned like all other tree nodes.
363 * When storing a 32 or 64 bit values, the offset can fit into 5 bits. The 16
364 * bit values need an extra bit to store the offset. This extra bit comes from
365 * a reuse of the last bit in the node type. This is possible by using bit 1 to
366 * indicate if bit 2 is part of the type or the slot.
370 * 0x?00 = 16 bit nodes
371 * 0x010 = 32 bit nodes
372 * 0x110 = 64 bit nodes
374 * Slot size and alignment
376 * 0b?00 : 16 bit values, type in 0-1, slot in 2-7
377 * 0b010 : 32 bit values, type in 0-2, slot in 3-7
378 * 0b110 : 64 bit values, type in 0-2, slot in 3-7
381 #define MAPLE_PARENT_ROOT 0x01
383 #define MAPLE_PARENT_SLOT_SHIFT 0x03
384 #define MAPLE_PARENT_SLOT_MASK 0xF8
386 #define MAPLE_PARENT_16B_SLOT_SHIFT 0x02
387 #define MAPLE_PARENT_16B_SLOT_MASK 0xFC
389 #define MAPLE_PARENT_RANGE64 0x06
390 #define MAPLE_PARENT_RANGE32 0x04
391 #define MAPLE_PARENT_NOT_RANGE16 0x02
394 * mte_parent_shift() - Get the parent shift for the slot storage.
395 * @parent: The parent pointer cast as an unsigned long
396 * Return: The shift into that pointer to the star to of the slot
398 static inline unsigned long mte_parent_shift(unsigned long parent)
400 /* Note bit 1 == 0 means 16B */
401 if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
402 return MAPLE_PARENT_SLOT_SHIFT;
404 return MAPLE_PARENT_16B_SLOT_SHIFT;
408 * mte_parent_slot_mask() - Get the slot mask for the parent.
409 * @parent: The parent pointer cast as an unsigned long.
410 * Return: The slot mask for that parent.
412 static inline unsigned long mte_parent_slot_mask(unsigned long parent)
414 /* Note bit 1 == 0 means 16B */
415 if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
416 return MAPLE_PARENT_SLOT_MASK;
418 return MAPLE_PARENT_16B_SLOT_MASK;
422 * mas_parent_enum() - Return the maple_type of the parent from the stored
424 * @mas: The maple state
425 * @node: The maple_enode to extract the parent's enum
426 * Return: The node->parent maple_type
429 enum maple_type mte_parent_enum(struct maple_enode *p_enode,
430 struct maple_tree *mt)
432 unsigned long p_type;
434 p_type = (unsigned long)p_enode;
435 if (p_type & MAPLE_PARENT_ROOT)
436 return 0; /* Validated in the caller. */
438 p_type &= MAPLE_NODE_MASK;
439 p_type = p_type & ~(MAPLE_PARENT_ROOT | mte_parent_slot_mask(p_type));
442 case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
444 return maple_arange_64;
445 return maple_range_64;
452 enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode)
454 return mte_parent_enum(ma_enode_ptr(mte_to_node(enode)->parent), mas->tree);
458 * mte_set_parent() - Set the parent node and encode the slot
459 * @enode: The encoded maple node.
460 * @parent: The encoded maple node that is the parent of @enode.
461 * @slot: The slot that @enode resides in @parent.
463 * Slot number is encoded in the enode->parent bit 3-6 or 2-6, depending on the
467 void mte_set_parent(struct maple_enode *enode, const struct maple_enode *parent,
470 unsigned long val = (unsigned long) parent;
473 enum maple_type p_type = mte_node_type(parent);
475 BUG_ON(p_type == maple_dense);
476 BUG_ON(p_type == maple_leaf_64);
480 case maple_arange_64:
481 shift = MAPLE_PARENT_SLOT_SHIFT;
482 type = MAPLE_PARENT_RANGE64;
491 val &= ~MAPLE_NODE_MASK; /* Clear all node metadata in parent */
492 val |= (slot << shift) | type;
493 mte_to_node(enode)->parent = ma_parent_ptr(val);
497 * mte_parent_slot() - get the parent slot of @enode.
498 * @enode: The encoded maple node.
500 * Return: The slot in the parent node where @enode resides.
502 static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
504 unsigned long val = (unsigned long) mte_to_node(enode)->parent;
511 * Okay to use MAPLE_PARENT_16B_SLOT_MASK as the last bit will be lost
512 * by shift if the parent shift is MAPLE_PARENT_SLOT_SHIFT
514 return (val & MAPLE_PARENT_16B_SLOT_MASK) >> mte_parent_shift(val);
518 * mte_parent() - Get the parent of @node.
519 * @node: The encoded maple node.
521 * Return: The parent maple node.
523 static inline struct maple_node *mte_parent(const struct maple_enode *enode)
525 return (void *)((unsigned long)
526 (mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK);
530 * ma_dead_node() - check if the @enode is dead.
531 * @enode: The encoded maple node
533 * Return: true if dead, false otherwise.
535 static inline bool ma_dead_node(const struct maple_node *node)
537 struct maple_node *parent = (void *)((unsigned long)
538 node->parent & ~MAPLE_NODE_MASK);
540 return (parent == node);
543 * mte_dead_node() - check if the @enode is dead.
544 * @enode: The encoded maple node
546 * Return: true if dead, false otherwise.
548 static inline bool mte_dead_node(const struct maple_enode *enode)
550 struct maple_node *parent, *node;
552 node = mte_to_node(enode);
553 parent = mte_parent(enode);
554 return (parent == node);
558 * mas_allocated() - Get the number of nodes allocated in a maple state.
559 * @mas: The maple state
561 * The ma_state alloc member is overloaded to hold a pointer to the first
562 * allocated node or to the number of requested nodes to allocate. If bit 0 is
563 * set, then the alloc contains the number of requested nodes. If there is an
564 * allocated node, then the total allocated nodes is in that node.
566 * Return: The total number of nodes allocated
568 static inline unsigned long mas_allocated(const struct ma_state *mas)
570 if (!mas->alloc || ((unsigned long)mas->alloc & 0x1))
573 return mas->alloc->total;
577 * mas_set_alloc_req() - Set the requested number of allocations.
578 * @mas: the maple state
579 * @count: the number of allocations.
581 * The requested number of allocations is either in the first allocated node,
582 * located in @mas->alloc->request_count, or directly in @mas->alloc if there is
583 * no allocated node. Set the request either in the node or do the necessary
584 * encoding to store in @mas->alloc directly.
586 static inline void mas_set_alloc_req(struct ma_state *mas, unsigned long count)
588 if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) {
592 mas->alloc = (struct maple_alloc *)(((count) << 1U) | 1U);
596 mas->alloc->request_count = count;
600 * mas_alloc_req() - get the requested number of allocations.
601 * @mas: The maple state
603 * The alloc count is either stored directly in @mas, or in
604 * @mas->alloc->request_count if there is at least one node allocated. Decode
605 * the request count if it's stored directly in @mas->alloc.
607 * Return: The allocation request count.
609 static inline unsigned int mas_alloc_req(const struct ma_state *mas)
611 if ((unsigned long)mas->alloc & 0x1)
612 return (unsigned long)(mas->alloc) >> 1;
614 return mas->alloc->request_count;
619 * ma_pivots() - Get a pointer to the maple node pivots.
620 * @node - the maple node
621 * @type - the node type
623 * Return: A pointer to the maple node pivots
625 static inline unsigned long *ma_pivots(struct maple_node *node,
626 enum maple_type type)
629 case maple_arange_64:
630 return node->ma64.pivot;
633 return node->mr64.pivot;
641 * ma_gaps() - Get a pointer to the maple node gaps.
642 * @node - the maple node
643 * @type - the node type
645 * Return: A pointer to the maple node gaps
647 static inline unsigned long *ma_gaps(struct maple_node *node,
648 enum maple_type type)
651 case maple_arange_64:
652 return node->ma64.gap;
662 * mte_pivot() - Get the pivot at @piv of the maple encoded node.
663 * @mn: The maple encoded node.
666 * Return: the pivot at @piv of @mn.
668 static inline unsigned long mte_pivot(const struct maple_enode *mn,
671 struct maple_node *node = mte_to_node(mn);
673 if (piv >= mt_pivots[piv]) {
677 switch (mte_node_type(mn)) {
678 case maple_arange_64:
679 return node->ma64.pivot[piv];
682 return node->mr64.pivot[piv];
690 * mas_safe_pivot() - get the pivot at @piv or mas->max.
691 * @mas: The maple state
692 * @pivots: The pointer to the maple node pivots
693 * @piv: The pivot to fetch
694 * @type: The maple node type
696 * Return: The pivot at @piv within the limit of the @pivots array, @mas->max
699 static inline unsigned long
700 mas_safe_pivot(const struct ma_state *mas, unsigned long *pivots,
701 unsigned char piv, enum maple_type type)
703 if (piv >= mt_pivots[type])
710 * mas_safe_min() - Return the minimum for a given offset.
711 * @mas: The maple state
712 * @pivots: The pointer to the maple node pivots
713 * @offset: The offset into the pivot array
715 * Return: The minimum range value that is contained in @offset.
717 static inline unsigned long
718 mas_safe_min(struct ma_state *mas, unsigned long *pivots, unsigned char offset)
721 return pivots[offset - 1] + 1;
727 * mas_logical_pivot() - Get the logical pivot of a given offset.
728 * @mas: The maple state
729 * @pivots: The pointer to the maple node pivots
730 * @offset: The offset into the pivot array
731 * @type: The maple node type
733 * When there is no value at a pivot (beyond the end of the data), then the
734 * pivot is actually @mas->max.
736 * Return: the logical pivot of a given @offset.
738 static inline unsigned long
739 mas_logical_pivot(struct ma_state *mas, unsigned long *pivots,
740 unsigned char offset, enum maple_type type)
742 unsigned long lpiv = mas_safe_pivot(mas, pivots, offset, type);
754 * mte_set_pivot() - Set a pivot to a value in an encoded maple node.
755 * @mn: The encoded maple node
756 * @piv: The pivot offset
757 * @val: The value of the pivot
759 static inline void mte_set_pivot(struct maple_enode *mn, unsigned char piv,
762 struct maple_node *node = mte_to_node(mn);
763 enum maple_type type = mte_node_type(mn);
765 BUG_ON(piv >= mt_pivots[type]);
770 node->mr64.pivot[piv] = val;
772 case maple_arange_64:
773 node->ma64.pivot[piv] = val;
782 * ma_slots() - Get a pointer to the maple node slots.
783 * @mn: The maple node
784 * @mt: The maple node type
786 * Return: A pointer to the maple node slots
788 static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt)
792 case maple_arange_64:
793 return mn->ma64.slot;
796 return mn->mr64.slot;
802 static inline bool mt_locked(const struct maple_tree *mt)
804 return mt_external_lock(mt) ? mt_lock_is_held(mt) :
805 lockdep_is_held(&mt->ma_lock);
808 static inline void *mt_slot(const struct maple_tree *mt,
809 void __rcu **slots, unsigned char offset)
811 return rcu_dereference_check(slots[offset], mt_locked(mt));
815 * mas_slot_locked() - Get the slot value when holding the maple tree lock.
816 * @mas: The maple state
817 * @slots: The pointer to the slots
818 * @offset: The offset into the slots array to fetch
820 * Return: The entry stored in @slots at the @offset.
822 static inline void *mas_slot_locked(struct ma_state *mas, void __rcu **slots,
823 unsigned char offset)
825 return rcu_dereference_protected(slots[offset], mt_locked(mas->tree));
829 * mas_slot() - Get the slot value when not holding the maple tree lock.
830 * @mas: The maple state
831 * @slots: The pointer to the slots
832 * @offset: The offset into the slots array to fetch
834 * Return: The entry stored in @slots at the @offset
836 static inline void *mas_slot(struct ma_state *mas, void __rcu **slots,
837 unsigned char offset)
839 return mt_slot(mas->tree, slots, offset);
843 * mas_root() - Get the maple tree root.
844 * @mas: The maple state.
846 * Return: The pointer to the root of the tree
848 static inline void *mas_root(struct ma_state *mas)
850 return rcu_dereference_check(mas->tree->ma_root, mt_locked(mas->tree));
853 static inline void *mt_root_locked(struct maple_tree *mt)
855 return rcu_dereference_protected(mt->ma_root, mt_locked(mt));
859 * mas_root_locked() - Get the maple tree root when holding the maple tree lock.
860 * @mas: The maple state.
862 * Return: The pointer to the root of the tree
864 static inline void *mas_root_locked(struct ma_state *mas)
866 return mt_root_locked(mas->tree);
869 static inline struct maple_metadata *ma_meta(struct maple_node *mn,
873 case maple_arange_64:
874 return &mn->ma64.meta;
876 return &mn->mr64.meta;
881 * ma_set_meta() - Set the metadata information of a node.
882 * @mn: The maple node
883 * @mt: The maple node type
884 * @offset: The offset of the highest sub-gap in this node.
885 * @end: The end of the data in this node.
887 static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt,
888 unsigned char offset, unsigned char end)
890 struct maple_metadata *meta = ma_meta(mn, mt);
897 * ma_meta_end() - Get the data end of a node from the metadata
898 * @mn: The maple node
899 * @mt: The maple node type
901 static inline unsigned char ma_meta_end(struct maple_node *mn,
904 struct maple_metadata *meta = ma_meta(mn, mt);
910 * ma_meta_gap() - Get the largest gap location of a node from the metadata
911 * @mn: The maple node
912 * @mt: The maple node type
914 static inline unsigned char ma_meta_gap(struct maple_node *mn,
917 BUG_ON(mt != maple_arange_64);
919 return mn->ma64.meta.gap;
923 * ma_set_meta_gap() - Set the largest gap location in a nodes metadata
924 * @mn: The maple node
925 * @mn: The maple node type
926 * @offset: The location of the largest gap.
928 static inline void ma_set_meta_gap(struct maple_node *mn, enum maple_type mt,
929 unsigned char offset)
932 struct maple_metadata *meta = ma_meta(mn, mt);
938 * mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes.
939 * @mat - the ma_topiary, a linked list of dead nodes.
940 * @dead_enode - the node to be marked as dead and added to the tail of the list
942 * Add the @dead_enode to the linked list in @mat.
944 static inline void mat_add(struct ma_topiary *mat,
945 struct maple_enode *dead_enode)
947 mte_set_node_dead(dead_enode);
948 mte_to_mat(dead_enode)->next = NULL;
950 mat->tail = mat->head = dead_enode;
954 mte_to_mat(mat->tail)->next = dead_enode;
955 mat->tail = dead_enode;
958 static void mte_destroy_walk(struct maple_enode *, struct maple_tree *);
959 static inline void mas_free(struct ma_state *mas, struct maple_enode *used);
962 * mas_mat_free() - Free all nodes in a dead list.
963 * @mas - the maple state
964 * @mat - the ma_topiary linked list of dead nodes to free.
966 * Free walk a dead list.
968 static void mas_mat_free(struct ma_state *mas, struct ma_topiary *mat)
970 struct maple_enode *next;
973 next = mte_to_mat(mat->head)->next;
974 mas_free(mas, mat->head);
980 * mas_mat_destroy() - Free all nodes and subtrees in a dead list.
981 * @mas - the maple state
982 * @mat - the ma_topiary linked list of dead nodes to free.
984 * Destroy walk a dead list.
986 static void mas_mat_destroy(struct ma_state *mas, struct ma_topiary *mat)
988 struct maple_enode *next;
991 next = mte_to_mat(mat->head)->next;
992 mte_destroy_walk(mat->head, mat->mtree);
997 * mas_descend() - Descend into the slot stored in the ma_state.
998 * @mas - the maple state.
1000 * Note: Not RCU safe, only use in write side or debug code.
1002 static inline void mas_descend(struct ma_state *mas)
1004 enum maple_type type;
1005 unsigned long *pivots;
1006 struct maple_node *node;
1010 type = mte_node_type(mas->node);
1011 pivots = ma_pivots(node, type);
1012 slots = ma_slots(node, type);
1015 mas->min = pivots[mas->offset - 1] + 1;
1016 mas->max = mas_safe_pivot(mas, pivots, mas->offset, type);
1017 mas->node = mas_slot(mas, slots, mas->offset);
1021 * mte_set_gap() - Set a maple node gap.
1022 * @mn: The encoded maple node
1023 * @gap: The offset of the gap to set
1024 * @val: The gap value
1026 static inline void mte_set_gap(const struct maple_enode *mn,
1027 unsigned char gap, unsigned long val)
1029 switch (mte_node_type(mn)) {
1032 case maple_arange_64:
1033 mte_to_node(mn)->ma64.gap[gap] = val;
1039 * mas_ascend() - Walk up a level of the tree.
1040 * @mas: The maple state
1042 * Sets the @mas->max and @mas->min to the correct values when walking up. This
1043 * may cause several levels of walking up to find the correct min and max.
1044 * May find a dead node which will cause a premature return.
1045 * Return: 1 on dead node, 0 otherwise
1047 static int mas_ascend(struct ma_state *mas)
1049 struct maple_enode *p_enode; /* parent enode. */
1050 struct maple_enode *a_enode; /* ancestor enode. */
1051 struct maple_node *a_node; /* ancestor node. */
1052 struct maple_node *p_node; /* parent node. */
1053 unsigned char a_slot;
1054 enum maple_type a_type;
1055 unsigned long min, max;
1056 unsigned long *pivots;
1057 unsigned char offset;
1058 bool set_max = false, set_min = false;
1060 a_node = mas_mn(mas);
1061 if (ma_is_root(a_node)) {
1066 p_node = mte_parent(mas->node);
1067 if (unlikely(a_node == p_node))
1069 a_type = mas_parent_enum(mas, mas->node);
1070 offset = mte_parent_slot(mas->node);
1071 a_enode = mt_mk_node(p_node, a_type);
1073 /* Check to make sure all parent information is still accurate */
1074 if (p_node != mte_parent(mas->node))
1077 mas->node = a_enode;
1078 mas->offset = offset;
1080 if (mte_is_root(a_enode)) {
1081 mas->max = ULONG_MAX;
1090 a_type = mas_parent_enum(mas, p_enode);
1091 a_node = mte_parent(p_enode);
1092 a_slot = mte_parent_slot(p_enode);
1093 pivots = ma_pivots(a_node, a_type);
1094 a_enode = mt_mk_node(a_node, a_type);
1096 if (!set_min && a_slot) {
1098 min = pivots[a_slot - 1] + 1;
1101 if (!set_max && a_slot < mt_pivots[a_type]) {
1103 max = pivots[a_slot];
1106 if (unlikely(ma_dead_node(a_node)))
1109 if (unlikely(ma_is_root(a_node)))
1112 } while (!set_min || !set_max);
1120 * mas_pop_node() - Get a previously allocated maple node from the maple state.
1121 * @mas: The maple state
1123 * Return: A pointer to a maple node.
1125 static inline struct maple_node *mas_pop_node(struct ma_state *mas)
1127 struct maple_alloc *ret, *node = mas->alloc;
1128 unsigned long total = mas_allocated(mas);
1130 /* nothing or a request pending. */
1131 if (unlikely(!total))
1135 /* single allocation in this ma_state */
1141 if (!node->node_count) {
1142 /* Single allocation in this node. */
1143 mas->alloc = node->slot[0];
1144 node->slot[0] = NULL;
1145 mas->alloc->total = node->total - 1;
1151 ret = node->slot[node->node_count];
1152 node->slot[node->node_count--] = NULL;
1157 ret->node_count = 0;
1158 if (ret->request_count) {
1159 mas_set_alloc_req(mas, ret->request_count + 1);
1160 ret->request_count = 0;
1162 return (struct maple_node *)ret;
1166 * mas_push_node() - Push a node back on the maple state allocation.
1167 * @mas: The maple state
1168 * @used: The used maple node
1170 * Stores the maple node back into @mas->alloc for reuse. Updates allocated and
1171 * requested node count as necessary.
1173 static inline void mas_push_node(struct ma_state *mas, struct maple_node *used)
1175 struct maple_alloc *reuse = (struct maple_alloc *)used;
1176 struct maple_alloc *head = mas->alloc;
1177 unsigned long count;
1178 unsigned int requested = mas_alloc_req(mas);
1180 memset(reuse, 0, sizeof(*reuse));
1181 count = mas_allocated(mas);
1183 if (count && (head->node_count < MAPLE_ALLOC_SLOTS - 1)) {
1186 head->slot[head->node_count] = reuse;
1192 if ((head) && !((unsigned long)head & 0x1)) {
1193 head->request_count = 0;
1194 reuse->slot[0] = head;
1195 reuse->total += head->total;
1201 mas_set_alloc_req(mas, requested - 1);
1205 * mas_alloc_nodes() - Allocate nodes into a maple state
1206 * @mas: The maple state
1207 * @gfp: The GFP Flags
1209 static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
1211 struct maple_alloc *node;
1212 unsigned long allocated = mas_allocated(mas);
1213 unsigned long success = allocated;
1214 unsigned int requested = mas_alloc_req(mas);
1216 void **slots = NULL;
1217 unsigned int max_req = 0;
1222 mas_set_alloc_req(mas, 0);
1223 if (mas->mas_flags & MA_STATE_PREALLOC) {
1226 WARN_ON(!allocated);
1229 if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS - 1) {
1230 node = (struct maple_alloc *)mt_alloc_one(gfp);
1235 node->slot[0] = mas->alloc;
1244 max_req = MAPLE_ALLOC_SLOTS;
1245 if (node->slot[0]) {
1246 unsigned int offset = node->node_count + 1;
1248 slots = (void **)&node->slot[offset];
1251 slots = (void **)&node->slot;
1254 max_req = min(requested, max_req);
1255 count = mt_alloc_bulk(gfp, max_req, slots);
1259 node->node_count += count;
1261 if (slots == (void **)&node->slot)
1265 node = node->slot[0];
1268 mas->alloc->total = success;
1272 /* Clean up potential freed allocations on bulk failure */
1273 memset(slots, 0, max_req * sizeof(unsigned long));
1275 mas_set_alloc_req(mas, requested);
1276 if (mas->alloc && !(((unsigned long)mas->alloc & 0x1)))
1277 mas->alloc->total = success;
1278 mas_set_err(mas, -ENOMEM);
1284 * mas_free() - Free an encoded maple node
1285 * @mas: The maple state
1286 * @used: The encoded maple node to free.
1288 * Uses rcu free if necessary, pushes @used back on the maple state allocations
1291 static inline void mas_free(struct ma_state *mas, struct maple_enode *used)
1293 struct maple_node *tmp = mte_to_node(used);
1295 if (mt_in_rcu(mas->tree))
1298 mas_push_node(mas, tmp);
1302 * mas_node_count() - Check if enough nodes are allocated and request more if
1303 * there is not enough nodes.
1304 * @mas: The maple state
1305 * @count: The number of nodes needed
1306 * @gfp: the gfp flags
1308 static void mas_node_count_gfp(struct ma_state *mas, int count, gfp_t gfp)
1310 unsigned long allocated = mas_allocated(mas);
1312 if (allocated < count) {
1313 mas_set_alloc_req(mas, count - allocated);
1314 mas_alloc_nodes(mas, gfp);
1319 * mas_node_count() - Check if enough nodes are allocated and request more if
1320 * there is not enough nodes.
1321 * @mas: The maple state
1322 * @count: The number of nodes needed
1324 * Note: Uses GFP_NOWAIT | __GFP_NOWARN for gfp flags.
1326 static void mas_node_count(struct ma_state *mas, int count)
1328 return mas_node_count_gfp(mas, count, GFP_NOWAIT | __GFP_NOWARN);
1332 * mas_start() - Sets up maple state for operations.
1333 * @mas: The maple state.
1335 * If mas->node == MAS_START, then set the min, max, depth, and offset to
1339 * - If mas->node is an error or not MAS_START, return NULL.
1340 * - If it's an empty tree: NULL & mas->node == MAS_NONE
1341 * - If it's a single entry: The entry & mas->node == MAS_ROOT
1342 * - If it's a tree: NULL & mas->node == safe root node.
1344 static inline struct maple_enode *mas_start(struct ma_state *mas)
1346 if (likely(mas_is_start(mas))) {
1347 struct maple_enode *root;
1349 mas->node = MAS_NONE;
1351 mas->max = ULONG_MAX;
1355 root = mas_root(mas);
1356 /* Tree with nodes */
1357 if (likely(xa_is_node(root))) {
1358 mas->node = mte_safe_root(root);
1363 if (unlikely(!root)) {
1364 mas->offset = MAPLE_NODE_SLOTS;
1368 /* Single entry tree */
1369 mas->node = MAS_ROOT;
1370 mas->offset = MAPLE_NODE_SLOTS;
1372 /* Single entry tree. */
1383 * ma_data_end() - Find the end of the data in a node.
1384 * @node: The maple node
1385 * @type: The maple node type
1386 * @pivots: The array of pivots in the node
1387 * @max: The maximum value in the node
1389 * Uses metadata to find the end of the data when possible.
1390 * Return: The zero indexed last slot with data (may be null).
1392 static inline unsigned char ma_data_end(struct maple_node *node,
1393 enum maple_type type,
1394 unsigned long *pivots,
1397 unsigned char offset;
1399 if (type == maple_arange_64)
1400 return ma_meta_end(node, type);
1402 offset = mt_pivots[type] - 1;
1403 if (likely(!pivots[offset]))
1404 return ma_meta_end(node, type);
1406 if (likely(pivots[offset] == max))
1409 return mt_pivots[type];
1413 * mas_data_end() - Find the end of the data (slot).
1414 * @mas: the maple state
1416 * This method is optimized to check the metadata of a node if the node type
1417 * supports data end metadata.
1419 * Return: The zero indexed last slot with data (may be null).
1421 static inline unsigned char mas_data_end(struct ma_state *mas)
1423 enum maple_type type;
1424 struct maple_node *node;
1425 unsigned char offset;
1426 unsigned long *pivots;
1428 type = mte_node_type(mas->node);
1430 if (type == maple_arange_64)
1431 return ma_meta_end(node, type);
1433 pivots = ma_pivots(node, type);
1434 offset = mt_pivots[type] - 1;
1435 if (likely(!pivots[offset]))
1436 return ma_meta_end(node, type);
1438 if (likely(pivots[offset] == mas->max))
1441 return mt_pivots[type];
1445 * mas_leaf_max_gap() - Returns the largest gap in a leaf node
1446 * @mas - the maple state
1448 * Return: The maximum gap in the leaf.
1450 static unsigned long mas_leaf_max_gap(struct ma_state *mas)
1453 unsigned long pstart, gap, max_gap;
1454 struct maple_node *mn;
1455 unsigned long *pivots;
1458 unsigned char max_piv;
1460 mt = mte_node_type(mas->node);
1462 slots = ma_slots(mn, mt);
1464 if (unlikely(ma_is_dense(mt))) {
1466 for (i = 0; i < mt_slots[mt]; i++) {
1481 * Check the first implied pivot optimizes the loop below and slot 1 may
1482 * be skipped if there is a gap in slot 0.
1484 pivots = ma_pivots(mn, mt);
1485 if (likely(!slots[0])) {
1486 max_gap = pivots[0] - mas->min + 1;
1492 /* reduce max_piv as the special case is checked before the loop */
1493 max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1;
1495 * Check end implied pivot which can only be a gap on the right most
1498 if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) {
1499 gap = ULONG_MAX - pivots[max_piv];
1504 for (; i <= max_piv; i++) {
1505 /* data == no gap. */
1506 if (likely(slots[i]))
1509 pstart = pivots[i - 1];
1510 gap = pivots[i] - pstart;
1514 /* There cannot be two gaps in a row. */
1521 * ma_max_gap() - Get the maximum gap in a maple node (non-leaf)
1522 * @node: The maple node
1523 * @gaps: The pointer to the gaps
1524 * @mt: The maple node type
1525 * @*off: Pointer to store the offset location of the gap.
1527 * Uses the metadata data end to scan backwards across set gaps.
1529 * Return: The maximum gap value
1531 static inline unsigned long
1532 ma_max_gap(struct maple_node *node, unsigned long *gaps, enum maple_type mt,
1535 unsigned char offset, i;
1536 unsigned long max_gap = 0;
1538 i = offset = ma_meta_end(node, mt);
1540 if (gaps[i] > max_gap) {
1551 * mas_max_gap() - find the largest gap in a non-leaf node and set the slot.
1552 * @mas: The maple state.
1554 * If the metadata gap is set to MAPLE_ARANGE64_META_MAX, there is no gap.
1556 * Return: The gap value.
1558 static inline unsigned long mas_max_gap(struct ma_state *mas)
1560 unsigned long *gaps;
1561 unsigned char offset;
1563 struct maple_node *node;
1565 mt = mte_node_type(mas->node);
1567 return mas_leaf_max_gap(mas);
1570 offset = ma_meta_gap(node, mt);
1571 if (offset == MAPLE_ARANGE64_META_MAX)
1574 gaps = ma_gaps(node, mt);
1575 return gaps[offset];
1579 * mas_parent_gap() - Set the parent gap and any gaps above, as needed
1580 * @mas: The maple state
1581 * @offset: The gap offset in the parent to set
1582 * @new: The new gap value.
1584 * Set the parent gap then continue to set the gap upwards, using the metadata
1585 * of the parent to see if it is necessary to check the node above.
1587 static inline void mas_parent_gap(struct ma_state *mas, unsigned char offset,
1590 unsigned long meta_gap = 0;
1591 struct maple_node *pnode;
1592 struct maple_enode *penode;
1593 unsigned long *pgaps;
1594 unsigned char meta_offset;
1595 enum maple_type pmt;
1597 pnode = mte_parent(mas->node);
1598 pmt = mas_parent_enum(mas, mas->node);
1599 penode = mt_mk_node(pnode, pmt);
1600 pgaps = ma_gaps(pnode, pmt);
1603 meta_offset = ma_meta_gap(pnode, pmt);
1604 if (meta_offset == MAPLE_ARANGE64_META_MAX)
1607 meta_gap = pgaps[meta_offset];
1609 pgaps[offset] = new;
1611 if (meta_gap == new)
1614 if (offset != meta_offset) {
1618 ma_set_meta_gap(pnode, pmt, offset);
1619 } else if (new < meta_gap) {
1621 new = ma_max_gap(pnode, pgaps, pmt, &meta_offset);
1622 ma_set_meta_gap(pnode, pmt, meta_offset);
1625 if (ma_is_root(pnode))
1628 /* Go to the parent node. */
1629 pnode = mte_parent(penode);
1630 pmt = mas_parent_enum(mas, penode);
1631 pgaps = ma_gaps(pnode, pmt);
1632 offset = mte_parent_slot(penode);
1633 penode = mt_mk_node(pnode, pmt);
1638 * mas_update_gap() - Update a nodes gaps and propagate up if necessary.
1639 * @mas - the maple state.
1641 static inline void mas_update_gap(struct ma_state *mas)
1643 unsigned char pslot;
1644 unsigned long p_gap;
1645 unsigned long max_gap;
1647 if (!mt_is_alloc(mas->tree))
1650 if (mte_is_root(mas->node))
1653 max_gap = mas_max_gap(mas);
1655 pslot = mte_parent_slot(mas->node);
1656 p_gap = ma_gaps(mte_parent(mas->node),
1657 mas_parent_enum(mas, mas->node))[pslot];
1659 if (p_gap != max_gap)
1660 mas_parent_gap(mas, pslot, max_gap);
1664 * mas_adopt_children() - Set the parent pointer of all nodes in @parent to
1665 * @parent with the slot encoded.
1666 * @mas - the maple state (for the tree)
1667 * @parent - the maple encoded node containing the children.
1669 static inline void mas_adopt_children(struct ma_state *mas,
1670 struct maple_enode *parent)
1672 enum maple_type type = mte_node_type(parent);
1673 struct maple_node *node = mas_mn(mas);
1674 void __rcu **slots = ma_slots(node, type);
1675 unsigned long *pivots = ma_pivots(node, type);
1676 struct maple_enode *child;
1677 unsigned char offset;
1679 offset = ma_data_end(node, type, pivots, mas->max);
1681 child = mas_slot_locked(mas, slots, offset);
1682 mte_set_parent(child, parent, offset);
1687 * mas_replace() - Replace a maple node in the tree with mas->node. Uses the
1688 * parent encoding to locate the maple node in the tree.
1689 * @mas - the ma_state to use for operations.
1690 * @advanced - boolean to adopt the child nodes and free the old node (false) or
1691 * leave the node (true) and handle the adoption and free elsewhere.
1693 static inline void mas_replace(struct ma_state *mas, bool advanced)
1694 __must_hold(mas->tree->lock)
1696 struct maple_node *mn = mas_mn(mas);
1697 struct maple_enode *old_enode;
1698 unsigned char offset = 0;
1699 void __rcu **slots = NULL;
1701 if (ma_is_root(mn)) {
1702 old_enode = mas_root_locked(mas);
1704 offset = mte_parent_slot(mas->node);
1705 slots = ma_slots(mte_parent(mas->node),
1706 mas_parent_enum(mas, mas->node));
1707 old_enode = mas_slot_locked(mas, slots, offset);
1710 if (!advanced && !mte_is_leaf(mas->node))
1711 mas_adopt_children(mas, mas->node);
1713 if (mte_is_root(mas->node)) {
1714 mn->parent = ma_parent_ptr(
1715 ((unsigned long)mas->tree | MA_ROOT_PARENT));
1716 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
1717 mas_set_height(mas);
1719 rcu_assign_pointer(slots[offset], mas->node);
1723 mas_free(mas, old_enode);
1727 * mas_new_child() - Find the new child of a node.
1728 * @mas: the maple state
1729 * @child: the maple state to store the child.
1731 static inline bool mas_new_child(struct ma_state *mas, struct ma_state *child)
1732 __must_hold(mas->tree->lock)
1735 unsigned char offset;
1737 unsigned long *pivots;
1738 struct maple_enode *entry;
1739 struct maple_node *node;
1742 mt = mte_node_type(mas->node);
1744 slots = ma_slots(node, mt);
1745 pivots = ma_pivots(node, mt);
1746 end = ma_data_end(node, mt, pivots, mas->max);
1747 for (offset = mas->offset; offset <= end; offset++) {
1748 entry = mas_slot_locked(mas, slots, offset);
1749 if (mte_parent(entry) == node) {
1751 mas->offset = offset + 1;
1752 child->offset = offset;
1762 * mab_shift_right() - Shift the data in mab right. Note, does not clean out the
1763 * old data or set b_node->b_end.
1764 * @b_node: the maple_big_node
1765 * @shift: the shift count
1767 static inline void mab_shift_right(struct maple_big_node *b_node,
1768 unsigned char shift)
1770 unsigned long size = b_node->b_end * sizeof(unsigned long);
1772 memmove(b_node->pivot + shift, b_node->pivot, size);
1773 memmove(b_node->slot + shift, b_node->slot, size);
1774 if (b_node->type == maple_arange_64)
1775 memmove(b_node->gap + shift, b_node->gap, size);
1779 * mab_middle_node() - Check if a middle node is needed (unlikely)
1780 * @b_node: the maple_big_node that contains the data.
1781 * @size: the amount of data in the b_node
1782 * @split: the potential split location
1783 * @slot_count: the size that can be stored in a single node being considered.
1785 * Return: true if a middle node is required.
1787 static inline bool mab_middle_node(struct maple_big_node *b_node, int split,
1788 unsigned char slot_count)
1790 unsigned char size = b_node->b_end;
1792 if (size >= 2 * slot_count)
1795 if (!b_node->slot[split] && (size >= 2 * slot_count - 1))
1802 * mab_no_null_split() - ensure the split doesn't fall on a NULL
1803 * @b_node: the maple_big_node with the data
1804 * @split: the suggested split location
1805 * @slot_count: the number of slots in the node being considered.
1807 * Return: the split location.
1809 static inline int mab_no_null_split(struct maple_big_node *b_node,
1810 unsigned char split, unsigned char slot_count)
1812 if (!b_node->slot[split]) {
1814 * If the split is less than the max slot && the right side will
1815 * still be sufficient, then increment the split on NULL.
1817 if ((split < slot_count - 1) &&
1818 (b_node->b_end - split) > (mt_min_slots[b_node->type]))
1827 * mab_calc_split() - Calculate the split location and if there needs to be two
1829 * @bn: The maple_big_node with the data
1830 * @mid_split: The second split, if required. 0 otherwise.
1832 * Return: The first split location. The middle split is set in @mid_split.
1834 static inline int mab_calc_split(struct ma_state *mas,
1835 struct maple_big_node *bn, unsigned char *mid_split, unsigned long min)
1837 unsigned char b_end = bn->b_end;
1838 int split = b_end / 2; /* Assume equal split. */
1839 unsigned char slot_min, slot_count = mt_slots[bn->type];
1842 * To support gap tracking, all NULL entries are kept together and a node cannot
1843 * end on a NULL entry, with the exception of the left-most leaf. The
1844 * limitation means that the split of a node must be checked for this condition
1845 * and be able to put more data in one direction or the other.
1847 if (unlikely((mas->mas_flags & MA_STATE_BULK))) {
1849 split = b_end - mt_min_slots[bn->type];
1851 if (!ma_is_leaf(bn->type))
1854 mas->mas_flags |= MA_STATE_REBALANCE;
1855 if (!bn->slot[split])
1861 * Although extremely rare, it is possible to enter what is known as the 3-way
1862 * split scenario. The 3-way split comes about by means of a store of a range
1863 * that overwrites the end and beginning of two full nodes. The result is a set
1864 * of entries that cannot be stored in 2 nodes. Sometimes, these two nodes can
1865 * also be located in different parent nodes which are also full. This can
1866 * carry upwards all the way to the root in the worst case.
1868 if (unlikely(mab_middle_node(bn, split, slot_count))) {
1870 *mid_split = split * 2;
1872 slot_min = mt_min_slots[bn->type];
1876 * Avoid having a range less than the slot count unless it
1877 * causes one node to be deficient.
1878 * NOTE: mt_min_slots is 1 based, b_end and split are zero.
1880 while (((bn->pivot[split] - min) < slot_count - 1) &&
1881 (split < slot_count - 1) && (b_end - split > slot_min))
1885 /* Avoid ending a node on a NULL entry */
1886 split = mab_no_null_split(bn, split, slot_count);
1890 *mid_split = mab_no_null_split(bn, *mid_split, slot_count);
1896 * mas_mab_cp() - Copy data from a maple state inclusively to a maple_big_node
1897 * and set @b_node->b_end to the next free slot.
1898 * @mas: The maple state
1899 * @mas_start: The starting slot to copy
1900 * @mas_end: The end slot to copy (inclusively)
1901 * @b_node: The maple_big_node to place the data
1902 * @mab_start: The starting location in maple_big_node to store the data.
1904 static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
1905 unsigned char mas_end, struct maple_big_node *b_node,
1906 unsigned char mab_start)
1909 struct maple_node *node;
1911 unsigned long *pivots, *gaps;
1912 int i = mas_start, j = mab_start;
1913 unsigned char piv_end;
1916 mt = mte_node_type(mas->node);
1917 pivots = ma_pivots(node, mt);
1919 b_node->pivot[j] = pivots[i++];
1920 if (unlikely(i > mas_end))
1925 piv_end = min(mas_end, mt_pivots[mt]);
1926 for (; i < piv_end; i++, j++) {
1927 b_node->pivot[j] = pivots[i];
1928 if (unlikely(!b_node->pivot[j]))
1931 if (unlikely(mas->max == b_node->pivot[j]))
1935 if (likely(i <= mas_end))
1936 b_node->pivot[j] = mas_safe_pivot(mas, pivots, i, mt);
1939 b_node->b_end = ++j;
1941 slots = ma_slots(node, mt);
1942 memcpy(b_node->slot + mab_start, slots + mas_start, sizeof(void *) * j);
1943 if (!ma_is_leaf(mt) && mt_is_alloc(mas->tree)) {
1944 gaps = ma_gaps(node, mt);
1945 memcpy(b_node->gap + mab_start, gaps + mas_start,
1946 sizeof(unsigned long) * j);
1951 * mas_leaf_set_meta() - Set the metadata of a leaf if possible.
1952 * @mas: The maple state
1953 * @node: The maple node
1954 * @pivots: pointer to the maple node pivots
1955 * @mt: The maple type
1956 * @end: The assumed end
1958 * Note, end may be incremented within this function but not modified at the
1959 * source. This is fine since the metadata is the last thing to be stored in a
1960 * node during a write.
1962 static inline void mas_leaf_set_meta(struct ma_state *mas,
1963 struct maple_node *node, unsigned long *pivots,
1964 enum maple_type mt, unsigned char end)
1966 /* There is no room for metadata already */
1967 if (mt_pivots[mt] <= end)
1970 if (pivots[end] && pivots[end] < mas->max)
1973 if (end < mt_slots[mt] - 1)
1974 ma_set_meta(node, mt, 0, end);
1978 * mab_mas_cp() - Copy data from maple_big_node to a maple encoded node.
1979 * @b_node: the maple_big_node that has the data
1980 * @mab_start: the start location in @b_node.
1981 * @mab_end: The end location in @b_node (inclusively)
1982 * @mas: The maple state with the maple encoded node.
1984 static inline void mab_mas_cp(struct maple_big_node *b_node,
1985 unsigned char mab_start, unsigned char mab_end,
1986 struct ma_state *mas, bool new_max)
1989 enum maple_type mt = mte_node_type(mas->node);
1990 struct maple_node *node = mte_to_node(mas->node);
1991 void __rcu **slots = ma_slots(node, mt);
1992 unsigned long *pivots = ma_pivots(node, mt);
1993 unsigned long *gaps = NULL;
1996 if (mab_end - mab_start > mt_pivots[mt])
1999 if (!pivots[mt_pivots[mt] - 1])
2000 slots[mt_pivots[mt]] = NULL;
2004 pivots[j++] = b_node->pivot[i++];
2005 } while (i <= mab_end && likely(b_node->pivot[i]));
2007 memcpy(slots, b_node->slot + mab_start,
2008 sizeof(void *) * (i - mab_start));
2011 mas->max = b_node->pivot[i - 1];
2014 if (likely(!ma_is_leaf(mt) && mt_is_alloc(mas->tree))) {
2015 unsigned long max_gap = 0;
2016 unsigned char offset = 15;
2018 gaps = ma_gaps(node, mt);
2020 gaps[--j] = b_node->gap[--i];
2021 if (gaps[j] > max_gap) {
2027 ma_set_meta(node, mt, offset, end);
2029 mas_leaf_set_meta(mas, node, pivots, mt, end);
2034 * mas_descend_adopt() - Descend through a sub-tree and adopt children.
2035 * @mas: the maple state with the maple encoded node of the sub-tree.
2037 * Descend through a sub-tree and adopt children who do not have the correct
2038 * parents set. Follow the parents which have the correct parents as they are
2039 * the new entries which need to be followed to find other incorrectly set
2042 static inline void mas_descend_adopt(struct ma_state *mas)
2044 struct ma_state list[3], next[3];
2048 * At each level there may be up to 3 correct parent pointers which indicates
2049 * the new nodes which need to be walked to find any new nodes at a lower level.
2052 for (i = 0; i < 3; i++) {
2059 while (!mte_is_leaf(list[0].node)) {
2061 for (i = 0; i < 3; i++) {
2062 if (mas_is_none(&list[i]))
2065 if (i && list[i-1].node == list[i].node)
2068 while ((n < 3) && (mas_new_child(&list[i], &next[n])))
2071 mas_adopt_children(&list[i], list[i].node);
2075 next[n++].node = MAS_NONE;
2077 /* descend by setting the list to the children */
2078 for (i = 0; i < 3; i++)
2084 * mas_bulk_rebalance() - Rebalance the end of a tree after a bulk insert.
2085 * @mas: The maple state
2086 * @end: The maple node end
2087 * @mt: The maple node type
2089 static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end,
2092 if (!(mas->mas_flags & MA_STATE_BULK))
2095 if (mte_is_root(mas->node))
2098 if (end > mt_min_slots[mt]) {
2099 mas->mas_flags &= ~MA_STATE_REBALANCE;
2105 * mas_store_b_node() - Store an @entry into the b_node while also copying the
2106 * data from a maple encoded node.
2107 * @wr_mas: the maple write state
2108 * @b_node: the maple_big_node to fill with data
2109 * @offset_end: the offset to end copying
2111 * Return: The actual end of the data stored in @b_node
2113 static inline void mas_store_b_node(struct ma_wr_state *wr_mas,
2114 struct maple_big_node *b_node, unsigned char offset_end)
2117 unsigned char b_end;
2118 /* Possible underflow of piv will wrap back to 0 before use. */
2120 struct ma_state *mas = wr_mas->mas;
2122 b_node->type = wr_mas->type;
2126 /* Copy start data up to insert. */
2127 mas_mab_cp(mas, 0, slot - 1, b_node, 0);
2128 b_end = b_node->b_end;
2129 piv = b_node->pivot[b_end - 1];
2133 if (piv + 1 < mas->index) {
2134 /* Handle range starting after old range */
2135 b_node->slot[b_end] = wr_mas->content;
2136 if (!wr_mas->content)
2137 b_node->gap[b_end] = mas->index - 1 - piv;
2138 b_node->pivot[b_end++] = mas->index - 1;
2141 /* Store the new entry. */
2142 mas->offset = b_end;
2143 b_node->slot[b_end] = wr_mas->entry;
2144 b_node->pivot[b_end] = mas->last;
2147 if (mas->last >= mas->max)
2150 /* Handle new range ending before old range ends */
2151 piv = mas_logical_pivot(mas, wr_mas->pivots, offset_end, wr_mas->type);
2152 if (piv > mas->last) {
2153 if (piv == ULONG_MAX)
2154 mas_bulk_rebalance(mas, b_node->b_end, wr_mas->type);
2156 if (offset_end != slot)
2157 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
2160 b_node->slot[++b_end] = wr_mas->content;
2161 if (!wr_mas->content)
2162 b_node->gap[b_end] = piv - mas->last + 1;
2163 b_node->pivot[b_end] = piv;
2166 slot = offset_end + 1;
2167 if (slot > wr_mas->node_end)
2170 /* Copy end data to the end of the node. */
2171 mas_mab_cp(mas, slot, wr_mas->node_end + 1, b_node, ++b_end);
2176 b_node->b_end = b_end;
2180 * mas_prev_sibling() - Find the previous node with the same parent.
2181 * @mas: the maple state
2183 * Return: True if there is a previous sibling, false otherwise.
2185 static inline bool mas_prev_sibling(struct ma_state *mas)
2187 unsigned int p_slot = mte_parent_slot(mas->node);
2189 if (mte_is_root(mas->node))
2196 mas->offset = p_slot - 1;
2202 * mas_next_sibling() - Find the next node with the same parent.
2203 * @mas: the maple state
2205 * Return: true if there is a next sibling, false otherwise.
2207 static inline bool mas_next_sibling(struct ma_state *mas)
2209 MA_STATE(parent, mas->tree, mas->index, mas->last);
2211 if (mte_is_root(mas->node))
2215 mas_ascend(&parent);
2216 parent.offset = mte_parent_slot(mas->node) + 1;
2217 if (parent.offset > mas_data_end(&parent))
2226 * mte_node_or_node() - Return the encoded node or MAS_NONE.
2227 * @enode: The encoded maple node.
2229 * Shorthand to avoid setting %NULLs in the tree or maple_subtree_state.
2231 * Return: @enode or MAS_NONE
2233 static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode)
2238 return ma_enode_ptr(MAS_NONE);
2242 * mas_wr_node_walk() - Find the correct offset for the index in the @mas.
2243 * @wr_mas: The maple write state
2245 * Uses mas_slot_locked() and does not need to worry about dead nodes.
2247 static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas)
2249 struct ma_state *mas = wr_mas->mas;
2250 unsigned char count;
2251 unsigned char offset;
2252 unsigned long index, min, max;
2254 if (unlikely(ma_is_dense(wr_mas->type))) {
2255 wr_mas->r_max = wr_mas->r_min = mas->index;
2256 mas->offset = mas->index = mas->min;
2260 wr_mas->node = mas_mn(wr_mas->mas);
2261 wr_mas->pivots = ma_pivots(wr_mas->node, wr_mas->type);
2262 count = wr_mas->node_end = ma_data_end(wr_mas->node, wr_mas->type,
2263 wr_mas->pivots, mas->max);
2264 offset = mas->offset;
2265 min = mas_safe_min(mas, wr_mas->pivots, offset);
2266 if (unlikely(offset == count))
2269 max = wr_mas->pivots[offset];
2271 if (unlikely(index <= max))
2274 if (unlikely(!max && offset))
2278 while (++offset < count) {
2279 max = wr_mas->pivots[offset];
2282 else if (unlikely(!max))
2291 wr_mas->r_max = max;
2292 wr_mas->r_min = min;
2293 wr_mas->offset_end = mas->offset = offset;
2297 * mas_topiary_range() - Add a range of slots to the topiary.
2298 * @mas: The maple state
2299 * @destroy: The topiary to add the slots (usually destroy)
2300 * @start: The starting slot inclusively
2301 * @end: The end slot inclusively
2303 static inline void mas_topiary_range(struct ma_state *mas,
2304 struct ma_topiary *destroy, unsigned char start, unsigned char end)
2307 unsigned char offset;
2309 MT_BUG_ON(mas->tree, mte_is_leaf(mas->node));
2310 slots = ma_slots(mas_mn(mas), mte_node_type(mas->node));
2311 for (offset = start; offset <= end; offset++) {
2312 struct maple_enode *enode = mas_slot_locked(mas, slots, offset);
2314 if (mte_dead_node(enode))
2317 mat_add(destroy, enode);
2322 * mast_topiary() - Add the portions of the tree to the removal list; either to
2323 * be freed or discarded (destroy walk).
2324 * @mast: The maple_subtree_state.
2326 static inline void mast_topiary(struct maple_subtree_state *mast)
2328 MA_WR_STATE(wr_mas, mast->orig_l, NULL);
2329 unsigned char r_start, r_end;
2330 unsigned char l_start, l_end;
2331 void __rcu **l_slots, **r_slots;
2333 wr_mas.type = mte_node_type(mast->orig_l->node);
2334 mast->orig_l->index = mast->orig_l->last;
2335 mas_wr_node_walk(&wr_mas);
2336 l_start = mast->orig_l->offset + 1;
2337 l_end = mas_data_end(mast->orig_l);
2339 r_end = mast->orig_r->offset;
2344 l_slots = ma_slots(mas_mn(mast->orig_l),
2345 mte_node_type(mast->orig_l->node));
2347 r_slots = ma_slots(mas_mn(mast->orig_r),
2348 mte_node_type(mast->orig_r->node));
2350 if ((l_start < l_end) &&
2351 mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_start))) {
2355 if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_end))) {
2360 if ((l_start > r_end) && (mast->orig_l->node == mast->orig_r->node))
2363 /* At the node where left and right sides meet, add the parts between */
2364 if (mast->orig_l->node == mast->orig_r->node) {
2365 return mas_topiary_range(mast->orig_l, mast->destroy,
2369 /* mast->orig_r is different and consumed. */
2370 if (mte_is_leaf(mast->orig_r->node))
2373 if (mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_end)))
2377 if (l_start <= l_end)
2378 mas_topiary_range(mast->orig_l, mast->destroy, l_start, l_end);
2380 if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_start)))
2383 if (r_start <= r_end)
2384 mas_topiary_range(mast->orig_r, mast->destroy, 0, r_end);
2388 * mast_rebalance_next() - Rebalance against the next node
2389 * @mast: The maple subtree state
2390 * @old_r: The encoded maple node to the right (next node).
2392 static inline void mast_rebalance_next(struct maple_subtree_state *mast)
2394 unsigned char b_end = mast->bn->b_end;
2396 mas_mab_cp(mast->orig_r, 0, mt_slot_count(mast->orig_r->node),
2398 mast->orig_r->last = mast->orig_r->max;
2402 * mast_rebalance_prev() - Rebalance against the previous node
2403 * @mast: The maple subtree state
2404 * @old_l: The encoded maple node to the left (previous node)
2406 static inline void mast_rebalance_prev(struct maple_subtree_state *mast)
2408 unsigned char end = mas_data_end(mast->orig_l) + 1;
2409 unsigned char b_end = mast->bn->b_end;
2411 mab_shift_right(mast->bn, end);
2412 mas_mab_cp(mast->orig_l, 0, end - 1, mast->bn, 0);
2413 mast->l->min = mast->orig_l->min;
2414 mast->orig_l->index = mast->orig_l->min;
2415 mast->bn->b_end = end + b_end;
2416 mast->l->offset += end;
2420 * mast_spanning_rebalance() - Rebalance nodes with nearest neighbour favouring
2421 * the node to the right. Checking the nodes to the right then the left at each
2422 * level upwards until root is reached. Free and destroy as needed.
2423 * Data is copied into the @mast->bn.
2424 * @mast: The maple_subtree_state.
2427 bool mast_spanning_rebalance(struct maple_subtree_state *mast)
2429 struct ma_state r_tmp = *mast->orig_r;
2430 struct ma_state l_tmp = *mast->orig_l;
2431 struct maple_enode *ancestor = NULL;
2432 unsigned char start, end;
2433 unsigned char depth = 0;
2435 r_tmp = *mast->orig_r;
2436 l_tmp = *mast->orig_l;
2438 mas_ascend(mast->orig_r);
2439 mas_ascend(mast->orig_l);
2442 (mast->orig_r->node == mast->orig_l->node)) {
2443 ancestor = mast->orig_r->node;
2444 end = mast->orig_r->offset - 1;
2445 start = mast->orig_l->offset + 1;
2448 if (mast->orig_r->offset < mas_data_end(mast->orig_r)) {
2450 ancestor = mast->orig_r->node;
2454 mast->orig_r->offset++;
2456 mas_descend(mast->orig_r);
2457 mast->orig_r->offset = 0;
2461 mast_rebalance_next(mast);
2463 unsigned char l_off = 0;
2464 struct maple_enode *child = r_tmp.node;
2467 if (ancestor == r_tmp.node)
2473 if (l_off < r_tmp.offset)
2474 mas_topiary_range(&r_tmp, mast->destroy,
2475 l_off, r_tmp.offset);
2477 if (l_tmp.node != child)
2478 mat_add(mast->free, child);
2480 } while (r_tmp.node != ancestor);
2482 *mast->orig_l = l_tmp;
2485 } else if (mast->orig_l->offset != 0) {
2487 ancestor = mast->orig_l->node;
2488 end = mas_data_end(mast->orig_l);
2491 mast->orig_l->offset--;
2493 mas_descend(mast->orig_l);
2494 mast->orig_l->offset =
2495 mas_data_end(mast->orig_l);
2499 mast_rebalance_prev(mast);
2501 unsigned char r_off;
2502 struct maple_enode *child = l_tmp.node;
2505 if (ancestor == l_tmp.node)
2508 r_off = mas_data_end(&l_tmp);
2510 if (l_tmp.offset < r_off)
2513 if (l_tmp.offset < r_off)
2514 mas_topiary_range(&l_tmp, mast->destroy,
2515 l_tmp.offset, r_off);
2517 if (r_tmp.node != child)
2518 mat_add(mast->free, child);
2520 } while (l_tmp.node != ancestor);
2522 *mast->orig_r = r_tmp;
2525 } while (!mte_is_root(mast->orig_r->node));
2527 *mast->orig_r = r_tmp;
2528 *mast->orig_l = l_tmp;
2533 * mast_ascend_free() - Add current original maple state nodes to the free list
2535 * @mast: the maple subtree state.
2537 * Ascend the original left and right sides and add the previous nodes to the
2538 * free list. Set the slots to point to the correct location in the new nodes.
2541 mast_ascend_free(struct maple_subtree_state *mast)
2543 MA_WR_STATE(wr_mas, mast->orig_r, NULL);
2544 struct maple_enode *left = mast->orig_l->node;
2545 struct maple_enode *right = mast->orig_r->node;
2547 mas_ascend(mast->orig_l);
2548 mas_ascend(mast->orig_r);
2549 mat_add(mast->free, left);
2552 mat_add(mast->free, right);
2554 mast->orig_r->offset = 0;
2555 mast->orig_r->index = mast->r->max;
2556 /* last should be larger than or equal to index */
2557 if (mast->orig_r->last < mast->orig_r->index)
2558 mast->orig_r->last = mast->orig_r->index;
2560 * The node may not contain the value so set slot to ensure all
2561 * of the nodes contents are freed or destroyed.
2563 wr_mas.type = mte_node_type(mast->orig_r->node);
2564 mas_wr_node_walk(&wr_mas);
2565 /* Set up the left side of things */
2566 mast->orig_l->offset = 0;
2567 mast->orig_l->index = mast->l->min;
2568 wr_mas.mas = mast->orig_l;
2569 wr_mas.type = mte_node_type(mast->orig_l->node);
2570 mas_wr_node_walk(&wr_mas);
2572 mast->bn->type = wr_mas.type;
2576 * mas_new_ma_node() - Create and return a new maple node. Helper function.
2577 * @mas: the maple state with the allocations.
2578 * @b_node: the maple_big_node with the type encoding.
2580 * Use the node type from the maple_big_node to allocate a new node from the
2581 * ma_state. This function exists mainly for code readability.
2583 * Return: A new maple encoded node
2585 static inline struct maple_enode
2586 *mas_new_ma_node(struct ma_state *mas, struct maple_big_node *b_node)
2588 return mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), b_node->type);
2592 * mas_mab_to_node() - Set up right and middle nodes
2594 * @mas: the maple state that contains the allocations.
2595 * @b_node: the node which contains the data.
2596 * @left: The pointer which will have the left node
2597 * @right: The pointer which may have the right node
2598 * @middle: the pointer which may have the middle node (rare)
2599 * @mid_split: the split location for the middle node
2601 * Return: the split of left.
2603 static inline unsigned char mas_mab_to_node(struct ma_state *mas,
2604 struct maple_big_node *b_node, struct maple_enode **left,
2605 struct maple_enode **right, struct maple_enode **middle,
2606 unsigned char *mid_split, unsigned long min)
2608 unsigned char split = 0;
2609 unsigned char slot_count = mt_slots[b_node->type];
2611 *left = mas_new_ma_node(mas, b_node);
2616 if (b_node->b_end < slot_count) {
2617 split = b_node->b_end;
2619 split = mab_calc_split(mas, b_node, mid_split, min);
2620 *right = mas_new_ma_node(mas, b_node);
2624 *middle = mas_new_ma_node(mas, b_node);
2631 * mab_set_b_end() - Add entry to b_node at b_node->b_end and increment the end
2633 * @b_node - the big node to add the entry
2634 * @mas - the maple state to get the pivot (mas->max)
2635 * @entry - the entry to add, if NULL nothing happens.
2637 static inline void mab_set_b_end(struct maple_big_node *b_node,
2638 struct ma_state *mas,
2644 b_node->slot[b_node->b_end] = entry;
2645 if (mt_is_alloc(mas->tree))
2646 b_node->gap[b_node->b_end] = mas_max_gap(mas);
2647 b_node->pivot[b_node->b_end++] = mas->max;
2651 * mas_set_split_parent() - combine_then_separate helper function. Sets the parent
2652 * of @mas->node to either @left or @right, depending on @slot and @split
2654 * @mas - the maple state with the node that needs a parent
2655 * @left - possible parent 1
2656 * @right - possible parent 2
2657 * @slot - the slot the mas->node was placed
2658 * @split - the split location between @left and @right
2660 static inline void mas_set_split_parent(struct ma_state *mas,
2661 struct maple_enode *left,
2662 struct maple_enode *right,
2663 unsigned char *slot, unsigned char split)
2665 if (mas_is_none(mas))
2668 if ((*slot) <= split)
2669 mte_set_parent(mas->node, left, *slot);
2671 mte_set_parent(mas->node, right, (*slot) - split - 1);
2677 * mte_mid_split_check() - Check if the next node passes the mid-split
2678 * @**l: Pointer to left encoded maple node.
2679 * @**m: Pointer to middle encoded maple node.
2680 * @**r: Pointer to right encoded maple node.
2682 * @*split: The split location.
2683 * @mid_split: The middle split.
2685 static inline void mte_mid_split_check(struct maple_enode **l,
2686 struct maple_enode **r,
2687 struct maple_enode *right,
2689 unsigned char *split,
2690 unsigned char mid_split)
2695 if (slot < mid_split)
2704 * mast_set_split_parents() - Helper function to set three nodes parents. Slot
2705 * is taken from @mast->l.
2706 * @mast - the maple subtree state
2707 * @left - the left node
2708 * @right - the right node
2709 * @split - the split location.
2711 static inline void mast_set_split_parents(struct maple_subtree_state *mast,
2712 struct maple_enode *left,
2713 struct maple_enode *middle,
2714 struct maple_enode *right,
2715 unsigned char split,
2716 unsigned char mid_split)
2719 struct maple_enode *l = left;
2720 struct maple_enode *r = right;
2722 if (mas_is_none(mast->l))
2728 slot = mast->l->offset;
2730 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2731 mas_set_split_parent(mast->l, l, r, &slot, split);
2733 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2734 mas_set_split_parent(mast->m, l, r, &slot, split);
2736 mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
2737 mas_set_split_parent(mast->r, l, r, &slot, split);
2741 * mas_wmb_replace() - Write memory barrier and replace
2742 * @mas: The maple state
2743 * @free: the maple topiary list of nodes to free
2744 * @destroy: The maple topiary list of nodes to destroy (walk and free)
2746 * Updates gap as necessary.
2748 static inline void mas_wmb_replace(struct ma_state *mas,
2749 struct ma_topiary *free,
2750 struct ma_topiary *destroy)
2752 /* All nodes must see old data as dead prior to replacing that data */
2753 smp_wmb(); /* Needed for RCU */
2755 /* Insert the new data in the tree */
2756 mas_replace(mas, true);
2758 if (!mte_is_leaf(mas->node))
2759 mas_descend_adopt(mas);
2761 mas_mat_free(mas, free);
2764 mas_mat_destroy(mas, destroy);
2766 if (mte_is_leaf(mas->node))
2769 mas_update_gap(mas);
2773 * mast_new_root() - Set a new tree root during subtree creation
2774 * @mast: The maple subtree state
2775 * @mas: The maple state
2777 static inline void mast_new_root(struct maple_subtree_state *mast,
2778 struct ma_state *mas)
2780 mas_mn(mast->l)->parent =
2781 ma_parent_ptr(((unsigned long)mas->tree | MA_ROOT_PARENT));
2782 if (!mte_dead_node(mast->orig_l->node) &&
2783 !mte_is_root(mast->orig_l->node)) {
2785 mast_ascend_free(mast);
2787 } while (!mte_is_root(mast->orig_l->node));
2789 if ((mast->orig_l->node != mas->node) &&
2790 (mast->l->depth > mas_mt_height(mas))) {
2791 mat_add(mast->free, mas->node);
2796 * mast_cp_to_nodes() - Copy data out to nodes.
2797 * @mast: The maple subtree state
2798 * @left: The left encoded maple node
2799 * @middle: The middle encoded maple node
2800 * @right: The right encoded maple node
2801 * @split: The location to split between left and (middle ? middle : right)
2802 * @mid_split: The location to split between middle and right.
2804 static inline void mast_cp_to_nodes(struct maple_subtree_state *mast,
2805 struct maple_enode *left, struct maple_enode *middle,
2806 struct maple_enode *right, unsigned char split, unsigned char mid_split)
2808 bool new_lmax = true;
2810 mast->l->node = mte_node_or_none(left);
2811 mast->m->node = mte_node_or_none(middle);
2812 mast->r->node = mte_node_or_none(right);
2814 mast->l->min = mast->orig_l->min;
2815 if (split == mast->bn->b_end) {
2816 mast->l->max = mast->orig_r->max;
2820 mab_mas_cp(mast->bn, 0, split, mast->l, new_lmax);
2823 mab_mas_cp(mast->bn, 1 + split, mid_split, mast->m, true);
2824 mast->m->min = mast->bn->pivot[split] + 1;
2828 mast->r->max = mast->orig_r->max;
2830 mab_mas_cp(mast->bn, 1 + split, mast->bn->b_end, mast->r, false);
2831 mast->r->min = mast->bn->pivot[split] + 1;
2836 * mast_combine_cp_left - Copy in the original left side of the tree into the
2837 * combined data set in the maple subtree state big node.
2838 * @mast: The maple subtree state
2840 static inline void mast_combine_cp_left(struct maple_subtree_state *mast)
2842 unsigned char l_slot = mast->orig_l->offset;
2847 mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
2851 * mast_combine_cp_right: Copy in the original right side of the tree into the
2852 * combined data set in the maple subtree state big node.
2853 * @mast: The maple subtree state
2855 static inline void mast_combine_cp_right(struct maple_subtree_state *mast)
2857 if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max)
2860 mas_mab_cp(mast->orig_r, mast->orig_r->offset + 1,
2861 mt_slot_count(mast->orig_r->node), mast->bn,
2863 mast->orig_r->last = mast->orig_r->max;
2867 * mast_sufficient: Check if the maple subtree state has enough data in the big
2868 * node to create at least one sufficient node
2869 * @mast: the maple subtree state
2871 static inline bool mast_sufficient(struct maple_subtree_state *mast)
2873 if (mast->bn->b_end > mt_min_slot_count(mast->orig_l->node))
2880 * mast_overflow: Check if there is too much data in the subtree state for a
2882 * @mast: The maple subtree state
2884 static inline bool mast_overflow(struct maple_subtree_state *mast)
2886 if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node))
2892 static inline void *mtree_range_walk(struct ma_state *mas)
2894 unsigned long *pivots;
2895 unsigned char offset;
2896 struct maple_node *node;
2897 struct maple_enode *next, *last;
2898 enum maple_type type;
2901 unsigned long max, min;
2902 unsigned long prev_max, prev_min;
2910 node = mte_to_node(next);
2911 type = mte_node_type(next);
2912 pivots = ma_pivots(node, type);
2913 end = ma_data_end(node, type, pivots, max);
2914 if (unlikely(ma_dead_node(node)))
2917 if (pivots[offset] >= mas->index) {
2920 max = pivots[offset];
2926 } while ((offset < end) && (pivots[offset] < mas->index));
2929 min = pivots[offset - 1] + 1;
2931 if (likely(offset < end && pivots[offset]))
2932 max = pivots[offset];
2935 slots = ma_slots(node, type);
2936 next = mt_slot(mas->tree, slots, offset);
2937 if (unlikely(ma_dead_node(node)))
2939 } while (!ma_is_leaf(type));
2941 mas->offset = offset;
2944 mas->min = prev_min;
2945 mas->max = prev_max;
2947 return (void *) next;
2955 * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
2956 * @mas: The starting maple state
2957 * @mast: The maple_subtree_state, keeps track of 4 maple states.
2958 * @count: The estimated count of iterations needed.
2960 * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
2961 * is hit. First @b_node is split into two entries which are inserted into the
2962 * next iteration of the loop. @b_node is returned populated with the final
2963 * iteration. @mas is used to obtain allocations. orig_l_mas keeps track of the
2964 * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
2965 * to account of what has been copied into the new sub-tree. The update of
2966 * orig_l_mas->last is used in mas_consume to find the slots that will need to
2967 * be either freed or destroyed. orig_l_mas->depth keeps track of the height of
2968 * the new sub-tree in case the sub-tree becomes the full tree.
2970 * Return: the number of elements in b_node during the last loop.
2972 static int mas_spanning_rebalance(struct ma_state *mas,
2973 struct maple_subtree_state *mast, unsigned char count)
2975 unsigned char split, mid_split;
2976 unsigned char slot = 0;
2977 struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
2979 MA_STATE(l_mas, mas->tree, mas->index, mas->index);
2980 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
2981 MA_STATE(m_mas, mas->tree, mas->index, mas->index);
2982 MA_TOPIARY(free, mas->tree);
2983 MA_TOPIARY(destroy, mas->tree);
2986 * The tree needs to be rebalanced and leaves need to be kept at the same level.
2987 * Rebalancing is done by use of the ``struct maple_topiary``.
2993 mast->destroy = &destroy;
2994 l_mas.node = r_mas.node = m_mas.node = MAS_NONE;
2995 if (!(mast->orig_l->min && mast->orig_r->max == ULONG_MAX) &&
2996 unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
2997 mast_spanning_rebalance(mast);
2999 mast->orig_l->depth = 0;
3002 * Each level of the tree is examined and balanced, pushing data to the left or
3003 * right, or rebalancing against left or right nodes is employed to avoid
3004 * rippling up the tree to limit the amount of churn. Once a new sub-section of
3005 * the tree is created, there may be a mix of new and old nodes. The old nodes
3006 * will have the incorrect parent pointers and currently be in two trees: the
3007 * original tree and the partially new tree. To remedy the parent pointers in
3008 * the old tree, the new data is swapped into the active tree and a walk down
3009 * the tree is performed and the parent pointers are updated.
3010 * See mas_descend_adopt() for more information..
3014 mast->bn->type = mte_node_type(mast->orig_l->node);
3015 split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
3016 &mid_split, mast->orig_l->min);
3017 mast_set_split_parents(mast, left, middle, right, split,
3019 mast_cp_to_nodes(mast, left, middle, right, split, mid_split);
3022 * Copy data from next level in the tree to mast->bn from next
3025 memset(mast->bn, 0, sizeof(struct maple_big_node));
3026 mast->bn->type = mte_node_type(left);
3027 mast->orig_l->depth++;
3029 /* Root already stored in l->node. */
3030 if (mas_is_root_limits(mast->l))
3033 mast_ascend_free(mast);
3034 mast_combine_cp_left(mast);
3035 l_mas.offset = mast->bn->b_end;
3036 mab_set_b_end(mast->bn, &l_mas, left);
3037 mab_set_b_end(mast->bn, &m_mas, middle);
3038 mab_set_b_end(mast->bn, &r_mas, right);
3040 /* Copy anything necessary out of the right node. */
3041 mast_combine_cp_right(mast);
3043 mast->orig_l->last = mast->orig_l->max;
3045 if (mast_sufficient(mast))
3048 if (mast_overflow(mast))
3051 /* May be a new root stored in mast->bn */
3052 if (mas_is_root_limits(mast->orig_l))
3055 mast_spanning_rebalance(mast);
3057 /* rebalancing from other nodes may require another loop. */
3062 l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
3063 mte_node_type(mast->orig_l->node));
3064 mast->orig_l->depth++;
3065 mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
3066 mte_set_parent(left, l_mas.node, slot);
3068 mte_set_parent(middle, l_mas.node, ++slot);
3071 mte_set_parent(right, l_mas.node, ++slot);
3073 if (mas_is_root_limits(mast->l)) {
3075 mast_new_root(mast, mas);
3077 mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent;
3080 if (!mte_dead_node(mast->orig_l->node))
3081 mat_add(&free, mast->orig_l->node);
3083 mas->depth = mast->orig_l->depth;
3084 *mast->orig_l = l_mas;
3085 mte_set_node_dead(mas->node);
3087 /* Set up mas for insertion. */
3088 mast->orig_l->depth = mas->depth;
3089 mast->orig_l->alloc = mas->alloc;
3090 *mas = *mast->orig_l;
3091 mas_wmb_replace(mas, &free, &destroy);
3092 mtree_range_walk(mas);
3093 return mast->bn->b_end;
3097 * mas_rebalance() - Rebalance a given node.
3098 * @mas: The maple state
3099 * @b_node: The big maple node.
3101 * Rebalance two nodes into a single node or two new nodes that are sufficient.
3102 * Continue upwards until tree is sufficient.
3104 * Return: the number of elements in b_node during the last loop.
3106 static inline int mas_rebalance(struct ma_state *mas,
3107 struct maple_big_node *b_node)
3109 char empty_count = mas_mt_height(mas);
3110 struct maple_subtree_state mast;
3111 unsigned char shift, b_end = ++b_node->b_end;
3113 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3114 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
3116 trace_ma_op(__func__, mas);
3119 * Rebalancing occurs if a node is insufficient. Data is rebalanced
3120 * against the node to the right if it exists, otherwise the node to the
3121 * left of this node is rebalanced against this node. If rebalancing
3122 * causes just one node to be produced instead of two, then the parent
3123 * is also examined and rebalanced if it is insufficient. Every level
3124 * tries to combine the data in the same way. If one node contains the
3125 * entire range of the tree, then that node is used as a new root node.
3127 mas_node_count(mas, 1 + empty_count * 3);
3128 if (mas_is_err(mas))
3131 mast.orig_l = &l_mas;
3132 mast.orig_r = &r_mas;
3134 mast.bn->type = mte_node_type(mas->node);
3136 l_mas = r_mas = *mas;
3138 if (mas_next_sibling(&r_mas)) {
3139 mas_mab_cp(&r_mas, 0, mt_slot_count(r_mas.node), b_node, b_end);
3140 r_mas.last = r_mas.index = r_mas.max;
3142 mas_prev_sibling(&l_mas);
3143 shift = mas_data_end(&l_mas) + 1;
3144 mab_shift_right(b_node, shift);
3145 mas->offset += shift;
3146 mas_mab_cp(&l_mas, 0, shift - 1, b_node, 0);
3147 b_node->b_end = shift + b_end;
3148 l_mas.index = l_mas.last = l_mas.min;
3151 return mas_spanning_rebalance(mas, &mast, empty_count);
3155 * mas_destroy_rebalance() - Rebalance left-most node while destroying the maple
3157 * @mas: The maple state
3158 * @end: The end of the left-most node.
3160 * During a mass-insert event (such as forking), it may be necessary to
3161 * rebalance the left-most node when it is not sufficient.
3163 static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end)
3165 enum maple_type mt = mte_node_type(mas->node);
3166 struct maple_node reuse, *newnode, *parent, *new_left, *left, *node;
3167 struct maple_enode *eparent;
3168 unsigned char offset, tmp, split = mt_slots[mt] / 2;
3169 void __rcu **l_slots, **slots;
3170 unsigned long *l_pivs, *pivs, gap;
3171 bool in_rcu = mt_in_rcu(mas->tree);
3173 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3176 mas_prev_sibling(&l_mas);
3180 /* Allocate for both left and right as well as parent. */
3181 mas_node_count(mas, 3);
3182 if (mas_is_err(mas))
3185 newnode = mas_pop_node(mas);
3191 newnode->parent = node->parent;
3192 slots = ma_slots(newnode, mt);
3193 pivs = ma_pivots(newnode, mt);
3194 left = mas_mn(&l_mas);
3195 l_slots = ma_slots(left, mt);
3196 l_pivs = ma_pivots(left, mt);
3197 if (!l_slots[split])
3199 tmp = mas_data_end(&l_mas) - split;
3201 memcpy(slots, l_slots + split + 1, sizeof(void *) * tmp);
3202 memcpy(pivs, l_pivs + split + 1, sizeof(unsigned long) * tmp);
3203 pivs[tmp] = l_mas.max;
3204 memcpy(slots + tmp, ma_slots(node, mt), sizeof(void *) * end);
3205 memcpy(pivs + tmp, ma_pivots(node, mt), sizeof(unsigned long) * end);
3207 l_mas.max = l_pivs[split];
3208 mas->min = l_mas.max + 1;
3209 eparent = mt_mk_node(mte_parent(l_mas.node),
3210 mas_parent_enum(&l_mas, l_mas.node));
3213 unsigned char max_p = mt_pivots[mt];
3214 unsigned char max_s = mt_slots[mt];
3217 memset(pivs + tmp, 0,
3218 sizeof(unsigned long *) * (max_p - tmp));
3220 if (tmp < mt_slots[mt])
3221 memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp));
3223 memcpy(node, newnode, sizeof(struct maple_node));
3224 ma_set_meta(node, mt, 0, tmp - 1);
3225 mte_set_pivot(eparent, mte_parent_slot(l_mas.node),
3228 /* Remove data from l_pivs. */
3230 memset(l_pivs + tmp, 0, sizeof(unsigned long) * (max_p - tmp));
3231 memset(l_slots + tmp, 0, sizeof(void *) * (max_s - tmp));
3232 ma_set_meta(left, mt, 0, split);
3237 /* RCU requires replacing both l_mas, mas, and parent. */
3238 mas->node = mt_mk_node(newnode, mt);
3239 ma_set_meta(newnode, mt, 0, tmp);
3241 new_left = mas_pop_node(mas);
3242 new_left->parent = left->parent;
3243 mt = mte_node_type(l_mas.node);
3244 slots = ma_slots(new_left, mt);
3245 pivs = ma_pivots(new_left, mt);
3246 memcpy(slots, l_slots, sizeof(void *) * split);
3247 memcpy(pivs, l_pivs, sizeof(unsigned long) * split);
3248 ma_set_meta(new_left, mt, 0, split);
3249 l_mas.node = mt_mk_node(new_left, mt);
3251 /* replace parent. */
3252 offset = mte_parent_slot(mas->node);
3253 mt = mas_parent_enum(&l_mas, l_mas.node);
3254 parent = mas_pop_node(mas);
3255 slots = ma_slots(parent, mt);
3256 pivs = ma_pivots(parent, mt);
3257 memcpy(parent, mte_to_node(eparent), sizeof(struct maple_node));
3258 rcu_assign_pointer(slots[offset], mas->node);
3259 rcu_assign_pointer(slots[offset - 1], l_mas.node);
3260 pivs[offset - 1] = l_mas.max;
3261 eparent = mt_mk_node(parent, mt);
3263 gap = mas_leaf_max_gap(mas);
3264 mte_set_gap(eparent, mte_parent_slot(mas->node), gap);
3265 gap = mas_leaf_max_gap(&l_mas);
3266 mte_set_gap(eparent, mte_parent_slot(l_mas.node), gap);
3270 mas_replace(mas, false);
3272 mas_update_gap(mas);
3276 * mas_split_final_node() - Split the final node in a subtree operation.
3277 * @mast: the maple subtree state
3278 * @mas: The maple state
3279 * @height: The height of the tree in case it's a new root.
3281 static inline bool mas_split_final_node(struct maple_subtree_state *mast,
3282 struct ma_state *mas, int height)
3284 struct maple_enode *ancestor;
3286 if (mte_is_root(mas->node)) {
3287 if (mt_is_alloc(mas->tree))
3288 mast->bn->type = maple_arange_64;
3290 mast->bn->type = maple_range_64;
3291 mas->depth = height;
3294 * Only a single node is used here, could be root.
3295 * The Big_node data should just fit in a single node.
3297 ancestor = mas_new_ma_node(mas, mast->bn);
3298 mte_set_parent(mast->l->node, ancestor, mast->l->offset);
3299 mte_set_parent(mast->r->node, ancestor, mast->r->offset);
3300 mte_to_node(ancestor)->parent = mas_mn(mas)->parent;
3302 mast->l->node = ancestor;
3303 mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true);
3304 mas->offset = mast->bn->b_end - 1;
3309 * mast_fill_bnode() - Copy data into the big node in the subtree state
3310 * @mast: The maple subtree state
3311 * @mas: the maple state
3312 * @skip: The number of entries to skip for new nodes insertion.
3314 static inline void mast_fill_bnode(struct maple_subtree_state *mast,
3315 struct ma_state *mas,
3319 struct maple_enode *old = mas->node;
3320 unsigned char split;
3322 memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap));
3323 memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot));
3324 memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot));
3325 mast->bn->b_end = 0;
3327 if (mte_is_root(mas->node)) {
3331 mat_add(mast->free, old);
3332 mas->offset = mte_parent_slot(mas->node);
3335 if (cp && mast->l->offset)
3336 mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0);
3338 split = mast->bn->b_end;
3339 mab_set_b_end(mast->bn, mast->l, mast->l->node);
3340 mast->r->offset = mast->bn->b_end;
3341 mab_set_b_end(mast->bn, mast->r, mast->r->node);
3342 if (mast->bn->pivot[mast->bn->b_end - 1] == mas->max)
3346 mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1,
3347 mast->bn, mast->bn->b_end);
3350 mast->bn->type = mte_node_type(mas->node);
3354 * mast_split_data() - Split the data in the subtree state big node into regular
3356 * @mast: The maple subtree state
3357 * @mas: The maple state
3358 * @split: The location to split the big node
3360 static inline void mast_split_data(struct maple_subtree_state *mast,
3361 struct ma_state *mas, unsigned char split)
3363 unsigned char p_slot;
3365 mab_mas_cp(mast->bn, 0, split, mast->l, true);
3366 mte_set_pivot(mast->r->node, 0, mast->r->max);
3367 mab_mas_cp(mast->bn, split + 1, mast->bn->b_end, mast->r, false);
3368 mast->l->offset = mte_parent_slot(mas->node);
3369 mast->l->max = mast->bn->pivot[split];
3370 mast->r->min = mast->l->max + 1;
3371 if (mte_is_leaf(mas->node))
3374 p_slot = mast->orig_l->offset;
3375 mas_set_split_parent(mast->orig_l, mast->l->node, mast->r->node,
3377 mas_set_split_parent(mast->orig_r, mast->l->node, mast->r->node,
3382 * mas_push_data() - Instead of splitting a node, it is beneficial to push the
3383 * data to the right or left node if there is room.
3384 * @mas: The maple state
3385 * @height: The current height of the maple state
3386 * @mast: The maple subtree state
3387 * @left: Push left or not.
3389 * Keeping the height of the tree low means faster lookups.
3391 * Return: True if pushed, false otherwise.
3393 static inline bool mas_push_data(struct ma_state *mas, int height,
3394 struct maple_subtree_state *mast, bool left)
3396 unsigned char slot_total = mast->bn->b_end;
3397 unsigned char end, space, split;
3399 MA_STATE(tmp_mas, mas->tree, mas->index, mas->last);
3401 tmp_mas.depth = mast->l->depth;
3403 if (left && !mas_prev_sibling(&tmp_mas))
3405 else if (!left && !mas_next_sibling(&tmp_mas))
3408 end = mas_data_end(&tmp_mas);
3410 space = 2 * mt_slot_count(mas->node) - 2;
3411 /* -2 instead of -1 to ensure there isn't a triple split */
3412 if (ma_is_leaf(mast->bn->type))
3415 if (mas->max == ULONG_MAX)
3418 if (slot_total >= space)
3421 /* Get the data; Fill mast->bn */
3424 mab_shift_right(mast->bn, end + 1);
3425 mas_mab_cp(&tmp_mas, 0, end, mast->bn, 0);
3426 mast->bn->b_end = slot_total + 1;
3428 mas_mab_cp(&tmp_mas, 0, end, mast->bn, mast->bn->b_end);
3431 /* Configure mast for splitting of mast->bn */
3432 split = mt_slots[mast->bn->type] - 2;
3434 /* Switch mas to prev node */
3435 mat_add(mast->free, mas->node);
3437 /* Start using mast->l for the left side. */
3438 tmp_mas.node = mast->l->node;
3441 mat_add(mast->free, tmp_mas.node);
3442 tmp_mas.node = mast->r->node;
3444 split = slot_total - split;
3446 split = mab_no_null_split(mast->bn, split, mt_slots[mast->bn->type]);
3447 /* Update parent slot for split calculation. */
3449 mast->orig_l->offset += end + 1;
3451 mast_split_data(mast, mas, split);
3452 mast_fill_bnode(mast, mas, 2);
3453 mas_split_final_node(mast, mas, height + 1);
3458 * mas_split() - Split data that is too big for one node into two.
3459 * @mas: The maple state
3460 * @b_node: The maple big node
3461 * Return: 1 on success, 0 on failure.
3463 static int mas_split(struct ma_state *mas, struct maple_big_node *b_node)
3466 struct maple_subtree_state mast;
3468 unsigned char mid_split, split = 0;
3471 * Splitting is handled differently from any other B-tree; the Maple
3472 * Tree splits upwards. Splitting up means that the split operation
3473 * occurs when the walk of the tree hits the leaves and not on the way
3474 * down. The reason for splitting up is that it is impossible to know
3475 * how much space will be needed until the leaf is (or leaves are)
3476 * reached. Since overwriting data is allowed and a range could
3477 * overwrite more than one range or result in changing one entry into 3
3478 * entries, it is impossible to know if a split is required until the
3481 * Splitting is a balancing act between keeping allocations to a minimum
3482 * and avoiding a 'jitter' event where a tree is expanded to make room
3483 * for an entry followed by a contraction when the entry is removed. To
3484 * accomplish the balance, there are empty slots remaining in both left
3485 * and right nodes after a split.
3487 MA_STATE(l_mas, mas->tree, mas->index, mas->last);
3488 MA_STATE(r_mas, mas->tree, mas->index, mas->last);
3489 MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last);
3490 MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);
3491 MA_TOPIARY(mat, mas->tree);
3493 trace_ma_op(__func__, mas);
3494 mas->depth = mas_mt_height(mas);
3495 /* Allocation failures will happen early. */
3496 mas_node_count(mas, 1 + mas->depth * 2);
3497 if (mas_is_err(mas))
3502 mast.orig_l = &prev_l_mas;
3503 mast.orig_r = &prev_r_mas;
3507 while (height++ <= mas->depth) {
3508 if (mt_slots[b_node->type] > b_node->b_end) {
3509 mas_split_final_node(&mast, mas, height);
3513 l_mas = r_mas = *mas;
3514 l_mas.node = mas_new_ma_node(mas, b_node);
3515 r_mas.node = mas_new_ma_node(mas, b_node);
3517 * Another way that 'jitter' is avoided is to terminate a split up early if the
3518 * left or right node has space to spare. This is referred to as "pushing left"
3519 * or "pushing right" and is similar to the B* tree, except the nodes left or
3520 * right can rarely be reused due to RCU, but the ripple upwards is halted which
3521 * is a significant savings.
3523 /* Try to push left. */
3524 if (mas_push_data(mas, height, &mast, true))
3527 /* Try to push right. */
3528 if (mas_push_data(mas, height, &mast, false))
3531 split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min);
3532 mast_split_data(&mast, mas, split);
3534 * Usually correct, mab_mas_cp in the above call overwrites
3537 mast.r->max = mas->max;
3538 mast_fill_bnode(&mast, mas, 1);
3539 prev_l_mas = *mast.l;
3540 prev_r_mas = *mast.r;
3543 /* Set the original node as dead */
3544 mat_add(mast.free, mas->node);
3545 mas->node = l_mas.node;
3546 mas_wmb_replace(mas, mast.free, NULL);
3547 mtree_range_walk(mas);
3552 * mas_reuse_node() - Reuse the node to store the data.
3553 * @wr_mas: The maple write state
3554 * @bn: The maple big node
3555 * @end: The end of the data.
3557 * Will always return false in RCU mode.
3559 * Return: True if node was reused, false otherwise.
3561 static inline bool mas_reuse_node(struct ma_wr_state *wr_mas,
3562 struct maple_big_node *bn, unsigned char end)
3564 /* Need to be rcu safe. */
3565 if (mt_in_rcu(wr_mas->mas->tree))
3568 if (end > bn->b_end) {
3569 int clear = mt_slots[wr_mas->type] - bn->b_end;
3571 memset(wr_mas->slots + bn->b_end, 0, sizeof(void *) * clear--);
3572 memset(wr_mas->pivots + bn->b_end, 0, sizeof(void *) * clear);
3574 mab_mas_cp(bn, 0, bn->b_end, wr_mas->mas, false);
3579 * mas_commit_b_node() - Commit the big node into the tree.
3580 * @wr_mas: The maple write state
3581 * @b_node: The maple big node
3582 * @end: The end of the data.
3584 static inline int mas_commit_b_node(struct ma_wr_state *wr_mas,
3585 struct maple_big_node *b_node, unsigned char end)
3587 struct maple_node *node;
3588 unsigned char b_end = b_node->b_end;
3589 enum maple_type b_type = b_node->type;
3591 if ((b_end < mt_min_slots[b_type]) &&
3592 (!mte_is_root(wr_mas->mas->node)) &&
3593 (mas_mt_height(wr_mas->mas) > 1))
3594 return mas_rebalance(wr_mas->mas, b_node);
3596 if (b_end >= mt_slots[b_type])
3597 return mas_split(wr_mas->mas, b_node);
3599 if (mas_reuse_node(wr_mas, b_node, end))
3602 mas_node_count(wr_mas->mas, 1);
3603 if (mas_is_err(wr_mas->mas))
3606 node = mas_pop_node(wr_mas->mas);
3607 node->parent = mas_mn(wr_mas->mas)->parent;
3608 wr_mas->mas->node = mt_mk_node(node, b_type);
3609 mab_mas_cp(b_node, 0, b_end, wr_mas->mas, true);
3611 mas_replace(wr_mas->mas, false);
3613 mas_update_gap(wr_mas->mas);
3618 * mas_root_expand() - Expand a root to a node
3619 * @mas: The maple state
3620 * @entry: The entry to store into the tree
3622 static inline int mas_root_expand(struct ma_state *mas, void *entry)
3624 void *contents = mas_root_locked(mas);
3625 enum maple_type type = maple_leaf_64;
3626 struct maple_node *node;
3628 unsigned long *pivots;
3631 mas_node_count(mas, 1);
3632 if (unlikely(mas_is_err(mas)))
3635 node = mas_pop_node(mas);
3636 pivots = ma_pivots(node, type);
3637 slots = ma_slots(node, type);
3638 node->parent = ma_parent_ptr(
3639 ((unsigned long)mas->tree | MA_ROOT_PARENT));
3640 mas->node = mt_mk_node(node, type);
3644 rcu_assign_pointer(slots[slot], contents);
3645 if (likely(mas->index > 1))
3648 pivots[slot++] = mas->index - 1;
3651 rcu_assign_pointer(slots[slot], entry);
3653 pivots[slot] = mas->last;
3654 if (mas->last != ULONG_MAX)
3657 mas_set_height(mas);
3659 /* swap the new root into the tree */
3660 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
3661 ma_set_meta(node, maple_leaf_64, 0, slot);
3665 static inline void mas_store_root(struct ma_state *mas, void *entry)
3667 if (likely((mas->last != 0) || (mas->index != 0)))
3668 mas_root_expand(mas, entry);
3669 else if (((unsigned long) (entry) & 3) == 2)
3670 mas_root_expand(mas, entry);
3672 rcu_assign_pointer(mas->tree->ma_root, entry);
3673 mas->node = MAS_START;
3678 * mas_is_span_wr() - Check if the write needs to be treated as a write that
3680 * @mas: The maple state
3681 * @piv: The pivot value being written
3682 * @type: The maple node type
3683 * @entry: The data to write
3685 * Spanning writes are writes that start in one node and end in another OR if
3686 * the write of a %NULL will cause the node to end with a %NULL.
3688 * Return: True if this is a spanning write, false otherwise.
3690 static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
3693 unsigned long last = wr_mas->mas->last;
3694 unsigned long piv = wr_mas->r_max;
3695 enum maple_type type = wr_mas->type;
3696 void *entry = wr_mas->entry;
3698 /* Contained in this pivot */
3702 max = wr_mas->mas->max;
3703 if (unlikely(ma_is_leaf(type))) {
3704 /* Fits in the node, but may span slots. */
3708 /* Writes to the end of the node but not null. */
3709 if ((last == max) && entry)
3713 * Writing ULONG_MAX is not a spanning write regardless of the
3714 * value being written as long as the range fits in the node.
3716 if ((last == ULONG_MAX) && (last == max))
3718 } else if (piv == last) {
3722 /* Detect spanning store wr walk */
3723 if (last == ULONG_MAX)
3727 trace_ma_write(__func__, wr_mas->mas, piv, entry);
3732 static inline void mas_wr_walk_descend(struct ma_wr_state *wr_mas)
3734 wr_mas->mas->depth++;
3735 wr_mas->type = mte_node_type(wr_mas->mas->node);
3736 mas_wr_node_walk(wr_mas);
3737 wr_mas->slots = ma_slots(wr_mas->node, wr_mas->type);
3740 static inline void mas_wr_walk_traverse(struct ma_wr_state *wr_mas)
3742 wr_mas->mas->max = wr_mas->r_max;
3743 wr_mas->mas->min = wr_mas->r_min;
3744 wr_mas->mas->node = wr_mas->content;
3745 wr_mas->mas->offset = 0;
3748 * mas_wr_walk() - Walk the tree for a write.
3749 * @wr_mas: The maple write state
3751 * Uses mas_slot_locked() and does not need to worry about dead nodes.
3753 * Return: True if it's contained in a node, false on spanning write.
3755 static bool mas_wr_walk(struct ma_wr_state *wr_mas)
3757 struct ma_state *mas = wr_mas->mas;
3760 mas_wr_walk_descend(wr_mas);
3761 if (unlikely(mas_is_span_wr(wr_mas)))
3764 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
3766 if (ma_is_leaf(wr_mas->type))
3769 mas_wr_walk_traverse(wr_mas);
3775 static bool mas_wr_walk_index(struct ma_wr_state *wr_mas)
3777 struct ma_state *mas = wr_mas->mas;
3780 mas_wr_walk_descend(wr_mas);
3781 wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
3783 if (ma_is_leaf(wr_mas->type))
3785 mas_wr_walk_traverse(wr_mas);
3791 * mas_extend_spanning_null() - Extend a store of a %NULL to include surrounding %NULLs.
3792 * @l_wr_mas: The left maple write state
3793 * @r_wr_mas: The right maple write state
3795 static inline void mas_extend_spanning_null(struct ma_wr_state *l_wr_mas,
3796 struct ma_wr_state *r_wr_mas)
3798 struct ma_state *r_mas = r_wr_mas->mas;
3799 struct ma_state *l_mas = l_wr_mas->mas;
3800 unsigned char l_slot;
3802 l_slot = l_mas->offset;
3803 if (!l_wr_mas->content)
3804 l_mas->index = l_wr_mas->r_min;
3806 if ((l_mas->index == l_wr_mas->r_min) &&
3808 !mas_slot_locked(l_mas, l_wr_mas->slots, l_slot - 1))) {
3810 l_mas->index = l_wr_mas->pivots[l_slot - 2] + 1;
3812 l_mas->index = l_mas->min;
3814 l_mas->offset = l_slot - 1;
3817 if (!r_wr_mas->content) {
3818 if (r_mas->last < r_wr_mas->r_max)
3819 r_mas->last = r_wr_mas->r_max;
3821 } else if ((r_mas->last == r_wr_mas->r_max) &&
3822 (r_mas->last < r_mas->max) &&
3823 !mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) {
3824 r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots,
3825 r_wr_mas->type, r_mas->offset + 1);
3830 static inline void *mas_state_walk(struct ma_state *mas)
3834 entry = mas_start(mas);
3835 if (mas_is_none(mas))
3838 if (mas_is_ptr(mas))
3841 return mtree_range_walk(mas);
3845 * mtree_lookup_walk() - Internal quick lookup that does not keep maple state up
3848 * @mas: The maple state.
3850 * Note: Leaves mas in undesirable state.
3851 * Return: The entry for @mas->index or %NULL on dead node.
3853 static inline void *mtree_lookup_walk(struct ma_state *mas)
3855 unsigned long *pivots;
3856 unsigned char offset;
3857 struct maple_node *node;
3858 struct maple_enode *next;
3859 enum maple_type type;
3868 node = mte_to_node(next);
3869 type = mte_node_type(next);
3870 pivots = ma_pivots(node, type);
3871 end = ma_data_end(node, type, pivots, max);
3872 if (unlikely(ma_dead_node(node)))
3875 if (pivots[offset] >= mas->index)
3880 } while ((offset < end) && (pivots[offset] < mas->index));
3882 if (likely(offset > end))
3883 max = pivots[offset];
3886 slots = ma_slots(node, type);
3887 next = mt_slot(mas->tree, slots, offset);
3888 if (unlikely(ma_dead_node(node)))
3890 } while (!ma_is_leaf(type));
3892 return (void *) next;
3900 * mas_new_root() - Create a new root node that only contains the entry passed
3902 * @mas: The maple state
3903 * @entry: The entry to store.
3905 * Only valid when the index == 0 and the last == ULONG_MAX
3907 * Return 0 on error, 1 on success.
3909 static inline int mas_new_root(struct ma_state *mas, void *entry)
3911 struct maple_enode *root = mas_root_locked(mas);
3912 enum maple_type type = maple_leaf_64;
3913 struct maple_node *node;
3915 unsigned long *pivots;
3917 if (!entry && !mas->index && mas->last == ULONG_MAX) {
3919 mas_set_height(mas);
3920 rcu_assign_pointer(mas->tree->ma_root, entry);
3921 mas->node = MAS_START;
3925 mas_node_count(mas, 1);
3926 if (mas_is_err(mas))
3929 node = mas_pop_node(mas);
3930 pivots = ma_pivots(node, type);
3931 slots = ma_slots(node, type);
3932 node->parent = ma_parent_ptr(
3933 ((unsigned long)mas->tree | MA_ROOT_PARENT));
3934 mas->node = mt_mk_node(node, type);
3935 rcu_assign_pointer(slots[0], entry);
3936 pivots[0] = mas->last;
3938 mas_set_height(mas);
3939 rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
3942 if (xa_is_node(root))
3943 mte_destroy_walk(root, mas->tree);
3948 * mas_wr_spanning_store() - Create a subtree with the store operation completed
3949 * and new nodes where necessary, then place the sub-tree in the actual tree.
3950 * Note that mas is expected to point to the node which caused the store to
3952 * @wr_mas: The maple write state
3954 * Return: 0 on error, positive on success.
3956 static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
3958 struct maple_subtree_state mast;
3959 struct maple_big_node b_node;
3960 struct ma_state *mas;
3961 unsigned char height;
3963 /* Left and Right side of spanning store */
3964 MA_STATE(l_mas, NULL, 0, 0);
3965 MA_STATE(r_mas, NULL, 0, 0);
3967 MA_WR_STATE(r_wr_mas, &r_mas, wr_mas->entry);
3968 MA_WR_STATE(l_wr_mas, &l_mas, wr_mas->entry);
3971 * A store operation that spans multiple nodes is called a spanning
3972 * store and is handled early in the store call stack by the function
3973 * mas_is_span_wr(). When a spanning store is identified, the maple
3974 * state is duplicated. The first maple state walks the left tree path
3975 * to ``index``, the duplicate walks the right tree path to ``last``.
3976 * The data in the two nodes are combined into a single node, two nodes,
3977 * or possibly three nodes (see the 3-way split above). A ``NULL``
3978 * written to the last entry of a node is considered a spanning store as
3979 * a rebalance is required for the operation to complete and an overflow
3980 * of data may happen.
3983 trace_ma_op(__func__, mas);
3985 if (unlikely(!mas->index && mas->last == ULONG_MAX))
3986 return mas_new_root(mas, wr_mas->entry);
3988 * Node rebalancing may occur due to this store, so there may be three new
3989 * entries per level plus a new root.
3991 height = mas_mt_height(mas);
3992 mas_node_count(mas, 1 + height * 3);
3993 if (mas_is_err(mas))
3997 * Set up right side. Need to get to the next offset after the spanning
3998 * store to ensure it's not NULL and to combine both the next node and
3999 * the node with the start together.
4002 /* Avoid overflow, walk to next slot in the tree. */
4006 r_mas.index = r_mas.last;
4007 mas_wr_walk_index(&r_wr_mas);
4008 r_mas.last = r_mas.index = mas->last;
4010 /* Set up left side. */
4012 mas_wr_walk_index(&l_wr_mas);
4014 if (!wr_mas->entry) {
4015 mas_extend_spanning_null(&l_wr_mas, &r_wr_mas);
4016 mas->offset = l_mas.offset;
4017 mas->index = l_mas.index;
4018 mas->last = l_mas.last = r_mas.last;
4021 /* expanding NULLs may make this cover the entire range */
4022 if (!l_mas.index && r_mas.last == ULONG_MAX) {
4023 mas_set_range(mas, 0, ULONG_MAX);
4024 return mas_new_root(mas, wr_mas->entry);
4027 memset(&b_node, 0, sizeof(struct maple_big_node));
4028 /* Copy l_mas and store the value in b_node. */
4029 mas_store_b_node(&l_wr_mas, &b_node, l_wr_mas.node_end);
4030 /* Copy r_mas into b_node. */
4031 if (r_mas.offset <= r_wr_mas.node_end)
4032 mas_mab_cp(&r_mas, r_mas.offset, r_wr_mas.node_end,
4033 &b_node, b_node.b_end + 1);
4037 /* Stop spanning searches by searching for just index. */
4038 l_mas.index = l_mas.last = mas->index;
4041 mast.orig_l = &l_mas;
4042 mast.orig_r = &r_mas;
4043 /* Combine l_mas and r_mas and split them up evenly again. */
4044 return mas_spanning_rebalance(mas, &mast, height + 1);
4048 * mas_wr_node_store() - Attempt to store the value in a node
4049 * @wr_mas: The maple write state
4051 * Attempts to reuse the node, but may allocate.
4053 * Return: True if stored, false otherwise
4055 static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas)
4057 struct ma_state *mas = wr_mas->mas;
4058 void __rcu **dst_slots;
4059 unsigned long *dst_pivots;
4060 unsigned char dst_offset;
4061 unsigned char new_end = wr_mas->node_end;
4062 unsigned char offset;
4063 unsigned char node_slots = mt_slots[wr_mas->type];
4064 struct maple_node reuse, *newnode;
4065 unsigned char copy_size, max_piv = mt_pivots[wr_mas->type];
4066 bool in_rcu = mt_in_rcu(mas->tree);
4068 offset = mas->offset;
4069 if (mas->last == wr_mas->r_max) {
4070 /* runs right to the end of the node */
4071 if (mas->last == mas->max)
4073 /* don't copy this offset */
4074 wr_mas->offset_end++;
4075 } else if (mas->last < wr_mas->r_max) {
4076 /* new range ends in this range */
4077 if (unlikely(wr_mas->r_max == ULONG_MAX))
4078 mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);
4082 if (wr_mas->end_piv == mas->last)
4083 wr_mas->offset_end++;
4085 new_end -= wr_mas->offset_end - offset - 1;
4088 /* new range starts within a range */
4089 if (wr_mas->r_min < mas->index)
4092 /* Not enough room */
4093 if (new_end >= node_slots)
4096 /* Not enough data. */
4097 if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) &&
4098 !(mas->mas_flags & MA_STATE_BULK))
4103 mas_node_count(mas, 1);
4104 if (mas_is_err(mas))
4107 newnode = mas_pop_node(mas);
4109 memset(&reuse, 0, sizeof(struct maple_node));
4113 newnode->parent = mas_mn(mas)->parent;
4114 dst_pivots = ma_pivots(newnode, wr_mas->type);
4115 dst_slots = ma_slots(newnode, wr_mas->type);
4116 /* Copy from start to insert point */
4117 memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * (offset + 1));
4118 memcpy(dst_slots, wr_mas->slots, sizeof(void *) * (offset + 1));
4119 dst_offset = offset;
4121 /* Handle insert of new range starting after old range */
4122 if (wr_mas->r_min < mas->index) {
4124 rcu_assign_pointer(dst_slots[dst_offset], wr_mas->content);
4125 dst_pivots[dst_offset++] = mas->index - 1;
4128 /* Store the new entry and range end. */
4129 if (dst_offset < max_piv)
4130 dst_pivots[dst_offset] = mas->last;
4131 mas->offset = dst_offset;
4132 rcu_assign_pointer(dst_slots[dst_offset], wr_mas->entry);
4135 * this range wrote to the end of the node or it overwrote the rest of
4138 if (wr_mas->offset_end > wr_mas->node_end || mas->last >= mas->max) {
4139 new_end = dst_offset;
4144 /* Copy to the end of node if necessary. */
4145 copy_size = wr_mas->node_end - wr_mas->offset_end + 1;
4146 memcpy(dst_slots + dst_offset, wr_mas->slots + wr_mas->offset_end,
4147 sizeof(void *) * copy_size);
4148 if (dst_offset < max_piv) {
4149 if (copy_size > max_piv - dst_offset)
4150 copy_size = max_piv - dst_offset;
4152 memcpy(dst_pivots + dst_offset,
4153 wr_mas->pivots + wr_mas->offset_end,
4154 sizeof(unsigned long) * copy_size);
4157 if ((wr_mas->node_end == node_slots - 1) && (new_end < node_slots - 1))
4158 dst_pivots[new_end] = mas->max;
4161 mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end);
4163 mas->node = mt_mk_node(newnode, wr_mas->type);
4164 mas_replace(mas, false);
4166 memcpy(wr_mas->node, newnode, sizeof(struct maple_node));
4168 trace_ma_write(__func__, mas, 0, wr_mas->entry);
4169 mas_update_gap(mas);
4174 * mas_wr_slot_store: Attempt to store a value in a slot.
4175 * @wr_mas: the maple write state
4177 * Return: True if stored, false otherwise
4179 static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas)
4181 struct ma_state *mas = wr_mas->mas;
4182 unsigned long lmax; /* Logical max. */
4183 unsigned char offset = mas->offset;
4185 if ((wr_mas->r_max > mas->last) && ((wr_mas->r_min != mas->index) ||
4186 (offset != wr_mas->node_end)))
4189 if (offset == wr_mas->node_end - 1)
4192 lmax = wr_mas->pivots[offset + 1];
4194 /* going to overwrite too many slots. */
4195 if (lmax < mas->last)
4198 if (wr_mas->r_min == mas->index) {
4199 /* overwriting two or more ranges with one. */
4200 if (lmax == mas->last)
4203 /* Overwriting all of offset and a portion of offset + 1. */
4204 rcu_assign_pointer(wr_mas->slots[offset], wr_mas->entry);
4205 wr_mas->pivots[offset] = mas->last;
4209 /* Doesn't end on the next range end. */
4210 if (lmax != mas->last)
4213 /* Overwriting a portion of offset and all of offset + 1 */
4214 if ((offset + 1 < mt_pivots[wr_mas->type]) &&
4215 (wr_mas->entry || wr_mas->pivots[offset + 1]))
4216 wr_mas->pivots[offset + 1] = mas->last;
4218 rcu_assign_pointer(wr_mas->slots[offset + 1], wr_mas->entry);
4219 wr_mas->pivots[offset] = mas->index - 1;
4220 mas->offset++; /* Keep mas accurate. */
4223 trace_ma_write(__func__, mas, 0, wr_mas->entry);
4224 mas_update_gap(mas);
4228 static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
4230 while ((wr_mas->mas->last > wr_mas->end_piv) &&
4231 (wr_mas->offset_end < wr_mas->node_end))
4232 wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end];
4234 if (wr_mas->mas->last > wr_mas->end_piv)
4235 wr_mas->end_piv = wr_mas->mas->max;
4238 static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas)
4240 struct ma_state *mas = wr_mas->mas;
4242 if (mas->last < wr_mas->end_piv && !wr_mas->slots[wr_mas->offset_end])
4243 mas->last = wr_mas->end_piv;
4245 /* Check next slot(s) if we are overwriting the end */
4246 if ((mas->last == wr_mas->end_piv) &&
4247 (wr_mas->node_end != wr_mas->offset_end) &&
4248 !wr_mas->slots[wr_mas->offset_end + 1]) {
4249 wr_mas->offset_end++;
4250 if (wr_mas->offset_end == wr_mas->node_end)
4251 mas->last = mas->max;
4253 mas->last = wr_mas->pivots[wr_mas->offset_end];
4254 wr_mas->end_piv = mas->last;
4257 if (!wr_mas->content) {
4258 /* If this one is null, the next and prev are not */
4259 mas->index = wr_mas->r_min;
4261 /* Check prev slot if we are overwriting the start */
4262 if (mas->index == wr_mas->r_min && mas->offset &&
4263 !wr_mas->slots[mas->offset - 1]) {
4265 wr_mas->r_min = mas->index =
4266 mas_safe_min(mas, wr_mas->pivots, mas->offset);
4267 wr_mas->r_max = wr_mas->pivots[mas->offset];
4272 static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
4274 unsigned char end = wr_mas->node_end;
4275 unsigned char new_end = end + 1;
4276 struct ma_state *mas = wr_mas->mas;
4277 unsigned char node_pivots = mt_pivots[wr_mas->type];
4279 if ((mas->index != wr_mas->r_min) && (mas->last == wr_mas->r_max)) {
4280 if (new_end < node_pivots)
4281 wr_mas->pivots[new_end] = wr_mas->pivots[end];
4283 if (new_end < node_pivots)
4284 ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
4286 rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry);
4287 mas->offset = new_end;
4288 wr_mas->pivots[end] = mas->index - 1;
4293 if ((mas->index == wr_mas->r_min) && (mas->last < wr_mas->r_max)) {
4294 if (new_end < node_pivots)
4295 wr_mas->pivots[new_end] = wr_mas->pivots[end];
4297 rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content);
4298 if (new_end < node_pivots)
4299 ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
4301 wr_mas->pivots[end] = mas->last;
4302 rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry);
4310 * mas_wr_bnode() - Slow path for a modification.
4311 * @wr_mas: The write maple state
4313 * This is where split, rebalance end up.
4315 static void mas_wr_bnode(struct ma_wr_state *wr_mas)
4317 struct maple_big_node b_node;
4319 trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
4320 memset(&b_node, 0, sizeof(struct maple_big_node));
4321 mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
4322 mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
4325 static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
4327 unsigned char node_slots;
4328 unsigned char node_size;
4329 struct ma_state *mas = wr_mas->mas;
4331 /* Direct replacement */
4332 if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
4333 rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
4334 if (!!wr_mas->entry ^ !!wr_mas->content)
4335 mas_update_gap(mas);
4339 /* Attempt to append */
4340 node_slots = mt_slots[wr_mas->type];
4341 node_size = wr_mas->node_end - wr_mas->offset_end + mas->offset + 2;
4342 if (mas->max == ULONG_MAX)
4345 /* slot and node store will not fit, go to the slow path */
4346 if (unlikely(node_size >= node_slots))
4349 if (wr_mas->entry && (wr_mas->node_end < node_slots - 1) &&
4350 (mas->offset == wr_mas->node_end) && mas_wr_append(wr_mas)) {
4351 if (!wr_mas->content || !wr_mas->entry)
4352 mas_update_gap(mas);
4356 if ((wr_mas->offset_end - mas->offset <= 1) && mas_wr_slot_store(wr_mas))
4358 else if (mas_wr_node_store(wr_mas))
4361 if (mas_is_err(mas))
4365 mas_wr_bnode(wr_mas);
4369 * mas_wr_store_entry() - Internal call to store a value
4370 * @mas: The maple state
4371 * @entry: The entry to store.
4373 * Return: The contents that was stored at the index.
4375 static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas)
4377 struct ma_state *mas = wr_mas->mas;
4379 wr_mas->content = mas_start(mas);
4380 if (mas_is_none(mas) || mas_is_ptr(mas)) {
4381 mas_store_root(mas, wr_mas->entry);
4382 return wr_mas->content;
4385 if (unlikely(!mas_wr_walk(wr_mas))) {
4386 mas_wr_spanning_store(wr_mas);
4387 return wr_mas->content;
4390 /* At this point, we are at the leaf node that needs to be altered. */
4391 wr_mas->end_piv = wr_mas->r_max;
4392 mas_wr_end_piv(wr_mas);
4395 mas_wr_extend_null(wr_mas);
4397 /* New root for a single pointer */
4398 if (unlikely(!mas->index && mas->last == ULONG_MAX)) {
4399 mas_new_root(mas, wr_mas->entry);
4400 return wr_mas->content;
4403 mas_wr_modify(wr_mas);
4404 return wr_mas->content;
4408 * mas_insert() - Internal call to insert a value
4409 * @mas: The maple state
4410 * @entry: The entry to store
4412 * Return: %NULL or the contents that already exists at the requested index
4413 * otherwise. The maple state needs to be checked for error conditions.
4415 static inline void *mas_insert(struct ma_state *mas, void *entry)
4417 MA_WR_STATE(wr_mas, mas, entry);
4420 * Inserting a new range inserts either 0, 1, or 2 pivots within the
4421 * tree. If the insert fits exactly into an existing gap with a value
4422 * of NULL, then the slot only needs to be written with the new value.
4423 * If the range being inserted is adjacent to another range, then only a
4424 * single pivot needs to be inserted (as well as writing the entry). If
4425 * the new range is within a gap but does not touch any other ranges,
4426 * then two pivots need to be inserted: the start - 1, and the end. As
4427 * usual, the entry must be written. Most operations require a new node
4428 * to be allocated and replace an existing node to ensure RCU safety,
4429 * when in RCU mode. The exception to requiring a newly allocated node
4430 * is when inserting at the end of a node (appending). When done
4431 * carefully, appending can reuse the node in place.
4433 wr_mas.content = mas_start(mas);
4437 if (mas_is_none(mas) || mas_is_ptr(mas)) {
4438 mas_store_root(mas, entry);
4442 /* spanning writes always overwrite something */
4443 if (!mas_wr_walk(&wr_mas))
4446 /* At this point, we are at the leaf node that needs to be altered. */
4447 wr_mas.offset_end = mas->offset;
4448 wr_mas.end_piv = wr_mas.r_max;
4450 if (wr_mas.content || (mas->last > wr_mas.r_max))
4456 mas_wr_modify(&wr_mas);
4457 return wr_mas.content;
4460 mas_set_err(mas, -EEXIST);
4461 return wr_mas.content;
4466 * mas_prev_node() - Find the prev non-null entry at the same level in the
4467 * tree. The prev value will be mas->node[mas->offset] or MAS_NONE.
4468 * @mas: The maple state
4469 * @min: The lower limit to search
4471 * The prev node value will be mas->node[mas->offset] or MAS_NONE.
4472 * Return: 1 if the node is dead, 0 otherwise.
4474 static inline int mas_prev_node(struct ma_state *mas, unsigned long min)
4479 struct maple_node *node;
4480 struct maple_enode *enode;
4481 unsigned long *pivots;
4483 if (mas_is_none(mas))
4489 if (ma_is_root(node))
4493 if (unlikely(mas_ascend(mas)))
4495 offset = mas->offset;
4500 mt = mte_node_type(mas->node);
4502 slots = ma_slots(node, mt);
4503 pivots = ma_pivots(node, mt);
4504 mas->max = pivots[offset];
4506 mas->min = pivots[offset - 1] + 1;
4507 if (unlikely(ma_dead_node(node)))
4515 enode = mas_slot(mas, slots, offset);
4516 if (unlikely(ma_dead_node(node)))
4520 mt = mte_node_type(mas->node);
4522 slots = ma_slots(node, mt);
4523 pivots = ma_pivots(node, mt);
4524 offset = ma_data_end(node, mt, pivots, mas->max);
4526 mas->min = pivots[offset - 1] + 1;
4528 if (offset < mt_pivots[mt])
4529 mas->max = pivots[offset];
4535 mas->node = mas_slot(mas, slots, offset);
4536 if (unlikely(ma_dead_node(node)))
4539 mas->offset = mas_data_end(mas);
4540 if (unlikely(mte_dead_node(mas->node)))
4546 mas->offset = offset;
4548 mas->min = pivots[offset - 1] + 1;
4550 if (unlikely(ma_dead_node(node)))
4553 mas->node = MAS_NONE;
4558 * mas_next_node() - Get the next node at the same level in the tree.
4559 * @mas: The maple state
4560 * @max: The maximum pivot value to check.
4562 * The next value will be mas->node[mas->offset] or MAS_NONE.
4563 * Return: 1 on dead node, 0 otherwise.
4565 static inline int mas_next_node(struct ma_state *mas, struct maple_node *node,
4568 unsigned long min, pivot;
4569 unsigned long *pivots;
4570 struct maple_enode *enode;
4572 unsigned char offset;
4576 if (mas->max >= max)
4581 if (ma_is_root(node))
4588 if (unlikely(mas_ascend(mas)))
4591 offset = mas->offset;
4594 mt = mte_node_type(mas->node);
4595 pivots = ma_pivots(node, mt);
4596 } while (unlikely(offset == ma_data_end(node, mt, pivots, mas->max)));
4598 slots = ma_slots(node, mt);
4599 pivot = mas_safe_pivot(mas, pivots, ++offset, mt);
4600 while (unlikely(level > 1)) {
4601 /* Descend, if necessary */
4602 enode = mas_slot(mas, slots, offset);
4603 if (unlikely(ma_dead_node(node)))
4609 mt = mte_node_type(mas->node);
4610 slots = ma_slots(node, mt);
4611 pivots = ma_pivots(node, mt);
4616 enode = mas_slot(mas, slots, offset);
4617 if (unlikely(ma_dead_node(node)))
4626 if (unlikely(ma_dead_node(node)))
4629 mas->node = MAS_NONE;
4634 * mas_next_nentry() - Get the next node entry
4635 * @mas: The maple state
4636 * @max: The maximum value to check
4637 * @*range_start: Pointer to store the start of the range.
4639 * Sets @mas->offset to the offset of the next node entry, @mas->last to the
4640 * pivot of the entry.
4642 * Return: The next entry, %NULL otherwise
4644 static inline void *mas_next_nentry(struct ma_state *mas,
4645 struct maple_node *node, unsigned long max, enum maple_type type)
4647 unsigned char count;
4648 unsigned long pivot;
4649 unsigned long *pivots;
4653 if (mas->last == mas->max) {
4654 mas->index = mas->max;
4658 pivots = ma_pivots(node, type);
4659 slots = ma_slots(node, type);
4660 mas->index = mas_safe_min(mas, pivots, mas->offset);
4661 if (ma_dead_node(node))
4664 if (mas->index > max)
4667 count = ma_data_end(node, type, pivots, mas->max);
4668 if (mas->offset > count)
4671 while (mas->offset < count) {
4672 pivot = pivots[mas->offset];
4673 entry = mas_slot(mas, slots, mas->offset);
4674 if (ma_dead_node(node))
4683 mas->index = pivot + 1;
4687 if (mas->index > mas->max) {
4688 mas->index = mas->last;
4692 pivot = mas_safe_pivot(mas, pivots, mas->offset, type);
4693 entry = mas_slot(mas, slots, mas->offset);
4694 if (ma_dead_node(node))
4708 static inline void mas_rewalk(struct ma_state *mas, unsigned long index)
4712 mas_set(mas, index);
4713 mas_state_walk(mas);
4714 if (mas_is_start(mas))
4722 * mas_next_entry() - Internal function to get the next entry.
4723 * @mas: The maple state
4724 * @limit: The maximum range start.
4726 * Set the @mas->node to the next entry and the range_start to
4727 * the beginning value for the entry. Does not check beyond @limit.
4728 * Sets @mas->index and @mas->last to the limit if it is hit.
4729 * Restarts on dead nodes.
4731 * Return: the next entry or %NULL.
4733 static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit)
4736 struct maple_enode *prev_node;
4737 struct maple_node *node;
4738 unsigned char offset;
4744 offset = mas->offset;
4745 prev_node = mas->node;
4747 mt = mte_node_type(mas->node);
4749 if (unlikely(mas->offset >= mt_slots[mt])) {
4750 mas->offset = mt_slots[mt] - 1;
4754 while (!mas_is_none(mas)) {
4755 entry = mas_next_nentry(mas, node, limit, mt);
4756 if (unlikely(ma_dead_node(node))) {
4757 mas_rewalk(mas, last);
4764 if (unlikely((mas->index > limit)))
4768 prev_node = mas->node;
4769 offset = mas->offset;
4770 if (unlikely(mas_next_node(mas, node, limit))) {
4771 mas_rewalk(mas, last);
4776 mt = mte_node_type(mas->node);
4779 mas->index = mas->last = limit;
4780 mas->offset = offset;
4781 mas->node = prev_node;
4786 * mas_prev_nentry() - Get the previous node entry.
4787 * @mas: The maple state.
4788 * @limit: The lower limit to check for a value.
4790 * Return: the entry, %NULL otherwise.
4792 static inline void *mas_prev_nentry(struct ma_state *mas, unsigned long limit,
4793 unsigned long index)
4795 unsigned long pivot, min;
4796 unsigned char offset;
4797 struct maple_node *mn;
4799 unsigned long *pivots;
4808 mt = mte_node_type(mas->node);
4809 offset = mas->offset - 1;
4810 if (offset >= mt_slots[mt])
4811 offset = mt_slots[mt] - 1;
4813 slots = ma_slots(mn, mt);
4814 pivots = ma_pivots(mn, mt);
4815 if (offset == mt_pivots[mt])
4818 pivot = pivots[offset];
4820 if (unlikely(ma_dead_node(mn))) {
4821 mas_rewalk(mas, index);
4825 while (offset && ((!mas_slot(mas, slots, offset) && pivot >= limit) ||
4827 pivot = pivots[--offset];
4829 min = mas_safe_min(mas, pivots, offset);
4830 entry = mas_slot(mas, slots, offset);
4831 if (unlikely(ma_dead_node(mn))) {
4832 mas_rewalk(mas, index);
4836 if (likely(entry)) {
4837 mas->offset = offset;
4844 static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min)
4849 while (likely(!mas_is_none(mas))) {
4850 entry = mas_prev_nentry(mas, min, mas->index);
4851 if (unlikely(mas->last < min))
4857 if (unlikely(mas_prev_node(mas, min))) {
4858 mas_rewalk(mas, mas->index);
4867 mas->index = mas->last = min;
4872 * mas_rev_awalk() - Internal function. Reverse allocation walk. Find the
4873 * highest gap address of a given size in a given node and descend.
4874 * @mas: The maple state
4875 * @size: The needed size.
4877 * Return: True if found in a leaf, false otherwise.
4880 static bool mas_rev_awalk(struct ma_state *mas, unsigned long size)
4882 enum maple_type type = mte_node_type(mas->node);
4883 struct maple_node *node = mas_mn(mas);
4884 unsigned long *pivots, *gaps;
4886 unsigned long gap = 0;
4887 unsigned long max, min, index;
4888 unsigned char offset;
4890 if (unlikely(mas_is_err(mas)))
4893 if (ma_is_dense(type)) {
4895 mas->offset = (unsigned char)(mas->index - mas->min);
4899 pivots = ma_pivots(node, type);
4900 slots = ma_slots(node, type);
4901 gaps = ma_gaps(node, type);
4902 offset = mas->offset;
4903 min = mas_safe_min(mas, pivots, offset);
4904 /* Skip out of bounds. */
4905 while (mas->last < min)
4906 min = mas_safe_min(mas, pivots, --offset);
4908 max = mas_safe_pivot(mas, pivots, offset, type);
4910 while (index <= max) {
4914 else if (!mas_slot(mas, slots, offset))
4915 gap = max - min + 1;
4918 if ((size <= gap) && (size <= mas->last - min + 1))
4922 /* Skip the next slot, it cannot be a gap. */
4927 max = pivots[offset];
4928 min = mas_safe_min(mas, pivots, offset);
4938 min = mas_safe_min(mas, pivots, offset);
4941 if (unlikely(index > max)) {
4942 mas_set_err(mas, -EBUSY);
4946 if (unlikely(ma_is_leaf(type))) {
4947 mas->offset = offset;
4949 mas->max = min + gap - 1;
4953 /* descend, only happens under lock. */
4954 mas->node = mas_slot(mas, slots, offset);
4957 mas->offset = mas_data_end(mas);
4961 if (mte_is_root(mas->node))
4962 mas_set_err(mas, -EBUSY);
4967 static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
4969 enum maple_type type = mte_node_type(mas->node);
4970 unsigned long pivot, min, gap = 0;
4971 unsigned char offset;
4972 unsigned long *gaps;
4973 unsigned long *pivots = ma_pivots(mas_mn(mas), type);
4974 void __rcu **slots = ma_slots(mas_mn(mas), type);
4977 if (ma_is_dense(type)) {
4978 mas->offset = (unsigned char)(mas->index - mas->min);
4982 gaps = ma_gaps(mte_to_node(mas->node), type);
4983 offset = mas->offset;
4984 min = mas_safe_min(mas, pivots, offset);
4985 for (; offset < mt_slots[type]; offset++) {
4986 pivot = mas_safe_pivot(mas, pivots, offset, type);
4987 if (offset && !pivot)
4990 /* Not within lower bounds */
4991 if (mas->index > pivot)
4996 else if (!mas_slot(mas, slots, offset))
4997 gap = min(pivot, mas->last) - max(mas->index, min) + 1;
5002 if (ma_is_leaf(type)) {
5006 if (mas->index <= pivot) {
5007 mas->node = mas_slot(mas, slots, offset);
5016 if (mas->last <= pivot) {
5017 mas_set_err(mas, -EBUSY);
5022 if (mte_is_root(mas->node))
5025 mas->offset = offset;
5030 * mas_walk() - Search for @mas->index in the tree.
5031 * @mas: The maple state.
5033 * mas->index and mas->last will be set to the range if there is a value. If
5034 * mas->node is MAS_NONE, reset to MAS_START.
5036 * Return: the entry at the location or %NULL.
5038 void *mas_walk(struct ma_state *mas)
5043 entry = mas_state_walk(mas);
5044 if (mas_is_start(mas))
5047 if (mas_is_ptr(mas)) {
5052 mas->last = ULONG_MAX;
5057 if (mas_is_none(mas)) {
5059 mas->last = ULONG_MAX;
5065 static inline bool mas_rewind_node(struct ma_state *mas)
5070 if (mte_is_root(mas->node)) {
5080 mas->offset = --slot;
5085 * mas_skip_node() - Internal function. Skip over a node.
5086 * @mas: The maple state.
5088 * Return: true if there is another node, false otherwise.
5090 static inline bool mas_skip_node(struct ma_state *mas)
5092 unsigned char slot, slot_count;
5093 unsigned long *pivots;
5096 mt = mte_node_type(mas->node);
5097 slot_count = mt_slots[mt] - 1;
5099 if (mte_is_root(mas->node)) {
5101 if (slot > slot_count) {
5102 mas_set_err(mas, -EBUSY);
5108 mt = mte_node_type(mas->node);
5109 slot_count = mt_slots[mt] - 1;
5111 } while (slot > slot_count);
5113 mas->offset = ++slot;
5114 pivots = ma_pivots(mas_mn(mas), mt);
5116 mas->min = pivots[slot - 1] + 1;
5118 if (slot <= slot_count)
5119 mas->max = pivots[slot];
5125 * mas_awalk() - Allocation walk. Search from low address to high, for a gap of
5127 * @mas: The maple state
5128 * @size: The size of the gap required
5130 * Search between @mas->index and @mas->last for a gap of @size.
5132 static inline void mas_awalk(struct ma_state *mas, unsigned long size)
5134 struct maple_enode *last = NULL;
5137 * There are 4 options:
5138 * go to child (descend)
5139 * go back to parent (ascend)
5140 * no gap found. (return, slot == MAPLE_NODE_SLOTS)
5141 * found the gap. (return, slot != MAPLE_NODE_SLOTS)
5143 while (!mas_is_err(mas) && !mas_anode_descend(mas, size)) {
5144 if (last == mas->node)
5152 * mas_fill_gap() - Fill a located gap with @entry.
5153 * @mas: The maple state
5154 * @entry: The value to store
5155 * @slot: The offset into the node to store the @entry
5156 * @size: The size of the entry
5157 * @index: The start location
5159 static inline void mas_fill_gap(struct ma_state *mas, void *entry,
5160 unsigned char slot, unsigned long size, unsigned long *index)
5162 MA_WR_STATE(wr_mas, mas, entry);
5163 unsigned char pslot = mte_parent_slot(mas->node);
5164 struct maple_enode *mn = mas->node;
5165 unsigned long *pivots;
5166 enum maple_type ptype;
5168 * mas->index is the start address for the search
5169 * which may no longer be needed.
5170 * mas->last is the end address for the search
5173 *index = mas->index;
5174 mas->last = mas->index + size - 1;
5177 * It is possible that using mas->max and mas->min to correctly
5178 * calculate the index and last will cause an issue in the gap
5179 * calculation, so fix the ma_state here
5182 ptype = mte_node_type(mas->node);
5183 pivots = ma_pivots(mas_mn(mas), ptype);
5184 mas->max = mas_safe_pivot(mas, pivots, pslot, ptype);
5185 mas->min = mas_safe_min(mas, pivots, pslot);
5188 mas_wr_store_entry(&wr_mas);
5192 * mas_sparse_area() - Internal function. Return upper or lower limit when
5193 * searching for a gap in an empty tree.
5194 * @mas: The maple state
5195 * @min: the minimum range
5196 * @max: The maximum range
5197 * @size: The size of the gap
5198 * @fwd: Searching forward or back
5200 static inline void mas_sparse_area(struct ma_state *mas, unsigned long min,
5201 unsigned long max, unsigned long size, bool fwd)
5203 unsigned long start = 0;
5205 if (!unlikely(mas_is_none(mas)))
5214 mas->last = start + size - 1;
5222 * mas_empty_area() - Get the lowest address within the range that is
5223 * sufficient for the size requested.
5224 * @mas: The maple state
5225 * @min: The lowest value of the range
5226 * @max: The highest value of the range
5227 * @size: The size needed
5229 int mas_empty_area(struct ma_state *mas, unsigned long min,
5230 unsigned long max, unsigned long size)
5232 unsigned char offset;
5233 unsigned long *pivots;
5236 if (mas_is_start(mas))
5238 else if (mas->offset >= 2)
5240 else if (!mas_skip_node(mas))
5244 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5245 mas_sparse_area(mas, min, max, size, true);
5249 /* The start of the window can only be within these values */
5252 mas_awalk(mas, size);
5254 if (unlikely(mas_is_err(mas)))
5255 return xa_err(mas->node);
5257 offset = mas->offset;
5258 if (unlikely(offset == MAPLE_NODE_SLOTS))
5261 mt = mte_node_type(mas->node);
5262 pivots = ma_pivots(mas_mn(mas), mt);
5264 mas->min = pivots[offset - 1] + 1;
5266 if (offset < mt_pivots[mt])
5267 mas->max = pivots[offset];
5269 if (mas->index < mas->min)
5270 mas->index = mas->min;
5272 mas->last = mas->index + size - 1;
5277 * mas_empty_area_rev() - Get the highest address within the range that is
5278 * sufficient for the size requested.
5279 * @mas: The maple state
5280 * @min: The lowest value of the range
5281 * @max: The highest value of the range
5282 * @size: The size needed
5284 int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
5285 unsigned long max, unsigned long size)
5287 struct maple_enode *last = mas->node;
5289 if (mas_is_start(mas)) {
5291 mas->offset = mas_data_end(mas);
5292 } else if (mas->offset >= 2) {
5294 } else if (!mas_rewind_node(mas)) {
5299 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5300 mas_sparse_area(mas, min, max, size, false);
5304 /* The start of the window can only be within these values. */
5308 while (!mas_rev_awalk(mas, size)) {
5309 if (last == mas->node) {
5310 if (!mas_rewind_node(mas))
5317 if (mas_is_err(mas))
5318 return xa_err(mas->node);
5320 if (unlikely(mas->offset == MAPLE_NODE_SLOTS))
5324 * mas_rev_awalk() has set mas->min and mas->max to the gap values. If
5325 * the maximum is outside the window we are searching, then use the last
5326 * location in the search.
5327 * mas->max and mas->min is the range of the gap.
5328 * mas->index and mas->last are currently set to the search range.
5331 /* Trim the upper limit to the max. */
5332 if (mas->max <= mas->last)
5333 mas->last = mas->max;
5335 mas->index = mas->last - size + 1;
5339 static inline int mas_alloc(struct ma_state *mas, void *entry,
5340 unsigned long size, unsigned long *index)
5345 if (mas_is_none(mas) || mas_is_ptr(mas)) {
5346 mas_root_expand(mas, entry);
5347 if (mas_is_err(mas))
5348 return xa_err(mas->node);
5351 return mte_pivot(mas->node, 0);
5352 return mte_pivot(mas->node, 1);
5355 /* Must be walking a tree. */
5356 mas_awalk(mas, size);
5357 if (mas_is_err(mas))
5358 return xa_err(mas->node);
5360 if (mas->offset == MAPLE_NODE_SLOTS)
5364 * At this point, mas->node points to the right node and we have an
5365 * offset that has a sufficient gap.
5369 min = mte_pivot(mas->node, mas->offset - 1) + 1;
5371 if (mas->index < min)
5374 mas_fill_gap(mas, entry, mas->offset, size, index);
5381 static inline int mas_rev_alloc(struct ma_state *mas, unsigned long min,
5382 unsigned long max, void *entry,
5383 unsigned long size, unsigned long *index)
5387 ret = mas_empty_area_rev(mas, min, max, size);
5391 if (mas_is_err(mas))
5392 return xa_err(mas->node);
5394 if (mas->offset == MAPLE_NODE_SLOTS)
5397 mas_fill_gap(mas, entry, mas->offset, size, index);
5405 * mas_dead_leaves() - Mark all leaves of a node as dead.
5406 * @mas: The maple state
5407 * @slots: Pointer to the slot array
5409 * Must hold the write lock.
5411 * Return: The number of leaves marked as dead.
5414 unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots)
5416 struct maple_node *node;
5417 enum maple_type type;
5421 for (offset = 0; offset < mt_slot_count(mas->node); offset++) {
5422 entry = mas_slot_locked(mas, slots, offset);
5423 type = mte_node_type(entry);
5424 node = mte_to_node(entry);
5425 /* Use both node and type to catch LE & BE metadata */
5429 mte_set_node_dead(entry);
5430 smp_wmb(); /* Needed for RCU */
5432 rcu_assign_pointer(slots[offset], node);
5438 static void __rcu **mas_dead_walk(struct ma_state *mas, unsigned char offset)
5440 struct maple_node *node, *next;
5441 void __rcu **slots = NULL;
5445 mas->node = ma_enode_ptr(next);
5447 slots = ma_slots(node, node->type);
5448 next = mas_slot_locked(mas, slots, offset);
5450 } while (!ma_is_leaf(next->type));
5455 static void mt_free_walk(struct rcu_head *head)
5458 struct maple_node *node, *start;
5459 struct maple_tree mt;
5460 unsigned char offset;
5461 enum maple_type type;
5462 MA_STATE(mas, &mt, 0, 0);
5464 node = container_of(head, struct maple_node, rcu);
5466 if (ma_is_leaf(node->type))
5469 mt_init_flags(&mt, node->ma_flags);
5472 mas.node = mt_mk_node(node, node->type);
5473 slots = mas_dead_walk(&mas, 0);
5474 node = mas_mn(&mas);
5476 mt_free_bulk(node->slot_len, slots);
5477 offset = node->parent_slot + 1;
5478 mas.node = node->piv_parent;
5479 if (mas_mn(&mas) == node)
5480 goto start_slots_free;
5482 type = mte_node_type(mas.node);
5483 slots = ma_slots(mte_to_node(mas.node), type);
5484 if ((offset < mt_slots[type]) && (slots[offset]))
5485 slots = mas_dead_walk(&mas, offset);
5487 node = mas_mn(&mas);
5488 } while ((node != start) || (node->slot_len < offset));
5490 slots = ma_slots(node, node->type);
5491 mt_free_bulk(node->slot_len, slots);
5496 mt_free_rcu(&node->rcu);
5499 static inline void __rcu **mas_destroy_descend(struct ma_state *mas,
5500 struct maple_enode *prev, unsigned char offset)
5502 struct maple_node *node;
5503 struct maple_enode *next = mas->node;
5504 void __rcu **slots = NULL;
5509 slots = ma_slots(node, mte_node_type(mas->node));
5510 next = mas_slot_locked(mas, slots, 0);
5511 if ((mte_dead_node(next)))
5512 next = mas_slot_locked(mas, slots, 1);
5514 mte_set_node_dead(mas->node);
5515 node->type = mte_node_type(mas->node);
5516 node->piv_parent = prev;
5517 node->parent_slot = offset;
5520 } while (!mte_is_leaf(next));
5525 static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags,
5529 struct maple_node *node = mte_to_node(enode);
5530 struct maple_enode *start;
5531 struct maple_tree mt;
5533 MA_STATE(mas, &mt, 0, 0);
5535 if (mte_is_leaf(enode))
5538 mt_init_flags(&mt, ma_flags);
5541 mas.node = start = enode;
5542 slots = mas_destroy_descend(&mas, start, 0);
5543 node = mas_mn(&mas);
5545 enum maple_type type;
5546 unsigned char offset;
5547 struct maple_enode *parent, *tmp;
5549 node->slot_len = mas_dead_leaves(&mas, slots);
5551 mt_free_bulk(node->slot_len, slots);
5552 offset = node->parent_slot + 1;
5553 mas.node = node->piv_parent;
5554 if (mas_mn(&mas) == node)
5555 goto start_slots_free;
5557 type = mte_node_type(mas.node);
5558 slots = ma_slots(mte_to_node(mas.node), type);
5559 if (offset >= mt_slots[type])
5562 tmp = mas_slot_locked(&mas, slots, offset);
5563 if (mte_node_type(tmp) && mte_to_node(tmp)) {
5566 slots = mas_destroy_descend(&mas, parent, offset);
5569 node = mas_mn(&mas);
5570 } while (start != mas.node);
5572 node = mas_mn(&mas);
5573 node->slot_len = mas_dead_leaves(&mas, slots);
5575 mt_free_bulk(node->slot_len, slots);
5582 mt_free_rcu(&node->rcu);
5586 * mte_destroy_walk() - Free a tree or sub-tree.
5587 * @enode - the encoded maple node (maple_enode) to start
5588 * @mn - the tree to free - needed for node types.
5590 * Must hold the write lock.
5592 static inline void mte_destroy_walk(struct maple_enode *enode,
5593 struct maple_tree *mt)
5595 struct maple_node *node = mte_to_node(enode);
5597 if (mt_in_rcu(mt)) {
5598 mt_destroy_walk(enode, mt->ma_flags, false);
5599 call_rcu(&node->rcu, mt_free_walk);
5601 mt_destroy_walk(enode, mt->ma_flags, true);
5605 static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
5607 if (!mas_is_start(wr_mas->mas)) {
5608 if (mas_is_none(wr_mas->mas)) {
5609 mas_reset(wr_mas->mas);
5611 wr_mas->r_max = wr_mas->mas->max;
5612 wr_mas->type = mte_node_type(wr_mas->mas->node);
5613 if (mas_is_span_wr(wr_mas))
5614 mas_reset(wr_mas->mas);
5623 * mas_store() - Store an @entry.
5624 * @mas: The maple state.
5625 * @entry: The entry to store.
5627 * The @mas->index and @mas->last is used to set the range for the @entry.
5628 * Note: The @mas should have pre-allocated entries to ensure there is memory to
5629 * store the entry. Please see mas_expected_entries()/mas_destroy() for more details.
5631 * Return: the first entry between mas->index and mas->last or %NULL.
5633 void *mas_store(struct ma_state *mas, void *entry)
5635 MA_WR_STATE(wr_mas, mas, entry);
5637 trace_ma_write(__func__, mas, 0, entry);
5638 #ifdef CONFIG_DEBUG_MAPLE_TREE
5639 if (mas->index > mas->last)
5640 pr_err("Error %lu > %lu %p\n", mas->index, mas->last, entry);
5641 MT_BUG_ON(mas->tree, mas->index > mas->last);
5642 if (mas->index > mas->last) {
5643 mas_set_err(mas, -EINVAL);
5650 * Storing is the same operation as insert with the added caveat that it
5651 * can overwrite entries. Although this seems simple enough, one may
5652 * want to examine what happens if a single store operation was to
5653 * overwrite multiple entries within a self-balancing B-Tree.
5655 mas_wr_store_setup(&wr_mas);
5656 mas_wr_store_entry(&wr_mas);
5657 return wr_mas.content;
5661 * mas_store_gfp() - Store a value into the tree.
5662 * @mas: The maple state
5663 * @entry: The entry to store
5664 * @gfp: The GFP_FLAGS to use for allocations if necessary.
5666 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
5669 int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp)
5671 MA_WR_STATE(wr_mas, mas, entry);
5673 mas_wr_store_setup(&wr_mas);
5674 trace_ma_write(__func__, mas, 0, entry);
5676 mas_wr_store_entry(&wr_mas);
5677 if (unlikely(mas_nomem(mas, gfp)))
5680 if (unlikely(mas_is_err(mas)))
5681 return xa_err(mas->node);
5687 * mas_store_prealloc() - Store a value into the tree using memory
5688 * preallocated in the maple state.
5689 * @mas: The maple state
5690 * @entry: The entry to store.
5692 void mas_store_prealloc(struct ma_state *mas, void *entry)
5694 MA_WR_STATE(wr_mas, mas, entry);
5696 mas_wr_store_setup(&wr_mas);
5697 trace_ma_write(__func__, mas, 0, entry);
5698 mas_wr_store_entry(&wr_mas);
5699 BUG_ON(mas_is_err(mas));
5704 * mas_preallocate() - Preallocate enough nodes for a store operation
5705 * @mas: The maple state
5706 * @entry: The entry that will be stored
5707 * @gfp: The GFP_FLAGS to use for allocations.
5709 * Return: 0 on success, -ENOMEM if memory could not be allocated.
5711 int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
5715 mas_node_count_gfp(mas, 1 + mas_mt_height(mas) * 3, gfp);
5716 mas->mas_flags |= MA_STATE_PREALLOC;
5717 if (likely(!mas_is_err(mas)))
5720 mas_set_alloc_req(mas, 0);
5721 ret = xa_err(mas->node);
5729 * mas_destroy() - destroy a maple state.
5730 * @mas: The maple state
5732 * Upon completion, check the left-most node and rebalance against the node to
5733 * the right if necessary. Frees any allocated nodes associated with this maple
5736 void mas_destroy(struct ma_state *mas)
5738 struct maple_alloc *node;
5741 * When using mas_for_each() to insert an expected number of elements,
5742 * it is possible that the number inserted is less than the expected
5743 * number. To fix an invalid final node, a check is performed here to
5744 * rebalance the previous node with the final node.
5746 if (mas->mas_flags & MA_STATE_REBALANCE) {
5749 if (mas_is_start(mas))
5752 mtree_range_walk(mas);
5753 end = mas_data_end(mas) + 1;
5754 if (end < mt_min_slot_count(mas->node) - 1)
5755 mas_destroy_rebalance(mas, end);
5757 mas->mas_flags &= ~MA_STATE_REBALANCE;
5759 mas->mas_flags &= ~(MA_STATE_BULK|MA_STATE_PREALLOC);
5761 while (mas->alloc && !((unsigned long)mas->alloc & 0x1)) {
5763 mas->alloc = node->slot[0];
5764 if (node->node_count > 0)
5765 mt_free_bulk(node->node_count,
5766 (void __rcu **)&node->slot[1]);
5767 kmem_cache_free(maple_node_cache, node);
5773 * mas_expected_entries() - Set the expected number of entries that will be inserted.
5774 * @mas: The maple state
5775 * @nr_entries: The number of expected entries.
5777 * This will attempt to pre-allocate enough nodes to store the expected number
5778 * of entries. The allocations will occur using the bulk allocator interface
5779 * for speed. Please call mas_destroy() on the @mas after inserting the entries
5780 * to ensure any unused nodes are freed.
5782 * Return: 0 on success, -ENOMEM if memory could not be allocated.
5784 int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
5786 int nonleaf_cap = MAPLE_ARANGE64_SLOTS - 2;
5787 struct maple_enode *enode = mas->node;
5792 * Sometimes it is necessary to duplicate a tree to a new tree, such as
5793 * forking a process and duplicating the VMAs from one tree to a new
5794 * tree. When such a situation arises, it is known that the new tree is
5795 * not going to be used until the entire tree is populated. For
5796 * performance reasons, it is best to use a bulk load with RCU disabled.
5797 * This allows for optimistic splitting that favours the left and reuse
5798 * of nodes during the operation.
5801 /* Optimize splitting for bulk insert in-order */
5802 mas->mas_flags |= MA_STATE_BULK;
5805 * Avoid overflow, assume a gap between each entry and a trailing null.
5806 * If this is wrong, it just means allocation can happen during
5807 * insertion of entries.
5809 nr_nodes = max(nr_entries, nr_entries * 2 + 1);
5810 if (!mt_is_alloc(mas->tree))
5811 nonleaf_cap = MAPLE_RANGE64_SLOTS - 2;
5813 /* Leaves; reduce slots to keep space for expansion */
5814 nr_nodes = DIV_ROUND_UP(nr_nodes, MAPLE_RANGE64_SLOTS - 2);
5815 /* Internal nodes */
5816 nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
5817 /* Add working room for split (2 nodes) + new parents */
5818 mas_node_count(mas, nr_nodes + 3);
5820 /* Detect if allocations run out */
5821 mas->mas_flags |= MA_STATE_PREALLOC;
5823 if (!mas_is_err(mas))
5826 ret = xa_err(mas->node);
5834 * mas_next() - Get the next entry.
5835 * @mas: The maple state
5836 * @max: The maximum index to check.
5838 * Returns the next entry after @mas->index.
5839 * Must hold rcu_read_lock or the write lock.
5840 * Can return the zero entry.
5842 * Return: The next entry or %NULL
5844 void *mas_next(struct ma_state *mas, unsigned long max)
5846 if (mas_is_none(mas) || mas_is_paused(mas))
5847 mas->node = MAS_START;
5849 if (mas_is_start(mas))
5850 mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
5852 if (mas_is_ptr(mas)) {
5855 mas->last = ULONG_MAX;
5860 if (mas->last == ULONG_MAX)
5863 /* Retries on dead nodes handled by mas_next_entry */
5864 return mas_next_entry(mas, max);
5866 EXPORT_SYMBOL_GPL(mas_next);
5869 * mt_next() - get the next value in the maple tree
5870 * @mt: The maple tree
5871 * @index: The start index
5872 * @max: The maximum index to check
5874 * Return: The entry at @index or higher, or %NULL if nothing is found.
5876 void *mt_next(struct maple_tree *mt, unsigned long index, unsigned long max)
5879 MA_STATE(mas, mt, index, index);
5882 entry = mas_next(&mas, max);
5886 EXPORT_SYMBOL_GPL(mt_next);
5889 * mas_prev() - Get the previous entry
5890 * @mas: The maple state
5891 * @min: The minimum value to check.
5893 * Must hold rcu_read_lock or the write lock.
5894 * Will reset mas to MAS_START if the node is MAS_NONE. Will stop on not
5897 * Return: the previous value or %NULL.
5899 void *mas_prev(struct ma_state *mas, unsigned long min)
5902 /* Nothing comes before 0 */
5907 if (unlikely(mas_is_ptr(mas)))
5910 if (mas_is_none(mas) || mas_is_paused(mas))
5911 mas->node = MAS_START;
5913 if (mas_is_start(mas)) {
5919 if (mas_is_ptr(mas)) {
5925 mas->index = mas->last = 0;
5926 return mas_root_locked(mas);
5928 return mas_prev_entry(mas, min);
5930 EXPORT_SYMBOL_GPL(mas_prev);
5933 * mt_prev() - get the previous value in the maple tree
5934 * @mt: The maple tree
5935 * @index: The start index
5936 * @min: The minimum index to check
5938 * Return: The entry at @index or lower, or %NULL if nothing is found.
5940 void *mt_prev(struct maple_tree *mt, unsigned long index, unsigned long min)
5943 MA_STATE(mas, mt, index, index);
5946 entry = mas_prev(&mas, min);
5950 EXPORT_SYMBOL_GPL(mt_prev);
5953 * mas_pause() - Pause a mas_find/mas_for_each to drop the lock.
5954 * @mas: The maple state to pause
5956 * Some users need to pause a walk and drop the lock they're holding in
5957 * order to yield to a higher priority thread or carry out an operation
5958 * on an entry. Those users should call this function before they drop
5959 * the lock. It resets the @mas to be suitable for the next iteration
5960 * of the loop after the user has reacquired the lock. If most entries
5961 * found during a walk require you to call mas_pause(), the mt_for_each()
5962 * iterator may be more appropriate.
5965 void mas_pause(struct ma_state *mas)
5967 mas->node = MAS_PAUSE;
5969 EXPORT_SYMBOL_GPL(mas_pause);
5972 * mas_find() - On the first call, find the entry at or after mas->index up to
5973 * %max. Otherwise, find the entry after mas->index.
5974 * @mas: The maple state
5975 * @max: The maximum value to check.
5977 * Must hold rcu_read_lock or the write lock.
5978 * If an entry exists, last and index are updated accordingly.
5979 * May set @mas->node to MAS_NONE.
5981 * Return: The entry or %NULL.
5983 void *mas_find(struct ma_state *mas, unsigned long max)
5985 if (unlikely(mas_is_paused(mas))) {
5986 if (unlikely(mas->last == ULONG_MAX)) {
5987 mas->node = MAS_NONE;
5990 mas->node = MAS_START;
5991 mas->index = ++mas->last;
5994 if (unlikely(mas_is_start(mas))) {
5995 /* First run or continue */
5998 if (mas->index > max)
6001 entry = mas_walk(mas);
6006 if (unlikely(!mas_searchable(mas)))
6009 /* Retries on dead nodes handled by mas_next_entry */
6010 return mas_next_entry(mas, max);
6014 * mas_find_rev: On the first call, find the first non-null entry at or below
6015 * mas->index down to %min. Otherwise find the first non-null entry below
6016 * mas->index down to %min.
6017 * @mas: The maple state
6018 * @min: The minimum value to check.
6020 * Must hold rcu_read_lock or the write lock.
6021 * If an entry exists, last and index are updated accordingly.
6022 * May set @mas->node to MAS_NONE.
6024 * Return: The entry or %NULL.
6026 void *mas_find_rev(struct ma_state *mas, unsigned long min)
6028 if (unlikely(mas_is_paused(mas))) {
6029 if (unlikely(mas->last == ULONG_MAX)) {
6030 mas->node = MAS_NONE;
6033 mas->node = MAS_START;
6034 mas->last = --mas->index;
6037 if (unlikely(mas_is_start(mas))) {
6038 /* First run or continue */
6041 if (mas->index < min)
6044 entry = mas_walk(mas);
6049 if (unlikely(!mas_searchable(mas)))
6052 if (mas->index < min)
6055 /* Retries on dead nodes handled by mas_next_entry */
6056 return mas_prev_entry(mas, min);
6058 EXPORT_SYMBOL_GPL(mas_find);
6061 * mas_erase() - Find the range in which index resides and erase the entire
6063 * @mas: The maple state
6065 * Must hold the write lock.
6066 * Searches for @mas->index, sets @mas->index and @mas->last to the range and
6067 * erases that range.
6069 * Return: the entry that was erased or %NULL, @mas->index and @mas->last are updated.
6071 void *mas_erase(struct ma_state *mas)
6074 MA_WR_STATE(wr_mas, mas, NULL);
6076 if (mas_is_none(mas) || mas_is_paused(mas))
6077 mas->node = MAS_START;
6079 /* Retry unnecessary when holding the write lock. */
6080 entry = mas_state_walk(mas);
6085 /* Must reset to ensure spanning writes of last slot are detected */
6087 mas_wr_store_setup(&wr_mas);
6088 mas_wr_store_entry(&wr_mas);
6089 if (mas_nomem(mas, GFP_KERNEL))
6094 EXPORT_SYMBOL_GPL(mas_erase);
6097 * mas_nomem() - Check if there was an error allocating and do the allocation
6098 * if necessary If there are allocations, then free them.
6099 * @mas: The maple state
6100 * @gfp: The GFP_FLAGS to use for allocations
6101 * Return: true on allocation, false otherwise.
6103 bool mas_nomem(struct ma_state *mas, gfp_t gfp)
6104 __must_hold(mas->tree->lock)
6106 if (likely(mas->node != MA_ERROR(-ENOMEM))) {
6111 if (gfpflags_allow_blocking(gfp) && !mt_external_lock(mas->tree)) {
6112 mtree_unlock(mas->tree);
6113 mas_alloc_nodes(mas, gfp);
6114 mtree_lock(mas->tree);
6116 mas_alloc_nodes(mas, gfp);
6119 if (!mas_allocated(mas))
6122 mas->node = MAS_START;
6126 void __init maple_tree_init(void)
6128 maple_node_cache = kmem_cache_create("maple_node",
6129 sizeof(struct maple_node), sizeof(struct maple_node),
6134 * mtree_load() - Load a value stored in a maple tree
6135 * @mt: The maple tree
6136 * @index: The index to load
6138 * Return: the entry or %NULL
6140 void *mtree_load(struct maple_tree *mt, unsigned long index)
6142 MA_STATE(mas, mt, index, index);
6145 trace_ma_read(__func__, &mas);
6148 entry = mas_start(&mas);
6149 if (unlikely(mas_is_none(&mas)))
6152 if (unlikely(mas_is_ptr(&mas))) {
6159 entry = mtree_lookup_walk(&mas);
6160 if (!entry && unlikely(mas_is_start(&mas)))
6164 if (xa_is_zero(entry))
6169 EXPORT_SYMBOL(mtree_load);
6172 * mtree_store_range() - Store an entry at a given range.
6173 * @mt: The maple tree
6174 * @index: The start of the range
6175 * @last: The end of the range
6176 * @entry: The entry to store
6177 * @gfp: The GFP_FLAGS to use for allocations
6179 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
6182 int mtree_store_range(struct maple_tree *mt, unsigned long index,
6183 unsigned long last, void *entry, gfp_t gfp)
6185 MA_STATE(mas, mt, index, last);
6186 MA_WR_STATE(wr_mas, &mas, entry);
6188 trace_ma_write(__func__, &mas, 0, entry);
6189 if (WARN_ON_ONCE(xa_is_advanced(entry)))
6197 mas_wr_store_entry(&wr_mas);
6198 if (mas_nomem(&mas, gfp))
6202 if (mas_is_err(&mas))
6203 return xa_err(mas.node);
6207 EXPORT_SYMBOL(mtree_store_range);
6210 * mtree_store() - Store an entry at a given index.
6211 * @mt: The maple tree
6212 * @index: The index to store the value
6213 * @entry: The entry to store
6214 * @gfp: The GFP_FLAGS to use for allocations
6216 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
6219 int mtree_store(struct maple_tree *mt, unsigned long index, void *entry,
6222 return mtree_store_range(mt, index, index, entry, gfp);
6224 EXPORT_SYMBOL(mtree_store);
6227 * mtree_insert_range() - Insert an entry at a give range if there is no value.
6228 * @mt: The maple tree
6229 * @first: The start of the range
6230 * @last: The end of the range
6231 * @entry: The entry to store
6232 * @gfp: The GFP_FLAGS to use for allocations.
6234 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
6235 * request, -ENOMEM if memory could not be allocated.
6237 int mtree_insert_range(struct maple_tree *mt, unsigned long first,
6238 unsigned long last, void *entry, gfp_t gfp)
6240 MA_STATE(ms, mt, first, last);
6242 if (WARN_ON_ONCE(xa_is_advanced(entry)))
6250 mas_insert(&ms, entry);
6251 if (mas_nomem(&ms, gfp))
6255 if (mas_is_err(&ms))
6256 return xa_err(ms.node);
6260 EXPORT_SYMBOL(mtree_insert_range);
6263 * mtree_insert() - Insert an entry at a give index if there is no value.
6264 * @mt: The maple tree
6265 * @index : The index to store the value
6266 * @entry: The entry to store
6267 * @gfp: The FGP_FLAGS to use for allocations.
6269 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
6270 * request, -ENOMEM if memory could not be allocated.
6272 int mtree_insert(struct maple_tree *mt, unsigned long index, void *entry,
6275 return mtree_insert_range(mt, index, index, entry, gfp);
6277 EXPORT_SYMBOL(mtree_insert);
6279 int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
6280 void *entry, unsigned long size, unsigned long min,
6281 unsigned long max, gfp_t gfp)
6285 MA_STATE(mas, mt, min, max - size);
6286 if (!mt_is_alloc(mt))
6289 if (WARN_ON_ONCE(mt_is_reserved(entry)))
6305 mas.last = max - size;
6306 ret = mas_alloc(&mas, entry, size, startp);
6307 if (mas_nomem(&mas, gfp))
6313 EXPORT_SYMBOL(mtree_alloc_range);
6315 int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
6316 void *entry, unsigned long size, unsigned long min,
6317 unsigned long max, gfp_t gfp)
6321 MA_STATE(mas, mt, min, max - size);
6322 if (!mt_is_alloc(mt))
6325 if (WARN_ON_ONCE(mt_is_reserved(entry)))
6339 ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
6340 if (mas_nomem(&mas, gfp))
6346 EXPORT_SYMBOL(mtree_alloc_rrange);
6349 * mtree_erase() - Find an index and erase the entire range.
6350 * @mt: The maple tree
6351 * @index: The index to erase
6353 * Erasing is the same as a walk to an entry then a store of a NULL to that
6354 * ENTIRE range. In fact, it is implemented as such using the advanced API.
6356 * Return: The entry stored at the @index or %NULL
6358 void *mtree_erase(struct maple_tree *mt, unsigned long index)
6362 MA_STATE(mas, mt, index, index);
6363 trace_ma_op(__func__, &mas);
6366 entry = mas_erase(&mas);
6371 EXPORT_SYMBOL(mtree_erase);
6374 * __mt_destroy() - Walk and free all nodes of a locked maple tree.
6375 * @mt: The maple tree
6377 * Note: Does not handle locking.
6379 void __mt_destroy(struct maple_tree *mt)
6381 void *root = mt_root_locked(mt);
6383 rcu_assign_pointer(mt->ma_root, NULL);
6384 if (xa_is_node(root))
6385 mte_destroy_walk(root, mt);
6389 EXPORT_SYMBOL_GPL(__mt_destroy);
6392 * mtree_destroy() - Destroy a maple tree
6393 * @mt: The maple tree
6395 * Frees all resources used by the tree. Handles locking.
6397 void mtree_destroy(struct maple_tree *mt)
6403 EXPORT_SYMBOL(mtree_destroy);
6406 * mt_find() - Search from the start up until an entry is found.
6407 * @mt: The maple tree
6408 * @index: Pointer which contains the start location of the search
6409 * @max: The maximum value to check
6411 * Handles locking. @index will be incremented to one beyond the range.
6413 * Return: The entry at or after the @index or %NULL
6415 void *mt_find(struct maple_tree *mt, unsigned long *index, unsigned long max)
6417 MA_STATE(mas, mt, *index, *index);
6419 #ifdef CONFIG_DEBUG_MAPLE_TREE
6420 unsigned long copy = *index;
6423 trace_ma_read(__func__, &mas);
6430 entry = mas_state_walk(&mas);
6431 if (mas_is_start(&mas))
6434 if (unlikely(xa_is_zero(entry)))
6440 while (mas_searchable(&mas) && (mas.index < max)) {
6441 entry = mas_next_entry(&mas, max);
6442 if (likely(entry && !xa_is_zero(entry)))
6446 if (unlikely(xa_is_zero(entry)))
6450 if (likely(entry)) {
6451 *index = mas.last + 1;
6452 #ifdef CONFIG_DEBUG_MAPLE_TREE
6453 if ((*index) && (*index) <= copy)
6454 pr_err("index not increased! %lx <= %lx\n",
6456 MT_BUG_ON(mt, (*index) && ((*index) <= copy));
6462 EXPORT_SYMBOL(mt_find);
6465 * mt_find_after() - Search from the start up until an entry is found.
6466 * @mt: The maple tree
6467 * @index: Pointer which contains the start location of the search
6468 * @max: The maximum value to check
6470 * Handles locking, detects wrapping on index == 0
6472 * Return: The entry at or after the @index or %NULL
6474 void *mt_find_after(struct maple_tree *mt, unsigned long *index,
6480 return mt_find(mt, index, max);
6482 EXPORT_SYMBOL(mt_find_after);
6484 #ifdef CONFIG_DEBUG_MAPLE_TREE
6485 atomic_t maple_tree_tests_run;
6486 EXPORT_SYMBOL_GPL(maple_tree_tests_run);
6487 atomic_t maple_tree_tests_passed;
6488 EXPORT_SYMBOL_GPL(maple_tree_tests_passed);
6491 extern void kmem_cache_set_non_kernel(struct kmem_cache *, unsigned int);
6492 void mt_set_non_kernel(unsigned int val)
6494 kmem_cache_set_non_kernel(maple_node_cache, val);
6497 extern unsigned long kmem_cache_get_alloc(struct kmem_cache *);
6498 unsigned long mt_get_alloc_size(void)
6500 return kmem_cache_get_alloc(maple_node_cache);
6503 extern void kmem_cache_zero_nr_tallocated(struct kmem_cache *);
6504 void mt_zero_nr_tallocated(void)
6506 kmem_cache_zero_nr_tallocated(maple_node_cache);
6509 extern unsigned int kmem_cache_nr_tallocated(struct kmem_cache *);
6510 unsigned int mt_nr_tallocated(void)
6512 return kmem_cache_nr_tallocated(maple_node_cache);
6515 extern unsigned int kmem_cache_nr_allocated(struct kmem_cache *);
6516 unsigned int mt_nr_allocated(void)
6518 return kmem_cache_nr_allocated(maple_node_cache);
6522 * mas_dead_node() - Check if the maple state is pointing to a dead node.
6523 * @mas: The maple state
6524 * @index: The index to restore in @mas.
6526 * Used in test code.
6527 * Return: 1 if @mas has been reset to MAS_START, 0 otherwise.
6529 static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
6531 if (unlikely(!mas_searchable(mas) || mas_is_start(mas)))
6534 if (likely(!mte_dead_node(mas->node)))
6537 mas_rewalk(mas, index);
6540 #endif /* not defined __KERNEL__ */
6543 * mas_get_slot() - Get the entry in the maple state node stored at @offset.
6544 * @mas: The maple state
6545 * @offset: The offset into the slot array to fetch.
6547 * Return: The entry stored at @offset.
6549 static inline struct maple_enode *mas_get_slot(struct ma_state *mas,
6550 unsigned char offset)
6552 return mas_slot(mas, ma_slots(mas_mn(mas), mte_node_type(mas->node)),
6558 * mas_first_entry() - Go the first leaf and find the first entry.
6559 * @mas: the maple state.
6560 * @limit: the maximum index to check.
6561 * @*r_start: Pointer to set to the range start.
6563 * Sets mas->offset to the offset of the entry, r_start to the range minimum.
6565 * Return: The first entry or MAS_NONE.
6567 static inline void *mas_first_entry(struct ma_state *mas, struct maple_node *mn,
6568 unsigned long limit, enum maple_type mt)
6572 unsigned long *pivots;
6576 mas->index = mas->min;
6577 if (mas->index > limit)
6582 while (likely(!ma_is_leaf(mt))) {
6583 MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
6584 slots = ma_slots(mn, mt);
6585 pivots = ma_pivots(mn, mt);
6587 entry = mas_slot(mas, slots, 0);
6588 if (unlikely(ma_dead_node(mn)))
6592 mt = mte_node_type(mas->node);
6594 MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
6597 slots = ma_slots(mn, mt);
6598 entry = mas_slot(mas, slots, 0);
6599 if (unlikely(ma_dead_node(mn)))
6602 /* Slot 0 or 1 must be set */
6603 if (mas->index > limit)
6609 pivots = ma_pivots(mn, mt);
6610 mas->index = pivots[0] + 1;
6612 entry = mas_slot(mas, slots, 1);
6613 if (unlikely(ma_dead_node(mn)))
6616 if (mas->index > limit)
6623 if (likely(!ma_dead_node(mn)))
6624 mas->node = MAS_NONE;
6628 /* Depth first search, post-order */
6629 static void mas_dfs_postorder(struct ma_state *mas, unsigned long max)
6632 struct maple_enode *p = MAS_NONE, *mn = mas->node;
6633 unsigned long p_min, p_max;
6635 mas_next_node(mas, mas_mn(mas), max);
6636 if (!mas_is_none(mas))
6639 if (mte_is_root(mn))
6644 while (mas->node != MAS_NONE) {
6648 mas_prev_node(mas, 0);
6659 /* Tree validations */
6660 static void mt_dump_node(const struct maple_tree *mt, void *entry,
6661 unsigned long min, unsigned long max, unsigned int depth);
6662 static void mt_dump_range(unsigned long min, unsigned long max,
6665 static const char spaces[] = " ";
6668 pr_info("%.*s%lu: ", depth * 2, spaces, min);
6670 pr_info("%.*s%lu-%lu: ", depth * 2, spaces, min, max);
6673 static void mt_dump_entry(void *entry, unsigned long min, unsigned long max,
6676 mt_dump_range(min, max, depth);
6678 if (xa_is_value(entry))
6679 pr_cont("value %ld (0x%lx) [%p]\n", xa_to_value(entry),
6680 xa_to_value(entry), entry);
6681 else if (xa_is_zero(entry))
6682 pr_cont("zero (%ld)\n", xa_to_internal(entry));
6683 else if (mt_is_reserved(entry))
6684 pr_cont("UNKNOWN ENTRY (%p)\n", entry);
6686 pr_cont("%p\n", entry);
6689 static void mt_dump_range64(const struct maple_tree *mt, void *entry,
6690 unsigned long min, unsigned long max, unsigned int depth)
6692 struct maple_range_64 *node = &mte_to_node(entry)->mr64;
6693 bool leaf = mte_is_leaf(entry);
6694 unsigned long first = min;
6697 pr_cont(" contents: ");
6698 for (i = 0; i < MAPLE_RANGE64_SLOTS - 1; i++)
6699 pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
6700 pr_cont("%p\n", node->slot[i]);
6701 for (i = 0; i < MAPLE_RANGE64_SLOTS; i++) {
6702 unsigned long last = max;
6704 if (i < (MAPLE_RANGE64_SLOTS - 1))
6705 last = node->pivot[i];
6706 else if (!node->slot[i] && max != mt_max[mte_node_type(entry)])
6708 if (last == 0 && i > 0)
6711 mt_dump_entry(mt_slot(mt, node->slot, i),
6712 first, last, depth + 1);
6713 else if (node->slot[i])
6714 mt_dump_node(mt, mt_slot(mt, node->slot, i),
6715 first, last, depth + 1);
6720 pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
6721 node, last, max, i);
6728 static void mt_dump_arange64(const struct maple_tree *mt, void *entry,
6729 unsigned long min, unsigned long max, unsigned int depth)
6731 struct maple_arange_64 *node = &mte_to_node(entry)->ma64;
6732 bool leaf = mte_is_leaf(entry);
6733 unsigned long first = min;
6736 pr_cont(" contents: ");
6737 for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++)
6738 pr_cont("%lu ", node->gap[i]);
6739 pr_cont("| %02X %02X| ", node->meta.end, node->meta.gap);
6740 for (i = 0; i < MAPLE_ARANGE64_SLOTS - 1; i++)
6741 pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
6742 pr_cont("%p\n", node->slot[i]);
6743 for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) {
6744 unsigned long last = max;
6746 if (i < (MAPLE_ARANGE64_SLOTS - 1))
6747 last = node->pivot[i];
6748 else if (!node->slot[i])
6750 if (last == 0 && i > 0)
6753 mt_dump_entry(mt_slot(mt, node->slot, i),
6754 first, last, depth + 1);
6755 else if (node->slot[i])
6756 mt_dump_node(mt, mt_slot(mt, node->slot, i),
6757 first, last, depth + 1);
6762 pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
6763 node, last, max, i);
6770 static void mt_dump_node(const struct maple_tree *mt, void *entry,
6771 unsigned long min, unsigned long max, unsigned int depth)
6773 struct maple_node *node = mte_to_node(entry);
6774 unsigned int type = mte_node_type(entry);
6777 mt_dump_range(min, max, depth);
6779 pr_cont("node %p depth %d type %d parent %p", node, depth, type,
6780 node ? node->parent : NULL);
6784 for (i = 0; i < MAPLE_NODE_SLOTS; i++) {
6786 pr_cont("OUT OF RANGE: ");
6787 mt_dump_entry(mt_slot(mt, node->slot, i),
6788 min + i, min + i, depth);
6792 case maple_range_64:
6793 mt_dump_range64(mt, entry, min, max, depth);
6795 case maple_arange_64:
6796 mt_dump_arange64(mt, entry, min, max, depth);
6800 pr_cont(" UNKNOWN TYPE\n");
6804 void mt_dump(const struct maple_tree *mt)
6806 void *entry = rcu_dereference_check(mt->ma_root, mt_locked(mt));
6808 pr_info("maple_tree(%p) flags %X, height %u root %p\n",
6809 mt, mt->ma_flags, mt_height(mt), entry);
6810 if (!xa_is_node(entry))
6811 mt_dump_entry(entry, 0, 0, 0);
6813 mt_dump_node(mt, entry, 0, mt_max[mte_node_type(entry)], 0);
6817 * Calculate the maximum gap in a node and check if that's what is reported in
6818 * the parent (unless root).
6820 static void mas_validate_gaps(struct ma_state *mas)
6822 struct maple_enode *mte = mas->node;
6823 struct maple_node *p_mn;
6824 unsigned long gap = 0, max_gap = 0;
6825 unsigned long p_end, p_start = mas->min;
6826 unsigned char p_slot;
6827 unsigned long *gaps = NULL;
6828 unsigned long *pivots = ma_pivots(mte_to_node(mte), mte_node_type(mte));
6831 if (ma_is_dense(mte_node_type(mte))) {
6832 for (i = 0; i < mt_slot_count(mte); i++) {
6833 if (mas_get_slot(mas, i)) {
6844 gaps = ma_gaps(mte_to_node(mte), mte_node_type(mte));
6845 for (i = 0; i < mt_slot_count(mte); i++) {
6846 p_end = mas_logical_pivot(mas, pivots, i, mte_node_type(mte));
6849 if (mas_get_slot(mas, i)) {
6854 gap += p_end - p_start + 1;
6856 void *entry = mas_get_slot(mas, i);
6860 if (gap != p_end - p_start + 1) {
6861 pr_err("%p[%u] -> %p %lu != %lu - %lu + 1\n",
6863 mas_get_slot(mas, i), gap,
6867 MT_BUG_ON(mas->tree,
6868 gap != p_end - p_start + 1);
6871 if (gap > p_end - p_start + 1) {
6872 pr_err("%p[%u] %lu >= %lu - %lu + 1 (%lu)\n",
6873 mas_mn(mas), i, gap, p_end, p_start,
6874 p_end - p_start + 1);
6875 MT_BUG_ON(mas->tree,
6876 gap > p_end - p_start + 1);
6884 p_start = p_end + 1;
6885 if (p_end >= mas->max)
6890 if (mte_is_root(mte))
6893 p_slot = mte_parent_slot(mas->node);
6894 p_mn = mte_parent(mte);
6895 MT_BUG_ON(mas->tree, max_gap > mas->max);
6896 if (ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap) {
6897 pr_err("gap %p[%u] != %lu\n", p_mn, p_slot, max_gap);
6901 MT_BUG_ON(mas->tree,
6902 ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap);
6905 static void mas_validate_parent_slot(struct ma_state *mas)
6907 struct maple_node *parent;
6908 struct maple_enode *node;
6909 enum maple_type p_type = mas_parent_enum(mas, mas->node);
6910 unsigned char p_slot = mte_parent_slot(mas->node);
6914 if (mte_is_root(mas->node))
6917 parent = mte_parent(mas->node);
6918 slots = ma_slots(parent, p_type);
6919 MT_BUG_ON(mas->tree, mas_mn(mas) == parent);
6921 /* Check prev/next parent slot for duplicate node entry */
6923 for (i = 0; i < mt_slots[p_type]; i++) {
6924 node = mas_slot(mas, slots, i);
6926 if (node != mas->node)
6927 pr_err("parent %p[%u] does not have %p\n",
6928 parent, i, mas_mn(mas));
6929 MT_BUG_ON(mas->tree, node != mas->node);
6930 } else if (node == mas->node) {
6931 pr_err("Invalid child %p at parent %p[%u] p_slot %u\n",
6932 mas_mn(mas), parent, i, p_slot);
6933 MT_BUG_ON(mas->tree, node == mas->node);
6938 static void mas_validate_child_slot(struct ma_state *mas)
6940 enum maple_type type = mte_node_type(mas->node);
6941 void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
6942 unsigned long *pivots = ma_pivots(mte_to_node(mas->node), type);
6943 struct maple_enode *child;
6946 if (mte_is_leaf(mas->node))
6949 for (i = 0; i < mt_slots[type]; i++) {
6950 child = mas_slot(mas, slots, i);
6951 if (!pivots[i] || pivots[i] == mas->max)
6957 if (mte_parent_slot(child) != i) {
6958 pr_err("Slot error at %p[%u]: child %p has pslot %u\n",
6959 mas_mn(mas), i, mte_to_node(child),
6960 mte_parent_slot(child));
6961 MT_BUG_ON(mas->tree, 1);
6964 if (mte_parent(child) != mte_to_node(mas->node)) {
6965 pr_err("child %p has parent %p not %p\n",
6966 mte_to_node(child), mte_parent(child),
6967 mte_to_node(mas->node));
6968 MT_BUG_ON(mas->tree, 1);
6974 * Validate all pivots are within mas->min and mas->max.
6976 static void mas_validate_limits(struct ma_state *mas)
6979 unsigned long prev_piv = 0;
6980 enum maple_type type = mte_node_type(mas->node);
6981 void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
6982 unsigned long *pivots = ma_pivots(mas_mn(mas), type);
6984 /* all limits are fine here. */
6985 if (mte_is_root(mas->node))
6988 for (i = 0; i < mt_slots[type]; i++) {
6991 piv = mas_safe_pivot(mas, pivots, i, type);
6993 if (!piv && (i != 0))
6996 if (!mte_is_leaf(mas->node)) {
6997 void *entry = mas_slot(mas, slots, i);
7000 pr_err("%p[%u] cannot be null\n",
7003 MT_BUG_ON(mas->tree, !entry);
7006 if (prev_piv > piv) {
7007 pr_err("%p[%u] piv %lu < prev_piv %lu\n",
7008 mas_mn(mas), i, piv, prev_piv);
7009 MT_BUG_ON(mas->tree, piv < prev_piv);
7012 if (piv < mas->min) {
7013 pr_err("%p[%u] %lu < %lu\n", mas_mn(mas), i,
7015 MT_BUG_ON(mas->tree, piv < mas->min);
7017 if (piv > mas->max) {
7018 pr_err("%p[%u] %lu > %lu\n", mas_mn(mas), i,
7020 MT_BUG_ON(mas->tree, piv > mas->max);
7023 if (piv == mas->max)
7026 for (i += 1; i < mt_slots[type]; i++) {
7027 void *entry = mas_slot(mas, slots, i);
7029 if (entry && (i != mt_slots[type] - 1)) {
7030 pr_err("%p[%u] should not have entry %p\n", mas_mn(mas),
7032 MT_BUG_ON(mas->tree, entry != NULL);
7035 if (i < mt_pivots[type]) {
7036 unsigned long piv = pivots[i];
7041 pr_err("%p[%u] should not have piv %lu\n",
7042 mas_mn(mas), i, piv);
7043 MT_BUG_ON(mas->tree, i < mt_pivots[type] - 1);
7048 static void mt_validate_nulls(struct maple_tree *mt)
7050 void *entry, *last = (void *)1;
7051 unsigned char offset = 0;
7053 MA_STATE(mas, mt, 0, 0);
7056 if (mas_is_none(&mas) || (mas.node == MAS_ROOT))
7059 while (!mte_is_leaf(mas.node))
7062 slots = ma_slots(mte_to_node(mas.node), mte_node_type(mas.node));
7064 entry = mas_slot(&mas, slots, offset);
7065 if (!last && !entry) {
7066 pr_err("Sequential nulls end at %p[%u]\n",
7067 mas_mn(&mas), offset);
7069 MT_BUG_ON(mt, !last && !entry);
7071 if (offset == mas_data_end(&mas)) {
7072 mas_next_node(&mas, mas_mn(&mas), ULONG_MAX);
7073 if (mas_is_none(&mas))
7076 slots = ma_slots(mte_to_node(mas.node),
7077 mte_node_type(mas.node));
7082 } while (!mas_is_none(&mas));
7086 * validate a maple tree by checking:
7087 * 1. The limits (pivots are within mas->min to mas->max)
7088 * 2. The gap is correctly set in the parents
7090 void mt_validate(struct maple_tree *mt)
7094 MA_STATE(mas, mt, 0, 0);
7097 if (!mas_searchable(&mas))
7100 mas_first_entry(&mas, mas_mn(&mas), ULONG_MAX, mte_node_type(mas.node));
7101 while (!mas_is_none(&mas)) {
7102 MT_BUG_ON(mas.tree, mte_dead_node(mas.node));
7103 if (!mte_is_root(mas.node)) {
7104 end = mas_data_end(&mas);
7105 if ((end < mt_min_slot_count(mas.node)) &&
7106 (mas.max != ULONG_MAX)) {
7107 pr_err("Invalid size %u of %p\n", end,
7109 MT_BUG_ON(mas.tree, 1);
7113 mas_validate_parent_slot(&mas);
7114 mas_validate_child_slot(&mas);
7115 mas_validate_limits(&mas);
7116 if (mt_is_alloc(mt))
7117 mas_validate_gaps(&mas);
7118 mas_dfs_postorder(&mas, ULONG_MAX);
7120 mt_validate_nulls(mt);
7126 #endif /* CONFIG_DEBUG_MAPLE_TREE */