1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_INTERVAL_TREE_H 3 #define _LINUX_INTERVAL_TREE_H 4 5 #include <linux/rbtree.h> 6 7 struct interval_tree_node { 8 struct rb_node rb; 9 unsigned long start; /* Start of interval */ 10 unsigned long last; /* Last location _in_ interval */ 11 unsigned long __subtree_last; 12 }; 13 14 extern void 15 interval_tree_insert(struct interval_tree_node *node, 16 struct rb_root_cached *root); 17 18 extern void 19 interval_tree_remove(struct interval_tree_node *node, 20 struct rb_root_cached *root); 21 22 extern struct interval_tree_node * 23 interval_tree_iter_first(struct rb_root_cached *root, 24 unsigned long start, unsigned long last); 25 26 extern struct interval_tree_node * 27 interval_tree_iter_next(struct interval_tree_node *node, 28 unsigned long start, unsigned long last); 29 30 /** 31 * struct interval_tree_span_iter - Find used and unused spans. 32 * @start_hole: Start of an interval for a hole when is_hole == 1 33 * @last_hole: Inclusive end of an interval for a hole when is_hole == 1 34 * @start_used: Start of a used interval when is_hole == 0 35 * @last_used: Inclusive end of a used interval when is_hole == 0 36 * @is_hole: 0 == used, 1 == is_hole, -1 == done iteration 37 * 38 * This iterator travels over spans in an interval tree. It does not return 39 * nodes but classifies each span as either a hole, where no nodes intersect, or 40 * a used, which is fully covered by nodes. Each iteration step toggles between 41 * hole and used until the entire range is covered. The returned spans always 42 * fully cover the requested range. 43 * 44 * The iterator is greedy, it always returns the largest hole or used possible, 45 * consolidating all consecutive nodes. 46 * 47 * Use interval_tree_span_iter_done() to detect end of iteration. 48 */ 49 struct interval_tree_span_iter { 50 /* private: not for use by the caller */ 51 struct interval_tree_node *nodes[2]; 52 unsigned long first_index; 53 unsigned long last_index; 54 55 /* public: */ 56 union { 57 unsigned long start_hole; 58 unsigned long start_used; 59 }; 60 union { 61 unsigned long last_hole; 62 unsigned long last_used; 63 }; 64 int is_hole; 65 }; 66 67 void interval_tree_span_iter_first(struct interval_tree_span_iter *state, 68 struct rb_root_cached *itree, 69 unsigned long first_index, 70 unsigned long last_index); 71 void interval_tree_span_iter_advance(struct interval_tree_span_iter *iter, 72 struct rb_root_cached *itree, 73 unsigned long new_index); 74 void interval_tree_span_iter_next(struct interval_tree_span_iter *state); 75 76 static inline bool 77 interval_tree_span_iter_done(struct interval_tree_span_iter *state) 78 { 79 return state->is_hole == -1; 80 } 81 82 #define interval_tree_for_each_span(span, itree, first_index, last_index) \ 83 for (interval_tree_span_iter_first(span, itree, \ 84 first_index, last_index); \ 85 !interval_tree_span_iter_done(span); \ 86 interval_tree_span_iter_next(span)) 87 88 #endif /* _LINUX_INTERVAL_TREE_H */ 89