1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 Red Black Trees 4 (C) 1999 Andrea Arcangeli <andrea (at) suse.de> 5 6 linux/include/linux/rbtree.h 7 8 To use rbtrees you'll have to implement your own insert and search cores. 9 This will avoid us to use callbacks and to drop drammatically performances. 10 I know it's not the cleaner way, but in C (not in C++) to get 11 performances and genericity... 12 13 See Documentation/rbtree.txt for documentation and samples. 14 */ 15 16 #ifndef _LINUX_RBTREE_H 17 #define _LINUX_RBTREE_H 18 19 #ifndef __UBOOT__ 20 #include <linux/kernel.h> 21 #endif 22 #include <linux/stddef.h> 23 24 struct rb_node { 25 unsigned long __rb_parent_color; 26 struct rb_node *rb_right; 27 struct rb_node *rb_left; 28 } __attribute__((aligned(sizeof(long)))); 29 /* The alignment might seem pointless, but allegedly CRIS needs it */ 30 31 struct rb_root { 32 struct rb_node *rb_node; 33 }; 34 35 36 #define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) 37 38 #define RB_ROOT (struct rb_root) { NULL, } 39 #define rb_entry(ptr, type, member) container_of(ptr, type, member) 40 41 #define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) 42 43 /* 'empty' nodes are nodes that are known not to be inserted in an rbree */ 44 #define RB_EMPTY_NODE(node) \ 45 ((node)->__rb_parent_color == (unsigned long)(node)) 46 #define RB_CLEAR_NODE(node) \ 47 ((node)->__rb_parent_color = (unsigned long)(node)) 48 49 50 extern void rb_insert_color(struct rb_node *, struct rb_root *); 51 extern void rb_erase(struct rb_node *, struct rb_root *); 52 53 54 /* Find logical next and previous nodes in a tree */ 55 extern struct rb_node *rb_next(const struct rb_node *); 56 extern struct rb_node *rb_prev(const struct rb_node *); 57 extern struct rb_node *rb_first(const struct rb_root *); 58 extern struct rb_node *rb_last(const struct rb_root *); 59 60 /* Postorder iteration - always visit the parent after its children */ 61 extern struct rb_node *rb_first_postorder(const struct rb_root *); 62 extern struct rb_node *rb_next_postorder(const struct rb_node *); 63 64 /* Fast replacement of a single node without remove/rebalance/add/rebalance */ 65 extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 66 struct rb_root *root); 67 68 static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, 69 struct rb_node ** rb_link) 70 { 71 node->__rb_parent_color = (unsigned long)parent; 72 node->rb_left = node->rb_right = NULL; 73 74 *rb_link = node; 75 } 76 77 #define rb_entry_safe(ptr, type, member) \ 78 ({ typeof(ptr) ____ptr = (ptr); \ 79 ____ptr ? rb_entry(____ptr, type, member) : NULL; \ 80 }) 81 82 /** 83 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of 84 * given type safe against removal of rb_node entry 85 * 86 * @pos: the 'type *' to use as a loop cursor. 87 * @n: another 'type *' to use as temporary storage 88 * @root: 'rb_root *' of the rbtree. 89 * @field: the name of the rb_node field within 'type'. 90 */ 91 #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ 92 for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ 93 pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ 94 typeof(*pos), field); 1; }); \ 95 pos = n) 96 97 #endif /* _LINUX_RBTREE_H */ 98
