LXR uboot/include/linux/rbtree.h

   1/*
   2  Red Black Trees
   3  (C) 1999  Andrea Arcangeli <andrea@suse.de>
   4  
   5 * SPDX-License-Identifier:     GPL-2.0+
   6
   7  linux/include/linux/rbtree.h
   8
   9  To use rbtrees you'll have to implement your own insert and search cores.
  10  This will avoid us to use callbacks and to drop drammatically performances.
  11  I know it's not the cleaner way,  but in C (not in C++) to get
  12  performances and genericity...
  13
  14  See Documentation/rbtree.txt for documentation and samples.
  15*/
  16
  17#ifndef _LINUX_RBTREE_H
  18#define _LINUX_RBTREE_H
  19
  20#ifndef __UBOOT__
  21#include <linux/kernel.h>
  22#endif
  23#include <linux/stddef.h>
  24
  25struct rb_node {
  26        unsigned long  __rb_parent_color;
  27        struct rb_node *rb_right;
  28        struct rb_node *rb_left;
  29} __attribute__((aligned(sizeof(long))));
  30    /* The alignment might seem pointless, but allegedly CRIS needs it */
  31
  32struct rb_root {
  33        struct rb_node *rb_node;
  34};
  35
  36
  37#define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3))
  38
  39#define RB_ROOT (struct rb_root) { NULL, }
  40#define rb_entry(ptr, type, member) container_of(ptr, type, member)
  41
  42#define RB_EMPTY_ROOT(root)  ((root)->rb_node == NULL)
  43
  44/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
  45#define RB_EMPTY_NODE(node)  \
  46        ((node)->__rb_parent_color == (unsigned long)(node))
  47#define RB_CLEAR_NODE(node)  \
  48        ((node)->__rb_parent_color = (unsigned long)(node))
  49
  50
  51extern void rb_insert_color(struct rb_node *, struct rb_root *);
  52extern void rb_erase(struct rb_node *, struct rb_root *);
  53
  54
  55/* Find logical next and previous nodes in a tree */
  56extern struct rb_node *rb_next(const struct rb_node *);
  57extern struct rb_node *rb_prev(const struct rb_node *);
  58extern struct rb_node *rb_first(const struct rb_root *);
  59extern struct rb_node *rb_last(const struct rb_root *);
  60
  61/* Postorder iteration - always visit the parent after its children */
  62extern struct rb_node *rb_first_postorder(const struct rb_root *);
  63extern struct rb_node *rb_next_postorder(const struct rb_node *);
  64
  65/* Fast replacement of a single node without remove/rebalance/add/rebalance */
  66extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
  67                            struct rb_root *root);
  68
  69static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
  70                                struct rb_node ** rb_link)
  71{
  72        node->__rb_parent_color = (unsigned long)parent;
  73        node->rb_left = node->rb_right = NULL;
  74
  75        *rb_link = node;
  76}
  77
  78#define rb_entry_safe(ptr, type, member) \
  79        ({ typeof(ptr) ____ptr = (ptr); \
  80           ____ptr ? rb_entry(____ptr, type, member) : NULL; \
  81        })
  82
  83/**
  84 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
  85 * given type safe against removal of rb_node entry
  86 *
  87 * @pos:        the 'type *' to use as a loop cursor.
  88 * @n:          another 'type *' to use as temporary storage
  89 * @root:       'rb_root *' of the rbtree.
  90 * @field:      the name of the rb_node field within 'type'.
  91 */
  92#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
  93        for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
  94             pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
  95                        typeof(*pos), field); 1; }); \
  96             pos = n)
  97
  98#endif  /* _LINUX_RBTREE_H */
  99