mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 05:48:40 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
280 lines
8.1 KiB
C
280 lines
8.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
Red Black Trees
|
|
(C) 1999 Andrea Arcangeli <andrea@suse.de>
|
|
(C) 2002 David Woodhouse <dwmw2@infradead.org>
|
|
(C) 2012 Michel Lespinasse <walken@google.com>
|
|
|
|
|
|
linux/include/linux/rbtree_augmented.h
|
|
*/
|
|
|
|
#ifndef _LINUX_RBTREE_AUGMENTED_H
|
|
#define _LINUX_RBTREE_AUGMENTED_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/rbtree.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
/*
|
|
* Please note - only struct rb_augment_callbacks and the prototypes for
|
|
* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
|
|
* The rest are implementation details you are not expected to depend on.
|
|
*
|
|
* See Documentation/rbtree.txt for documentation and samples.
|
|
*/
|
|
|
|
struct rb_augment_callbacks {
|
|
void (*propagate)(struct rb_node *node, struct rb_node *stop);
|
|
void (*copy)(struct rb_node *old, struct rb_node *new);
|
|
void (*rotate)(struct rb_node *old, struct rb_node *new);
|
|
};
|
|
|
|
extern void __rb_insert_augmented(struct rb_node *node,
|
|
struct rb_root *root,
|
|
bool newleft, struct rb_node **leftmost,
|
|
void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
|
|
/*
|
|
* Fixup the rbtree and update the augmented information when rebalancing.
|
|
*
|
|
* On insertion, the user must update the augmented information on the path
|
|
* leading to the inserted node, then call rb_link_node() as usual and
|
|
* rb_insert_augmented() instead of the usual rb_insert_color() call.
|
|
* If rb_insert_augmented() rebalances the rbtree, it will callback into
|
|
* a user provided function to update the augmented information on the
|
|
* affected subtrees.
|
|
*/
|
|
static inline void
|
|
rb_insert_augmented(struct rb_node *node, struct rb_root *root,
|
|
const struct rb_augment_callbacks *augment)
|
|
{
|
|
__rb_insert_augmented(node, root, false, NULL, augment->rotate);
|
|
}
|
|
|
|
static inline void
|
|
rb_insert_augmented_cached(struct rb_node *node,
|
|
struct rb_root_cached *root, bool newleft,
|
|
const struct rb_augment_callbacks *augment)
|
|
{
|
|
__rb_insert_augmented(node, &root->rb_root,
|
|
newleft, &root->rb_leftmost, augment->rotate);
|
|
}
|
|
|
|
#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
|
|
rbtype, rbaugmented, rbcompute) \
|
|
static inline void \
|
|
rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
|
|
{ \
|
|
while (rb != stop) { \
|
|
rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
|
|
rbtype augmented = rbcompute(node); \
|
|
if (node->rbaugmented == augmented) \
|
|
break; \
|
|
node->rbaugmented = augmented; \
|
|
rb = rb_parent(&node->rbfield); \
|
|
} \
|
|
} \
|
|
static inline void \
|
|
rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
|
|
{ \
|
|
rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
|
|
rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
|
|
new->rbaugmented = old->rbaugmented; \
|
|
} \
|
|
static void \
|
|
rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
|
|
{ \
|
|
rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
|
|
rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
|
|
new->rbaugmented = old->rbaugmented; \
|
|
old->rbaugmented = rbcompute(old); \
|
|
} \
|
|
rbstatic const struct rb_augment_callbacks rbname = { \
|
|
.propagate = rbname ## _propagate, \
|
|
.copy = rbname ## _copy, \
|
|
.rotate = rbname ## _rotate \
|
|
};
|
|
|
|
|
|
#define RB_RED 0
|
|
#define RB_BLACK 1
|
|
|
|
#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
|
|
|
|
#define __rb_color(pc) ((pc) & 1)
|
|
#define __rb_is_black(pc) __rb_color(pc)
|
|
#define __rb_is_red(pc) (!__rb_color(pc))
|
|
#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
|
|
#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
|
|
#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
|
|
|
|
static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
|
|
{
|
|
rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
|
|
}
|
|
|
|
static inline void rb_set_parent_color(struct rb_node *rb,
|
|
struct rb_node *p, int color)
|
|
{
|
|
rb->__rb_parent_color = (unsigned long)p | color;
|
|
}
|
|
|
|
static inline void
|
|
__rb_change_child(struct rb_node *old, struct rb_node *new,
|
|
struct rb_node *parent, struct rb_root *root)
|
|
{
|
|
if (parent) {
|
|
if (parent->rb_left == old)
|
|
WRITE_ONCE(parent->rb_left, new);
|
|
else
|
|
WRITE_ONCE(parent->rb_right, new);
|
|
} else
|
|
WRITE_ONCE(root->rb_node, new);
|
|
}
|
|
|
|
static inline void
|
|
__rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
|
|
struct rb_node *parent, struct rb_root *root)
|
|
{
|
|
if (parent) {
|
|
if (parent->rb_left == old)
|
|
rcu_assign_pointer(parent->rb_left, new);
|
|
else
|
|
rcu_assign_pointer(parent->rb_right, new);
|
|
} else
|
|
rcu_assign_pointer(root->rb_node, new);
|
|
}
|
|
|
|
extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
|
|
void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
|
|
|
|
static __always_inline struct rb_node *
|
|
__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
|
|
struct rb_node **leftmost,
|
|
const struct rb_augment_callbacks *augment)
|
|
{
|
|
struct rb_node *child = node->rb_right;
|
|
struct rb_node *tmp = node->rb_left;
|
|
struct rb_node *parent, *rebalance;
|
|
unsigned long pc;
|
|
|
|
if (leftmost && node == *leftmost)
|
|
*leftmost = rb_next(node);
|
|
|
|
if (!tmp) {
|
|
/*
|
|
* Case 1: node to erase has no more than 1 child (easy!)
|
|
*
|
|
* Note that if there is one child it must be red due to 5)
|
|
* and node must be black due to 4). We adjust colors locally
|
|
* so as to bypass __rb_erase_color() later on.
|
|
*/
|
|
pc = node->__rb_parent_color;
|
|
parent = __rb_parent(pc);
|
|
__rb_change_child(node, child, parent, root);
|
|
if (child) {
|
|
child->__rb_parent_color = pc;
|
|
rebalance = NULL;
|
|
} else
|
|
rebalance = __rb_is_black(pc) ? parent : NULL;
|
|
tmp = parent;
|
|
} else if (!child) {
|
|
/* Still case 1, but this time the child is node->rb_left */
|
|
tmp->__rb_parent_color = pc = node->__rb_parent_color;
|
|
parent = __rb_parent(pc);
|
|
__rb_change_child(node, tmp, parent, root);
|
|
rebalance = NULL;
|
|
tmp = parent;
|
|
} else {
|
|
struct rb_node *successor = child, *child2;
|
|
|
|
tmp = child->rb_left;
|
|
if (!tmp) {
|
|
/*
|
|
* Case 2: node's successor is its right child
|
|
*
|
|
* (n) (s)
|
|
* / \ / \
|
|
* (x) (s) -> (x) (c)
|
|
* \
|
|
* (c)
|
|
*/
|
|
parent = successor;
|
|
child2 = successor->rb_right;
|
|
|
|
augment->copy(node, successor);
|
|
} else {
|
|
/*
|
|
* Case 3: node's successor is leftmost under
|
|
* node's right child subtree
|
|
*
|
|
* (n) (s)
|
|
* / \ / \
|
|
* (x) (y) -> (x) (y)
|
|
* / /
|
|
* (p) (p)
|
|
* / /
|
|
* (s) (c)
|
|
* \
|
|
* (c)
|
|
*/
|
|
do {
|
|
parent = successor;
|
|
successor = tmp;
|
|
tmp = tmp->rb_left;
|
|
} while (tmp);
|
|
child2 = successor->rb_right;
|
|
WRITE_ONCE(parent->rb_left, child2);
|
|
WRITE_ONCE(successor->rb_right, child);
|
|
rb_set_parent(child, successor);
|
|
|
|
augment->copy(node, successor);
|
|
augment->propagate(parent, successor);
|
|
}
|
|
|
|
tmp = node->rb_left;
|
|
WRITE_ONCE(successor->rb_left, tmp);
|
|
rb_set_parent(tmp, successor);
|
|
|
|
pc = node->__rb_parent_color;
|
|
tmp = __rb_parent(pc);
|
|
__rb_change_child(node, successor, tmp, root);
|
|
|
|
if (child2) {
|
|
successor->__rb_parent_color = pc;
|
|
rb_set_parent_color(child2, parent, RB_BLACK);
|
|
rebalance = NULL;
|
|
} else {
|
|
unsigned long pc2 = successor->__rb_parent_color;
|
|
successor->__rb_parent_color = pc;
|
|
rebalance = __rb_is_black(pc2) ? parent : NULL;
|
|
}
|
|
tmp = successor;
|
|
}
|
|
|
|
augment->propagate(tmp, NULL);
|
|
return rebalance;
|
|
}
|
|
|
|
static __always_inline void
|
|
rb_erase_augmented(struct rb_node *node, struct rb_root *root,
|
|
const struct rb_augment_callbacks *augment)
|
|
{
|
|
struct rb_node *rebalance = __rb_erase_augmented(node, root,
|
|
NULL, augment);
|
|
if (rebalance)
|
|
__rb_erase_color(rebalance, root, augment->rotate);
|
|
}
|
|
|
|
static __always_inline void
|
|
rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
|
|
const struct rb_augment_callbacks *augment)
|
|
{
|
|
struct rb_node *rebalance = __rb_erase_augmented(node, &root->rb_root,
|
|
&root->rb_leftmost,
|
|
augment);
|
|
if (rebalance)
|
|
__rb_erase_color(rebalance, &root->rb_root, augment->rotate);
|
|
}
|
|
|
|
#endif /* _LINUX_RBTREE_AUGMENTED_H */
|