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24#ifndef _LINUX_RBTREE_AUGMENTED_H
25#define _LINUX_RBTREE_AUGMENTED_H
26
27#include <linux/compiler.h>
28#include <linux/rbtree.h>
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38struct rb_augment_callbacks {
39 void (*propagate)(struct rb_node *node, struct rb_node *stop);
40 void (*copy)(struct rb_node *old, struct rb_node *new);
41 void (*rotate)(struct rb_node *old, struct rb_node *new);
42};
43
44extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
45 void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
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56static inline void
57rb_insert_augmented(struct rb_node *node, struct rb_root *root,
58 const struct rb_augment_callbacks *augment)
59{
60 __rb_insert_augmented(node, root, augment->rotate);
61}
62
63#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
64 rbtype, rbaugmented, rbcompute) \
65static inline void \
66rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
67{ \
68 while (rb != stop) { \
69 rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
70 rbtype augmented = rbcompute(node); \
71 if (node->rbaugmented == augmented) \
72 break; \
73 node->rbaugmented = augmented; \
74 rb = rb_parent(&node->rbfield); \
75 } \
76} \
77static inline void \
78rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
79{ \
80 rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
81 rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
82 new->rbaugmented = old->rbaugmented; \
83} \
84static void \
85rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
86{ \
87 rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
88 rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
89 new->rbaugmented = old->rbaugmented; \
90 old->rbaugmented = rbcompute(old); \
91} \
92rbstatic const struct rb_augment_callbacks rbname = { \
93 rbname ## _propagate, rbname ## _copy, rbname ## _rotate \
94};
95
96
97#define RB_RED 0
98#define RB_BLACK 1
99
100#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
101
102#define __rb_color(pc) ((pc) & 1)
103#define __rb_is_black(pc) __rb_color(pc)
104#define __rb_is_red(pc) (!__rb_color(pc))
105#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
106#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
107#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
108
109static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
110{
111 rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
112}
113
114static inline void rb_set_parent_color(struct rb_node *rb,
115 struct rb_node *p, int color)
116{
117 rb->__rb_parent_color = (unsigned long)p | color;
118}
119
120static inline void
121__rb_change_child(struct rb_node *old, struct rb_node *new,
122 struct rb_node *parent, struct rb_root *root)
123{
124 if (parent) {
125 if (parent->rb_left == old)
126 WRITE_ONCE(parent->rb_left, new);
127 else
128 WRITE_ONCE(parent->rb_right, new);
129 } else
130 WRITE_ONCE(root->rb_node, new);
131}
132
133extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
134 void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
135
136static __always_inline struct rb_node *
137__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
138 const struct rb_augment_callbacks *augment)
139{
140 struct rb_node *child = node->rb_right;
141 struct rb_node *tmp = node->rb_left;
142 struct rb_node *parent, *rebalance;
143 unsigned long pc;
144
145 if (!tmp) {
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153 pc = node->__rb_parent_color;
154 parent = __rb_parent(pc);
155 __rb_change_child(node, child, parent, root);
156 if (child) {
157 child->__rb_parent_color = pc;
158 rebalance = NULL;
159 } else
160 rebalance = __rb_is_black(pc) ? parent : NULL;
161 tmp = parent;
162 } else if (!child) {
163
164 tmp->__rb_parent_color = pc = node->__rb_parent_color;
165 parent = __rb_parent(pc);
166 __rb_change_child(node, tmp, parent, root);
167 rebalance = NULL;
168 tmp = parent;
169 } else {
170 struct rb_node *successor = child, *child2;
171
172 tmp = child->rb_left;
173 if (!tmp) {
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183 parent = successor;
184 child2 = successor->rb_right;
185
186 augment->copy(node, successor);
187 } else {
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201
202 do {
203 parent = successor;
204 successor = tmp;
205 tmp = tmp->rb_left;
206 } while (tmp);
207 child2 = successor->rb_right;
208 WRITE_ONCE(parent->rb_left, child2);
209 WRITE_ONCE(successor->rb_right, child);
210 rb_set_parent(child, successor);
211
212 augment->copy(node, successor);
213 augment->propagate(parent, successor);
214 }
215
216 tmp = node->rb_left;
217 WRITE_ONCE(successor->rb_left, tmp);
218 rb_set_parent(tmp, successor);
219
220 pc = node->__rb_parent_color;
221 tmp = __rb_parent(pc);
222 __rb_change_child(node, successor, tmp, root);
223
224 if (child2) {
225 successor->__rb_parent_color = pc;
226 rb_set_parent_color(child2, parent, RB_BLACK);
227 rebalance = NULL;
228 } else {
229 unsigned long pc2 = successor->__rb_parent_color;
230 successor->__rb_parent_color = pc;
231 rebalance = __rb_is_black(pc2) ? parent : NULL;
232 }
233 tmp = successor;
234 }
235
236 augment->propagate(tmp, NULL);
237 return rebalance;
238}
239
240static __always_inline void
241rb_erase_augmented(struct rb_node *node, struct rb_root *root,
242 const struct rb_augment_callbacks *augment)
243{
244 struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
245 if (rebalance)
246 __rb_erase_color(rebalance, root, augment->rotate);
247}
248
249#endif
250