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12#ifndef _LINUX_RBTREE_AUGMENTED_H
13#define _LINUX_RBTREE_AUGMENTED_H
14
15#include <linux/compiler.h>
16#include <linux/rbtree.h>
17#include <linux/rcupdate.h>
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27struct rb_augment_callbacks {
28 void (*propagate)(struct rb_node *node, struct rb_node *stop);
29 void (*copy)(struct rb_node *old, struct rb_node *new);
30 void (*rotate)(struct rb_node *old, struct rb_node *new);
31};
32
33extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
34 void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
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46static inline void
47rb_insert_augmented(struct rb_node *node, struct rb_root *root,
48 const struct rb_augment_callbacks *augment)
49{
50 __rb_insert_augmented(node, root, augment->rotate);
51}
52
53static inline void
54rb_insert_augmented_cached(struct rb_node *node,
55 struct rb_root_cached *root, bool newleft,
56 const struct rb_augment_callbacks *augment)
57{
58 if (newleft)
59 root->rb_leftmost = node;
60 rb_insert_augmented(node, &root->rb_root, augment);
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 .propagate = rbname ## _propagate, \
94 .copy = rbname ## _copy, \
95 .rotate = rbname ## _rotate \
96};
97
98
99#define RB_RED 0
100#define RB_BLACK 1
101
102#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
103
104#define __rb_color(pc) ((pc) & 1)
105#define __rb_is_black(pc) __rb_color(pc)
106#define __rb_is_red(pc) (!__rb_color(pc))
107#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
108#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
109#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
110
111static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
112{
113 rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
114}
115
116static inline void rb_set_parent_color(struct rb_node *rb,
117 struct rb_node *p, int color)
118{
119 rb->__rb_parent_color = (unsigned long)p | color;
120}
121
122static inline void
123__rb_change_child(struct rb_node *old, struct rb_node *new,
124 struct rb_node *parent, struct rb_root *root)
125{
126 if (parent) {
127 if (parent->rb_left == old)
128 WRITE_ONCE(parent->rb_left, new);
129 else
130 WRITE_ONCE(parent->rb_right, new);
131 } else
132 WRITE_ONCE(root->rb_node, new);
133}
134
135static inline void
136__rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
137 struct rb_node *parent, struct rb_root *root)
138{
139 if (parent) {
140 if (parent->rb_left == old)
141 rcu_assign_pointer(parent->rb_left, new);
142 else
143 rcu_assign_pointer(parent->rb_right, new);
144 } else
145 rcu_assign_pointer(root->rb_node, new);
146}
147
148extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
149 void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
150
151static __always_inline struct rb_node *
152__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
153 const struct rb_augment_callbacks *augment)
154{
155 struct rb_node *child = node->rb_right;
156 struct rb_node *tmp = node->rb_left;
157 struct rb_node *parent, *rebalance;
158 unsigned long pc;
159
160 if (!tmp) {
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168 pc = node->__rb_parent_color;
169 parent = __rb_parent(pc);
170 __rb_change_child(node, child, parent, root);
171 if (child) {
172 child->__rb_parent_color = pc;
173 rebalance = NULL;
174 } else
175 rebalance = __rb_is_black(pc) ? parent : NULL;
176 tmp = parent;
177 } else if (!child) {
178
179 tmp->__rb_parent_color = pc = node->__rb_parent_color;
180 parent = __rb_parent(pc);
181 __rb_change_child(node, tmp, parent, root);
182 rebalance = NULL;
183 tmp = parent;
184 } else {
185 struct rb_node *successor = child, *child2;
186
187 tmp = child->rb_left;
188 if (!tmp) {
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198 parent = successor;
199 child2 = successor->rb_right;
200
201 augment->copy(node, successor);
202 } else {
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216
217 do {
218 parent = successor;
219 successor = tmp;
220 tmp = tmp->rb_left;
221 } while (tmp);
222 child2 = successor->rb_right;
223 WRITE_ONCE(parent->rb_left, child2);
224 WRITE_ONCE(successor->rb_right, child);
225 rb_set_parent(child, successor);
226
227 augment->copy(node, successor);
228 augment->propagate(parent, successor);
229 }
230
231 tmp = node->rb_left;
232 WRITE_ONCE(successor->rb_left, tmp);
233 rb_set_parent(tmp, successor);
234
235 pc = node->__rb_parent_color;
236 tmp = __rb_parent(pc);
237 __rb_change_child(node, successor, tmp, root);
238
239 if (child2) {
240 successor->__rb_parent_color = pc;
241 rb_set_parent_color(child2, parent, RB_BLACK);
242 rebalance = NULL;
243 } else {
244 unsigned long pc2 = successor->__rb_parent_color;
245 successor->__rb_parent_color = pc;
246 rebalance = __rb_is_black(pc2) ? parent : NULL;
247 }
248 tmp = successor;
249 }
250
251 augment->propagate(tmp, NULL);
252 return rebalance;
253}
254
255static __always_inline void
256rb_erase_augmented(struct rb_node *node, struct rb_root *root,
257 const struct rb_augment_callbacks *augment)
258{
259 struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
260 if (rebalance)
261 __rb_erase_color(rebalance, root, augment->rotate);
262}
263
264static __always_inline void
265rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
266 const struct rb_augment_callbacks *augment)
267{
268 if (root->rb_leftmost == node)
269 root->rb_leftmost = rb_next(node);
270 rb_erase_augmented(node, &root->rb_root, augment);
271}
272
273#endif
274