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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}
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73
74#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
75 RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \
76static inline void \
77RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \
78{ \
79 while (rb != stop) { \
80 RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \
81 if (RBCOMPUTE(node, true)) \
82 break; \
83 rb = rb_parent(&node->RBFIELD); \
84 } \
85} \
86static inline void \
87RBNAME ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
88{ \
89 RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
90 RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
91 new->RBAUGMENTED = old->RBAUGMENTED; \
92} \
93static void \
94RBNAME ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
95{ \
96 RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
97 RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
98 new->RBAUGMENTED = old->RBAUGMENTED; \
99 RBCOMPUTE(old, false); \
100} \
101RBSTATIC const struct rb_augment_callbacks RBNAME = { \
102 .propagate = RBNAME ## _propagate, \
103 .copy = RBNAME ## _copy, \
104 .rotate = RBNAME ## _rotate \
105};
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120#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
121 RBTYPE, RBAUGMENTED, RBCOMPUTE) \
122static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
123{ \
124 RBSTRUCT *child; \
125 RBTYPE max = RBCOMPUTE(node); \
126 if (node->RBFIELD.rb_left) { \
127 child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \
128 if (child->RBAUGMENTED > max) \
129 max = child->RBAUGMENTED; \
130 } \
131 if (node->RBFIELD.rb_right) { \
132 child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \
133 if (child->RBAUGMENTED > max) \
134 max = child->RBAUGMENTED; \
135 } \
136 if (exit && node->RBAUGMENTED == max) \
137 return true; \
138 node->RBAUGMENTED = max; \
139 return false; \
140} \
141RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
142 RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max)
143
144
145#define RB_RED 0
146#define RB_BLACK 1
147
148#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
149
150#define __rb_color(pc) ((pc) & 1)
151#define __rb_is_black(pc) __rb_color(pc)
152#define __rb_is_red(pc) (!__rb_color(pc))
153#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
154#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
155#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
156
157static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
158{
159 rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
160}
161
162static inline void rb_set_parent_color(struct rb_node *rb,
163 struct rb_node *p, int color)
164{
165 rb->__rb_parent_color = (unsigned long)p | color;
166}
167
168static inline void
169__rb_change_child(struct rb_node *old, struct rb_node *new,
170 struct rb_node *parent, struct rb_root *root)
171{
172 if (parent) {
173 if (parent->rb_left == old)
174 WRITE_ONCE(parent->rb_left, new);
175 else
176 WRITE_ONCE(parent->rb_right, new);
177 } else
178 WRITE_ONCE(root->rb_node, new);
179}
180
181static inline void
182__rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
183 struct rb_node *parent, struct rb_root *root)
184{
185 if (parent) {
186 if (parent->rb_left == old)
187 rcu_assign_pointer(parent->rb_left, new);
188 else
189 rcu_assign_pointer(parent->rb_right, new);
190 } else
191 rcu_assign_pointer(root->rb_node, new);
192}
193
194extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
195 void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
196
197static __always_inline struct rb_node *
198__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
199 const struct rb_augment_callbacks *augment)
200{
201 struct rb_node *child = node->rb_right;
202 struct rb_node *tmp = node->rb_left;
203 struct rb_node *parent, *rebalance;
204 unsigned long pc;
205
206 if (!tmp) {
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214 pc = node->__rb_parent_color;
215 parent = __rb_parent(pc);
216 __rb_change_child(node, child, parent, root);
217 if (child) {
218 child->__rb_parent_color = pc;
219 rebalance = NULL;
220 } else
221 rebalance = __rb_is_black(pc) ? parent : NULL;
222 tmp = parent;
223 } else if (!child) {
224
225 tmp->__rb_parent_color = pc = node->__rb_parent_color;
226 parent = __rb_parent(pc);
227 __rb_change_child(node, tmp, parent, root);
228 rebalance = NULL;
229 tmp = parent;
230 } else {
231 struct rb_node *successor = child, *child2;
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233 tmp = child->rb_left;
234 if (!tmp) {
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244 parent = successor;
245 child2 = successor->rb_right;
246
247 augment->copy(node, successor);
248 } else {
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263 do {
264 parent = successor;
265 successor = tmp;
266 tmp = tmp->rb_left;
267 } while (tmp);
268 child2 = successor->rb_right;
269 WRITE_ONCE(parent->rb_left, child2);
270 WRITE_ONCE(successor->rb_right, child);
271 rb_set_parent(child, successor);
272
273 augment->copy(node, successor);
274 augment->propagate(parent, successor);
275 }
276
277 tmp = node->rb_left;
278 WRITE_ONCE(successor->rb_left, tmp);
279 rb_set_parent(tmp, successor);
280
281 pc = node->__rb_parent_color;
282 tmp = __rb_parent(pc);
283 __rb_change_child(node, successor, tmp, root);
284
285 if (child2) {
286 rb_set_parent_color(child2, parent, RB_BLACK);
287 rebalance = NULL;
288 } else {
289 rebalance = rb_is_black(successor) ? parent : NULL;
290 }
291 successor->__rb_parent_color = pc;
292 tmp = successor;
293 }
294
295 augment->propagate(tmp, NULL);
296 return rebalance;
297}
298
299static __always_inline void
300rb_erase_augmented(struct rb_node *node, struct rb_root *root,
301 const struct rb_augment_callbacks *augment)
302{
303 struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
304 if (rebalance)
305 __rb_erase_color(rebalance, root, augment->rotate);
306}
307
308static __always_inline void
309rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
310 const struct rb_augment_callbacks *augment)
311{
312 if (root->rb_leftmost == node)
313 root->rb_leftmost = rb_next(node);
314 rb_erase_augmented(node, &root->rb_root, augment);
315}
316
317#endif
318