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/* 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>    tools/linux/include/linux/rbtree_augmented.h   Copied from:  linux/include/linux/rbtree_augmented.h*/ #ifndef _TOOLS_LINUX_RBTREE_AUGMENTED_H#define _TOOLS_LINUX_RBTREE_AUGMENTED_H #include <linux/compiler.h>#include <linux/rbtree.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/core-api/rbtree.rst 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,	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 voidrb_insert_augmented(struct rb_node *node, struct rb_root *root,		    const struct rb_augment_callbacks *augment){	__rb_insert_augmented(node, root, augment->rotate);} static inline voidrb_insert_augmented_cached(struct rb_node *node,			   struct rb_root_cached *root, bool newleft,			   const struct rb_augment_callbacks *augment){	if (newleft)		root->rb_leftmost = node;	rb_insert_augmented(node, &root->rb_root, augment);} /* * Template for declaring augmented rbtree callbacks (generic case) * * RBSTATIC:    'static' or empty * RBNAME:      name of the rb_augment_callbacks structure * RBSTRUCT:    struct type of the tree nodes * RBFIELD:     name of struct rb_node field within RBSTRUCT * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree * RBCOMPUTE:   name of function that recomputes the RBAUGMENTED data */ #define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME,				\			     RBSTRUCT, RBFIELD, 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);	\		if (RBCOMPUTE(node, true))				\			break;						\		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;				\	RBCOMPUTE(old, false);						\}									\RBSTATIC const struct rb_augment_callbacks RBNAME = {			\	.propagate = RBNAME ## _propagate,				\	.copy = RBNAME ## _copy,					\	.rotate = RBNAME ## _rotate					\}; /* * Template for declaring augmented rbtree callbacks, * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes. * * RBSTATIC:    'static' or empty * RBNAME:      name of the rb_augment_callbacks structure * RBSTRUCT:    struct type of the tree nodes * RBFIELD:     name of struct rb_node field within RBSTRUCT * RBTYPE:      type of the RBAUGMENTED field * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree * RBCOMPUTE:   name of function that returns the per-node RBTYPE scalar */ #define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD,	      \				 RBTYPE, RBAUGMENTED, RBCOMPUTE)	      \static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit)	      \{									      \	RBSTRUCT *child;						      \	RBTYPE max = RBCOMPUTE(node);					      \	if (node->RBFIELD.rb_left) {					      \		child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD);   \		if (child->RBAUGMENTED > max)				      \			max = child->RBAUGMENTED;			      \	}								      \	if (node->RBFIELD.rb_right) {					      \		child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD);  \		if (child->RBAUGMENTED > max)				      \			max = child->RBAUGMENTED;			      \	}								      \	if (exit && node->RBAUGMENTED == max)				      \		return true;						      \	node->RBAUGMENTED = max;					      \	return false;							      \}									      \RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME,					      \		     RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max)  #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);} 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,		     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 (!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 voidrb_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, augment);	if (rebalance)		__rb_erase_color(rebalance, root, augment->rotate);} static __always_inline voidrb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,			  const struct rb_augment_callbacks *augment){	if (root->rb_leftmost == node)		root->rb_leftmost = rb_next(node);	rb_erase_augmented(node, &root->rb_root, augment);} #endif /* _TOOLS_LINUX_RBTREE_AUGMENTED_H */