Skip to content
Snippets Groups Projects
Select Git revision
  • f8bbd7f7b0c6eb3accc30deab9aafb2c50f9ee9a
  • master default protected
  • early-display
  • variant-emmc-nvme-boot
  • 2023-01-25
  • v3
  • variant-emmc-nvme-boot
  • 2020-06-01
8 results

snapshot.commit

Blame
  • Forked from Reform / reform-boundary-uboot
    Source project has a limited visibility.
    rbtree_augmented.h 6.30 KiB
    /*
      Red Black Trees
      (C) 1999  Andrea Arcangeli <andrea@suse.de>
      (C) 2002  David Woodhouse <dwmw2@infradead.org>
      (C) 2012  Michel Lespinasse <walken@google.com>
    
     * SPDX-License-Identifier:	GPL-2.0+
    
      linux/include/linux/rbtree_augmented.h
    */
    
    #ifndef _LINUX_RBTREE_AUGMENTED_H
    #define _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/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,
    	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
    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, 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 = {			\
    	rbname ## _propagate, rbname ## _copy, 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)
    			parent->rb_left = new;
    		else
    			parent->rb_right = new;
    	} else
    		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, *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);
    			parent->rb_left = child2 = successor->rb_right;
    			successor->rb_right = child;
    			rb_set_parent(child, successor);
    			augment->copy(node, successor);
    			augment->propagate(parent, successor);
    		}
    
    		successor->rb_left = tmp = node->rb_left;
    		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, augment);
    	if (rebalance)
    		__rb_erase_color(rebalance, root, augment->rotate);
    }
    
    #endif	/* _LINUX_RBTREE_AUGMENTED_H */