X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=include%2Flinux%2Frbtree.h;h=1d2b1768c17fcaf6e076c7b2868316faf475c391;hb=406df85345f942d9348443983d81a01e013e920b;hp=6ff28e026bbedb761a93de8852c4aabcad58958b;hpb=f82642e33899766892499b163e60560fbbf87773;p=oweals%2Fu-boot.git diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index 6ff28e026b..1d2b1768c1 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -1,21 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* Red Black Trees (C) 1999 Andrea Arcangeli - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - + linux/include/linux/rbtree.h To use rbtrees you'll have to implement your own insert and search cores. @@ -23,138 +10,88 @@ I know it's not the cleaner way, but in C (not in C++) to get performances and genericity... - Some example of insert and search follows here. The search is a plain - normal search over an ordered tree. The insert instead must be implemented - int two steps: as first thing the code must insert the element in - order as a red leaf in the tree, then the support library function - rb_insert_color() must be called. Such function will do the - not trivial work to rebalance the rbtree if necessary. - ------------------------------------------------------------------------ -static inline struct page * rb_search_page_cache(struct inode * inode, - unsigned long offset) -{ - struct rb_node * n = inode->i_rb_page_cache.rb_node; - struct page * page; - - while (n) - { - page = rb_entry(n, struct page, rb_page_cache); - - if (offset < page->offset) - n = n->rb_left; - else if (offset > page->offset) - n = n->rb_right; - else - return page; - } - return NULL; -} - -static inline struct page * __rb_insert_page_cache(struct inode * inode, - unsigned long offset, - struct rb_node * node) -{ - struct rb_node ** p = &inode->i_rb_page_cache.rb_node; - struct rb_node * parent = NULL; - struct page * page; - - while (*p) - { - parent = *p; - page = rb_entry(parent, struct page, rb_page_cache); - - if (offset < page->offset) - p = &(*p)->rb_left; - else if (offset > page->offset) - p = &(*p)->rb_right; - else - return page; - } - - rb_link_node(node, parent, p); - - return NULL; -} - -static inline struct page * rb_insert_page_cache(struct inode * inode, - unsigned long offset, - struct rb_node * node) -{ - struct page * ret; - if ((ret = __rb_insert_page_cache(inode, offset, node))) - goto out; - rb_insert_color(node, &inode->i_rb_page_cache); - out: - return ret; -} ------------------------------------------------------------------------ + See Documentation/rbtree.txt for documentation and samples. */ #ifndef _LINUX_RBTREE_H #define _LINUX_RBTREE_H +#ifndef __UBOOT__ +#include +#endif #include -struct rb_node -{ - unsigned long rb_parent_color; -#define RB_RED 0 -#define RB_BLACK 1 +struct rb_node { + unsigned long __rb_parent_color; struct rb_node *rb_right; struct rb_node *rb_left; } __attribute__((aligned(sizeof(long)))); /* The alignment might seem pointless, but allegedly CRIS needs it */ -struct rb_root -{ +struct rb_root { struct rb_node *rb_node; }; -#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3)) -#define rb_color(r) ((r)->rb_parent_color & 1) -#define rb_is_red(r) (!rb_color(r)) -#define rb_is_black(r) rb_color(r) -#define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0) -#define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0) - -static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) -{ - rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p; -} -static inline void rb_set_color(struct rb_node *rb, int color) -{ - rb->rb_parent_color = (rb->rb_parent_color & ~1) | color; -} +#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) #define RB_ROOT (struct rb_root) { NULL, } #define rb_entry(ptr, type, member) container_of(ptr, type, member) -#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) -#define RB_EMPTY_NODE(node) (rb_parent(node) == node) -#define RB_CLEAR_NODE(node) (rb_set_parent(node, node)) +#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) + +/* 'empty' nodes are nodes that are known not to be inserted in an rbree */ +#define RB_EMPTY_NODE(node) \ + ((node)->__rb_parent_color == (unsigned long)(node)) +#define RB_CLEAR_NODE(node) \ + ((node)->__rb_parent_color = (unsigned long)(node)) + extern void rb_insert_color(struct rb_node *, struct rb_root *); extern void rb_erase(struct rb_node *, struct rb_root *); + /* Find logical next and previous nodes in a tree */ -extern struct rb_node *rb_next(struct rb_node *); -extern struct rb_node *rb_prev(struct rb_node *); -extern struct rb_node *rb_first(struct rb_root *); -extern struct rb_node *rb_last(struct rb_root *); +extern struct rb_node *rb_next(const struct rb_node *); +extern struct rb_node *rb_prev(const struct rb_node *); +extern struct rb_node *rb_first(const struct rb_root *); +extern struct rb_node *rb_last(const struct rb_root *); + +/* Postorder iteration - always visit the parent after its children */ +extern struct rb_node *rb_first_postorder(const struct rb_root *); +extern struct rb_node *rb_next_postorder(const struct rb_node *); /* Fast replacement of a single node without remove/rebalance/add/rebalance */ -extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, +extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, struct rb_root *root); static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, struct rb_node ** rb_link) { - node->rb_parent_color = (unsigned long )parent; + node->__rb_parent_color = (unsigned long)parent; node->rb_left = node->rb_right = NULL; *rb_link = node; } +#define rb_entry_safe(ptr, type, member) \ + ({ typeof(ptr) ____ptr = (ptr); \ + ____ptr ? rb_entry(____ptr, type, member) : NULL; \ + }) + +/** + * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of + * given type safe against removal of rb_node entry + * + * @pos: the 'type *' to use as a loop cursor. + * @n: another 'type *' to use as temporary storage + * @root: 'rb_root *' of the rbtree. + * @field: the name of the rb_node field within 'type'. + */ +#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ + for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ + pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ + typeof(*pos), field); 1; }); \ + pos = n) + #endif /* _LINUX_RBTREE_H */