RB-tree support on U-Boot
Now it's used at UBI module. Of course other modules can use it.
If you want to use it, please define CONFIG_RBTREE
Signed-off-by: Kyungmin Park [EMAIL PROTECTED]
---
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
new file mode 100644
index 000..a4956c4
--- /dev/null
+++ b/include/linux/rbtree.h
@@ -0,0 +1,160 @@
+/*
+ Red Black Trees
+ (C) 1999 Andrea Arcangeli [EMAIL PROTECTED]
+
+ 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.
+ This will avoid us to use callbacks and to drop drammatically performances.
+ 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;
+}
+---
+*/
+
+#ifndef_LINUX_RBTREE_H
+#define_LINUX_RBTREE_H
+
+#include linux/stddef.h
+
+struct rb_node
+{
+ unsigned long rb_parent_color;
+#defineRB_RED 0
+#defineRB_BLACK1
+ 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_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_ROOT(struct rb_root) { NULL, }
+#definerb_entry(ptr, type, member)
