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-rw-r--r--include/linux/rbtree.h147
-rw-r--r--include/linux/rbtree_augmented.h220
2 files changed, 269 insertions, 98 deletions
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index ad892d1..b5994e3 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -1,7 +1,7 @@
/*
Red Black Trees
(C) 1999 Andrea Arcangeli <andrea@suse.de>
-
+
* SPDX-License-Identifier: GPL-2.0+
linux/include/linux/rbtree.h
@@ -11,138 +11,89 @@
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
+#define __UBOOT__
+#ifndef __UBOOT__
+#include <linux/kernel.h>
+#endif
#include <linux/stddef.h>
-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 */
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h
new file mode 100644
index 0000000..a86797e
--- /dev/null
+++ b/include/linux/rbtree_augmented.h
@@ -0,0 +1,220 @@
+/*
+ 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 */