[src/trunk]: src/sys/external/bsd/drm2/include/linux Draft interval tree.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c18a3ffef5f3
branches:  trunk
changeset: 834816:c18a3ffef5f3
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 27 06:32:17 2018 +0000

description:
Draft interval tree.

diffstat:

 sys/external/bsd/drm2/include/linux/interval_tree.h |  135 ++++++++++++++++++++
 1 files changed, 135 insertions(+), 0 deletions(-)

diffs (139 lines):

diff -r bd03d190cf09 -r c18a3ffef5f3 sys/external/bsd/drm2/include/linux/interval_tree.h
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/external/bsd/drm2/include/linux/interval_tree.h       Mon Aug 27 06:32:17 2018 +0000
@@ -0,0 +1,135 @@
+/*     $NetBSD: interval_tree.h,v 1.1 2018/08/27 06:32:17 riastradh Exp $      */
+
+/*-
+ * Copyright (c) 2018 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Taylor R. Campbell.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef        _LINUX_INTERVAL_TREE_H_
+#define        _LINUX_INTERVAL_TREE_H_
+
+#include <sys/rbtree.h>
+
+struct rb_root {
+       struct rb_tree  rbr_tree;
+};
+
+struct interval_tree_node {
+       struct rb_node  itn_node;
+       unsigned long   start;  /* inclusive */
+       unsigned long   last;   /* inclusive */
+};
+
+static inline int
+interval_tree_compare_nodes(void *cookie, const void *va, const void *vb)
+{
+       const struct interval_tree_node *na = va;
+       const struct interval_tree_node *nb = vb;
+
+       if (na->start < nb->start)
+               return -1;
+       if (na->start > nb->start)
+               return +1;
+       if (na->last < nb->last)
+               return -1;
+       if (na->last > nb->last)
+               return +1;
+       return 0;
+}
+
+static inline int
+interval_tree_compare_key(void *cookie, const void *vn, const void *vk)
+{
+       const struct interval_tree_node *n = va;
+       const unsigned long *k = vk;
+
+       if (n->last < k)
+               return -1;
+       if (k < n->first)
+               return +1;
+       return 0;
+}
+
+static const struct rb_tree_ops interval_tree_ops = {
+       .rbto_compare_nodes_fn = interval_tree_compare_nodes,
+       .rbto_compare_key_fn = interval_tree_compare_key,
+       .rbto_node_offset = offsetof(struct interval_tree_node, itn_node),
+};
+
+static inline void
+interval_tree_insert(struct interval_tree_node *node, struct rb_root *root)
+{
+       struct interval_tree_node *collision __diagused;
+
+       collision = rb_tree_insert_node(&root->rbr_tree, node);
+       KASSERT(collision == node);
+}
+
+static inline void
+interval_tree_remove(struct interval_tree_node *node, struct rb_root *root)
+{
+
+       rb_tree_remove_node(&root->rbr_tree, node);
+}
+
+static inline struct interval_node *
+interval_tree_iter_first(struct rb_root *root, unsigned long start,
+    unsigned long last)
+{
+       struct interval_node *node;
+
+       node = rb_tree_find_node_geq(&root->rbr_tree, &start);
+       if (node == NULL)
+               return NULL;
+       KASSERT(node->start <= start);
+       if (last < node->start)
+               return NULL;
+
+       return node;
+}
+
+/*
+ * XXX Linux's interval_tree_iter_next doesn't take the root as an
+ * argument, which makes this difficult.  So we'll just patch those
+ * uses.
+ */
+static inline struct interval_node *
+interval_tree_iter_next(struct rb_root *root, struct interval_node *node,
+    unsigned long start, unsigned long last)
+{
+       struct interval_node *next;
+
+       KASSERT(node != NULL);
+       next = rb_tree_iterate(&root->rbr_tree, node, RB_DIR_RIGHT);
+       if (next == NULL)
+               return NULL;
+       KASSERT(node->start <= start);
+       if (last < node->start)
+               return NULL;
+}
+
+#endif /* _LINUX_INTERVAL_TREE_H_ */