515.43.04

kernel-open/nvidia-uvm/uvm_rb_tree.c

@@ -0,0 +1,114 @@
+/*******************************************************************************
+    Copyright (c) 2020 NVIDIA Corporation
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to
+    deal in the Software without restriction, including without limitation the
+    rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+    sell copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+        The above copyright notice and this permission notice shall be
+        included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+
+*******************************************************************************/
+
+#include "uvm_rb_tree.h"
+
+static uvm_rb_tree_node_t *get_uvm_rb_tree_node(struct rb_node *rb_node)
+{
+    return rb_entry(rb_node, uvm_rb_tree_node_t, rb_node);
+}
+
+static uvm_rb_tree_node_t *uvm_rb_tree_find_node(uvm_rb_tree_t *tree,
+                                                 NvU64 key,
+                                                 uvm_rb_tree_node_t **parent,
+                                                 uvm_rb_tree_node_t **next)
+{
+    struct rb_node *rb_node = tree->rb_root.rb_node;
+    uvm_rb_tree_node_t *node = NULL;
+    uvm_rb_tree_node_t *_parent = NULL;
+
+    while (rb_node) {
+        node = get_uvm_rb_tree_node(rb_node);
+
+        if (key < node->key)
+            rb_node = rb_node->rb_left;
+        else if (key > node->key)
+            rb_node = rb_node->rb_right;
+        else
+            break;
+
+        _parent = node;
+    }
+
+    if (!rb_node)
+        node = NULL;
+
+    if (parent)
+        *parent = _parent;
+    if (next) {
+        *next = NULL; // Handles the empty tree case
+        if (node) {
+            *next = uvm_rb_tree_next(tree, node);
+        }
+        else if (_parent) {
+            if (_parent->key > key)
+                *next = _parent;
+            else
+                *next = uvm_rb_tree_next(tree, _parent);
+        }
+    }
+
+    return node;
+}
+
+void uvm_rb_tree_init(uvm_rb_tree_t *tree)
+{
+    memset(tree, 0, sizeof(*tree));
+    tree->rb_root = RB_ROOT;
+    INIT_LIST_HEAD(&tree->head);
+}
+
+NV_STATUS uvm_rb_tree_insert(uvm_rb_tree_t *tree, uvm_rb_tree_node_t *node)
+{
+    uvm_rb_tree_node_t *match, *parent;
+
+    match = uvm_rb_tree_find_node(tree, node->key, &parent, NULL);
+    if (match)
+        return NV_ERR_IN_USE;
+
+    // If there's no parent and we didn't match on the root node, the tree is
+    // empty.
+    if (!parent) {
+        rb_link_node(&node->rb_node, NULL, &tree->rb_root.rb_node);
+        rb_insert_color(&node->rb_node, &tree->rb_root);
+        list_add(&node->list, &tree->head);
+        return NV_OK;
+    }
+
+    if (node->key < parent->key) {
+        rb_link_node(&node->rb_node, &parent->rb_node, &parent->rb_node.rb_left);
+        list_add_tail(&node->list, &parent->list);
+    }
+    else {
+        rb_link_node(&node->rb_node, &parent->rb_node, &parent->rb_node.rb_right);
+        list_add(&node->list, &parent->list);
+    }
+
+    rb_insert_color(&node->rb_node, &tree->rb_root);
+    return NV_OK;
+}
+
+uvm_rb_tree_node_t *uvm_rb_tree_find(uvm_rb_tree_t *tree, NvU64 key)
+{
+    return uvm_rb_tree_find_node(tree, key, NULL, NULL);
+}