Merge remote-tracking branch 'origin' into for-6.18/intel-thc-hid

Needed as a basisi for followup support for quicki2c advanced BIOS features.

Signed-off-by: Jiri Kosina <jkosina@suse.com>

1 files changed, 13 insertions, 16 deletions

diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs
index 8d978c896747..b8fe6be6fcc4 100644
--- a/rust/kernel/rbtree.rs
+++ b/rust/kernel/rbtree.rs
@@ -191,6 +191,12 @@ impl<K, V> RBTree<K, V> {
         }
     }
 
+    /// Returns true if this tree is empty.
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.root.rb_node.is_null()
+    }
+
     /// Returns an iterator over the tree nodes, sorted by key.
     pub fn iter(&self) -> Iter<'_, K, V> {
         Iter {
@@ -769,23 +775,14 @@ impl<'a, K, V> Cursor<'a, K, V> {
         // the tree cannot change. By the tree invariant, all nodes are valid.
         unsafe { bindings::rb_erase(&mut (*this).links, addr_of_mut!(self.tree.root)) };
 
-        let current = match (prev, next) {
-            (_, Some(next)) => next,
-            (Some(prev), None) => prev,
-            (None, None) => {
-                return (None, node);
-            }
-        };
+        // INVARIANT:
+        // - `current` is a valid node in the [`RBTree`] pointed to by `self.tree`.
+        let cursor = next.or(prev).map(|current| Self {
+            current,
+            tree: self.tree,
+        });
 
-        (
-            // INVARIANT:
-            // - `current` is a valid node in the [`RBTree`] pointed to by `self.tree`.
-            Some(Self {
-                current,
-                tree: self.tree,
-            }),
-            node,
-        )
+        (cursor, node)
     }
 
     /// Remove the previous node, returning it if it exists.