kho: add a struct for radix callbacks

A future commit will add more callbacks for the KHO radix tree. Add a
struct for collecting the callbacks.

Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Link: https://patch.msgid.link/20260801084833.1897543-8-pratyush@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h
index 9157fe08f9ce..486e193d58f4 100644
--- a/include/linux/kho_radix_tree.h
+++ b/include/linux/kho_radix_tree.h
@@ -38,14 +38,23 @@ struct kho_radix_tree {
 	struct mutex lock; /* protects the tree's structure and root pointer */
 };
 
-typedef int (*kho_radix_tree_walk_callback_t)(unsigned long key);
+/**
+ * struct kho_radix_walk_cb - Callbacks for KHO radix tree walk.
+ * @leaf:      Called on each present key in the radix tree.
+ *
+ * For each callback, a return value of 0 continues the walk and a non-zero
+ * return value is directly returned to the caller.
+ */
+struct kho_radix_walk_cb {
+	int (*leaf)(unsigned long key);
+};
 
 #ifdef CONFIG_KEXEC_HANDOVER
 
 int kho_radix_add_key(struct kho_radix_tree *tree, unsigned long key);
 void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key);
 int kho_radix_walk_tree(struct kho_radix_tree *tree,
-			kho_radix_tree_walk_callback_t cb);
+			const struct kho_radix_walk_cb *cb);
 
 #else  /* #ifdef CONFIG_KEXEC_HANDOVER */
 
@@ -58,7 +67,7 @@ static inline void kho_radix_del_key(struct kho_radix_tree *tree,
 				     unsigned long key) { }
 
 static inline int kho_radix_walk_tree(struct kho_radix_tree *tree,
-				      kho_radix_tree_walk_callback_t cb)
+				      const struct kho_radix_walk_cb *cb)
 {
 	return -EOPNOTSUPP;
 }