From: "Pratyush Yadav (Google)" <[email protected]>

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) <[email protected]>
---
 include/linux/kho_radix_tree.h     | 15 ++++++++++++---
 kernel/liveupdate/kexec_handover.c | 27 +++++++++++++++------------
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h
index f368f3b9f923..426a9cc9bcde 100644
--- a/include/linux/kho_radix_tree.h
+++ b/include/linux/kho_radix_tree.h
@@ -34,14 +34,23 @@ 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 */
 
@@ -54,7 +63,7 @@ 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;
 }
diff --git a/kernel/liveupdate/kexec_handover.c 
b/kernel/liveupdate/kexec_handover.c
index 7e556afae283..dbe075348ce4 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -278,16 +278,18 @@ void kho_radix_del_key(struct kho_radix_tree *tree, 
unsigned long key)
 }
 EXPORT_SYMBOL_GPL(kho_radix_del_key);
 
-static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf,
-                              unsigned long key,
-                              kho_radix_tree_walk_callback_t cb)
+static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key,
+                              const struct kho_radix_walk_cb *cb)
 {
        unsigned long *bitmap = (unsigned long *)leaf;
        unsigned int i;
        int err;
 
+       if (!cb->leaf)
+               return 0;
+
        for_each_set_bit(i, bitmap, PAGE_SIZE * BITS_PER_BYTE) {
-               err = cb(key | i);
+               err = cb->leaf(key | i);
                if (err)
                        return err;
        }
@@ -297,7 +299,7 @@ static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf,
 
 static int __kho_radix_walk_tree(struct kho_radix_node *root,
                                 unsigned int level, unsigned long start,
-                                kho_radix_tree_walk_callback_t cb)
+                                const struct kho_radix_walk_cb *cb)
 {
        struct kho_radix_node *node;
        struct kho_radix_leaf *leaf;
@@ -337,18 +339,16 @@ static int __kho_radix_walk_tree(struct kho_radix_node 
*root,
 /**
  * kho_radix_walk_tree - Traverses the radix tree and calls a callback for 
each key.
  * @tree: A pointer to the KHO radix tree to walk.
- * @cb: A callback function of type kho_radix_tree_walk_callback_t that will be
- *      invoked for each key in the tree.
+ * @cb:   Set of callbacks to be invoked during the tree walk.
  *
- * This function walks the radix tree, searching from the specified top level
- * down to the lowest level (level 0). For each key found, it invokes the
- * provided callback.
+ * This function walks the radix tree, searching from the top level down to the
+ * lowest level (level 0), invoking the appropriate callbacks.
  *
  * Return: 0 if the walk completed the specified tree, or the non-zero return
  *         value from the callback that stopped the walk.
  */
 int kho_radix_walk_tree(struct kho_radix_tree *tree,
-                       kho_radix_tree_walk_callback_t cb)
+                       const struct kho_radix_walk_cb *cb)
 {
        if (WARN_ON_ONCE(!tree->root))
                return -EINVAL;
@@ -1414,6 +1414,9 @@ EXPORT_SYMBOL_GPL(kho_retrieve_subtree);
 
 static void __init kho_mem_retrieve(void)
 {
+       const struct kho_radix_walk_cb cb = {
+               .leaf = kho_preserved_memory_reserve,
+       };
        const void *fdt = kho_get_fdt();
        int err;
 
@@ -1427,7 +1430,7 @@ static void __init kho_mem_retrieve(void)
        kho_in.radix_tree.root = kho_get_mem_map(fdt);
        mutex_init(&kho_in.radix_tree.lock);
 
-       err = kho_radix_walk_tree(&kho_in.radix_tree, 
kho_preserved_memory_reserve);
+       err = kho_radix_walk_tree(&kho_in.radix_tree, &cb);
        if (err) {
                /*
                 * Failed to initialize preserved memory. Clear FDT and radix
-- 
2.54.0.1032.g2f8565e1d1-goog


Reply via email to