From: "Pratyush Yadav (Google)" Add kho_radix_destroy_tree() which allows destroying the radix tree and freeing all its pages. This is will be used by the upcoming scratch extension mechanism. It creates a radix tree to track free blocks and then frees them after telling memblock about them. Reviewed-by: Pasha Tatashin Signed-off-by: Pratyush Yadav (Google) --- include/linux/kho_radix_tree.h | 3 +++ kernel/liveupdate/kexec_handover.c | 35 ++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index 4138621e0e87..66ca936b3f06 100644 --- a/include/linux/kho_radix_tree.h +++ b/include/linux/kho_radix_tree.h @@ -54,6 +54,7 @@ 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, const struct kho_radix_walk_cb *cb, void *data); +void kho_radix_destroy_tree(struct kho_radix_tree *tree); #else /* #ifdef CONFIG_KEXEC_HANDOVER */ @@ -71,6 +72,8 @@ static inline int kho_radix_walk_tree(struct kho_radix_tree *tree, return -EOPNOTSUPP; } +static inline void kho_radix_destroy_tree(struct kho_radix_tree *tree) { } + #endif /* #ifdef CONFIG_KEXEC_HANDOVER */ #endif /* _LINUX_KHO_RADIX_TREE_H */ diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index a5800b960cf6..105dc0f3e691 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -301,6 +301,41 @@ void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key) } EXPORT_SYMBOL_GPL(kho_radix_del_key); +static void __kho_radix_destroy_tree(struct kho_radix_node *root, + unsigned int level) +{ + unsigned long i; + + if (level == 0) { + kho_radix_free_node(root); + return; + } + + for (i = 0; i < PAGE_SIZE / sizeof(phys_addr_t); i++) { + if (root->table[i]) + __kho_radix_destroy_tree(phys_to_virt(root->table[i]), + level - 1); + } + + kho_radix_free_node(root); +} + +/** + * kho_radix_destroy_tree - Destroy the radix tree + * @tree: The radix tree to destroy + * + * Walk @tree and free all its nodes. + */ +void kho_radix_destroy_tree(struct kho_radix_tree *tree) +{ + if (!tree->root) + return; + + __kho_radix_destroy_tree(tree->root, KHO_TREE_MAX_DEPTH - 1); + tree->root = NULL; +} +EXPORT_SYMBOL_GPL(kho_radix_destroy_tree); + static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key, const struct kho_radix_walk_cb *cb, void *data) { -- 2.55.0.141.g00534a21ce-goog