Re: [PATCH 05/12] kho: add data argument to radix walk callback

[Pasha Tatashin <pasha.tatashin@soleen.com>]

On 04-29 15:39, Pratyush Yadav wrote:
> From: "Pratyush Yadav (Google)" <pratyush@kernel.org>
> 
> Add an opaque data pointer argument to kho_radix_walk_cb_t. This can be
> used for callers to pass extra information to the callback.
> 
> Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
> ---
>  include/linux/kho_radix_tree.h     |  8 ++++----
>  kernel/liveupdate/kexec_handover.c | 24 +++++++++++++-----------
>  2 files changed, 17 insertions(+), 15 deletions(-)

Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> 

> 
> diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h
> index fe7151d89361..6c0f7d82716b 100644
> --- a/include/linux/kho_radix_tree.h
> +++ b/include/linux/kho_radix_tree.h
> @@ -44,8 +44,8 @@ struct kho_radix_tree {
>   * return value is directly returned to the caller.
>   */
>  struct kho_radix_walk_cb {
> -	int (*key)(unsigned long key);
> -	int (*table)(phys_addr_t phys);
> +	int (*key)(unsigned long key, void *data);
> +	int (*table)(phys_addr_t phys, void *data);
>  };
>  
>  #ifdef CONFIG_KEXEC_HANDOVER
> @@ -53,7 +53,7 @@ struct kho_radix_walk_cb {
>  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);
> +			const struct kho_radix_walk_cb *cb, void *data);
>  
>  #else  /* #ifdef CONFIG_KEXEC_HANDOVER */
>  
> @@ -66,7 +66,7 @@ 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,
> -				      const struct kho_radix_walk_cb *cb)
> +				      const struct kho_radix_walk_cb *cb, void *data)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index 94ca831b41c9..d0a4f78eccfe 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -267,14 +267,14 @@ 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,
> -			       const struct kho_radix_walk_cb *cb)
> +			       const struct kho_radix_walk_cb *cb, void *data)
>  {
>  	unsigned long *bitmap = (unsigned long *)leaf;
>  	unsigned int i;
>  	int err;
>  
>  	if (cb->table) {
> -		err = cb->table(virt_to_phys(leaf));
> +		err = cb->table(virt_to_phys(leaf), data);
>  		if (err)
>  			return err;
>  	}
> @@ -283,7 +283,7 @@ static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key,
>  		return 0;
>  
>  	for_each_set_bit(i, bitmap, PAGE_SIZE * BITS_PER_BYTE) {
> -		err = cb->key(key | i);
> +		err = cb->key(key | i, data);
>  		if (err)
>  			return err;
>  	}
> @@ -293,7 +293,7 @@ static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key,
>  
>  static int __kho_radix_walk_tree(struct kho_radix_node *root,
>  				 unsigned int level, unsigned long start,
> -				 const struct kho_radix_walk_cb *cb)
> +				 const struct kho_radix_walk_cb *cb, void *data)
>  {
>  	struct kho_radix_node *node;
>  	struct kho_radix_leaf *leaf;
> @@ -302,7 +302,7 @@ static int __kho_radix_walk_tree(struct kho_radix_node *root,
>  	int err;
>  
>  	if (cb->table) {
> -		err = cb->table(virt_to_phys(root));
> +		err = cb->table(virt_to_phys(root), data);
>  		if (err)
>  			return err;
>  	}
> @@ -323,10 +323,10 @@ static int __kho_radix_walk_tree(struct kho_radix_node *root,
>  			 * node is pointing to the level 0 bitmap.
>  			 */
>  			leaf = (struct kho_radix_leaf *)node;
> -			err = kho_radix_walk_leaf(leaf, key, cb);
> +			err = kho_radix_walk_leaf(leaf, key, cb, data);
>  		} else {
>  			err  = __kho_radix_walk_tree(node, level - 1,
> -						     key, cb);
> +						     key, cb, data);
>  		}
>  
>  		if (err)
> @@ -340,6 +340,7 @@ 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:   Set of callbacks to be invoked during the tree walk.
> + * @data: Opaque data pointer passed to each callback in @cb.
>   *
>   * This function walks the radix tree, searching from the top level down to the
>   * lowest level (level 0), invoking the appropriate callbacks.
> @@ -348,14 +349,15 @@ static int __kho_radix_walk_tree(struct kho_radix_node *root,
>   *         value from the callback that stopped the walk.
>   */
>  int kho_radix_walk_tree(struct kho_radix_tree *tree,
> -			const struct kho_radix_walk_cb *cb)
> +			const struct kho_radix_walk_cb *cb, void *data)
>  {
>  	if (WARN_ON_ONCE(!tree->root))
>  		return -EINVAL;
>  
>  	guard(mutex)(&tree->lock);
>  
> -	return __kho_radix_walk_tree(tree->root, KHO_TREE_MAX_DEPTH - 1, 0, cb);
> +	return __kho_radix_walk_tree(tree->root, KHO_TREE_MAX_DEPTH - 1, 0, cb,
> +				     data);
>  }
>  EXPORT_SYMBOL_GPL(kho_radix_walk_tree);
>  
> @@ -501,7 +503,7 @@ static struct page *__init kho_get_preserved_page(phys_addr_t phys,
>  	return pfn_to_page(pfn);
>  }
>  
> -static int __init kho_preserved_memory_reserve(unsigned long key)
> +static int __init kho_preserved_memory_reserve(unsigned long key, void *data)
>  {
>  	union kho_page_info info;
>  	struct page *page;
> @@ -1392,7 +1394,7 @@ static int __init kho_mem_retrieve(const void *fdt)
>  
>  	kho_in.radix_tree.root = phys_to_virt(kho_get_mem_map_phys(fdt));
>  	mutex_init(&kho_in.radix_tree.lock);
> -	return kho_radix_walk_tree(&kho_in.radix_tree, &cb);
> +	return kho_radix_walk_tree(&kho_in.radix_tree, &cb, NULL);
>  }
>  
>  static __init int kho_out_fdt_setup(void)
> -- 
> 2.54.0.545.g6539524ca2-goog
>