From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9EEC03E3152 for ; Fri, 5 Jun 2026 18:35:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684529; cv=none; b=U5Gaz43T34spHU1SG500dPDbBoIqIIaGq3NjmV1rVzSGqyYfwP8FnFOigT7v8sPWxpF+WQ5TznMJKUDeY1p7usWBYBNGWuQR2SsxcEZh8WA3KQeSFR+TCMy2VsQDrrtpvVJliZ61srCB7XIpgdjKg/lOYvUdTcD+QXBrO8KM8e8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684529; c=relaxed/simple; bh=tSSQtFStz452Pkv/PmTb4DwMU7lzbc43oOnJYfN5GT4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RaR7gzSbSig9mRIOrDO04CJ1CJ0L3MJEImg42wEzyVBAqLW2phThZlqlctyADzBek5JrhPDPe0Cfwz87HoeXSy7TDdEtwlHeXRe3p0g/NkZUpt7O1C0WHpUeYYH0COLSTM1QMvnIyKUiMo60jDgPyRjgiCz1aUyZUCH83iwrnBQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AJSBHGNR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AJSBHGNR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CF961F0089A; Fri, 5 Jun 2026 18:35:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780684527; bh=sy6ojk1d+tdK/kdjiYdwMCtmPtof9JNqEAxHhL3pkyA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AJSBHGNRx27gBO59IJQX64bjQPvI1lQz/ZrLOX8eFzLfRcasMMQ5o5FADulVTfKgQ ttkoP2/FH7ji786zuFkiEhLxKcKDHPpsTdKxumBRrExnnUhzl5bMtXsSWvZtjcAzPG J0Y+o+5bKwOjoFj63tZcCk8pPoneEoNkdE/vuo/hOix7mndykoveQ8afXIZgG6oGbA zqRdEDlzG7rVlpmMiKRyV+BFZ3OaKYlMGa0cAXndLG6oy8yxnQ7kkT+qfmmFdfxxpT zxf0yCmyTuKUPGSxyi7N8I22P0B+SgxUvh6PRdAtZD/OlS4vTSvK3q09waOS9rZWz0 WoqZbaFpehRUQ== From: Pratyush Yadav To: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu , Jork Loeser Cc: kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 06/18] kho: add a struct for radix callbacks Date: Fri, 5 Jun 2026 20:34:39 +0200 Message-ID: <20260605183501.3884950-7-pratyush@kernel.org> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog In-Reply-To: <20260605183501.3884950-1-pratyush@kernel.org> References: <20260605183501.3884950-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Pratyush Yadav (Google)" 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) --- 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