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 0BFAB4D8D84 for ; Wed, 29 Jul 2026 14:56:40 +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=1785337002; cv=none; b=K7FIywPGEM0k4P2upJXw94l0VscdQo00jTS+LNfTY6YKNYmeRmYEIMrdmAJmDP+AP+KUVhfmPuLB0C9V2j8LeoCvNbbzHsnCLPN52je6cGYDP4YprQjXcEWzbya79Y76QdJNkcN/OeaR65Y18rZ6ox71a4vkECNLsAcSVjgg31g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785337002; c=relaxed/simple; bh=stIpLquvHeS0PQ4z8qoKTI8ciYAtC3mby2ixH6eEqh0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uZSioVms0UxMeHMnkJ6E3nEkBTGxkA8zSXaa2eIkD822WMgwup4X65yoWypN0h2bfIvASaB573XjsQzdsy5zBvQuaBl9FM8DZBw5thzVwxCGkP6zQ0JbXzh5ZBimhAMPTv0Unam8YguXzGTjYIEiHwZGeU9h1gyqWToqg/WY+v8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l2ZTFT8W; 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="l2ZTFT8W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C5471F000E9; Wed, 29 Jul 2026 14:56:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785337000; bh=DfNI/eg3j2X2k/CIkH0J/irJxPI8VWbcAw18DR1ugaU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=l2ZTFT8WN7ZImRicWiaeYLQvUk13Ic8ciRIrgtf2MjFSCJrAy7Omv3vznmh0Ttq8A 6KcMQvRPHsIBjMNiiDcxfBhXUccZdbbN0XJ2mHDlSyaZQgk4KXjcpJ/x6wkOQ+WxFX Lynjo6w/Ba27ba9cn6apfb1/uxNxq8pUgzbi6NvkFjvibxGOqHFQQW1LD00vXpERXc X/AbkG5+nih1aHrVrL8GvE5+DrEWfG1ChVThT3o0Qfub2qQIf7j4a7WqtWfnvRRK6k kdidY0sPTN3AyQSs4GtVoVhjYnBTSl9QMLthUZrH54aYQq2hqzL0chgV/j9WvQbfrG SXSKayJ6IEvEA== 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 v5 07/22] kho: add a struct for radix callbacks Date: Wed, 29 Jul 2026 16:55:52 +0200 Message-ID: <20260729145610.2827231-8-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.508.g3f0d502094-goog In-Reply-To: <20260729145610.2827231-1-pratyush@kernel.org> References: <20260729145610.2827231-1-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 e3408e1844dc..9fb07c0ef18e 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -281,16 +281,18 @@ 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; } @@ -300,7 +302,7 @@ 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; @@ -340,18 +342,16 @@ 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; @@ -1417,6 +1417,9 @@ 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; @@ -1430,7 +1433,7 @@ 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 -- 2.55.0.508.g3f0d502094-goog