From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 448A53F166E for ; Wed, 29 Apr 2026 13:39:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777469993; cv=none; b=Q0qoicpYQnHnaVQM632nctG+6DxV3ddZj1iSDqnZGEAiVY6sWoNkPohQqkyrwC1CGjyZo/rGghmSusVvzGj7Y7R0KBulb3dHLquauW/8J93rJJttuftG5UQGS9XY6ea+caKNevefgbT7xtwTaZ8jACA605FG0xoqlAFxMk7t7fg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777469993; c=relaxed/simple; bh=tnjp4B+bCIr0sG99AF+rCD8R2O3pqFA0kGLY1BJsYzk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iHD7wK9u+5063FL+mqv/+7lAE8k7+abNFm4QZ5cjKl2L/CmDbkAN5TI65v1Spr27AON77ajNW4nLka6U/1d1wyFn8SpbBhXFwMh+zs9HRGKqI/SFLkzCosnzyt7WG85VEwbWXm+rRekjunUctwe8FA3n0BSsCDYGIsLaOXMfexo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=np2Qg1Og; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="np2Qg1Og" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F97AC2BCC4; Wed, 29 Apr 2026 13:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777469991; bh=tnjp4B+bCIr0sG99AF+rCD8R2O3pqFA0kGLY1BJsYzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=np2Qg1OgEt3WN2MkvhLzhwY8UbvPQFLhzjnwDrKCU8Kn62aAROgNpcfLruLLIFqp9 IAUL+1FxC8YHK1/fZzgVsHelhu/opytSHJgcIN+O8CD7IktoVyTXP8Gi7/xIp/S1q3 zGORtXd+I/acbf57qO5HQLDXDcvIvXKCf9FZKX45ThMjKe9XBNb3PiuDrRNAMuu710 8zu86r369RHIlhs8R0B+730jKoHmVkdqOKD+Q4dbNv3Xt1bALxSzLY0+rz2TgwMVNz zoISlzkM3+pyKFBoEkeT5wnTdQ0mNdSLGezpn9lPGnEvXgMld3rJogD2+dF+fFRlaC DTtiFvTKOBU+A== From: Pratyush Yadav To: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu Cc: kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/12] kho: add a struct for radix callbacks Date: Wed, 29 Apr 2026 15:39:05 +0200 Message-ID: <20260429133928.850721-4-pratyush@kernel.org> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog In-Reply-To: <20260429133928.850721-1-pratyush@kernel.org> References: <20260429133928.850721-1-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 | 29 ++++++++++++++++------------- 2 files changed, 28 insertions(+), 16 deletions(-) diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index f368f3b9f923..030da6399d28 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. + * @key: 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 (*key)(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 5758dc6fab5d..4a5d1b47799c 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -266,16 +266,18 @@ 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->key) + return 0; + for_each_set_bit(i, bitmap, PAGE_SIZE * BITS_PER_BYTE) { - err = cb(key | i); + err = cb->key(key | i); if (err) return err; } @@ -285,7 +287,7 @@ 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; @@ -325,18 +327,16 @@ 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; @@ -1374,10 +1374,13 @@ EXPORT_SYMBOL_GPL(kho_retrieve_subtree); static int __init kho_mem_retrieve(const void *fdt) { + const struct kho_radix_walk_cb cb = { + .key = kho_preserved_memory_reserve, + }; + 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, - kho_preserved_memory_reserve); + return kho_radix_walk_tree(&kho_in.radix_tree, &cb); } static __init int kho_out_fdt_setup(void) -- 2.54.0.545.g6539524ca2-goog