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 8854E3F4854 for ; Sat, 25 Jul 2026 17:22:16 +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=1785000137; cv=none; b=jfOXywNlQldGlK7P7iEDitC7Q/AUw0jSmoWQte2bzhVYXKrnUbDVlZyxw9RaO1PsG4udcWV6/rX8Xe2EDJaHiORhGVYWAAFBNUIQdbNHGn8zN6/LsPkca6eQAJH3qLLauqmg3vZRkyZ2PouX8hMkvd0Jrfi5c5aWDZNLcape/tc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785000137; c=relaxed/simple; bh=hllSASPlNN6o2UJ8Uqq7N6o4uBJKheIYG84kWtxGGEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Qd/JPkNsv6nGA4B2HnmtbeqLTppIPDVk0OP669e1t81ugjt1EReIXVADGyZguQ095OqFNGIalRS4iHyLG3CPZMnG2WDCo9/X7m5JY8Kx9qfdFktuAD2TIKmmWkAy2NEhQ2du753Eque50DuLVTWVE0fPRxEegPSfB/zQ7nvixvs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XsaMviWT; 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="XsaMviWT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 479441F00A3D; Sat, 25 Jul 2026 17:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785000136; bh=emKiA6xrFIOZliOLnZcankBaWPBYScZ46CleF/fKzoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XsaMviWTbAehjg/bTEo8zneL+lukGZJmWsf75GVE/Itbfdrajxr80eE2kdoahrr3e pwgoibI/ue6XE6h05TXZmDukSfp6yk4yZetHTkWrJz5OeZ8UdjMY52aSmgefrY6E7h ayaswZjAAIktHF3YXsDSw1IDlbIYaToZyuklafCyB9KB5NT6oCzyxvOLl+ZqApkxjX qVNCoTL0oy4e5QJiTjW3ONoNYxCeKQInpLI518RTE08oHj3IHn2V+LGDWNg21LjcZV ph6ZZ6hVbjALbc02fXXtOZfQKEw5FWyq7Tza4z1n5U+dq+oQaXY6BT24Df7r/tX7+l MZsaHoJDXrRzA== 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 v4 12/21] kho: add kho_radix_init_tree() Date: Sat, 25 Jul 2026 19:21:12 +0200 Message-ID: <20260725172133.4018491-13-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog In-Reply-To: <20260725172133.4018491-1-pratyush@kernel.org> References: <20260725172133.4018491-1-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)" Move the initialization logic of the radix tree into kho_radix_init_tree() instead of having users open-code it. Makes the boundaries cleaner and reduces code duplication when a new user of the radix tree will be added in a future commit. Signed-off-by: Pratyush Yadav (Google) --- include/linux/kho_radix_tree.h | 7 ++++ kernel/liveupdate/kexec_handover.c | 62 +++++++++++++++++++++--------- 2 files changed, 51 insertions(+), 18 deletions(-) diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index 66ca936b3f06..5d6ae2893684 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); +int kho_radix_init_tree(struct kho_radix_tree *tree, struct kho_radix_node *root); void kho_radix_destroy_tree(struct kho_radix_tree *tree); #else /* #ifdef CONFIG_KEXEC_HANDOVER */ @@ -72,6 +73,12 @@ static inline int kho_radix_walk_tree(struct kho_radix_tree *tree, return -EOPNOTSUPP; } +static inline int kho_radix_init_tree(struct kho_radix_tree *tree, + struct kho_radix_node *root) +{ + return 0; +} + static inline void kho_radix_destroy_tree(struct kho_radix_tree *tree) { } #endif /* #ifdef CONFIG_KEXEC_HANDOVER */ diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 105dc0f3e691..04bfcbf9cc55 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -320,6 +320,30 @@ static void __kho_radix_destroy_tree(struct kho_radix_node *root, kho_radix_free_node(root); } +/** + * kho_radix_init_tree - initialize the radix tree. + * @tree: the tree to initialize. + * @root: root table of the radix tree. + * + * Initialize the radix tree with the given root node. If root is %NULL, an + * empty root table is allocated. If root is not %NULL, it is the caller's + * responsibility to make sure the root is valid and in the correct format. + * + * Return: 0 on success, -errno on failure. + */ +int kho_radix_init_tree(struct kho_radix_tree *tree, struct kho_radix_node *root) +{ + if (!root) + root = kho_radix_alloc_node(); + if (!root) + return -ENOMEM; + + tree->root = root; + mutex_init(&tree->lock); + return 0; +} +EXPORT_SYMBOL_GPL(kho_radix_init_tree); + /** * kho_radix_destroy_tree - Destroy the radix tree * @tree: The radix tree to destroy @@ -1499,18 +1523,23 @@ static void __init kho_mem_retrieve(void) * catches that and never sets kho_in.scratch_phys, which stops memory * retrieval. */ - kho_in.radix_tree.root = kho_get_mem_map(fdt); - mutex_init(&kho_in.radix_tree.lock); + err = kho_radix_init_tree(&kho_in.radix_tree, kho_get_mem_map(fdt)); + if (err) + goto err; err = kho_radix_walk_tree(&kho_in.radix_tree, &cb, NULL); - if (err) { - /* - * Failed to initialize preserved memory. Clear FDT and radix - * so KHO users don't treat it as a KHO boot. - */ - kho_in.fdt_phys = 0; - kho_in.radix_tree.root = NULL; - } + if (err) + goto err; + + return; + +err: + /* + * Failed to initialize preserved memory. Clear FDT and radix so KHO + * users don't treat it as a KHO boot. + */ + kho_in.fdt_phys = 0; + kho_in.radix_tree.root = NULL; } static __init int kho_out_fdt_setup(void) @@ -1636,16 +1665,14 @@ static __init int kho_init(void) if (!kho_enable) return 0; - tree->root = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!tree->root) { - err = -ENOMEM; + err = kho_radix_init_tree(tree, NULL); + if (err) goto err_free_scratch; - } kho_out.fdt = kho_alloc_preserve(PAGE_SIZE); if (IS_ERR(kho_out.fdt)) { err = PTR_ERR(kho_out.fdt); - goto err_free_kho_radix_tree_root; + goto err_free_kho_radix_tree; } err = kho_debugfs_init(); @@ -1696,9 +1723,8 @@ static __init int kho_init(void) err_free_fdt: kho_unpreserve_free(kho_out.fdt); -err_free_kho_radix_tree_root: - kfree(tree->root); - tree->root = NULL; +err_free_kho_radix_tree: + kho_radix_destroy_tree(tree); err_free_scratch: kho_out.fdt = NULL; for (int i = 0; i < kho_scratch_cnt; i++) { -- 2.55.0.229.g6434b31f56-goog