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 42D643A960A for ; Sat, 25 Jul 2026 17:22:14 +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=1785000135; cv=none; b=Jcht7CttsKpePuUC/Ck5WiBWYbgkyvopUIQ8Jsfm7W6P7f1XcVae3jODOCNmxiCNsGYl8GQ+iNJALPH3kF3sUe23BR5P7H4v7GbtG33k+w3PxJLSJsWnRuoI9kEEdB46tR70vQr8e2YfDC90sCslJ9YpRbnBpBwgKeyI0h1DLUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785000135; c=relaxed/simple; bh=VBclwby+tzMfAx2bwRSH7n/2E6AxW4Sv0nXcvv18J5s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pmI05fZgDfCyjDdf16zyynkAsQvnk2o9OXJihC7h7VHw+QHl36ShaEl6tWyOcySV1fXsBCuIIAvnu2aMsrCgxcryprB1roE5ldY0RQ6l+KLUhM2jaI3+XGNQDA5W1vPReBMosumAABmdoSkFU92zYDs1B+p7eSWm4kx+4a1FEqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g/SO7DQW; 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="g/SO7DQW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B42EC1F00A3A; Sat, 25 Jul 2026 17:22:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785000133; bh=cm6Vup04LkzIMCjH2BafW4iokUdQRkQPK1I9Bq3XG78=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=g/SO7DQWVgBWUxlPwflXp6dj6uM9mlIzRw9e5Xs5q6WSaW9S3cfnjqI8ZNfybhDVO rj5kVk4SLWWSQYCdB7/ANB3LoFxdfZict9mD+0FfhKFnpAyOrFq3RQ5jiDPpZniR+V dg9vl11jHBndmmSgyBquXq3TQy3Qr8iatmi2+cALjg9LuYnzrucfWvThNGIRZdBVkZ k5kAO+i75Kp8lfJaF8OtKE0TaRuTsjnkbbFhoqd8riUGe83wy92g2CdPUJNK86vk23 uhCUFRt3mKxNv5iKvIjxANHCU9Vti8Qgfk9pLyE2lZeTyu7Tk5f+UMR1/mEdVe45kh VMgHL9DEm7kWw== 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 11/21] kho: allow destroying KHO radix tree Date: Sat, 25 Jul 2026 19:21:11 +0200 Message-ID: <20260725172133.4018491-12-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)" Add kho_radix_destroy_tree() which allows destroying the radix tree and freeing all its pages. This is will be used by the upcoming scratch extension mechanism. It creates a radix tree to track free blocks and then frees them after telling memblock about them. Reviewed-by: Pasha Tatashin Signed-off-by: Pratyush Yadav (Google) --- include/linux/kho_radix_tree.h | 3 +++ kernel/liveupdate/kexec_handover.c | 35 ++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index 4138621e0e87..66ca936b3f06 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); +void kho_radix_destroy_tree(struct kho_radix_tree *tree); #else /* #ifdef CONFIG_KEXEC_HANDOVER */ @@ -71,6 +72,8 @@ static inline int kho_radix_walk_tree(struct kho_radix_tree *tree, return -EOPNOTSUPP; } +static inline void kho_radix_destroy_tree(struct kho_radix_tree *tree) { } + #endif /* #ifdef CONFIG_KEXEC_HANDOVER */ #endif /* _LINUX_KHO_RADIX_TREE_H */ diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index a5800b960cf6..105dc0f3e691 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -301,6 +301,41 @@ void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key) } EXPORT_SYMBOL_GPL(kho_radix_del_key); +static void __kho_radix_destroy_tree(struct kho_radix_node *root, + unsigned int level) +{ + unsigned long i; + + if (level == 0) { + kho_radix_free_node(root); + return; + } + + for (i = 0; i < PAGE_SIZE / sizeof(phys_addr_t); i++) { + if (root->table[i]) + __kho_radix_destroy_tree(phys_to_virt(root->table[i]), + level - 1); + } + + kho_radix_free_node(root); +} + +/** + * kho_radix_destroy_tree - Destroy the radix tree + * @tree: The radix tree to destroy + * + * Walk @tree and free all its nodes. + */ +void kho_radix_destroy_tree(struct kho_radix_tree *tree) +{ + if (!tree->root) + return; + + __kho_radix_destroy_tree(tree->root, KHO_TREE_MAX_DEPTH - 1); + tree->root = NULL; +} +EXPORT_SYMBOL_GPL(kho_radix_destroy_tree); + static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key, const struct kho_radix_walk_cb *cb, void *data) { -- 2.55.0.229.g6434b31f56-goog