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 0890B4E3781 for ; Wed, 29 Jul 2026 14:56:51 +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=1785337012; cv=none; b=pF9F2tBC5uCzonM0MI90R7jQcqWvL6SZuwzeuKk8rm7UJGvZYm1A/ImjGV+oFR5Sp7NxiGA0+m4wwzUgRwMxKm5scFqa/kDw/Ll5jD+iTLUgSsp52W8hysgkZjrr0syKf4uMOcYHVZrFGDN3NEPYYD2K1Kprn/kucER96vFyMUs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785337012; c=relaxed/simple; bh=0BxM/hX/Po3VBKVU+45xHNEj31Qd2Veu50KcvLfxD7I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PY4oqYzlwZLrQrtLE4q2a6q/JAsjCDvgtODMVGFxmyd4niLDD0dFfAEBTvRm3NZ9NoKKLDZjycUsvpPlQIxqjkCj486HxOnT+v2kdneXxpIHvkW4SGYm27H6nwMBtFe6ZosHbvUKNBxrBLy2t3wEcUE0rhzKZjqWqRiKhJLXRY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cmcDkLrd; 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="cmcDkLrd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B837A1F00A3D; Wed, 29 Jul 2026 14:56:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785337010; bh=eB8c193KoCNkyC5Nboc/hf64d3uhVb8xp38FM/W9Qug=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cmcDkLrd/1MzkczVxXfn8+N7BEZgaGnoK2Qul8jd38HbrcPnqqNA2scwqgczjzfqP n2B3FvU1/BUI9Ng5WsXvZw58vm2gZf0aUM5+yHts+hJvDl47TZbDONnf0r0wXopNDF kve/+Nk99KMzpl42bjjygebEvlKfnZ4inHN2Q/t25n2BEClogWCUT3caAa0gIhBZFU T0hMFANNLSdB61yH98EOw0SVcnqGKuv9M/MgEdJAfp9xJnnulqeOgJ4oF9YjTh1swA YZG0MOy/oYa354qkSNLXnCG8vHcFrFzUuM/qZ8u7ZRGWi7SRxNZ3BtWeeKKPyYR12g LvEfCJvOqpC0w== 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 11/22] kho: allow destroying KHO radix tree Date: Wed, 29 Jul 2026 16:55:56 +0200 Message-ID: <20260729145610.2827231-12-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)" 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) { -- 2.55.0.508.g3f0d502094-goog