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 343113AE188 for ; Sat, 1 Aug 2026 08:49:09 +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=1785574151; cv=none; b=dLwVb5YITJ2BDRaQvwOo75PNctV+uAWgpk1ptvWpxEJC8YUSQzBdBOxc4Bg5fac3Ry8fDMEQaxLatWa85/628qqVwRvQMWpg7sSdKQYRt9FkQ1EKd5hCyltjIbY5+wtupg5SBYTntNFgfeV/HOJxV4bxWW3aBPRsJkxf82Pm+3g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785574151; c=relaxed/simple; bh=Sh+jc1pfjXYVzm5eDHhnCNYjDNywXqO1b6k8d7zmISY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Uh75vxwAm9Twd+vYorAmNHqQXY4t3QpCrAqa8yL3nBf11A4/Dzo3sK81R2U8WIpkFehl3DDkGLwTA4x59rhsfc2HuHRF7ZaEFXjwm/YoUg/aUbAybDpq4pAM4EDISwLssJkfCQC27/ey+WTol7FMI9v0WHo+ihaKEzcN4Xgy4E8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lIthDNSy; 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="lIthDNSy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CC5D1F00ACF; Sat, 1 Aug 2026 08:49:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785574149; bh=XNgyD4SOWKFNe9Izm+Nzxp4NQgOd4T3wYTp8t2mLDNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lIthDNSy0aXfb6XajVGZ/pNVTaDscF9eSGuWw+2YxyfporzOSHAp+NcDsWeWQQsMV vS0sqCTwPq1zJ7Wsj0UTGoPecmOVIqAd1ZQyjs83LAiy/rldf3nIgkwEwkvJ2+TygU EsvGeR+Hzt16AO7rAyyOJHe4P7VoIOYXVqnonOpYKBwEy65Wq7LA4WGiARaz1ALjp3 AgP96sGbaSobbJiwIGvFcIrTKvBRUW86MdBKs+JjJF/UCpRVyIzyepVhm/RFeu5xQq 1kFeFANT6mc/brEa6Z4RuX4+oD3D38OXABBZPSUy33vvo09bnfqNsyRaNixcLkotmx fuLUQSdl4heFw== 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 v6 07/22] kho: add a struct for radix callbacks Date: Sat, 1 Aug 2026 10:48:16 +0200 Message-ID: <20260801084833.1897543-8-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.571.g244d577d93-goog In-Reply-To: <20260801084833.1897543-1-pratyush@kernel.org> References: <20260801084833.1897543-1-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 9157fe08f9ce..486e193d58f4 100644 --- a/include/linux/kho_radix_tree.h +++ b/include/linux/kho_radix_tree.h @@ -38,14 +38,23 @@ 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 */ @@ -58,7 +67,7 @@ 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 -- 2.55.0.571.g244d577d93-goog