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bh=pcpHltz9li0iTs1WsD5eIIz6ruG9qO5py8BOvyZzad8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=k5z1XPTEJRdBV0HODe/jQ+vpX6f+RThVFgxm6WznsGEnXwv53CwoMVJge+88qVlWp Z1tyoMxl0JrOHUJrBJD4/ApBHDT4H82zBzmkh6/D2A455Y7lumK83pnewWubv2U++U zo/vxYmmRYWx+H6E7d9XqmBMdR2qdDvZuDMkCUwJtW7weia1kg/guXna1KG5QFaw67 vOrIxucadXjuDq0Z2C4o0e8XHoBfGe17r+3eZp02lVDCBJPnNLLWNC/LRh02+nBdIJ jegyG6EnJkk0noOLhISOr5a7PN+AfQZxAvqVWGIkKmAGp+PKboyQ6Kv4kKJP9xzLlS xjOPA7oRHLbDg== 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 v3 07/21] kho: add a struct for radix callbacks Date: Thu, 9 Jul 2026 19:37:56 +0200 Message-ID: <20260709173821.429921-8-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.141.g00534a21ce-goog In-Reply-To: <20260709173821.429921-1-pratyush@kernel.org> References: <20260709173821.429921-1-pratyush@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E58701A0006 X-Stat-Signature: 65g3stw5tfqyoika5xh941ijmrok4hpt X-HE-Tag: 1783618730-912744 X-HE-Meta: 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 QVOakMXN ArRlo3ASTfkKYnUHSKqvH+nZydkjTojG6XMjW74wPErwiLYij1P2eMJBAGFXB2vTpqn9PuhoheviiKiBoijvK+14t5gcVDQL8RBiNDXiRlQ79h9/F2vA7fzS3m4gAY0han2QM3usDHqYDZxsypw98FUFZp9JRXEz79PXt3hwSrAqwNq2YB9pJRqjBFa/6quSztRZj11b55DbvYPm5tclAy0eCBg36Rd7BwAevHh22ahFuQfA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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 f368f3b9f923..426a9cc9bcde 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. + * @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 */ @@ -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 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 -- 2.55.0.141.g00534a21ce-goog