linux-kernel - [PATCH 1/6] firewire: core: use scoped_guard() to manage critical section to update topology

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Message-ID: <20250915234747.915922-2-o-takashi@sakamocchi.jp>
Date: Tue, 16 Sep 2025 08:47:42 +0900
From: Takashi Sakamoto <o-takashi@...amocchi.jp>
To: linux1394-devel@...ts.sourceforge.net
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 1/6] firewire: core: use scoped_guard() to manage critical section to update topology

At present, guard() macro is used for the critical section to update
topology. It is inconvenient to add the other critical sections into
the function.

This commit uses scoped_guard() macro instead.

Signed-off-by: Takashi Sakamoto <o-takashi@...amocchi.jp>
---
 drivers/firewire/core-topology.c | 74 +++++++++++++++-----------------
 1 file changed, 34 insertions(+), 40 deletions(-)

diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
index 5f8fb1201d80..17aaf14cab0b 100644
--- a/drivers/firewire/core-topology.c
+++ b/drivers/firewire/core-topology.c
@@ -458,46 +458,40 @@ void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
 
 	trace_bus_reset_handle(card->index, generation, node_id, bm_abdicate, self_ids, self_id_count);
 
-	guard(spinlock_irqsave)(&card->lock);
-
-	/*
-	 * If the selfID buffer is not the immediate successor of the
-	 * previously processed one, we cannot reliably compare the
-	 * old and new topologies.
-	 */
-	if (!is_next_generation(generation, card->generation) &&
-	    card->local_node != NULL) {
-		fw_destroy_nodes(card);
-		card->bm_retries = 0;
-	}
-
-	card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
-	card->node_id = node_id;
-	/*
-	 * Update node_id before generation to prevent anybody from using
-	 * a stale node_id together with a current generation.
-	 */
-	smp_wmb();
-	card->generation = generation;
-	card->reset_jiffies = get_jiffies_64();
-	card->bm_node_id  = 0xffff;
-	card->bm_abdicate = bm_abdicate;
-	fw_schedule_bm_work(card, 0);
-
-	local_node = build_tree(card, self_ids, self_id_count, generation);
-
-	update_topology_map(card, self_ids, self_id_count);
-
-	card->color++;
-
-	if (local_node == NULL) {
-		fw_err(card, "topology build failed\n");
-		/* FIXME: We need to issue a bus reset in this case. */
-	} else if (card->local_node == NULL) {
-		card->local_node = local_node;
-		for_each_fw_node(card, local_node, report_found_node);
-	} else {
-		update_tree(card, local_node);
+	scoped_guard(spinlock, &card->lock) {
+		// If the selfID buffer is not the immediate successor of the
+		// previously processed one, we cannot reliably compare the
+		// old and new topologies.
+		if (!is_next_generation(generation, card->generation) && card->local_node != NULL) {
+			fw_destroy_nodes(card);
+			card->bm_retries = 0;
+		}
+		card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
+		card->node_id = node_id;
+		// Update node_id before generation to prevent anybody from using
+		// a stale node_id together with a current generation.
+		smp_wmb();
+		card->generation = generation;
+		card->reset_jiffies = get_jiffies_64();
+		card->bm_node_id  = 0xffff;
+		card->bm_abdicate = bm_abdicate;
+		fw_schedule_bm_work(card, 0);
+
+		local_node = build_tree(card, self_ids, self_id_count, generation);
+
+		update_topology_map(card, self_ids, self_id_count);
+
+		card->color++;
+
+		if (local_node == NULL) {
+			fw_err(card, "topology build failed\n");
+			// FIXME: We need to issue a bus reset in this case.
+		} else if (card->local_node == NULL) {
+			card->local_node = local_node;
+			for_each_fw_node(card, local_node, report_found_node);
+		} else {
+			update_tree(card, local_node);
+		}
 	}
 }
 EXPORT_SYMBOL(fw_core_handle_bus_reset);
-- 
2.48.1