firewire: core: use spin lock specific to topology map

At present, the operation for read transaction to topology map register is
not protected by any kind of lock primitives. This causes a potential
problem to result in the mixed content of topology map.

This commit adds and uses spin lock specific to topology map.

Link: https://lore.kernel.org/r/20250915234747.915922-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index f3260aacf730..aeb71c39e57e 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -129,7 +129,11 @@ struct fw_card {
 
 	bool broadcast_channel_allocated;
 	u32 broadcast_channel;
-	__be32 topology_map[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
+
+	struct {
+		__be32 buffer[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
+		spinlock_t lock;
+	} topology_map;
 
 	__be32 maint_utility_register;