Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
+24
-10
+14
-8
drivers/firewire/core-topology.c
+14
-8
drivers/firewire/core-topology.c
···
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}
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}
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static void update_topology_map(struct fw_card *card,
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u32 *self_ids, int self_id_count)
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static void update_topology_map(__be32 *buffer, size_t buffer_size, int root_node_id,
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const u32 *self_ids, int self_id_count)
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{
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int node_count = (card->root_node->node_id & 0x3f) + 1;
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__be32 *map = card->topology_map;
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__be32 *map = buffer;
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int node_count = (root_node_id & 0x3f) + 1;
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memset(map, 0, buffer_size);
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*map++ = cpu_to_be32((self_id_count + 2) << 16);
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*map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
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*map++ = cpu_to_be32(be32_to_cpu(buffer[1]) + 1);
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*map++ = cpu_to_be32((node_count << 16) | self_id_count);
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while (self_id_count--)
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*map++ = cpu_to_be32p(self_ids++);
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fw_compute_block_crc(card->topology_map);
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fw_compute_block_crc(buffer);
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}
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void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
···
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local_node = build_tree(card, self_ids, self_id_count, generation);
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update_topology_map(card, self_ids, self_id_count);
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card->color++;
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if (local_node == NULL) {
···
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} else {
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update_tree(card, local_node);
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}
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}
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// Just used by transaction layer.
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scoped_guard(spinlock, &card->topology_map.lock) {
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update_topology_map(card->topology_map.buffer, sizeof(card->topology_map.buffer),
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card->root_node->node_id, self_ids, self_id_count);
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}
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}
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EXPORT_SYMBOL(fw_core_handle_bus_reset);
+5
-1
drivers/firewire/core-transaction.c
+5
-1
drivers/firewire/core-transaction.c
···
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}
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start = (offset - topology_map_region.start) / 4;
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memcpy(payload, &card->topology_map[start], length);
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// NOTE: This can be without irqsave when we can guarantee that fw_send_request() for local
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// destination never runs in any type of IRQ context.
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scoped_guard(spinlock_irqsave, &card->topology_map.lock)
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memcpy(payload, &card->topology_map.buffer[start], length);
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fw_send_response(card, request, RCODE_COMPLETE);
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}
+5
-1
include/linux/firewire.h
+5
-1
include/linux/firewire.h
···
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bool broadcast_channel_allocated;
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u32 broadcast_channel;
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__be32 topology_map[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
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struct {
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__be32 buffer[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
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spinlock_t lock;
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} topology_map;
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__be32 maint_utility_register;
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