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Commit c8a12d45 authored by Stefan Richter's avatar Stefan Richter
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firewire: reorder struct fw_card for better cache efficiency 



topology_map is by far the largest member in struct fw_card.  Move it to
the very end of the struct so that card pointer dereferences have better
chances to hit the CPU cache.

This requires to increase the topology_map backing store to the size
specified in IEEE 1394, i.e. 256 rather than 255 quadlets.  Otherwise
the topology_map response handler may access invalid memory.

Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent d6f95a3d

drivers/firewire/fw-transaction.h

+3 −7
Original line number Diff line number Diff line
@@ -237,13 +237,6 @@ struct fw_card { 
	int link_speed;

	int config_rom_generation;



	/*

	 * We need to store up to 4 self ID for a maximum of 63

	 * devices plus 3 words for the topology map header.

	 */

	u32 topology_map[252 + 3];

	u32 broadcast_channel;



	spinlock_t lock; /* Take this lock when handling the lists in

			  * this struct. */

	struct fw_node *local_node;
@@ -261,6 +254,9 @@ struct fw_card { 
	struct delayed_work work;

	int bm_retries;

	int bm_generation;



	u32 broadcast_channel;

	u32 topology_map[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];

};



static inline struct fw_card *fw_card_get(struct fw_card *card)