mlx4_core: Pass cache line size to device FW

ConnectX can work more efficiently if the CPU cache line size is passed
to it with the INIT_HCA firmware command.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/net/mlx4/fw.c b/drivers/net/mlx4/fw.c
index cee199c..3c16602 100644
--- a/drivers/net/mlx4/fw.c
+++ b/drivers/net/mlx4/fw.c
@@ -33,6 +33,7 @@
  */
 
 #include <linux/mlx4/cmd.h>
+#include <linux/cache.h>
 
 #include "fw.h"
 #include "icm.h"
@@ -698,6 +699,7 @@
 #define INIT_HCA_IN_SIZE		 0x200
 #define INIT_HCA_VERSION_OFFSET		 0x000
 #define	 INIT_HCA_VERSION		 2
+#define INIT_HCA_CACHELINE_SZ_OFFSET	 0x0e
 #define INIT_HCA_FLAGS_OFFSET		 0x014
 #define INIT_HCA_QPC_OFFSET		 0x020
 #define	 INIT_HCA_QPC_BASE_OFFSET	 (INIT_HCA_QPC_OFFSET + 0x10)
@@ -735,6 +737,9 @@
 
 	*((u8 *) mailbox->buf + INIT_HCA_VERSION_OFFSET) = INIT_HCA_VERSION;
 
+	*((u8 *) mailbox->buf + INIT_HCA_CACHELINE_SZ_OFFSET) =
+		(ilog2(cache_line_size()) - 4) << 5;
+
 #if defined(__LITTLE_ENDIAN)
 	*(inbox + INIT_HCA_FLAGS_OFFSET / 4) &= ~cpu_to_be32(1 << 1);
 #elif defined(__BIG_ENDIAN)