mlx4_core: Add module parameter to enable QoS support

Add a module parameter "enable_qos" to mlx4_core.  If this param is
set, enable support for QoS in the INIT_HCA command.  By default, the
parameter is set to 0 (disabled).

Signed-off-by: Jack Morgenstein <jackm@dev.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 2b5006b..0851ebd 100644
--- a/drivers/net/mlx4/fw.c
+++ b/drivers/net/mlx4/fw.c
@@ -46,6 +46,10 @@
 extern void __buggy_use_of_MLX4_GET(void);
 extern void __buggy_use_of_MLX4_PUT(void);
 
+static int enable_qos;
+module_param(enable_qos, bool, 0444);
+MODULE_PARM_DESC(enable_qos, "Enable Quality of Service support in the HCA (default: off)");
+
 #define MLX4_GET(dest, source, offset)				      \
 	do {							      \
 		void *__p = (char *) (source) + (offset);	      \
@@ -737,6 +741,10 @@
 	if (dev->caps.flags & MLX4_DEV_CAP_FLAG_IPOIB_CSUM)
 		*(inbox + INIT_HCA_FLAGS_OFFSET / 4) |= cpu_to_be32(1 << 3);
 
+	/* Enable QoS support if module parameter set */
+	if (enable_qos)
+		*(inbox + INIT_HCA_FLAGS_OFFSET / 4) |= cpu_to_be32(1 << 2);
+
 	/* QPC/EEC/CQC/EQC/RDMARC attributes */
 
 	MLX4_PUT(inbox, param->qpc_base,      INIT_HCA_QPC_BASE_OFFSET);