cma: add module parameter to the response timeout

OFED 1.2 removed the rdma_set_option call used to adjust
response timeout. We are running into some cases on larger
clusters that require longer timeouts then the default.

V2: Adjusted for rebase to kernel 3.7-rc4

Signed-off by: Arlin Davis <[email protected]>
Signed-off-by: Vladimir Sokolovsky <[email protected]>
Signed-off-by: Jack Morgenstein <[email protected]>
(Ported from Mellanox OFED 2.4)

Signed-off-by: Mukesh Kacker <[email protected]>

Author: Arlin Davis

drivers/infiniband/core/cma.c

@@ -65,6 +65,10 @@ MODULE_LICENSE("Dual BSD/GPL");
 #define CMA_CM_MRA_SETTING (IB_CM_MRA_FLAG_DELAY | 24)
 #define CMA_IBOE_PACKET_LIFETIME 18
 
+static int cma_response_timeout = CMA_CM_RESPONSE_TIMEOUT;
+module_param_named(cma_response_timeout, cma_response_timeout, int, 0644);
+MODULE_PARM_DESC(cma_response_timeout, "CMA_CM_RESPONSE_TIMEOUT (default=20)");
+
 static void cma_add_one(struct ib_device *device);
 static void cma_remove_one(struct ib_device *device);
 
@@ -2762,7 +2766,7 @@ static int cma_resolve_ib_udp(struct rdma_id_private *id_priv,
 
 	req.path = id_priv->id.route.path_rec;
 	req.service_id = rdma_get_service_id(&id_priv->id, cma_dst_addr(id_priv));
-	req.timeout_ms = 1 << (CMA_CM_RESPONSE_TIMEOUT - 8);
+	req.timeout_ms = 1 << (cma_response_timeout - 8);
 	req.max_cm_retries = CMA_MAX_CM_RETRIES;
 
 	ret = ib_send_cm_sidr_req(id_priv->cm_id.ib, &req);
@@ -2830,8 +2834,8 @@ static int cma_connect_ib(struct rdma_id_private *id_priv,
 	req.flow_control = conn_param->flow_control;
 	req.retry_count = min_t(u8, 7, conn_param->retry_count);
 	req.rnr_retry_count = min_t(u8, 7, conn_param->rnr_retry_count);
-	req.remote_cm_response_timeout = CMA_CM_RESPONSE_TIMEOUT;
-	req.local_cm_response_timeout = CMA_CM_RESPONSE_TIMEOUT;
+	req.remote_cm_response_timeout = cma_response_timeout;
+	req.local_cm_response_timeout = cma_response_timeout;
 	req.max_cm_retries = CMA_MAX_CM_RETRIES;
 	req.srq = id_priv->srq ? 1 : 0;