IB/srp: Make queue size configurable

Certain storage configurations, e.g. a sufficiently large array of
hard disks in a RAID configuration, need a queue depth above 64 to
achieve optimal performance. Hence make the queue depth configurable.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Tested-by: Jack Wang <xjtuwjp@gmail.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp
index b95067e..b9688de 100644
--- a/Documentation/ABI/stable/sysfs-driver-ib_srp
+++ b/Documentation/ABI/stable/sysfs-driver-ib_srp
@@ -63,6 +63,10 @@
 		  over multiple CPU's.
 		* tl_retry_count, a number in the range 2..7 specifying the
 		  IB RC retry count.
+		* queue_size, the maximum number of commands that the
+		  initiator is allowed to queue per SCSI host. The default
+		  value for this parameter is 62. The lowest supported value
+		  is 2.
 
 What:		/sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev
 Date:		January 2, 2006