Add a kernel module parameter for configuring the maximum segment size.
This patch enables testing SCSI support for segments smaller than the
page size.

Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
  drivers/scsi/scsi_debug.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index bebda917b138..ea8f762c55c3 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c

@@ -770,6 +770,7 @@ static int sdebug_sector_size = DEF_SECTOR_SIZE;
  static int sdeb_tur_ms_to_ready = DEF_TUR_MS_TO_READY;
  static int sdebug_virtual_gb = DEF_VIRTUAL_GB;
  static int sdebug_vpd_use_hostno = DEF_VPD_USE_HOSTNO;
+static unsigned int sdebug_max_segment_size = -1U >   static unsigned int sdebug_lbpu = DEF_LBPU;
  static unsigned int sdebug_lbpws = DEF_LBPWS;
  static unsigned int sdebug_lbpws10 = DEF_LBPWS10;

@@ -5851,6 +5852,7 @@ module_param_named(ndelay, sdebug_ndelay, int, S_IRUGO | S_IWUSR);
  module_param_named(no_lun_0, sdebug_no_lun_0, int, S_IRUGO | S_IWUSR);
  module_param_named(no_rwlock, sdebug_no_rwlock, bool, S_IRUGO | S_IWUSR);
  module_param_named(no_uld, sdebug_no_uld, int, S_IRUGO);
+module_param_named(max_segment_size, sdebug_max_segment_size, uint, S_IRUGO);

  module_param_named(num_parts, sdebug_num_parts, int, S_IRUGO);
  module_param_named(num_tgts, sdebug_num_tgts, int, S_IRUGO | S_IWUSR);
  module_param_named(opt_blks, sdebug_opt_blks, int, S_IRUGO);

@@ -7815,6 +7817,7 @@ static int sdebug_driver_probe(struct device *dev)
  
  	sdebug_driver_template.can_queue = sdebug_max_queue;
  	sdebug_driver_template.cmd_per_lun = sdebug_max_queue;
+	sdebug_driver_template.max_segment_size = sdebug_max_segment_size;
  	if (!sdebug_clustering)
  		sdebug_driver_template.dma_boundary = PAGE_SIZE - 1;