[SCSI] fc class: add fc host default default dev loss setting

This patch adds a fc_host setting to store the
default dev_loss_tmo. It is used if the driver
has a callack to get the value from the LLD. If
the callback is not set, then we use the fc class
module default value.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

drivers/scsi/scsi_transport_fc.c

@@ -2525,7 +2525,11 @@ fc_rport_create(struct Scsi_Host *shost, int channel,
 
 	rport->maxframe_size = -1;
 	rport->supported_classes = FC_COS_UNSPECIFIED;
-	rport->dev_loss_tmo = fc_dev_loss_tmo;
+	if (fci->f->get_host_def_dev_loss_tmo) {
+		fci->f->get_host_def_dev_loss_tmo(shost);
+		rport->dev_loss_tmo = fc_host_def_dev_loss_tmo(shost);
+	} else
+		rport->dev_loss_tmo = fc_dev_loss_tmo;
 	memcpy(&rport->node_name, &ids->node_name, sizeof(rport->node_name));
 	memcpy(&rport->port_name, &ids->port_name, sizeof(rport->port_name));
 	rport->port_id = ids->port_id;

include/scsi/scsi_transport_fc.h

@@ -496,6 +496,7 @@ struct fc_host_attrs {
 	u64 fabric_name;
 	char symbolic_name[FC_SYMBOLIC_NAME_SIZE];
 	char system_hostname[FC_SYMBOLIC_NAME_SIZE];
+	u32 def_dev_loss_tmo;
 
 	/* Private (Transport-managed) Attributes */
 	enum fc_tgtid_binding_type  tgtid_bind_type;
@@ -580,6 +581,8 @@ struct fc_host_attrs {
 	(((struct fc_host_attrs *)(x)->shost_data)->devloss_work_q_name)
 #define fc_host_devloss_work_q(x) \
 	(((struct fc_host_attrs *)(x)->shost_data)->devloss_work_q)
+#define fc_host_def_dev_loss_tmo(x) \
+	(((struct fc_host_attrs *)(x)->shost_data)->def_dev_loss_tmo)
 
 
 struct fc_bsg_buffer {
@@ -640,6 +643,7 @@ struct fc_function_template {
 	void	(*get_host_fabric_name)(struct Scsi_Host *);
 	void	(*get_host_symbolic_name)(struct Scsi_Host *);
 	void	(*set_host_system_hostname)(struct Scsi_Host *);
+	void	(*get_host_def_dev_loss_tmo)(struct Scsi_Host *);
 
 	struct fc_host_statistics * (*get_fc_host_stats)(struct Scsi_Host *);
 	void	(*reset_fc_host_stats)(struct Scsi_Host *);