From: Quinn Tran <quinn.tran@cavium.com>
Date: Thu, 28 Dec 2017 12:33:19 -0800
Subject: scsi: qla2xxx: Add option for use reserve exch for ELS
Patch-mainline: v4.16-rc1
Git-commit: 9ecf0b0dd5b934a89eeaa15723d10beb6c33074c
References: bsc#1077338

Add option to tell FW to reserve 1/2 of emergency exchanges for ELS.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/qla2xxx/qla_gbl.h  |    1 +
 drivers/scsi/qla2xxx/qla_init.c |    6 ++++++
 drivers/scsi/qla2xxx/qla_os.c   |    6 ++++++
 3 files changed, 13 insertions(+)

--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -148,6 +148,7 @@ extern int ql2xuctrlirq;
 extern int ql2xnvmeenable;
 extern int ql2xautodetectsfp;
 extern int ql2xenablemsix;
+extern int qla2xuseresexchforels;
 
 extern int qla2x00_loop_reset(scsi_qla_host_t *);
 extern void qla2x00_abort_all_cmds(scsi_qla_host_t *, int);
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -3348,6 +3348,12 @@ qla24xx_update_fw_options(scsi_qla_host_
 			ha->fw_options[2] |= BIT_4;
 		else
 			ha->fw_options[2] &= ~BIT_4;
+
+		/* Reserve 1/2 of emergency exchanges for ELS.*/
+		if (qla2xuseresexchforels)
+			ha->fw_options[2] |= BIT_8;
+		else
+			ha->fw_options[2] &= ~BIT_8;
 	}
 
 	ql_dbg(ql_dbg_init, vha, 0x00e8,
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -277,6 +277,12 @@ MODULE_PARM_DESC(ql2xenablemsix,
 		 " 1 -- enable MSI-X interrupt mechanism.\n"
 		 " 2 -- enable MSI interrupt mechanism.\n");
 
+int qla2xuseresexchforels;
+module_param(qla2xuseresexchforels, int, 0444);
+MODULE_PARM_DESC(qla2xuseresexchforels,
+		 "Reserve 1/2 of emergency exchanges for ELS.\n"
+		 " 0 (default): disabled");
+
 /*
  * SCSI host template entry points
  */