[RFC PATCH v2 17/19] scsi: megaraid_sas: Add param to control target based error handle

[Wenchao Hao <haowenchao2@huawei.com>]

Add new param target_eh to control if enable target based error
handler, since megaraid_sas did not define callback eh_device_reset,
so only target based error handler is enabled; and megaraid_sas
defined eh_host_reset, so make it fallback to further recover
when target based recovery can not recover all error commands.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 drivers/scsi/megaraid/megaraid_sas_base.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 050eed8e2684..cc00cd5b213d 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -45,6 +45,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_dbg.h>
+#include <scsi/scsi_eh.h>
 #include "megaraid_sas_fusion.h"
 #include "megaraid_sas.h"
 
@@ -127,6 +128,10 @@ int host_tagset_enable = 1;
 module_param(host_tagset_enable, int, 0444);
 MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disable Default: enable(1)");
 
+static bool target_eh;
+module_param(target_eh, bool, 0444);
+MODULE_PARM_DESC(target_eh, "target based error handle (def=0)");
+
 MODULE_LICENSE("GPL");
 MODULE_VERSION(MEGASAS_VERSION);
 MODULE_AUTHOR("megaraidlinux.pdl@broadcom.com");
@@ -2174,6 +2179,19 @@ static void megasas_slave_destroy(struct scsi_device *sdev)
 	sdev->hostdata = NULL;
 }
 
+static int megasas_target_alloc(struct scsi_target *starget)
+{
+	if (target_eh)
+		return scsi_target_setup_eh(starget, 1);
+	return 0;
+}
+
+static void megasas_target_destroy(struct scsi_target *starget)
+{
+	if (target_eh)
+		scsi_target_clear_eh(starget);
+}
+
 /*
 * megasas_complete_outstanding_ioctls - Complete outstanding ioctls after a
 *                                       kill adapter
@@ -3525,6 +3543,8 @@ static const struct scsi_host_template megasas_template = {
 	.change_queue_depth = scsi_change_queue_depth,
 	.max_segment_size = 0xffffffff,
 	.cmd_size = sizeof(struct megasas_cmd_priv),
+	.target_alloc = megasas_target_alloc,
+	.target_destroy = megasas_target_destroy,
 };
 
 /**
-- 
2.35.3