megaraid_sas: task management code optimizations

This patch will do code optmization for task management functions.
Below are key changes:

1. Remove reset_device hook as it was not being used and driver was
setting this to NULL.

2. Create wrapper functions for task abort and target reset and inside
   these functions adapter specific calls be made. e.g. fusion adapters
   support task abort and target reset so task abort and target reset
   should be issued to fusion adapters only and for MFI adapters, print
   a message saying feature not supported.
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -2670,33 +2670,66 @@ blk_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
 }
 
 /**
- * megasas_reset_device -	Device reset handler entry point
+ * megasas_reset_bus_host -	Bus & host reset handler entry point
  */
-static int megasas_reset_device(struct scsi_cmnd *scmd)
+static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
 {
+	int ret;
+	struct megasas_instance *instance;
+
+	instance = (struct megasas_instance *)scmd->device->host->hostdata;
+
 	/*
 	 * First wait for all commands to complete
 	 */
-	return megasas_generic_reset(scmd);
+	if (instance->ctrl_context)
+		ret = megasas_reset_fusion(scmd->device->host, 1);
+	else
+		ret = megasas_generic_reset(scmd);
+
+	return ret;
 }
 
 /**
- * megasas_reset_bus_host -	Bus & host reset handler entry point
+ * megasas_task_abort - Issues task abort request to firmware
+ *			(supported only for fusion adapters)
+ * @scmd:		SCSI command pointer
  */
-static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
+static int megasas_task_abort(struct scsi_cmnd *scmd)
 {
 	int ret;
 	struct megasas_instance *instance;
 
 	instance = (struct megasas_instance *)scmd->device->host->hostdata;
 
-	/*
-	 * First wait for all commands to complete
+	if (instance->ctrl_context)
+		ret = megasas_task_abort_fusion(scmd);
+	else {
+		sdev_printk(KERN_NOTICE, scmd->device, "TASK ABORT not supported\n");
+		ret = FAILED;
+	}
+
+	return ret;
+}
+
+/**
+ * megasas_reset_target:  Issues target reset request to firmware
+ *                        (supported only for fusion adapters)
+ * @scmd:                 SCSI command pointer
  */
+static int megasas_reset_target(struct scsi_cmnd *scmd)
+{
+	int ret;
+	struct megasas_instance *instance;
+
+	instance = (struct megasas_instance *)scmd->device->host->hostdata;
+
 	if (instance->ctrl_context)
-		ret = megasas_reset_fusion(scmd->device->host, 1);
-	else
-		ret = megasas_generic_reset(scmd);
+		ret = megasas_reset_target_fusion(scmd);
+	else {
+		sdev_printk(KERN_NOTICE, scmd->device, "TARGET RESET not supported\n");
+		ret = FAILED;
+	}
 
 	return ret;
 }
@@ -2969,8 +3002,8 @@ static struct scsi_host_template megasas_template = {
 	.slave_alloc = megasas_slave_alloc,
 	.slave_destroy = megasas_slave_destroy,
 	.queuecommand = megasas_queue_command,
-	.eh_device_reset_handler = megasas_reset_device,
-	.eh_bus_reset_handler = megasas_reset_bus_host,
+	.eh_target_reset_handler = megasas_reset_target,
+	.eh_abort_handler = megasas_task_abort,
 	.eh_host_reset_handler = megasas_reset_bus_host,
 	.eh_timed_out = megasas_reset_timer,
 	.shost_attrs = megaraid_host_attrs,
@@ -5598,14 +5631,6 @@ static int megasas_io_attach(struct megasas_instance *instance)
 	host->max_lun = MEGASAS_MAX_LUN;
 	host->max_cmd_len = 16;
 
-	/* Fusion only supports host reset */
-	if (instance->ctrl_context) {
-		host->hostt->eh_device_reset_handler = NULL;
-		host->hostt->eh_bus_reset_handler = NULL;
-		host->hostt->eh_target_reset_handler = megasas_reset_target_fusion;
-		host->hostt->eh_abort_handler = megasas_task_abort_fusion;
-	}
-
 	/*
 	 * Notify the mid-layer about the new controller
 	 */