scsi: megaraid_sas: Use Block layer API to check SCSI device in-flight IO requests

Remove usage of device_busy counter from driver. Instead of device_busy
counter now driver uses 'nr_active' counter of request_queue to get the
number of inflight request for a LUN.

Link: https://lore.kernel.org/r/1579000882-20246-11-git-send-email-anand.lodnoor@broadcom.com
Link : https://patchwork.kernel.org/patch/11249297/Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Anand Lodnoor <anand.lodnoor@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas_fusion.c

@@ -364,6 +364,35 @@ megasas_fusion_update_can_queue(struct megasas_instance *instance, int fw_boot_c
 		instance->max_fw_cmds = instance->max_fw_cmds-1;
 	}
 }
+
+static inline void
+megasas_get_msix_index(struct megasas_instance *instance,
+		       struct scsi_cmnd *scmd,
+		       struct megasas_cmd_fusion *cmd,
+		       u8 data_arms)
+{
+	int sdev_busy;
+
+	/* nr_hw_queue = 1 for MegaRAID */
+	struct blk_mq_hw_ctx *hctx =
+		scmd->device->request_queue->queue_hw_ctx[0];
+
+	sdev_busy = atomic_read(&hctx->nr_active);
+
+	if (instance->perf_mode == MR_BALANCED_PERF_MODE &&
+	    sdev_busy > (data_arms * MR_DEVICE_HIGH_IOPS_DEPTH))
+		cmd->request_desc->SCSIIO.MSIxIndex =
+			mega_mod64((atomic64_add_return(1, &instance->high_iops_outstanding) /
+					MR_HIGH_IOPS_BATCH_COUNT), instance->low_latency_index_start);
+	else if (instance->msix_load_balance)
+		cmd->request_desc->SCSIIO.MSIxIndex =
+			(mega_mod64(atomic64_add_return(1, &instance->total_io_count),
+				instance->msix_vectors));
+	else
+		cmd->request_desc->SCSIIO.MSIxIndex =
+			instance->reply_map[raw_smp_processor_id()];
+}
+
 /**
  * megasas_free_cmds_fusion -	Free all the cmds in the free cmd pool
  * @instance:		Adapter soft state
@@ -2829,19 +2858,7 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 			fp_possible = (io_info.fpOkForIo > 0) ? true : false;
 	}
 
-	if ((instance->perf_mode == MR_BALANCED_PERF_MODE) &&
-		atomic_read(&scp->device->device_busy) >
-		(io_info.data_arms * MR_DEVICE_HIGH_IOPS_DEPTH))
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			mega_mod64((atomic64_add_return(1, &instance->high_iops_outstanding) /
-				MR_HIGH_IOPS_BATCH_COUNT), instance->low_latency_index_start);
-	else if (instance->msix_load_balance)
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			(mega_mod64(atomic64_add_return(1, &instance->total_io_count),
-				    instance->msix_vectors));
-	else
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			instance->reply_map[raw_smp_processor_id()];
+	megasas_get_msix_index(instance, scp, cmd, io_info.data_arms);
 
 	if (instance->adapter_type >= VENTURA_SERIES) {
 		/* FP for Optimal raid level 1.
@@ -3162,18 +3179,7 @@ megasas_build_syspd_fusion(struct megasas_instance *instance,
 
 	cmd->request_desc->SCSIIO.DevHandle = io_request->DevHandle;
 
-	if ((instance->perf_mode == MR_BALANCED_PERF_MODE) &&
-		atomic_read(&scmd->device->device_busy) > MR_DEVICE_HIGH_IOPS_DEPTH)
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			mega_mod64((atomic64_add_return(1, &instance->high_iops_outstanding) /
-				MR_HIGH_IOPS_BATCH_COUNT), instance->low_latency_index_start);
-	else if (instance->msix_load_balance)
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			(mega_mod64(atomic64_add_return(1, &instance->total_io_count),
-				    instance->msix_vectors));
-	else
-		cmd->request_desc->SCSIIO.MSIxIndex =
-			instance->reply_map[raw_smp_processor_id()];
+	megasas_get_msix_index(instance, scmd, cmd, 1);
 
 	if (!fp_possible) {
 		/* system pd firmware path */