From: Mike McGowen <Mike.McGowen@microchip.com>
Date: Tue, 1 Feb 2022 15:48:48 -0600
Subject: scsi: smartpqi: Speed up RAID 10 sequential reads
Patch-mainline: v5.18-rc1
Git-commit: 5d8fbce04d36dfd837d655e3d1b66e44b8fafbe5
References: jsc#PED-1557

Use all data disks for sequential read operations.

Testing discovered inconsistent performance on RAID 10 volumes when
performing 256K sequential reads. The driver was only using a single
tracker to determine which physical drive to send a request to for AIO
requests.

Change the single tracker (next_bypass_group) to an array of trackers based
on the number of data disks in a row of the RAID map.

Link: https://lore.kernel.org/r/164375212842.440833.6733971458765002128.stgit@brunhilda.pdev.net
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Signed-off-by: Mike McGowen <Mike.McGowen@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Martin Wilck <mwilck@suse.com>
---
 drivers/scsi/smartpqi/smartpqi.h      |    5 +++--
 drivers/scsi/smartpqi/smartpqi_init.c |    6 +++---
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/scsi/smartpqi/smartpqi.h
+++ b/drivers/scsi/smartpqi/smartpqi.h
@@ -918,7 +918,8 @@ union pqi_reset_register {
 #define PQI_MAX_TRANSFER_SIZE			(1024U * 1024U)
 #define PQI_MAX_TRANSFER_SIZE_KDUMP		(512 * 1024U)
 
-#define RAID_MAP_MAX_ENTRIES		1024
+#define RAID_MAP_MAX_ENTRIES			1024
+#define RAID_MAP_MAX_DATA_DISKS_PER_ROW		128
 
 #define PQI_PHYSICAL_DEVICE_BUS		0
 #define PQI_RAID_VOLUME_BUS		1
@@ -1125,7 +1126,7 @@ struct pqi_scsi_dev {
 	u8	ncq_prio_support;
 	bool	raid_bypass_configured;	/* RAID bypass configured */
 	bool	raid_bypass_enabled;	/* RAID bypass enabled */
-	u32	next_bypass_group;
+	u32	next_bypass_group[RAID_MAP_MAX_DATA_DISKS_PER_ROW];
 	struct raid_map *raid_map;	/* RAID bypass map */
 	u32	max_transfer_encrypted;
 
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -2058,7 +2058,7 @@ static void pqi_scsi_update_device(struc
 		sizeof(existing_device->box));
 	memcpy(existing_device->phys_connector, new_device->phys_connector,
 		sizeof(existing_device->phys_connector));
-	existing_device->next_bypass_group = 0;
+	memset(existing_device->next_bypass_group, 0, sizeof(existing_device->next_bypass_group));
 	kfree(existing_device->raid_map);
 	existing_device->raid_map = new_device->raid_map;
 	existing_device->raid_bypass_configured =
@@ -2963,11 +2963,11 @@ static int pqi_raid_bypass_submit_scsi_c
 		if (rmd.is_write) {
 			pqi_calc_aio_r1_nexus(raid_map, &rmd);
 		} else {
-			group = device->next_bypass_group;
+			group = device->next_bypass_group[rmd.map_index];
 			next_bypass_group = group + 1;
 			if (next_bypass_group >= rmd.layout_map_count)
 				next_bypass_group = 0;
-			device->next_bypass_group = next_bypass_group;
+			device->next_bypass_group[rmd.map_index] = next_bypass_group;
 			rmd.map_index += group * rmd.data_disks_per_row;
 		}
 	} else if ((device->raid_level == SA_RAID_5 ||