Commit 664f0dce authored by Sreekanth Reddy's avatar Sreekanth Reddy Committed by Martin K. Petersen
Browse files

scsi: mpt3sas: Add support for shared host tagset for CPU hotplug 

MPT Fusion adapters can steer completions to individual queues and we now
have support for shared host-wide tags in the I/O stack. The addition of
the host-wide tags allows us to enable multiqueue support for MPT Fusion
adapters. Once host-wise tags are enabled, the CPU hotplug feature is also
supported.

Allow use of host-wide tags to be disabled through the "host_tagset_enable"
module parameter. Once we do not have any major performance regressions
using host-wide tags, we will drop the hand-crafted interrupt affinity
settings.

Performance is meeting expectations. About 3.1M IOPS using 24 Drive SSD on
Aero controllers.

Link: https://lore.kernel.org/r/20210202095832.23072-1-sreekanth.reddy@broadcom.com


Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarSreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d309ae07

drivers/scsi/mpt3sas/mpt3sas_base.c

+33 −17
Original line number Diff line number Diff line
@@ -3648,24 +3648,15 @@ _base_get_msix_index(struct MPT3SAS_ADAPTER *ioc, 
		    base_mod64(atomic64_add_return(1,

		    &ioc->total_io_cnt), ioc->reply_queue_count) : 0;



	return ioc->cpu_msix_table[raw_smp_processor_id()];

}

	if (scmd && ioc->shost->nr_hw_queues > 1) {

		u32 tag = blk_mq_unique_tag(scmd->request);



/**

 * _base_sdev_nr_inflight_request -get number of inflight requests

 *				   of a request queue.

 * @q: request_queue object

 *

 * returns number of inflight request of a request queue.

 */

inline unsigned long

_base_sdev_nr_inflight_request(struct request_queue *q)

{

	struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[0];



	return atomic_read(&hctx->nr_active);

		return blk_mq_unique_tag_to_hwq(tag) +

			ioc->high_iops_queues;

	}



	return ioc->cpu_msix_table[raw_smp_processor_id()];

}



/**

 * _base_get_high_iops_msix_index - get the msix index of
@@ -3686,7 +3677,8 @@ _base_get_high_iops_msix_index(struct MPT3SAS_ADAPTER *ioc, 
	 * reply queues in terms of batch count 16 when outstanding

	 * IOs on the target device is >=8.

	 */

	if (_base_sdev_nr_inflight_request(scmd->device->request_queue) >



	if (atomic_read(&scmd->device->device_busy) >

	    MPT3SAS_DEVICE_HIGH_IOPS_DEPTH)

		return base_mod64((

		    atomic64_add_return(1, &ioc->high_iops_outstanding) /
@@ -3739,8 +3731,23 @@ mpt3sas_base_get_smid_scsiio(struct MPT3SAS_ADAPTER *ioc, u8 cb_idx, 
	struct scsi_cmnd *scmd)

{

	struct scsiio_tracker *request = scsi_cmd_priv(scmd);

	unsigned int tag = scmd->request->tag;

	u16 smid;

	u32 tag, unique_tag;



	unique_tag = blk_mq_unique_tag(scmd->request);

	tag = blk_mq_unique_tag_to_tag(unique_tag);



	/*

	 * Store hw queue number corresponding to the tag.

	 * This hw queue number is used later to determine

	 * the unique_tag using the logic below. This unique_tag

	 * is used to retrieve the scmd pointer corresponding

	 * to tag using scsi_host_find_tag() API.

	 *

	 * tag = smid - 1;

	 * unique_tag = ioc->io_queue_num[tag] << BLK_MQ_UNIQUE_TAG_BITS | tag;

	 */

	ioc->io_queue_num[tag] = blk_mq_unique_tag_to_hwq(unique_tag);



	smid = tag + 1;

	request->cb_idx = cb_idx;
@@ -3831,6 +3838,7 @@ mpt3sas_base_free_smid(struct MPT3SAS_ADAPTER *ioc, u16 smid) 


		mpt3sas_base_clear_st(ioc, st);

		_base_recovery_check(ioc);

		ioc->io_queue_num[smid - 1] = 0;

		return;

	}
@@ -5362,6 +5370,9 @@ _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc) 
		kfree(ioc->chain_lookup);

		ioc->chain_lookup = NULL;

	}



	kfree(ioc->io_queue_num);

	ioc->io_queue_num = NULL;

}



/**
@@ -5773,6 +5784,11 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc) 
		    ioc_info(ioc, "internal(0x%p): depth(%d), start smid(%d)\n",

			     ioc->internal,

			     ioc->internal_depth, ioc->internal_smid));



	ioc->io_queue_num = kcalloc(ioc->scsiio_depth,

	    sizeof(u16), GFP_KERNEL);

	if (!ioc->io_queue_num)

		goto out;

	/*

	 * The number of NVMe page sized blocks needed is:

	 *     (((sg_tablesize * 8) - 1) / (page_size - 8)) + 1

drivers/scsi/mpt3sas/mpt3sas_base.h

+1 −0
Original line number Diff line number Diff line
@@ -1439,6 +1439,7 @@ struct MPT3SAS_ADAPTER { 
	spinlock_t	scsi_lookup_lock;

	int		pending_io_count;

	wait_queue_head_t reset_wq;

	u16		*io_queue_num;



	/* PCIe SGL */

	struct dma_pool *pcie_sgl_dma_pool;

drivers/scsi/mpt3sas/mpt3sas_scsih.c

+41 −1
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/interrupt.h>

#include <linux/aer.h>

#include <linux/raid_class.h>

#include <linux/blk-mq-pci.h>

#include <asm/unaligned.h>



#include "mpt3sas_base.h"
@@ -168,6 +169,11 @@ MODULE_PARM_DESC(multipath_on_hba, 
	"\t SAS 2.0 & SAS 3.0 HBA - This will be disabled,\n\t\t"

	"\t SAS 3.5 HBA - This will be enabled)");



static 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)");



/* raid transport support */

static struct raid_template *mpt3sas_raid_template;

static struct raid_template *mpt2sas_raid_template;
@@ -1743,10 +1749,12 @@ mpt3sas_scsih_scsi_lookup_get(struct MPT3SAS_ADAPTER *ioc, u16 smid) 
	struct scsi_cmnd *scmd = NULL;

	struct scsiio_tracker *st;

	Mpi25SCSIIORequest_t *mpi_request;

	u16 tag = smid - 1;



	if (smid > 0  &&

	    smid <= ioc->scsiio_depth - INTERNAL_SCSIIO_CMDS_COUNT) {

		u32 unique_tag = smid - 1;

		u32 unique_tag =

		    ioc->io_queue_num[tag] << BLK_MQ_UNIQUE_TAG_BITS | tag;



		mpi_request = mpt3sas_base_get_msg_frame(ioc, smid);
@@ -11599,6 +11607,22 @@ scsih_scan_finished(struct Scsi_Host *shost, unsigned long time) 
	return 1;

}



/**

 * scsih_map_queues - map reply queues with request queues

 * @shost: SCSI host pointer

 */

static int scsih_map_queues(struct Scsi_Host *shost)

{

	struct MPT3SAS_ADAPTER *ioc =

	    (struct MPT3SAS_ADAPTER *)shost->hostdata;



	if (ioc->shost->nr_hw_queues == 1)

		return 0;



	return blk_mq_pci_map_queues(&shost->tag_set.map[HCTX_TYPE_DEFAULT],

	    ioc->pdev, ioc->high_iops_queues);

}



/* shost template for SAS 2.0 HBA devices */

static struct scsi_host_template mpt2sas_driver_template = {

	.module				= THIS_MODULE,
@@ -11666,6 +11690,7 @@ static struct scsi_host_template mpt3sas_driver_template = { 
	.sdev_attrs			= mpt3sas_dev_attrs,

	.track_queue_depth		= 1,

	.cmd_size			= sizeof(struct scsiio_tracker),

	.map_queues			= scsih_map_queues,

};



/* raid transport support for SAS 3.0 HBA devices */
@@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	} else

		ioc->hide_drives = 0;



	shost->host_tagset = 0;

	shost->nr_hw_queues = 1;



	if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&

	    host_tagset_enable && ioc->smp_affinity_enable) {



		shost->host_tagset = 1;

		shost->nr_hw_queues =

		    ioc->reply_queue_count - ioc->high_iops_queues;



		dev_info(&ioc->pdev->dev,

		    "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",

		    shost->can_queue, shost->nr_hw_queues);

	}



	rv = scsi_add_host(shost, &pdev->dev);

	if (rv) {

		ioc_err(ioc, "failure at %s:%d/%s()!\n",