scsi: qla2xxx: Add Block Multi Queue functionality.

Orabug: 25477809

Tell the SCSI layer how many hardware queues we have based on the number
of max queue pairs created. The number of max queue pairs created will
depend on number of MSI-X vector count.

This feature can be turned on via CONFIG_SCSI_MQ_DEFAULT or passing
scsi_mod.use_blk_mq=Y as a parameter to the kernel

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Sawan Chandak <sawan.chandak@cavium.com>
Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 6c657167a3b485d2781438e92cf20b6ced997e78..034c61c5bfe997b0027add03c995b1546c5a6f7b 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -721,11 +721,21 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
        struct scsi_qla_host *base_vha = pci_get_drvdata(ha->pdev);
        srb_t *sp;
        int rval;
-       struct qla_qpair *qpair;
+       struct qla_qpair *qpair = NULL;
+       uint32_t tag;
+       uint16_t hwq;
 
-       if (vha->vp_idx && vha->qpair) {
-               qpair = vha->qpair;
-               return qla2xxx_mqueuecommand(host, cmd, qpair);
+       if (ha->mqenable) {
+               if (shost_use_blk_mq(vha->host)) {
+                       tag = blk_mq_unique_tag(cmd->request);
+                       hwq = blk_mq_unique_tag_to_hwq(tag);
+                       qpair = ha->queue_pair_map[hwq];
+               } else if (vha->vp_idx && vha->qpair) {
+                       qpair = vha->qpair;
+               }
+
+               if (qpair)
+                       return qla2xxx_mqueuecommand(host, cmd, qpair);
        }
 
        if (ha->flags.eeh_busy) {
@@ -2473,6 +2483,8 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
        uint16_t req_length = 0, rsp_length = 0;
        struct req_que *req = NULL;
        struct rsp_que *rsp = NULL;
+       int cpu_id;
+       cpumask_t cpu_mask;
 
        bars = pci_select_bars(pdev, IORESOURCE_MEM | IORESOURCE_IO);
        sht = &qla2xxx_driver_template;
@@ -2834,6 +2846,17 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
                goto probe_init_failed;
        }
 
+       if (ha->mqenable && shost_use_blk_mq(host)) {
+               /* number of hardware queues supported by blk/scsi-mq*/
+               host->nr_hw_queues = ha->max_qpairs;
+
+               ql_dbg(ql_dbg_init, base_vha, 0x0192,
+                       "blk/scsi-mq enabled, HW queues = %d.\n",
+                               host->nr_hw_queues);
+       } else
+               ql_dbg(ql_dbg_init, base_vha, 0x0193,
+                       "blk/scsi-mq disabled.\n");
+
        qlt_probe_one_stage1(base_vha, ha);
 
        pci_save_state(pdev);
@@ -2928,6 +2951,15 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
        if (ha->mqenable) {
                base_vha->qps_hint = alloc_percpu(struct qla_percpu_qp_hint);
                ha->wq = alloc_workqueue("qla2xxx_wq", WQ_MEM_RECLAIM, 1);
+               /* Create start of day qpairs for Block MQ */
+               if (shost_use_blk_mq(host)) {
+                       cpumask_clear(&cpu_mask);
+                       for (cpu_id = 0; cpu_id < ha->max_qpairs; cpu_id++) {
+                               cpumask_set_cpu(cpu_id, &cpu_mask);
+                               qla2xxx_create_qpair(base_vha, &cpu_mask, 5, 0);
+                               cpumask_clear_cpu(cpu_id, &cpu_mask);
+                       }
+               }
        }
        if (ha->flags.running_gold_fw)
                goto skip_dpc;