scsi: hisi_sas: Select a suitable queue for internal I/Os

For when managed interrupts are used (and shost->nr_hw_queues is set), a
fixed queue - set per-device - is still used for internal I/Os.

If all the CPUs mapped to that queue are offlined, then the completions for
that queue are not serviced and any internal I/Os will time out.

Fix by selecting a queue for internal I/Os from the queue mapped from the
current CPU in this scenario.

This is still not ideal as it does not deal with CPU hotplug for inflight
internal I/Os, and needs proper support from [0].

[0] https://lore.kernel.org/linux-scsi/20200703130122.111448-1-hare@suse.de/T/#m7d77d049b18f33a24ef206af69ebb66d07440556

Link: https://lore.kernel.org/r/1607347855-59091-1-git-send-email-john.garry@huawei.com
Fixes: 8d98416a ("scsi: hisi_sas: Switch v3 hw to MQ")
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -452,6 +452,12 @@ static int hisi_sas_task_prep(struct sas_task *task,
 		blk_tag = blk_mq_unique_tag(scmd->request);
 		dq_index = blk_mq_unique_tag_to_hwq(blk_tag);
 		*dq_pointer = dq = &hisi_hba->dq[dq_index];
+	} else if (hisi_hba->shost->nr_hw_queues)  {
+		struct Scsi_Host *shost = hisi_hba->shost;
+		struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
+		int queue = qmap->mq_map[raw_smp_processor_id()];
+
+		*dq_pointer = dq = &hisi_hba->dq[queue];
 	} else {
 		*dq_pointer = dq = sas_dev->dq;
 	}

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -2452,6 +2452,11 @@ static int interrupt_init_v3_hw(struct hisi_hba *hisi_hba)
 			rc = -ENOENT;
 			goto free_irq_vectors;
 		}
+		cq->irq_mask = pci_irq_get_affinity(pdev, i + BASE_VECTORS_V3_HW);
+		if (!cq->irq_mask) {
+			dev_err(dev, "could not get cq%d irq affinity!\n", i);
+			return -ENOENT;
+		}
 	}
 
 	return 0;