blk-mq: Allow PCI vector offset for mapping queues

The PCI interrupt vectors intended to be associated with a queue may
not start at 0; a driver may allocate pre_vectors for special use. This
patch adds an offset parameter so blk-mq may find the intended affinity
mask and updates all drivers using this API accordingly.

Cc: Don Brace <don.brace@microsemi.com>
Cc: <qla2xxx-upstream@qlogic.com>
Cc: <linux-scsi@vger.kernel.org>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-pci.c

@@ -21,6 +21,7 @@
  * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
  * @set:	tagset to provide the mapping for
  * @pdev:	PCI device associated with @set.
+ * @offset:	Offset to use for the pci irq vector
  *
  * This function assumes the PCI device @pdev has at least as many available
  * interrupt vectors as @set has queues.  It will then query the vector
@@ -28,13 +29,14 @@
  * that maps a queue to the CPUs that have irq affinity for the corresponding
  * vector.
  */
-int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+			    int offset)
 {
 	const struct cpumask *mask;
 	unsigned int queue, cpu;
 
 	for (queue = 0; queue < set->nr_hw_queues; queue++) {
-		mask = pci_irq_get_affinity(pdev, queue);
+		mask = pci_irq_get_affinity(pdev, queue + offset);
 		if (!mask)
 			goto fallback;
 

drivers/nvme/host/pci.c

@@ -414,7 +414,7 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
 {
 	struct nvme_dev *dev = set->driver_data;
 
-	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev));
+	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev), 0);
 }
 
 /**

drivers/scsi/qla2xxx/qla_os.c

@@ -6805,7 +6805,7 @@ static int qla2xxx_map_queues(struct Scsi_Host *shost)
 	if (USER_CTRL_IRQ(vha->hw))
 		rc = blk_mq_map_queues(&shost->tag_set);
 	else
-		rc = blk_mq_pci_map_queues(&shost->tag_set, vha->hw->pdev);
+		rc = blk_mq_pci_map_queues(&shost->tag_set, vha->hw->pdev, 0);
 	return rc;
 }
 

drivers/scsi/smartpqi/smartpqi_init.c

@@ -5348,7 +5348,7 @@ static int pqi_map_queues(struct Scsi_Host *shost)
 {
 	struct pqi_ctrl_info *ctrl_info = shost_to_hba(shost);
 
-	return blk_mq_pci_map_queues(&shost->tag_set, ctrl_info->pci_dev);
+	return blk_mq_pci_map_queues(&shost->tag_set, ctrl_info->pci_dev, 0);
 }
 
 static int pqi_getpciinfo_ioctl(struct pqi_ctrl_info *ctrl_info,

include/linux/blk-mq-pci.h

@@ -5,6 +5,7 @@
 struct blk_mq_tag_set;
 struct pci_dev;
 
-int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+			  int offset);
 
 #endif /* _LINUX_BLK_MQ_PCI_H */