// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2016 Christoph Hellwig. */ #include <linux/kobject.h> #include <linux/blkdev.h> #include <linux/blk-mq.h> #include <linux/blk-mq-pci.h> #include <linux/pci.h> #include <linux/module.h> #include "blk-mq.h" /** * blk_mq_pci_map_queues - provide a default queue mapping for PCI device * @qmap: CPU to hardware queue map. * @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 * corresponding to each queue for it's affinity mask and built queue mapping * that maps a queue to the CPUs that have irq affinity for the corresponding * vector. */ int blk_mq_pci_map_queues(struct blk_mq_queue_map *qmap, struct pci_dev *pdev, int offset) { const struct cpumask *mask; unsigned int queue, cpu; for (queue = 0; queue < qmap->nr_queues; queue++) { mask = pci_irq_get_affinity(pdev, queue + offset); if (!mask) goto fallback; for_each_cpu(cpu, mask) qmap->mq_map[cpu] = qmap->queue_offset + queue; } return 0; fallback: WARN_ON_ONCE(qmap->nr_queues > 1); blk_mq_clear_mq_map(qmap); return 0; } EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);