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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2016 Christoph Hellwig.4 */5#include <linux/kobject.h>6#include <linux/blkdev.h>7#include <linux/blk-mq-pci.h>8#include <linux/pci.h>9#include <linux/module.h>10 11#include "blk-mq.h"12 13/**14 * blk_mq_pci_map_queues - provide a default queue mapping for PCI device15 * @qmap: CPU to hardware queue map.16 * @pdev: PCI device associated with @set.17 * @offset: Offset to use for the pci irq vector18 *19 * This function assumes the PCI device @pdev has at least as many available20 * interrupt vectors as @set has queues. It will then query the vector21 * corresponding to each queue for it's affinity mask and built queue mapping22 * that maps a queue to the CPUs that have irq affinity for the corresponding23 * vector.24 */25void blk_mq_pci_map_queues(struct blk_mq_queue_map *qmap, struct pci_dev *pdev,26 int offset)27{28 const struct cpumask *mask;29 unsigned int queue, cpu;30 31 for (queue = 0; queue < qmap->nr_queues; queue++) {32 mask = pci_irq_get_affinity(pdev, queue + offset);33 if (!mask)34 goto fallback;35 36 for_each_cpu(cpu, mask)37 qmap->mq_map[cpu] = qmap->queue_offset + queue;38 }39 40 return;41 42fallback:43 WARN_ON_ONCE(qmap->nr_queues > 1);44 blk_mq_clear_mq_map(qmap);45}46EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);47