blob: 76944e3271bf34a730e62fa0b27266abce86942e [file] [log] [blame]
* Copyright (c) 2016 Christoph Hellwig.
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
#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>
* 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.
* 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_tag_set *set, struct pci_dev *pdev)
const struct cpumask *mask;
unsigned int queue, cpu;
for (queue = 0; queue < set->nr_hw_queues; queue++) {
mask = pci_irq_get_affinity(pdev, queue);
if (!mask)
goto fallback;
for_each_cpu(cpu, mask)
set->mq_map[cpu] = queue;
return 0;
WARN_ON_ONCE(set->nr_hw_queues > 1);
set->mq_map[cpu] = 0;
return 0;