Commit 973c4e37 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe

blk-mq: provide a default queue mapping for PCI device

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent da695ba2
......@@ -22,4 +22,4 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o
obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
obj-$(CONFIG_PCI) += blk-mq-pci.o
/*
* 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/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 vetors as @set has queues. It will then queuery 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)
return -EINVAL;
for_each_cpu(cpu, mask)
set->mq_map[cpu] = queue;
}
return 0;
}
EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
#ifndef _LINUX_BLK_MQ_PCI_H
#define _LINUX_BLK_MQ_PCI_H
struct blk_mq_tag_set;
struct pci_dev;
int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
#endif /* _LINUX_BLK_MQ_PCI_H */
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