kernel_optimize_test/block/blk-mq-pci.c
Christoph Hellwig 973c4e372c blk-mq: provide a default queue mapping for PCI device
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15 08:42:03 -06:00

46 lines
1.4 KiB
C

/*
* 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);