blob: c3afbca1129956348389c3e6d26b1402c03fd6c3 [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/device.h>
#include <linux/blk-mq.h>
#include <linux/blk-mq-virtio.h>
#include <linux/virtio_config.h>
#include <linux/module.h>
#include "blk-mq.h"
* blk_mq_virtio_map_queues - provide a default queue mapping for virtio device
* @set: tagset to provide the mapping for
* @vdev: virtio device associated with @set.
* @first_vec: first interrupt vectors to use for queues (usually 0)
* This function assumes the virtio device @vdev 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_virtio_map_queues(struct blk_mq_tag_set *set,
struct virtio_device *vdev, int first_vec)
const struct cpumask *mask;
unsigned int queue, cpu;
if (!vdev->config->get_vq_affinity)
goto fallback;
for (queue = 0; queue < set->nr_hw_queues; queue++) {
mask = vdev->config->get_vq_affinity(vdev, first_vec + queue);
if (!mask)
goto fallback;
for_each_cpu(cpu, mask)
set->mq_map[cpu] = queue;
return 0;
return blk_mq_map_queues(set);