// SPDX-License-Identifier: GPL-2.0
|
/*
|
* Copyright (c) 2016 Christoph Hellwig.
|
*/
|
#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
|
* @qmap: CPU to hardware queue map.
|
* @vdev: virtio device to provide a mapping for.
|
* @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 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_virtio_map_queues(struct blk_mq_queue_map *qmap,
|
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 < qmap->nr_queues; queue++) {
|
mask = vdev->config->get_vq_affinity(vdev, first_vec + queue);
|
if (!mask)
|
goto fallback;
|
|
for_each_cpu(cpu, mask)
|
qmap->mq_map[cpu] = qmap->queue_offset + queue;
|
}
|
|
return 0;
|
fallback:
|
return blk_mq_map_queues(qmap);
|
}
|
EXPORT_SYMBOL_GPL(blk_mq_virtio_map_queues);
|
|
MODULE_DESCRIPTION("Virtio Device Default Queue Mapping");
|
MODULE_LICENSE("GPL v2");
|
