// 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);