/* * Copyright (c) 2017 Sagi Grimberg. * * 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-rdma.h> #include <rdma/ib_verbs.h> /** * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device * @set: tagset to provide the mapping for * @dev: rdma device associated with @set. * @first_vec: first interrupt vectors to use for queues (usually 0) * * This function assumes the rdma device @dev has at least as many available * interrupt vetors as @set has queues. It will then query it's affinity mask * and built queue mapping that maps a queue to the CPUs that have irq affinity * for the corresponding vector. * * In case either the driver passed a @dev with less vectors than * @set->nr_hw_queues, or @dev does not provide an affinity mask for a * vector, we fallback to the naive mapping. */ int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set, struct ib_device *dev, int first_vec) { const struct cpumask *mask; unsigned int queue, cpu; for (queue = 0; queue < set->nr_hw_queues; queue++) { mask = ib_get_vector_affinity(dev, first_vec + queue); if (!mask) goto fallback; for_each_cpu(cpu, mask) set->mq_map[cpu] = queue; } return 0; fallback: return blk_mq_map_queues(set); } EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);