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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (c) 2017 Sagi Grimberg.
- */
- #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
- * @map: CPU to hardware queue map.
- * @dev: rdma device to provide a mapping for.
- * @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.
- */
- void blk_mq_rdma_map_queues(struct blk_mq_queue_map *map,
- struct ib_device *dev, int first_vec)
- {
- const struct cpumask *mask;
- unsigned int queue, cpu;
- for (queue = 0; queue < map->nr_queues; queue++) {
- mask = ib_get_vector_affinity(dev, first_vec + queue);
- if (!mask)
- goto fallback;
- for_each_cpu(cpu, mask)
- map->mq_map[cpu] = map->queue_offset + queue;
- }
- return;
- fallback:
- blk_mq_map_queues(map);
- }
- EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);
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