45 lines
1.3 KiB
C
45 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2017 Sagi Grimberg.
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*/
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#include <linux/blk-mq.h>
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#include <linux/blk-mq-rdma.h>
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#include <rdma/ib_verbs.h>
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/**
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* blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
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* @map: CPU to hardware queue map.
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* @dev: rdma device to provide a mapping for.
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* @first_vec: first interrupt vectors to use for queues (usually 0)
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*
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* This function assumes the rdma device @dev has at least as many available
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* interrupt vetors as @set has queues. It will then query it's affinity mask
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* and built queue mapping that maps a queue to the CPUs that have irq affinity
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* for the corresponding vector.
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*
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* In case either the driver passed a @dev with less vectors than
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* @set->nr_hw_queues, or @dev does not provide an affinity mask for a
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* vector, we fallback to the naive mapping.
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*/
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void blk_mq_rdma_map_queues(struct blk_mq_queue_map *map,
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struct ib_device *dev, int first_vec)
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{
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const struct cpumask *mask;
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unsigned int queue, cpu;
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for (queue = 0; queue < map->nr_queues; queue++) {
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mask = ib_get_vector_affinity(dev, first_vec + queue);
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if (!mask)
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goto fallback;
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for_each_cpu(cpu, mask)
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map->mq_map[cpu] = map->queue_offset + queue;
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}
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return;
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fallback:
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blk_mq_map_queues(map);
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}
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EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);
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