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8c16567d | 1 | // SPDX-License-Identifier: GPL-2.0 |
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2 | /* |
3 | * Copyright (c) 2017 Sagi Grimberg. | |
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4 | */ |
5 | #include <linux/blk-mq.h> | |
6 | #include <linux/blk-mq-rdma.h> | |
7 | #include <rdma/ib_verbs.h> | |
8 | ||
9 | /** | |
10 | * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device | |
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11 | * @map: CPU to hardware queue map. |
12 | * @dev: rdma device to provide a mapping for. | |
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13 | * @first_vec: first interrupt vectors to use for queues (usually 0) |
14 | * | |
15 | * This function assumes the rdma device @dev has at least as many available | |
16 | * interrupt vetors as @set has queues. It will then query it's affinity mask | |
17 | * and built queue mapping that maps a queue to the CPUs that have irq affinity | |
18 | * for the corresponding vector. | |
19 | * | |
20 | * In case either the driver passed a @dev with less vectors than | |
21 | * @set->nr_hw_queues, or @dev does not provide an affinity mask for a | |
22 | * vector, we fallback to the naive mapping. | |
23 | */ | |
e42b3867 | 24 | int blk_mq_rdma_map_queues(struct blk_mq_queue_map *map, |
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25 | struct ib_device *dev, int first_vec) |
26 | { | |
27 | const struct cpumask *mask; | |
28 | unsigned int queue, cpu; | |
29 | ||
e42b3867 | 30 | for (queue = 0; queue < map->nr_queues; queue++) { |
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31 | mask = ib_get_vector_affinity(dev, first_vec + queue); |
32 | if (!mask) | |
33 | goto fallback; | |
34 | ||
35 | for_each_cpu(cpu, mask) | |
e42b3867 | 36 | map->mq_map[cpu] = map->queue_offset + queue; |
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37 | } |
38 | ||
39 | return 0; | |
40 | ||
41 | fallback: | |
e42b3867 | 42 | return blk_mq_map_queues(map); |
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43 | } |
44 | EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues); |