Commit | Line | Data |
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3dcf60bc | 1 | // SPDX-License-Identifier: GPL-2.0 |
75bb4625 JA |
2 | /* |
3 | * CPU <-> hardware queue mapping helpers | |
4 | * | |
5 | * Copyright (C) 2013-2014 Jens Axboe | |
6 | */ | |
320ae51f JA |
7 | #include <linux/kernel.h> |
8 | #include <linux/threads.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/smp.h> | |
12 | #include <linux/cpu.h> | |
13 | ||
14 | #include <linux/blk-mq.h> | |
15 | #include "blk.h" | |
16 | #include "blk-mq.h" | |
17 | ||
843477d4 JA |
18 | static int cpu_to_queue_index(struct blk_mq_queue_map *qmap, |
19 | unsigned int nr_queues, const int cpu) | |
320ae51f | 20 | { |
843477d4 | 21 | return qmap->queue_offset + (cpu % nr_queues); |
320ae51f JA |
22 | } |
23 | ||
24 | static int get_first_sibling(unsigned int cpu) | |
25 | { | |
26 | unsigned int ret; | |
27 | ||
06931e62 | 28 | ret = cpumask_first(topology_sibling_cpumask(cpu)); |
320ae51f JA |
29 | if (ret < nr_cpu_ids) |
30 | return ret; | |
31 | ||
32 | return cpu; | |
33 | } | |
34 | ||
ed76e329 | 35 | int blk_mq_map_queues(struct blk_mq_queue_map *qmap) |
320ae51f | 36 | { |
ed76e329 JA |
37 | unsigned int *map = qmap->mq_map; |
38 | unsigned int nr_queues = qmap->nr_queues; | |
fe631457 | 39 | unsigned int cpu, first_sibling; |
320ae51f | 40 | |
fe631457 | 41 | for_each_possible_cpu(cpu) { |
320ae51f | 42 | /* |
fe631457 MG |
43 | * First do sequential mapping between CPUs and queues. |
44 | * In case we still have CPUs to map, and we have some number of | |
ef025d7e BVA |
45 | * threads per cores then map sibling threads to the same queue |
46 | * for performance optimizations. | |
320ae51f | 47 | */ |
fe631457 | 48 | if (cpu < nr_queues) { |
843477d4 | 49 | map[cpu] = cpu_to_queue_index(qmap, nr_queues, cpu); |
fe631457 MG |
50 | } else { |
51 | first_sibling = get_first_sibling(cpu); | |
52 | if (first_sibling == cpu) | |
843477d4 | 53 | map[cpu] = cpu_to_queue_index(qmap, nr_queues, cpu); |
fe631457 MG |
54 | else |
55 | map[cpu] = map[first_sibling]; | |
320ae51f | 56 | } |
320ae51f JA |
57 | } |
58 | ||
320ae51f JA |
59 | return 0; |
60 | } | |
9e5a7e22 | 61 | EXPORT_SYMBOL_GPL(blk_mq_map_queues); |
320ae51f | 62 | |
cd669f88 BVA |
63 | /** |
64 | * blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index | |
65 | * @qmap: CPU to hardware queue map. | |
66 | * @index: hardware queue index. | |
67 | * | |
f14bbe77 JA |
68 | * We have no quick way of doing reverse lookups. This is only used at |
69 | * queue init time, so runtime isn't important. | |
70 | */ | |
ed76e329 | 71 | int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index) |
f14bbe77 JA |
72 | { |
73 | int i; | |
74 | ||
75 | for_each_possible_cpu(i) { | |
ed76e329 | 76 | if (index == qmap->mq_map[i]) |
bffed457 | 77 | return local_memory_node(cpu_to_node(i)); |
f14bbe77 JA |
78 | } |
79 | ||
80 | return NUMA_NO_NODE; | |
81 | } |