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5
6#include <linux/kernel.h>
7#include <linux/threads.h>
8#include <linux/module.h>
9#include <linux/mm.h>
10#include <linux/smp.h>
11#include <linux/cpu.h>
12
13#include <linux/blk-mq.h>
14#include "blk.h"
15#include "blk-mq.h"
16
17static int cpu_to_queue_index(unsigned int nr_cpus, unsigned int nr_queues,
18 const int cpu)
19{
20 return cpu * nr_queues / nr_cpus;
21}
22
23static int get_first_sibling(unsigned int cpu)
24{
25 unsigned int ret;
26
27 ret = cpumask_first(topology_sibling_cpumask(cpu));
28 if (ret < nr_cpu_ids)
29 return ret;
30
31 return cpu;
32}
33
34int blk_mq_map_queues(struct blk_mq_tag_set *set)
35{
36 unsigned int *map = set->mq_map;
37 unsigned int nr_queues = set->nr_hw_queues;
38 const struct cpumask *online_mask = cpu_online_mask;
39 unsigned int i, nr_cpus, nr_uniq_cpus, queue, first_sibling;
40 cpumask_var_t cpus;
41
42 if (!alloc_cpumask_var(&cpus, GFP_ATOMIC))
43 return -ENOMEM;
44
45 cpumask_clear(cpus);
46 nr_cpus = nr_uniq_cpus = 0;
47 for_each_cpu(i, online_mask) {
48 nr_cpus++;
49 first_sibling = get_first_sibling(i);
50 if (!cpumask_test_cpu(first_sibling, cpus))
51 nr_uniq_cpus++;
52 cpumask_set_cpu(i, cpus);
53 }
54
55 queue = 0;
56 for_each_possible_cpu(i) {
57 if (!cpumask_test_cpu(i, online_mask)) {
58 map[i] = 0;
59 continue;
60 }
61
62
63
64
65
66
67 if (nr_queues >= nr_cpus || nr_cpus == nr_uniq_cpus) {
68 map[i] = cpu_to_queue_index(nr_cpus, nr_queues, queue);
69 queue++;
70 continue;
71 }
72
73
74
75
76
77
78 first_sibling = get_first_sibling(i);
79 if (first_sibling == i) {
80 map[i] = cpu_to_queue_index(nr_uniq_cpus, nr_queues,
81 queue);
82 queue++;
83 } else
84 map[i] = map[first_sibling];
85 }
86
87 free_cpumask_var(cpus);
88 return 0;
89}
90EXPORT_SYMBOL_GPL(blk_mq_map_queues);
91
92
93
94
95
96int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
97{
98 int i;
99
100 for_each_possible_cpu(i) {
101 if (index == mq_map[i])
102 return local_memory_node(cpu_to_node(i));
103 }
104
105 return NUMA_NO_NODE;
106}
107