1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/topology.c
4 *
5 * Copyright (C) 2007 Paul Mundt
6 */
7#include <linux/cpu.h>
8#include <linux/cpumask.h>
9#include <linux/init.h>
10#include <linux/percpu.h>
11#include <linux/topology.h>
12#include <linux/node.h>
13#include <linux/nodemask.h>
14#include <linux/export.h>
15
16static DEFINE_PER_CPU(struct cpu, cpu_devices);
17
18cpumask_t cpu_core_map[NR_CPUS];
19EXPORT_SYMBOL(cpu_core_map);
20
21static cpumask_t cpu_coregroup_map(int cpu)
22{
23 /*
24 * Presently all SH-X3 SMP cores are multi-cores, so just keep it
25 * simple until we have a method for determining topology..
26 */
27 return *cpu_possible_mask;
28}
29
30const struct cpumask *cpu_coregroup_mask(int cpu)
31{
32 return &cpu_core_map[cpu];
33}
34
35int arch_update_cpu_topology(void)
36{
37 unsigned int cpu;
38
39 for_each_possible_cpu(cpu)
40 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
41
42 return 0;
43}
44
45static int __init topology_init(void)
46{
47 int i, ret;
48
49 for_each_present_cpu(i) {
50 struct cpu *c = &per_cpu(cpu_devices, i);
51
52 c->hotpluggable = 1;
53
54 ret = register_cpu(cpu: c, num: i);
55 if (unlikely(ret))
56 printk(KERN_WARNING "%s: register_cpu %d failed (%d)\n",
57 __func__, i, ret);
58 }
59
60#if defined(CONFIG_NUMA) && !defined(CONFIG_SMP)
61 /*
62 * In the UP case, make sure the CPU association is still
63 * registered under each node. Without this, sysfs fails
64 * to make the connection between nodes other than node0
65 * and cpu0.
66 */
67 for_each_online_node(i)
68 if (i != numa_node_id())
69 register_cpu_under_node(raw_smp_processor_id(), i);
70#endif
71
72 return 0;
73}
74subsys_initcall(topology_init);
75

source code of linux/arch/sh/kernel/topology.c