1 /*
2 * arch/parisc/kernel/topology.c
3 *
4 * Copyright (C) 2017 Helge Deller <deller@gmx.de>
5 *
6 * based on arch/arm/kernel/topology.c
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13 #include <linux/percpu.h>
14 #include <linux/sched.h>
15 #include <linux/sched/topology.h>
16 #include <linux/cpu.h>
17
18 #include <asm/topology.h>
19 #include <asm/sections.h>
20
21 static DEFINE_PER_CPU(struct cpu, cpu_devices);
22
23 /*
24 * store_cpu_topology is called at boot when only one cpu is running
25 * and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
26 * which prevents simultaneous write access to cpu_topology array
27 */
28 void store_cpu_topology(unsigned int cpuid)
29 {
30 struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
31 struct cpuinfo_parisc *p;
32 int max_socket = -1;
33 unsigned long cpu;
34
35 /* If the cpu topology has been already set, just return */
36 if (cpuid_topo->core_id != -1)
37 return;
38
39 #ifdef CONFIG_HOTPLUG_CPU
40 per_cpu(cpu_devices, cpuid).hotpluggable = 1;
41 #endif
42 if (register_cpu(&per_cpu(cpu_devices, cpuid), cpuid))
43 pr_warn("Failed to register CPU%d device", cpuid);
44
45 /* create cpu topology mapping */
46 cpuid_topo->thread_id = -1;
47 cpuid_topo->core_id = 0;
48
49 p = &per_cpu(cpu_data, cpuid);
50 for_each_online_cpu(cpu) {
51 const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);
52
53 if (cpu == cpuid) /* ignore current cpu */
54 continue;
55
56 if (cpuinfo->cpu_loc == p->cpu_loc) {
57 cpuid_topo->core_id = cpu_topology[cpu].core_id;
58 if (p->cpu_loc) {
59 cpuid_topo->core_id++;
60 cpuid_topo->package_id = cpu_topology[cpu].package_id;
61 continue;
62 }
63 }
64
65 if (cpuid_topo->package_id == -1)
66 max_socket = max(max_socket, cpu_topology[cpu].package_id);
67 }
68
69 if (cpuid_topo->package_id == -1)
70 cpuid_topo->package_id = max_socket + 1;
71
72 update_siblings_masks(cpuid);
73
74 pr_info("CPU%u: cpu core %d of socket %d\n",
75 cpuid,
76 cpu_topology[cpuid].core_id,
77 cpu_topology[cpuid].package_id);
78 }
79
80 /*
81 * init_cpu_topology is called at boot when only one cpu is running
82 * which prevent simultaneous write access to cpu_topology array
83 */
84 void __init init_cpu_topology(void)
85 {
86 reset_cpu_topology();
87 }
88
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