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
21static 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 */
28void 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 */
84void __init init_cpu_topology(void)
85{
86	reset_cpu_topology();
87}
88