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parisc: Add CPU topology support

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Add topology support, including multi-core scheduler support on
PA8800/PA8900 CPUs and enhanced output in /proc/cpuinfo, e.g.
lscpu now reports on a single-socket, dual-core machine:

Architecture:          parisc64
CPU(s):                2
On-line CPU(s) list:   0,1
Thread(s) per core:    1
Core(s) per socket:    2
Socket(s):             1
CPU family:            PA-RISC 2.0
Model name:            PA8800 (Mako)

Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Helge Deller
2017-09-21 21:55:01 +02:00
parent 05f016d2ca
commit bf7b4c1b3c
6 changed files with 200 additions and 28 deletions
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157
arch/parisc/kernel/topology.c
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@@ -1,37 +1,142 @@
/*
* arch/parisc/kernel/topology.c - Populate sysfs with topology information
* arch/parisc/kernel/topology.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* Copyright (C) 2017 Helge Deller <deller@gmx.de>
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
* based on arch/arm/kernel/topology.c
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/cache.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/sched/topology.h>
static DEFINE_PER_CPU(struct cpu, cpu_devices);
#include <asm/topology.h>
static int __init topology_init(void)
/*
* cpu topology table
*/
struct cputopo_parisc cpu_topology[NR_CPUS] __read_mostly;
EXPORT_SYMBOL_GPL(cpu_topology);
const struct cpumask *cpu_coregroup_mask(int cpu)
{
int num;
for_each_present_cpu(num) {
register_cpu(&per_cpu(cpu_devices, num), num);
}
return 0;
return &cpu_topology[cpu].core_sibling;
}
subsys_initcall(topology_init);
static void update_siblings_masks(unsigned int cpuid)
{
struct cputopo_parisc *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
int cpu;
/* update core and thread sibling masks */
for_each_possible_cpu(cpu) {
cpu_topo = &cpu_topology[cpu];
if (cpuid_topo->socket_id != cpu_topo->socket_id)
continue;
cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
if (cpu != cpuid)
cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
if (cpuid_topo->core_id != cpu_topo->core_id)
continue;
cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
if (cpu != cpuid)
cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
}
smp_wmb();
}
static int dualcores_found __initdata;
/*
* store_cpu_topology is called at boot when only one cpu is running
* and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
* which prevents simultaneous write access to cpu_topology array
*/
void __init store_cpu_topology(unsigned int cpuid)
{
struct cputopo_parisc *cpuid_topo = &cpu_topology[cpuid];
struct cpuinfo_parisc *p;
int max_socket = -1;
unsigned long cpu;
/* If the cpu topology has been already set, just return */
if (cpuid_topo->core_id != -1)
return;
/* create cpu topology mapping */
cpuid_topo->thread_id = -1;
cpuid_topo->core_id = 0;
p = &per_cpu(cpu_data, cpuid);
for_each_online_cpu(cpu) {
const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);
if (cpu == cpuid) /* ignore current cpu */
continue;
if (cpuinfo->cpu_loc == p->cpu_loc) {
cpuid_topo->core_id = cpu_topology[cpu].core_id;
if (p->cpu_loc) {
cpuid_topo->core_id++;
cpuid_topo->socket_id = cpu_topology[cpu].socket_id;
dualcores_found = 1;
continue;
}
}
if (cpuid_topo->socket_id == -1)
max_socket = max(max_socket, cpu_topology[cpu].socket_id);
}
if (cpuid_topo->socket_id == -1)
cpuid_topo->socket_id = max_socket + 1;
update_siblings_masks(cpuid);
pr_info("CPU%u: thread %d, cpu %d, socket %d\n",
cpuid, cpu_topology[cpuid].thread_id,
cpu_topology[cpuid].core_id,
cpu_topology[cpuid].socket_id);
}
static struct sched_domain_topology_level parisc_mc_topology[] = {
#ifdef CONFIG_SCHED_MC
{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
#endif
{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
{ NULL, },
};
/*
* init_cpu_topology is called at boot when only one cpu is running
* which prevent simultaneous write access to cpu_topology array
*/
void __init init_cpu_topology(void)
{
unsigned int cpu;
/* init core mask and capacity */
for_each_possible_cpu(cpu) {
struct cputopo_parisc *cpu_topo = &(cpu_topology[cpu]);
cpu_topo->thread_id = -1;
cpu_topo->core_id = -1;
cpu_topo->socket_id = -1;
cpumask_clear(&cpu_topo->core_sibling);
cpumask_clear(&cpu_topo->thread_sibling);
}
smp_wmb();
/* Set scheduler topology descriptor */
if (dualcores_found)
set_sched_topology(parisc_mc_topology);
}