linux_old1/arch/arm64/kernel/topology.c

96 lines
2.3 KiB
C

/*
* arch/arm64/kernel/topology.c
*
* Copyright (C) 2011,2013,2014 Linaro Limited.
*
* Based on the arm32 version written by Vincent Guittot in turn based on
* arch/sh/kernel/topology.c
*
* 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/cpu.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/node.h>
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <asm/topology.h>
/*
* cpu topology table
*/
struct cpu_topology cpu_topology[NR_CPUS];
EXPORT_SYMBOL_GPL(cpu_topology);
const struct cpumask *cpu_coregroup_mask(int cpu)
{
return &cpu_topology[cpu].core_sibling;
}
static void update_siblings_masks(unsigned int cpuid)
{
struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
int cpu;
if (cpuid_topo->cluster_id == -1) {
/*
* DT does not contain topology information for this cpu
* reset it to default behaviour
*/
pr_debug("CPU%u: No topology information configured\n", cpuid);
cpuid_topo->core_id = 0;
cpumask_set_cpu(cpuid, &cpuid_topo->core_sibling);
cpumask_set_cpu(cpuid, &cpuid_topo->thread_sibling);
return;
}
/* update core and thread sibling masks */
for_each_possible_cpu(cpu) {
cpu_topo = &cpu_topology[cpu];
if (cpuid_topo->cluster_id != cpu_topo->cluster_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);
}
}
void store_cpu_topology(unsigned int cpuid)
{
update_siblings_masks(cpuid);
}
/*
* 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 power*/
for_each_possible_cpu(cpu) {
struct cpu_topology *cpu_topo = &cpu_topology[cpu];
cpu_topo->thread_id = -1;
cpu_topo->core_id = -1;
cpu_topo->cluster_id = -1;
cpumask_clear(&cpu_topo->core_sibling);
cpumask_clear(&cpu_topo->thread_sibling);
}
}