149 lines
3.7 KiB
C
149 lines
3.7 KiB
C
/*
|
|
* arch/arm/kernel/topology.c
|
|
*
|
|
* Copyright (C) 2011 Linaro Limited.
|
|
* Written by: Vincent Guittot
|
|
*
|
|
* 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/cputype.h>
|
|
#include <asm/topology.h>
|
|
|
|
#define MPIDR_SMP_BITMASK (0x3 << 30)
|
|
#define MPIDR_SMP_VALUE (0x2 << 30)
|
|
|
|
#define MPIDR_MT_BITMASK (0x1 << 24)
|
|
|
|
/*
|
|
* These masks reflect the current use of the affinity levels.
|
|
* The affinity level can be up to 16 bits according to ARM ARM
|
|
*/
|
|
|
|
#define MPIDR_LEVEL0_MASK 0x3
|
|
#define MPIDR_LEVEL0_SHIFT 0
|
|
|
|
#define MPIDR_LEVEL1_MASK 0xF
|
|
#define MPIDR_LEVEL1_SHIFT 8
|
|
|
|
#define MPIDR_LEVEL2_MASK 0xFF
|
|
#define MPIDR_LEVEL2_SHIFT 16
|
|
|
|
struct cputopo_arm cpu_topology[NR_CPUS];
|
|
|
|
const struct cpumask *cpu_coregroup_mask(int cpu)
|
|
{
|
|
return &cpu_topology[cpu].core_sibling;
|
|
}
|
|
|
|
/*
|
|
* 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 store_cpu_topology(unsigned int cpuid)
|
|
{
|
|
struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
|
|
unsigned int mpidr;
|
|
unsigned int cpu;
|
|
|
|
/* If the cpu topology has been already set, just return */
|
|
if (cpuid_topo->core_id != -1)
|
|
return;
|
|
|
|
mpidr = read_cpuid_mpidr();
|
|
|
|
/* create cpu topology mapping */
|
|
if ((mpidr & MPIDR_SMP_BITMASK) == MPIDR_SMP_VALUE) {
|
|
/*
|
|
* This is a multiprocessor system
|
|
* multiprocessor format & multiprocessor mode field are set
|
|
*/
|
|
|
|
if (mpidr & MPIDR_MT_BITMASK) {
|
|
/* core performance interdependency */
|
|
cpuid_topo->thread_id = (mpidr >> MPIDR_LEVEL0_SHIFT)
|
|
& MPIDR_LEVEL0_MASK;
|
|
cpuid_topo->core_id = (mpidr >> MPIDR_LEVEL1_SHIFT)
|
|
& MPIDR_LEVEL1_MASK;
|
|
cpuid_topo->socket_id = (mpidr >> MPIDR_LEVEL2_SHIFT)
|
|
& MPIDR_LEVEL2_MASK;
|
|
} else {
|
|
/* largely independent cores */
|
|
cpuid_topo->thread_id = -1;
|
|
cpuid_topo->core_id = (mpidr >> MPIDR_LEVEL0_SHIFT)
|
|
& MPIDR_LEVEL0_MASK;
|
|
cpuid_topo->socket_id = (mpidr >> MPIDR_LEVEL1_SHIFT)
|
|
& MPIDR_LEVEL1_MASK;
|
|
}
|
|
} else {
|
|
/*
|
|
* This is an uniprocessor system
|
|
* we are in multiprocessor format but uniprocessor system
|
|
* or in the old uniprocessor format
|
|
*/
|
|
cpuid_topo->thread_id = -1;
|
|
cpuid_topo->core_id = 0;
|
|
cpuid_topo->socket_id = -1;
|
|
}
|
|
|
|
/* update core and thread sibling masks */
|
|
for_each_possible_cpu(cpu) {
|
|
struct cputopo_arm *cpu_topo = &cpu_topology[cpu];
|
|
|
|
if (cpuid_topo->socket_id == cpu_topo->socket_id) {
|
|
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) {
|
|
cpumask_set_cpu(cpuid,
|
|
&cpu_topo->thread_sibling);
|
|
if (cpu != cpuid)
|
|
cpumask_set_cpu(cpu,
|
|
&cpuid_topo->thread_sibling);
|
|
}
|
|
}
|
|
}
|
|
smp_wmb();
|
|
|
|
printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
|
|
cpuid, cpu_topology[cpuid].thread_id,
|
|
cpu_topology[cpuid].core_id,
|
|
cpu_topology[cpuid].socket_id, mpidr);
|
|
}
|
|
|
|
/*
|
|
* init_cpu_topology is called at boot when only one cpu is running
|
|
* which prevent simultaneous write access to cpu_topology array
|
|
*/
|
|
void init_cpu_topology(void)
|
|
{
|
|
unsigned int cpu;
|
|
|
|
/* init core mask */
|
|
for_each_possible_cpu(cpu) {
|
|
struct cputopo_arm *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();
|
|
}
|